HomeMy WebLinkAbout2026-10-20 PSPHSP Committee Packet
Edmonds City Council Agenda
October 20, 2026
Posted: 10/16/2026 10:42 AM Page 1
Agenda
Edmonds City Council
Public Safety, Planning, Human Services,
and Personnel (PSPHSP) Committee
CITY COUNCIL CONFERENCE ROOM
121 - 5TH AVENUE N, EDMONDS, WA 98020
ZOOM: HTTPS://ZOOM.US/J/95798484261 PHONE: +1 253 215 8782 MEETING ID: 957 9848 4261
OCTOBER 20, 2026, 4:30 PM
STAFF AND COUNCILMEMBERS ATTEND COMMITTEE MEETINGS VIRTUALLY, AND MEMBERS OF THE
PUBLIC ARE ENCOURAGED TO ATTEND THE SAME WAY.
IF MEMBERS OF THE PUBLIC CANNOT ACCESS THE VIRTUAL COMMITTEE MEETINGS WITH THEIR
PERSONAL DEVICES, A MONITOR IS PROVIDED AT THE CITY COUNCIL CONFERENCE ROOM AT 121
5TH AVE N, EDMONDS WA.
1. CALL TO ORDER
2. COMMITTEE BUSINESS
1. Update: Police Department Patrol Staffing Levels Only One Reading Required –
Police Services (20 minutes)
2. New E-Bike Ordinance – Chapter 5.75 First Reading – Police Services (10 minutes)
3. Family Burial Grounds Permanent Regulations First Reading – Planning and
Development Services (15 minutes)
4. Deer Creek Critical Aquifer Recharge Area Draft Code and Next Steps First
Reading – Planning and Development Services (15 minutes)
ADJOURNMENT
For disability accommodations, materials in alternate formats, accessibility information, or language interpretation/ translation needs, please
contact the City Clerk at 425-775-2525 at your earliest opportunity. Providing at least 72-hour notice will help ensure availability.
City Council Agenda Item 2.1
October 20, 2026 - Public Safety, Planning, Human Services, and Personnel (PSPHSP) Committee
TITLE:Update: Police Department Patrol Staffing Levels (Only One
Reading Required)
DEPARTMENT:Police Services
PRESENTER:Chief Loi Dawkins
NEEDED FROM COUNCIL:Informational
RECOMMENDATION:N/A
BUDGET:
Total Dollar Amount:0.00 ☐ Approved in Budget
Fund(s):General Fund ☐ Budget Reallocation Required
☒ No Budget Impact
PROBLEM/ISSUE STATEMENT:
Council President Dotsch has requested an informational presentation on the Police
Department Staffing.
CONTEXT, ANALYSIS, & ALTERNATIVES:
Chief Dawkins will be presenting information about current department staffing as well as
offering historical numbers and state numbers for comparison. Chief will speak to the current
limitations the department has based on current staffing numbers as well as future impacts.
RECOMMENDATION:
N/A
BUDGET IMPACTS:
N/A
ITEM HISTORY:
N/A
ADDITIONAL INFORMATION:
ATTACHMENTS:
N/A
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City Council Agenda Item 2.2
October 20, 2026 - Public Safety, Planning, Human Services, and Personnel (PSPHSP) Committee
TITLE:New E-Bike Ordinance – Chapter 5.75 (First Reading)
DEPARTMENT:Police Services
PRESENTER:Chief Loi Dawkins
NEEDED FROM COUNCIL:Action
RECOMMENDATION:Forward to full Council Consent agenda for adoption: Ordinance
changes relating to Chapter 5.75 that will encompass E-Bikes
(electric-assist bicycles, micromobility devices, and other
powered personal transporters).
BUDGET:
Total Dollar Amount:0.00 ☐ Approved in Budget
Fund(s):General Fund ☐ Budget Reallocation Required
☒ No Budget Impact
PROBLEM/ISSUE STATEMENT:
In Edmonds, we have received strong community feedback and concern about how children
and adults are using E-Bikes (electric-assist bicycles, micromobility devices, and other powered
personal transporters). The mayor and some council members have inquired about
enforcement. While we do not have a good way to differentiate between human powered
bicycles, e-bikes, e-scooters, and motorcycles when it comes to collisions and complaints.
However, we have identified three collisions since June 2025 involving electric bikes in the City
of Edmonds. Additonally, here are some recent local news stories:
While not a collision with a vehicle, in May 2025, a 13-year-old boy riding an e-bike
collided with a low wire in Everett, which resulted in a fatality.
A fatal collision occurred on August 5, 2026, near Mill Creek/Bothell, where a 14-year-
old boy riding an e-bike collided with a Toyota Camry at 184th Street Southeast and
36th Avenue Southeast and later passed away at Harborview Medical Center.
Everett now has the fifth-highest rate of e-bike hospitalizations an the third-highest rate
of electric scooter hospitalizations among cities throughout Washington, according to a
city council memo. Statewide, 149 people were hospitalized with e-bike-related injuries
last year, and the rate of injury jumped 483% between 2020 and 2024.
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CONTEXT, ANALYSIS, & ALTERNATIVES:
This ordinance has been reviewed and approved to form by Sharon Cates with lighthouse law
on 9/16/26.
Our goal is to respond to the issue and create consistency across our jurisdictions while we wait
for state law to catch up to the technology. The recommended ordinance was taken from a
model ordinance Everett PD created which was informed by other cities discussions and
workgroup meetings.
RECOMMENDATION:
Forward to full Council Consent agenda for adoption: Ordinance changes relating to Chapter
5.75 that will encompass E-Bikes (electric-assist bicycles, micromobility devices, and other
powered personal transporters).
BUDGET IMPACTS:
N/A
ITEM HISTORY:
Nothing additional.
ADDITIONAL INFORMATION:
ATTACHMENTS:
1. Draft Ordinance Amending ECC Title 5
2. Draft Code Changes – Attachment A
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ORDINANCE NO.
AN ORDINANCE OF THE CITY OF EDMONDS,
WASHINGTON, AMENDING TITLE 5 OF THE EDMONDS
CITY CODE TO ADOPT REGULATIONS, CIVIL
PENALTIES, AND CRIMINAL PENALTIES FOR THE USE
OF ELECTRIC-ASSISTED BICYCLES AND POWERED
PERSONAL TRANSPORTERS ON CITY STREETS
SIDEWALKS, PATHS, AND TRAILS; PROVIDING FOR
SEVERABILITY; AND SETTING AN EFFECTIVE DATE.
WHEREAS, there is a need to address the increased use of electric-assisted bicycles,
the dangers they pose to the community, changes in state law, and to establish consistent
regulations of sidewalks, paths, and roadways; and
WHEREAS, e-bike use in the United States is on a sharp upward trajectory, with
annual sales increasing from approximately 325,000 in 2018 to over 1.1 million in 2022—
nearly a fourfold rise—and projected to continue growing substantially; and
WHEREAS, emergency department visits in the United States for e-bike–related
injuries grew dramatically between 2017 and 2022, from just 751 cases to 23,493—doubling
each year—while e-scooter injuries increased by over 45% per year; and
WHEREAS, data reveals that head, neck, and upper/lower extremity injuries are the
most common serious e-bike injuries, and that e-bikes impose a greater risk of high-impact
trauma due to their speed and weight; and
WHEREAS, risks to youth are especially concerning: e-bikes became in the United
States the leading cause of pediatric trauma activations at one Level 1 hospital (surpassing
motor vehicle crashes), with e-bike–related hospital activations jumping from 2% of cases in
2017 to 64% in 2023; e-bike injuries among children and teens increased by over 300% from
2019 to 2023, and are now four times more likely to involve fractures or head injuries than
accidents involving traditional bicycles; and
WHEREAS, helmet usage is notably lower in e-bike crashes—teens involved in e-bike
trauma activations were significantly less likely to wear helmets than those in pedal-bike
incidents—heightening preventable risk; and
WHEREAS, these trends are similar in Washington state. While pedal bike injuries
still dominate total injuries, the rate of change has slightly decreased between 2020 and 2024.
E-bike injuries have increased 483% during the same period, and hospitalizations increased
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from zero in 2020 to 149 cases in 2025. EMS calls for e-bike and e-scooter injuries have
tripled since 2020; and
WHEREAS, for Washington State e-bike and e-scooter injuries between 2020 and
2024, riders were wearing a helmet only 30% of the time; and
WHEREAS, [Insert local statistic if available]; and
WHEREAS, the Washington State Legislature recently passed ESSB 6110 (Laws of
2026, ch. ___) amending RCW 46.04.169 to clarify that vehicles capable of exceeding 20
mph solely on their electric motor, or vehicles designed or intended by the manufacturer or
seller to be easily configured so they no longer meet e‑bike requirements, are excluded from
the definition of “electric‑assisted bicycle”; and the Legislature recognized the need for a
regulatory framework for electric motorcycles; and
WHEREAS, Washington law establishes a three‑class system for electric‑assisted
bicycles (Class 1, Class 2, Class 3) and a maximum motor power of 750 watts (RCW
46.04.169); and
WHEREAS, state law requires permanent class labeling on new e‑bikes and prohibits
tampering that alters speed capability unless the label is appropriately replaced (RCW
46.37.690); and
WHEREAS, the operation of Class 3 electric‑assisted bicycles on sidewalks is
restricted unless authorized by local ordinance, and operators must be at least 16 years old
(RCW 46.61.710; RCW 46.20.500); and
WHEREAS, because there are many new devices with electric motors that do not fall
into any existing definition of e-bikes, motorized foot scooters, or electric motorcycles, and
new devices capable of reaching high speeds continue to become available, it is necessary to
create regulations to cover these devices based on their speed capacity; and
WHEREAS, the City finds it necessary to amend its municipal code in a manner that
promotes safe, equitable use of e‑bikes, reduces conflicts in pedestrian‑rich areas, and protects
public health, safety, and welfare; and
WHEREAS, the City has the authority and responsibility to provide for the
accountability of all practices dangerous to public health or safety, and to make necessary for
the preservation of public health, peace, and good order, and to provide for the punishment of
all persons charged with violating any City ordinance;
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NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF EDMONDS,
WASHINGTON, DO ORDAIN AS FOLLOWS:
Section 1. Title 5 of the Edmonds City Code, entitled “Public Safety and
Morals” is hereby amended to adopt a new Chapter 5.75 entitled “Electric-Assisted Bicycles,
Micromobility Devices, and Powered Personal Transporters” to read as set forth in Attachment
A hereto, which is incorporated herein by this reference as if set forth in full.
Section 2. Severability. If any section, subsection, clause, sentence or
phrase of this ordinance should be held to be invalid or unconstitutional, such decision shall not
affect the validity oof the remaining portions of this ordinance.
Section 3. Effective Date. This ordinance, being an exercise of power
specifically delegated to the City legislative body, is not subject to referendum and shall take
effect five (5) days after passage and publication of an approved summary thereof consisting of
the title.
APPROVED:
MAYOR MIKE ROSEN
ATTEST/AUTHENTICATED:
CITY CLERK, LUKE LONIE
APPROVED AS TO FORM:
OFFICE OF THE CITY ATTORNEY:
BY ___________________________________
JEFF TARADAY
FILED WITH THE CITY CLERK:
PASSED BY THE CITY COUNCIL:
PUBLISHED:
EFFECTIVE DATE:
ORDINANCE NO.
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SUMMARY OF ORDINANCE NO. __________
of the City of Edmonds, Washington
On the ____ day of ___________ 2026, the City Council of the City of Edmonds,
passed Ordinance No. _____________. A summary of the content of said ordinance, consisting
of the title, provides as follows:
AN ORDINANCE OF THE CITY OF EDMONDS,
WASHINGTON, AMENDING TITLE 5 OF THE EDMONDS
CITY CODE TO ADOPT REGULATIONS, CIVIL PENALTIES,
AND CRIMINAL PENALTIES FOR THE USE OF ELECTRIC-
ASSISTED BICYCLES AND POWERED PERSONAL
TRANSPORTERS ON CITY STREETS SIDEWALKS, PATHS,
AND TRAILS; PROVIDING FOR SEVERABILITY; AND
SETTING AN EFFECTIVE DATE.
The full text of this Ordinance will be mailed upon request.
DATED this _____ day of ________________ 2026.
CITY CLERK, LUKE LONIE
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Chapter 5.75
ELECTRIC-ASSISTED BICYCLES, MICROMOBILITY DEVICES,
AND POWERED PERSONAL TRANSPORTERS
5.75.010 Purpose.
It is the purpose of this chapter to establish regulations, civil penalties, and criminal penalties for
the use of electric-assisted bicycles and powered personal transporters on City streets, sidewalks,
paths, and trails.
5.75.20.1 Definitions.
A. “Bicycle” means every device propelled solely by human power, or an electric-assisted
bicycle as defined in RCW 46.04.169, upon which a person or persons may ride, having two (2)
tandem wheels, either of which is sixteen (16) inches or more in diameter, or three (3) wheels, any
one of which is twenty (20) inches or more in diameter.
B. “City property” means all property owned or controlled by the city, including without
limitation, all city rights-of-way that are not a city street or sidewalk.
C. “City street” has the same meaning as RWW 46.04.120 now or hereinafter amended.
D. “Electric-assisted bicycle” or “ebike” means a bicycle with two (2) or three (3) wheels, a
saddle, fully operative pedals for human propulsion, and an electric motor. The electric-assisted
bicycle’s electric motor must have a power output of no more than 750 watts. The electric-assisted
bicycle must meet the requirements of one of the following three classifications:
1. “Class 1 electric-assisted bicycle” provides assistance only when the rider is pedaling
and ceases assistance at twenty (20) miles per hour;
2. “Class 2 electric-assisted bicycle” may be propelled exclusively by the motor and is
not capable of providing assistance at speeds of twenty (20) miles per hour or greater;
3. “Class 3 electric-assisted bicycle” provides assistance only when the rider is pedaling,
ceases assistance at twenty-eight (28) miles per hour, and is equipped with a
speedometer.
E. “Electric-assisted bicycle” does not include:
1. Any vehicle capable of exceeding twenty (20) miles per hour solely on its electric
motor; or
2. Any vehicle designed, manufactured, or intended by the manufacturer or seller to be
easily configured so that it does not meet the requirements of an electric-assisted
bicycle, whether by means of a mechanical switch or button, a software setting, an
online application, or other similar method intended to alter factory configuration.
These exclusions have the meaning provided in RCW 46.04.169, as amended by Laws of 2026,
ch. ___ (ESSB 6110) or as amended in the future.
F. “Electric motorcycle” means a motor-powered vehicle excluded from the definition of
“electric-assisted bicycle” under subsection (4)D of this section and encompassed within
“motorcycle” or “moped” definitions under chapter 46.04 RCW. If 46.04 RCW is hereafter
amended to include a definition for “Electric motorcycle,” it shall be adopted by reference.
G. “Micromobility device” means personal or shared nonmotorized scooters, “motorized foot
scooters” as defined in RCW 46.04.336, and “electric personal assistive mobility devices”
(EPAMD) as defined in RCW 46.04.1695, and any powered personal transporter that has a
maximum speed of no greater than twenty (20) miles per hour on level ground.
H. “Motorized foot scooter” is as defined in EMC 46.80.020.
I. “Powered personal transporters” means a small device, not otherwise defined in this
chapter, that is designed to carry one or more persons and propelled by an electric or other motor,
including devices capable of speeds greater than 20 miles per hour solely on its electric or other
motor regardless of the number or configuration of wheels. The term includes, but is not limited
to: high-speed electric scooters, electric unicycles or other single-wheel self-balancing devices,
electric skateboards, , and other similar powered mobility devices. It does not include
bicycles as defined in RCW 46.04.169, and this section; motorized foot scooters
as defined in RCW 46.04.336 and EMC 46.80.020; electric personal assistive mobility devices
(EPAMDs) as defined in RCW 46.04.1695; wheelchairs, power wheelchairs, or other medically
necessary mobility aids used by persons with disabilities; or motor vehicles, mopeds, or
motorcycles as defined in RCW 46.04.
I. “Powered personal transporters” means a small device, not otherwise defined in this
chapter, that is designed to carry one or more persons and propelled by an electric or other motor,
including devices capable of speeds greater than twenty (20) miles per hour solely on its electric
or other motor. The term includes, but is not limited to: high-speed electric scooters, electric
skateboards, self-balancing devices, and other similar powered mobility devices. It does not
include bicycles as defined in RCW 46.04.169, and this section; motorized foot
scooters as defined in RCW 46.04.336 and EMC 46.80.020; electric personal assistive mobility
devices (EPAMDs) as defined in RCW 46.04.1695; wheelchairs, power wheelchairs, or other
medically necessary mobility aids used by persons with disabilities; or motor vehicles, mopeds, or
motorcycles as defined in RCW 46.04.
J. “Operator” means any person who rides or controls an electric-assisted bicycle or powered
personal transporter.
K. “Rules of the road” means all rules applicable to vehicles, bicycles, micromobility devices,
powered personal transporters, or pedestrian traffic as set forth in state or local law, rule or
regulation.
L. “Shared-use path” means a public paved path designated for bicycle and pedestrian travel.
M. “Sidewalk” means that property between the curb lines or the lateral lines of a roadway
and the adjacent property set aside and intended for the use of pedestrians, or such portion of
private property parallel and in proximity to a public highway and dedicated to use by pedestrians.
5.75.030 Equipment and labeling.
A. Any electric-assisted bicycle sold, repaired, or operated in the City must comply with the
Cclass label and anti-tampering requirements set out in RCW 46.37.690.
B. Class 3 electric-assisted bicycles shall be equipped with a speedometer (RCW 46.04.169).
C. Every electric-assisted bicycle must comply with the lighting requirements of RCW
46.61.780 when in use during the hours of darkness as defined in RCW 46.37.020.
D. Every electric-assisted bicycle shall be equipped with a brake that will enable the operator
to make the braked wheels skid on dry, level, clean pavement.
E. No motorized foot scooter, bicycle, or other wheeled recreational device shall be operated
in a manner that creates continuous sound associated with a gasoline-powered engine so as to
unreasonably disturb or interfere with the peace and comfort of owners or occupants of real
property. Nothing in this section shall limit enforcement of the City’s noise ordinance.
F. It is unlawful to sell or operate a motorized foot scooter, bicycle, or other wheeled device
that is powered by an internal combustion engine that is not equipped with a muffler in good
working order and in constant operation to prevent excessive or unusual noise.
G. Equipment and labeling violations are punishable as a traffic infraction.
5.75.040 Operating rules.
A. Operators shall obey all applicable rules of the road and traffic laws.
B. Operators on any sidewalk or shared-use path shall operate in a careful and prudent
manner and a rate of speed no greater than is reasonable and proper under the conditions existing
at the point of operation, taking into account the amount and character of pedestrian traffic, grade
and width of sidewalk or public path, and condition of surface, and shall obey all traffic control
devices.
C. Operators may use electric-assisted bicycles on the shoulder of the roadway or any
specially designated bicycle lane consistent with RCW 46.61.770.
D. Where the City posts speed limits on streets or bicycle lanes, electric-assisted bicycles
and powered personal transporters shall not be operated in excess of the posted speed limits.
E. Operators may not use any motorized foot scooter or micromobility device on any city
street with a maximum speed limit above thirty miles per hour, unless the device is operated
within a designated bicycle lane.
F. Class 3 electric-assisted bicycles and powered personal transporters may not be operated
on a shared-use path consistent with RCW 46.61.710. Class 1 and Class 2 electric-assist bicycles
and micromobility devices may operate on shared paths consistent with this chapter.
G. On shared-use paths and sidewalks (where permitted), operators shall:
1. Be granted all of the rights and are subject to all the duties applicable to the
pedestrian under RCW 46.61;
2. Yield the right of way to pedestrians and human-powered devices and shall give an
audible signal before overtaking and passing a pedestrian or human-powered devices;
3. Not operate in excess of fifteen (15) miles per hour; and
4. Slow to ten (10) miles per hour or less when within fifty (50) feet of pedestrians or in
congested areas.
H. Class 3 electric-assisted bicycles and powered personal transporters may not ride on the
sidewalk and shared-use path unless there is no alternative to travel over the sidewalk or shared-
use path as part of a city street.
I. No bicycle, any class of electric-assisted bicycle, or powered personal transporter may
ride on the sidewalk in the [City of Edmonds (designated area/s)],
1. as necessary to enter or leave an adjacent property; and
2. Upon any section of sidewalk designated, and indicated with clearly posted signs, as a
trail or shared-use path consistent with this chapter; and
3. Upon any section of sidewalk designated by the City of Edmonds and indicated with
clearly posted signs as mobility corridors where use is permitted consistent with this
chapter.
J. No bicycle, any class of electric-assisted bicycle, micromobility device, or powered
personal transporter may ride on any City property where it is restricted in other chapters of this
code or by clearly posted signs.
K. It shall not be a violation of this section to walk a bicycle, electric-assisted bicycle,
micromobility device, or powered personal transporter in a location where operating that device
is prohibited or to start and stop from the curb ramp of any sidewalk.
L. Electric Motorcycles are motorcycles and may only operate as allowed under Title 46
RCW.
5.75.050 Operating in Parks.
A. It is unlawful for any person to operate an electric-assisted bicycle, micromobility device,
powered personal transporter, or electric motorcycle in a City Park, except (1) Class 1I and Class
2II electric-assisted bicycles, micromobility devices, or powered personal transporters that have a
maximum speed of no greater than twenty (20) miles per hour on level ground, may operate in
areas designated on signs posted by the parks department as open to such operation and (2) upon
such areas authorized for use by motor vehicles, such as parking lots.
B. For shared-use paths that pass through a park or extend continuously beyond park
boundaries, operators shall comply with the rules for shared-use paths in this chapter.
C. Operators of an electric-assisted bicycle, micromobility device, or powered personal
transporter in a City Park must comply with all rules and regulations and are subject to all of the
liability and penalties of this chapter.
5.75.060 Age and helmet requirement.
A. No driver’s license is required for operation of an electric-assisted bicycle, micromobility
device, or powered personal transporter.
B. Persons under sixteen (16) years of age may not operate a cClass 3 electric-assisted bicycle
or a PPT capable of exceeding twenty (20) miles per hour solely on its motor.
C. Persons under eleven (11) years of age may not operate an electric-assisted bicycle,
micromobility device, or a powered personal transporter unless under direct supervision of a
person over the age of eighteen (18).
D. Helmets are mandatory for operators of Class 3 electric-assisted bicycles and for operators
of powered personal transporters capable of exceeding twenty (20) miles per hour solely on their
motor, as well as for all operators under the age of sixteen (16) years on any class of electric-
assisted bicycle, micromobility device, or powered personal transporter.
Commented [SEC1]: It seems like this section should be an
extension of the above sentence and read "except as necessary..." and the other two subsections should be the only ones.
5.75.070 Parking and storage; obstruction of public spaces.
A. No person shall park or leave an electric-assisted bicycle, micromobility device, or
powered personal transporter in a manner that blocks building entrances, bus stops, ramps, or
reduces sidewalk clearance below three (3) feet; violations are subject to removal or relocation.
B. No person may connect a battery charger for an electric-assisted bicycle, micromobility
device, or powered personal transporter to any public outlet for the purpose of charging, powering,
or supplying electricity to such device unless the outlet is specifically designated for such purpose.
5.75.080 Exemptions.
A. Police officers operating a bicycle, electric-assisted bicycle, micromobility device, or
powered personal transporter in the performance of their duties may operate on any sidewalk and
multi-use trails, including operating on the sidewalk in the [City of Edmonds].
B. The provisions of this chapter shall not apply to mobility devices used as reasonable
accommodation under the ADA;
C. The provisions of this chapter shall not apply to devices operated under a City permit for
special events.
5.75.090 Negligent Operation of an Electric-Assisted Bicycle, Micromobility Device, or
Powered Personal Transporter.
A. A person commits the offense of Negligent Operation of an Electric-Assisted Bicycle,
Micromobility Device, or Powered Personal Transporter when such person operates a device in a
manner that is both negligent and endangers or is likely to endanger any person or property.
1. It is an affirmative defense to Negligent Operation of an Electric-assisted Bicycle,
Micromobility Device, or Powered Personal Transporter that must be proved by the
defendant by a preponderance of the evidence that the driver was operating the device
on private property with the consent of the owner in a manner consistent with the
owner’s consent.
2. Violation of this section is a traffic infraction and is subject to a penalty of $250two
hundred fifty dollars.
B. For the purposes of this section, “negligent” means the failure to exercise ordinary care and
is the doing of some act that a reasonably careful person would not do under the same or similar
circumstances or the failure to do something that a reasonably careful person would do under the
same or similar circumstances.
5.75.100 Reckless Endangerment with an Electric-assisted Bicycle, Micromobility
Device, or Powered Personal Transporter.
A. A person commits the offense of Reckless Endangerment with an Electric-assisted Bicycle,
Micromobility Device, or Powered Personal Transporter when such person recklessly engages in
conduct which creates a substantial risk of serious physical injury to another person.
B. Reckless Endangerment with an Electric-assisted Bicycle, Micromobility Device, or
Powered Personal Transporter is a gross misdemeanor.
C. A parent, guardian, institution, agency, or other person having a lawful right to physical
custody of an operator, who knowingly provides an operator under the age of 16 with an electric-
assisted bicycle or powered personal transporter is liable for any violation of this section by the
operator under the age of sixteen (16) and is liable for a traffic infraction punishable by a fine of
$250.
5.75.110 Tampering with Electric-assisted bicycle.
A. No person may intentionally modify, tamper with, alter, or disable any component of an
electric-assisted bicycle, including but not limited to the motor, controller, software, gearing, or
sensors, for the purpose of changing the bicycle’s class designation or increasing its maximum
assisted speed beyond the manufacturer’s specifications.
B. A person who intentionally modifies an electric-assisted bicycle in a manner that changes
its class designation or maximum assisted speed shall not operate or permit operation of the
device until the class label accurately reflecting the modification has been replaced in accordance
with RCW 46.37.690.
C. An electric-assisted bicycle that provides assisted speeds in excess of the limits established
in RCW 46.04.169 for Class 1, Class 2, or Class 3 electric-assisted bicycles is presumed to have
been unlawfully modified unless the operator produces documentation from the manufacturer or a
certified technician verifying the bicycle’s compliant configuration.
D. It is unlawful to knowingly operate an electric-assisted bicycle that has been modified in
violation of this section on any public roadway, sidewalk, shared-use path, trail, or other facility
where bicycles or electric-assisted bicycles are permitted.
E. A violation of this section is a traffic infraction punishable by a fine of $250, plus any
restitution or assessments authorized by law.
5.75.120 Penalty.
A. Unless otherwise established in the Everett Municipal Code, a violation of this chapter is a
traffic infraction punishable by a fine of $50 for the first offense and $150 for each subsequent
offense.
B. It is unlawful for the parent or guardian of any person under the age of sixteen (16) to
knowingly authorize or permit a person under the age of sixteen (16) to operate in violation of this
chapter.
C. The [Edmonds Municipal Court] has jurisdiction over operators who are sixteen (16) or
seventeen (17) years old on the date of the alleged offense as authorized under RCW 13.04.030.
D. For first-time juvenile violations, completion of an approved safety course, if available,
may substitute for civil penalties at the City’s discretion.
E. For operators under the age of sixteen (16) who violate any provision of this chapter, a law
enforcement officer may release a regulated device to the parent or legal guardian instead of
issuing a citation or impounding the device pursuant to this chapter.
F. The court may also order a person found to have committed an infraction under this chapter
to make restitution in an amount no greater than $5,000.
5.75.130 Enforcement.
A. The [Edmonds] Police Department shall have the authority to enforce the provisions of this
chapter, except as otherwise authorized herein. This authority does not supersede or preclude
enforcement by other state or local authorities.
B. Any person, or the parent or guardian of any person under the age of sixteen (16), requested
to identify themselves to a law enforcement officer pursuant to an investigation under this chapter
has a duty to provide name and current address.
5.75.140 Impound.
A. When an operator is cited for a violation of this chapter, a law enforcement officer may
take custody of an electric-assisted bicycle, micromobility device, or powered personal transporter
for public safety or evidentiary purposes.
B. For operators under the age of sixteen (16), if the officer does not impound the device, the
officer may release it only to the parent or legal guardian.
C. The officer must provide the violator with a written notice setting forth the procedure for
reclaiming the device.
D. The procedure for reclaiming the device shall be promulgated by the Chief of Police [or
other person designated by the Mayor].
E. Only the parent or legal guardian of a violator or an adult owner can reclaim a device
impounded pursuant to this section.
F. A fine of $50fifty-dollar fee for the cost of impound and administrative processing shall be
paid to the city clerk prior to the release of any property impounded under this provision.
G. Any unclaimed devices may be disposed of in accordance with state law.
5.75.150 Administrative rules.
The [Police Chief or Public Works Director or other person designated by the Mayor], or both,
may adopt administrative rules, consistent with this chapter and state law, to implement speed
signage, facility designations, conspicuity requirements, and battery safety/charging protocols.
City Council Agenda Item 2.3
October 20, 2026 - Public Safety, Planning, Human Services, and Personnel (PSPHSP) Committee
TITLE:Family Burial Grounds Permanent Regulations (First Reading)
DEPARTMENT:Planning and Development Services
PRESENTER:Duane Wakan
NEEDED FROM COUNCIL:Informational
RECOMMENDATION:Move the topic to full Council for a public hearing on November
10, 2026, with potential action at the same meeting.
BUDGET:
Total Dollar Amount:0 ☐Approved in Budget
Fund(s):0 ☐Budget Reallocation Required
☒No Budget Impact
PROBLEM/ISSUE STATEMENT:
This is an introduction to a draft ordinance to permanently prohibit family burial grounds on
private property.
Substitute HB 2239 authorizes cities and counties to enact ordinances to regulate or
prohibit the establishment of family burial grounds allowing individuals to establish private
"family burial grounds" on their own land. Should a city, town, or county chose to regulate
family burial grounds, SHB 2239 prescribes local procedures to ensure the owner of the
property on which a family burial ground is located remediates, at the owner's expense, any
violation of the provisions governing the construction and installation of mausoleums,
columbaria, and similar structures on a family burial ground. The bill passed the legislature and
became law on March 24, 2026, with an effective date of June 11, 2026.
CONTEXT, ANALYSIS, & ALTERNATIVES:
Previous steps to implement SHB 2239 include:
The topic was first introduced to Council Committee on May 19 and to full Council on
May 26, 2026.
Council adopted interim Ordinance No. 4437 on June 2, 2026, which established
temporary regulations prohibiting family burial grounds in order to meet the June 11
deadline and to allow staff additional time to work with the Planning Board to craft
permanent regulations.
On August 12, 2026, the Planning Board recommended a permanent prohibition of
family burial grounds in Edmonds for several reasons:
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IItteemm 22..33
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o It was found that there was incompatibility with the urban/suburban
environment.
o Property turnover would create complications for future owners.
o There would be environmental and groundwater concerns (formaldehyde,
wildlife, etc.).
o Family burial grounds would impact neighborhood character both visually and
psychologically with backyard grave sites.
RECOMMENDATION:
Move the topic to full Council for a public hearing on November 10, 2026, with potential action
at the same meeting.
BUDGET IMPACTS:
There are no budget impacts.
ITEM HISTORY:
City Council adopted interim Ordinance No. 4437 on June 2, 2026, establishing temporary
regulations prohibiting family burial grounds.
ADDITIONAL INFORMATION:
Staff issued a SEPA Determination of Non-Significance for the project on October 14, 2026.
ATTACHMENTS:
Attachment 1: Draft Permanent Ordinance Family Burial Grounds
Attachment 2: Interim Ordinance 4437
Attachment 3: Excerpt PB minutes 8.12.26
Attachment 4: SHB 2239 Bill Summary
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CITY OF EDMONDS, WASHINGTON
ORDINANCE NO. _____
AN ORDINANCE OF THE CITY OF EDMONDS, WASHINGTON,
ADOPTING PERMANENT DEVELOPMENT REGULATIONS TO
PROHIBIT FAMILY BURIAL GROUNDS WITHIN THE CITY AND
REPEALING THE INTERIM DEVELOPMENT REGULATIONS THAT
WERE ADOPTED WITH ORDINANCE 4437.
WHEREAS, during the 2026 legislative session, the Washington Legislature adopted
Substitute House Bill 2239, enacted as Chapter 173, Laws of 2026, relating to family burial
grounds on privately owned property; and
WHEREAS, SHB 2239 became effective on June 11, 2026, and established a new
statutory framework under which family burial grounds may be established on privately owned
property, subject to the requirements and limitations set forth in state law; and
WHEREAS, SHB 2239 reflects the Legislature’s intent to provide greater flexibility and
options for individuals and families in choosing places of interment and to honor individual and
family connectivity with land; and
WHEREAS, SHB 2239 also recognizes that local governments may regulate family
burial grounds through applicable official controls; and
WHEREAS, the City’s existing zoning, nuisance, public health, and other regulations
were not drafted with family burial grounds in mind and do not presently contain standards
specifically addressing the siting, review, operation, maintenance, disclosure, mapping, access,
setbacks, buffers, recordkeeping, or long-term protection of family burial grounds; and
WHEREAS, the establishment of family burial grounds may raise public welfare issues
that differ from ordinary residential or accessory uses; and
WHEREAS, the City Council adopted by Ordinance No. 4437, a temporary prohibition
of new family burial grounds to provide time to evaluate local regulations consistent with state
law at their June 2, 2026 meeting; and
WHEREAS, the Planning Board made a recommendation to establish a permanent
prohibition on family burial grounds in the City of Edmonds at their August 12, 2026 meeting;
and
WHEREAS, the City Council held a public hearing at their [ ] meeting to discuss an
amendment in Title 16 of the Edmonds Community Development Code (ECDC) to permanently
prohibit family burial grounds in the city consistent with SHB 2239 (2026); and
WHEREAS, the City Council finds that a permanent official control prohibiting the
establishment, creation, expansion, or use of property as a family burial ground is necessary for
the preservation of the public health, safety, and welfare; NOW, THEREFORE,
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THE CITY COUNCIL OF THE CITY OF EDMONDS DOES ORDAIN AS
FOLLOWS:
Section 1. Repealer. Ordinance 4437 is hereby repealed.
Section 2. Prohibition of Family Burial Grounds. Section 16.00.030 of the Edmonds
Community Development Code, which currently shows as a repealed code section, shall
henceforth be entitled “Family burial grounds prohibited” and shall read as follows: “No person
may establish, create, expand, or otherwise use their property for a family burial ground, as
defined in SHB 2239, within the City.”
Section 3. Findings of Fact. The city council hereby adopts the recitals above as its
findings of fact justifying the adoption of this ordinance.
Section 4. Severability. If any section, sentence, clause or phrase of this ordinance
should be held to be unconstitutional or unlawful by a court of competent jurisdiction, such
invalidity or unconstitutionality shall not affect the validity or constitutionality of any other
section, sentence, clause or phrase of this ordinance.
Section 5. Effective Date. This ordinance, being an exercise of a power specifically
delegated to the City legislative body, is not subject to referendum and shall take effect five (5)
days after passage and publication of an approved summary thereof consisting of the title.
APPROVED:
MAYOR MIKE ROSEN
ATTEST/AUTHENTICATED:
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CITY CLERK, LUKE LONIE
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APPROVED AS TO FORM:
OFFICE OF THE CITY ATTORNEY:
BY
JEFF TARADAY
FILED WITH THE CITY CLERK:
PASSED BY THE CITY COUNCIL:
PUBLISHED:
EFFECTIVE DATE:
ORDINANCE NO.
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1
SUMMARY OF ORDINANCE NO. __________
of the City of Edmonds, Washington
On the ____ day of ___________, 2026, the City Council of the City of Edmonds, passed
Ordinance No. _____________. A summary of the content of said ordinance, consisting of the
title, provides as follows:
AN ORDINANCE OF THE CITY OF EDMONDS, WASHINGTON,
ESTABLISHING A PERMANENT REGULATION TO PROHIBIT
FAMILY BURIAL GROUNDS WITHIN THE CITY
.
The full text of this Ordinance will be mailed upon request.
DATED this _____ day of ________________, 2026.
CITY CLERK, LUKE LONIE
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Everett Daily Herald
Affidavit of Publication
State of Washington }
County of Snohomish ss
Michael Gates being first duly sworn, upon
oath deposes and says: that he /she is the legal
representative of the Everett Daily Herald a
daily newspaper. The said newspaper is a legal
newspaper by order of the superior court in the
county in which it is published and is now and
has been for more than six months prior to the
date of the first publication of the Notice
hereinafter referred to, published in the English
language continually as a daily newspaper in
Snohomish County, Washington and is and
always has been printed in whole or part in the
Everett Dail y Herald and 1s of general
circulation in said County, and is a legal
newspaper. in accordance with the Chapter 99
of the Laws of 1921 , as amended by Chapter
213 , Laws of 1941. and approved as a legal
newspaper by order of the Superior Court of
Snohomish Count y , State of Washington, by
order dated June 16 , 1941, and that the annexed
is a true copy of EDH I031887 ORD ANCE 0 .
4437 as it was published in the regular and
entire issue of said paper and not as a
supplement forrn thereof for a period of I
issue(s), such publication commencing on
06/05 /2026 and ending on 06/05/2026 and that
said newspaper was regularly distributed to its
sub scribers during all of said period.
The amount
24 .08 .
publication is
Subscribed and ·sworn before me on thi s
day of J w,..-y___..
Notary Pub lic in and for the State of
Washington .
Cit) .,n,dmond.~ • U(J.'\L \OS J .. ,irl).l\t,
LLKE LU,I[
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Classified Proof
ORDINANCE SUMMARY
ofthe City ofEdrnonds , Washington
On the 2nd day of June, 2026, the City Council of the City of
Edmonds passed !he following Ordinance . The summary of said
ordinance consisting ~:~l~~e~c;~r~~~~~~; follows :
AN ORDINANCE OF THE CITY OF EDMONDS .
11/ASHINGTON, ESTABLISHING AN INTERl!-.1 REGL1LATION
TO PROHIBIT FAMILY BURIAL GROUNDS WITHIN THE
CITY ON A TEMPORARY BASIS .
ThefUII teit ofthisOrdinance wlll be mailed upon request.
g~~Eglt~~trB~~ w~rt
2026
Published : June 5, 2026 EDH1031887
Proofed by Pospica l, Randie , 06 /05 /2026 08: 16 :52 am Page: 2
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Planning Board Meeting Minutes August 12, 2026 Page 3 of 5
requirements for at least 25 years and ensuring middle housing density standards remain compliant.
• Analyze how RCW 17.10.300 (transit-oriented development) affects Edmonds' code, including determining appropriate floor area ratio limits and building heights near Amtrak and Swift Lake BRT station areas and identifying which zones should receive the additional FAR bonus for affordable housing.
• Verify that existing zoning allows step housing (supportive, transitional, emergency, and permanent supportive housing) wherever residences or hotels are permitted, including analyzing whether additional hotel zones need to be added to meet projected needs and documenting any required analysis and potential code changes.
• Confirm the exact requirements for religious-affordable housing under HB 1859, including whether the religious organization must retain ownership of the property and how this interacts with developer participation, and report the findings back to staff and the Planning Board.
• Compile and present definitions and design criteria for childcare centers (including occupancy limits, age groups, and allowable locations) for use in future discussions on childcare center siting regulations.
• Bring back to the Planning Board several example unified development code frameworks from other cities (such as South Bend, Indiana) for review and feedback on preferred structure and organization of Edmonds' future UDC.
2. Family Burial Ground permanent regulations State law now allows family burial grounds on private property under certain conditions, but explicitly allows cities to prohibit or regulate them. Edmonds had an interim prohibition and needed a permanent policy recommendation.
Concerns discussed:
• Compatibility with an urban/suburban environment
• Property turnover and complications for future owners
• Environmental and groundwater concerns (formaldehyde, wildlife, etc.)
• Neighborhood character (visual and psychological impacts of backyard grave sites).
ACTION: Establish a permanent prohibition on family burial grounds in the City of Edmonds. Moved: Lee Hankins Second: Nick Maxwell Result: Passed 6-0 SUBCOMMITTEE REPORT
None.
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FINAL BILL REPORT
SHB 22223399
C 117733 L 2266
Synopsis as Enacted
Brief Description:: Providing Washingtonians and their loved ones with location choices for
interment of remains..
Sponsors:: House Committee on Civil Rights && Judiciary ((originally sponsored by
Representatives Abell,, Bernbaum,, Chase,, Simmons,, Walsh,, Burnett and Engell))..
House Committee on Civil Rights && Judiciary
Senate Committee on Law && Justice
Background::
Disposition of Human Remains on Private Land..
State law defines ""human remains"" as the body of a deceased person,, in any stage of
decomposition,, as well as the remains following cremation,, alkaline hydrolysis,, or natural
organic reduction..
Disposition of human remains after cremation,, alkaline hydrolysis,, or natural organic
reduction may occur on private lands with the consent of the property owner.. Otherwise,, it
is a misdemeanor to dispose of any human remains in any place except a building dedicated
exclusively for religious purposes or a cemetery,, such as a burial park for earth interments,,
a mausoleum for crypt interments,, and a columbarium for permanent niche interments..
State Law Governing Private Cemeteries..
Private cemeteries are governed as ""cemetery authorities,,"" meaning entities that either hold
a certificate of authority from the Funeral and Cemetery Board ((Board)) or operate
cemeteries that are outside the Board''s jurisdiction..
In order to operate a private cemetery,, an individual or legal entity must form a corporation
and obtain a cemetery license from the Board,, which administers and enforces state law
related to operations of cemeteries.. A private cemetery is subject to various requirements
related to cemetery property and endowment care fund requirements..
This analysis was prepared by non--partisan legislative staff for the use of legislative
members in their deliberations.. This analysis is not part of the legislation nor does it
constitute a statement of legislative intent..
SHB 22223399-- 11 --House Bill Report
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Relocation of Human Remains from a Cemetery Plot..
Human remains may be removed from a cemetery plot with the consent of the cemetery
authority and the written consent of a surviving family member of the decedent in the
following order:: surviving spouse or state--registered domestic partner;; surviving children;;
surviving parents;; and surviving siblings.. If the required consent cannot be obtained,,
permission from the superior court is sufficient..
Local Government Regulation of Private Cemeteries..
In addition to state law,, private cemeteries may be subject to local regulations..
Tax Exemptions for Cemeteries..
All lands,, buildings,, and personal property used exclusively for public burial grounds or
cemeteries that do not discriminate based on race,, color,, national origin,, or ancestry are
exempt from taxation..
The Washington State Department of Archaeology and Historic Preservation..
The Washington State Department of Archaeology and Historic Preservation ((DAHP)) is
responsible for the study and preservation of the state''s archaeological and historical
resources.. State law requires the DAHP to maintain a centralized database and geographic
information systems spatial layer of all known cemeteries and burial sites in Washington..
Summary::
Establishing a Family Burial Ground..
A natural person may designate an area of land the person owns as a ""family burial ground,,""
defined as an area of private land designated for the burial of human remains,, and in which
interment may be,, but is not required to be,, restricted to a group of persons who are related
to each other by birth,, marriage,, or adoption.. ""Family burial ground"" includes any
mausoleums or columbaria constructed on a family burial ground..
If a property is co--owned by two or more persons,, written consent of all co--owners is
required before a family burial ground may be established on the property.. A family burial
ground may not be established on property co--owned by a combination of natural persons
and legal entities..
A family burial ground may not comprise more than 1100 percent of the parcel and is subject
to specified setback requirements.. The property owner may not offer plots in the family
burial ground for sale or charge fees in connection with the burials.. Before selling the
property,, the property owner must inform buyers and disclose the existence of the family
burial ground in the seller''s disclosure statement..
Mausoleums and Columbaria on a Family Burial Ground..
A mausoleum,, columbarium,, or similar structure constructed on a family burial ground
SHB 22223399-- 22 --House Bill Report
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must be constructed with such material and workmanship as to ensure its durability and
permanence and must be of class A fireproof construction.. A mausoleum,, columbarium,, or
similar structure must also be constructed and installed in compliance with all applicable
building permitting laws,, public health laws,, and laws governing class A construction.. A
violation of these requirements is a civil infraction..
Reporting Interments in a Family Burial Ground..
Within 3300 days of an interment in the family burial ground,, the owner must record the
interment with the county auditor and provide specified information about the deceased
person and the location of the grave,, mausoleum,, or columbarium.. The property owner
must also report each interment to the DAHP..
Relocation of Human Remains from a Family Burial Ground..
A property owner may relocate human remains from a family burial ground on their
property with the written consent of one of the following surviving family members of the
decedent,, in the order named:: surviving spouse or state--registered domestic partner;;
surviving children;; surviving parents;; or surviving siblings.. The consenting family member
has the right to designate another lawful place for disposition of human remains in which
the relocated human remains will be reinterred..
If the property owner is unable to obtain consent for relocation of remains from a surviving
family member,, the property owner may petition the superior court for an order authorizing
the relocation.. In cases where the relocation is authorized by the superior court,, the
property owner has the right to designate another lawful place in which the relocated
remains will be reinterred.. However,, in designating a place,, the property owner must make
all reasonable efforts to consult with any surviving family members..
Upon obtaining the required consent or court authorization,, the property owner must obtain
a permit from the DAHP to disinter the human remains from the family burial ground and to
reinter the remains in another lawful place..
Local Government Regulation of Family Burial Grounds..
Cities and counties are authorized to enact ordinances regulating or prohibiting the
establishment of family burial grounds.. Cities,, towns,, and counties must prescribe local
procedures to ensure the owner of the property on which a family burial ground is located
remediates,, at the owner''s expense,, any violation of the provisions governing the
construction and installation of mausoleums,, columbaria,, and similar structures on a family
burial ground..
Other Provisions..
Family burial grounds are included as a lawful place for disposition of human remains,,
along with cemeteries.. Family burial grounds are also exempt from the cemetery licensing
requirement and are not subject to the authority of the Board..
SHB 22223399-- 33 --House Bill Report
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The tax exemption for public burial grounds and cemeteries does not apply to family burial
grounds..
Votes on Final Passage::
House 9966 00
Senate 4466 22 ((Senate amended))
House 9966 00 ((House concurred))
Final Passage Votes
Effective::June 1111,, 22002266
January 11,, 22002277 ((Section 2200))
SHB 22223399-- 44 --House Bill Report
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City Council Agenda Item 2.4
October 20, 2026 - Public Safety, Planning, Human Services, and Personnel (PSPHSP) Committee
TITLE:Deer Creek Critical Aquifer Recharge Area Draft Code and Next
Steps (First Reading)
DEPARTMENT:Planning and Development Services
PRESENTER:Mike Clugston
NEEDED FROM COUNCIL:Informational
RECOMMENDATION:Move to full Council for discussion on November 24, 2026.
BUDGET:
Total Dollar Amount:0 ☐Approved in Budget
Fund(s):0 ☐Budget Reallocation Required
☒No Budget Impact
PROBLEM/ISSUE STATEMENT:
Concern about the potential contamination of Olympic View Water and Sewer District’s Deer
Creek aquifer by per-and polyfluoroalkyl substances (PFAS) led the City to prohibit the use of
shallow subsurface stormwater discharge techniques within the Deer Creek Critical Aquifer
Recharge Area (CARA) as part of the 2025 Critical Areas Ordinance periodic update.
Because there are no other feasible means of managing stormwater within the Deer Creek
CARA, prohibiting shallow subsurface discharge effectively meant no development or
redevelopment could occur in the area, except for interior work and very minor work outside of
buildings.
To avoid frustration and confusion during the permitting process which would have resulted
from the inability to effectively manage new stormwater runoff, Council adopted Ordinance
4430, which was a moratorium suspending acceptance of permit applications that would trigger
stormwater management requirements within the Deer Creek CARA. The six-month pause,
effective February 18, 2026, was intended to provide time to:
Complete the Deer Creek PFAS study;
Evaluate whether other feasible stormwater management alternatives exist for this
area;
Consider potential amendments to CARA and/or stormwater regulations informed by
completed scientific analysis; and
Avoid the futile processing of applications.
The Deer Creek PFAS study could not be completed during the initial six-month permit
moratorium so Council extended that on August 18, 2026 for another six months (Ordinance
4445). The completed study was received on August 27, 2026, and introduced to Council on
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September 8, 2026 (Attachment 1). The study is the current best available science that can be
applied to the management of PFAS in stormwater within the City’s critical aquifer recharge
areas.
CONTEXT, ANALYSIS, & ALTERNATIVES:
Using the recommendations in the study for PFAS source control, stormwater management,
and aquifer protection, staff developed the draft code language in Attachment 2 to apply to the
Deer Creek CARA. However, should the City ultimately annex Esperance, the requirements
would also apply to Olympic View’s 228th Street Wellfield as well.
As recommended in the study, source control is prioritized, with six new categories added to
the existing table in ECDC 23.10.420(B). These include:
•Roof covering materials
•Specialty pavement sealants and surface treatments (applied outside routine paving)
•Playground surfacing and outdoor polymeric recreational surfacing (including poured-in-
place rubber, engineered wood fiber with polymeric binders, and rubber tile systems)
•Compost and bulk organic soil amendments (including compost, biosolids-derived
products, digestate, and mixed organic mulches) applied within a CARA
•Class B firefighting foams containing intentionally added PFAS (including aqueous film-
forming foams, film-forming fluoroprotein foams, and comparable fluorinated
formulations)
•Stormwater management facilities, including engineered infiltration BMPs and Class V
UIC wells
This approach remains consistent with the regulatory controls described in Olympic View’s
2023 Watershed Protection Plan.
The study also identifies the need to develop a monitoring and adaptive management strategy;
this is consistent with the critical areas ordinance in ECDC 23.10.70.B. However, due to current
resource limitations as well as the potential complexities and financial commitments of such a
program, staff are unable to create that program and then go through Planning Board and
Council review processes prior to the expiration of the current building permit moratorium in
Ordinance 4445 on February 26, 2027. As a result, staff is proposing a phased implementation
of new CARA regulations.
This approach would have Council evaluate and adopt interim CARA code updates in December
2026. That would provide staff with an additional six months to then work with the Planning
Board and Council on adopting permanent regulations, which would include a monitoring and
adaptive management strategy by June 2027. Council may also consider lifting the building
permit moratorium in December 2026 as part of the phased implementation, with the
knowledge that the additional source control protections are already in place.
Alternatively, Council could choose to direct staff to create a set of permanent CARA
regulations while retaining the building permit moratorium. Work on permanent code could
start in the near future but the building permit moratorium would likely need to be extended
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again in early 2027 to allow sufficient time to take the permanent regulations through Planning
Board and Council.
RECOMMENDATION:
Move to full Council for discussion on November 24, 2026.
BUDGET IMPACTS:
No immediate budget reallocation is required. Depending on how the monitoring and adaptive
management plan is structured, additional funding may be necessary for stormwater sampling
and related work.
ITEM HISTORY:
N/A
ADDITIONAL INFORMATION:
The building permit moratorium has resulted in some temporary loss of revenue associated
with development activity within the Deer Creek CARA, including permit fees, plan review fees,
impact fees, and other development-related charges that would otherwise have been collected
during the moratorium period. Multiple potential applicants for a variety of projects like new
construction and remodels have been turned away during the moratorium.
ATTACHMENTS:
Attachment 1 - Deer Creek Critical Aquifer Recharge Area Literature and Desktop Review PFAS
Source Identification Study
Attachment 2 - Draft CARA Code
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Deer Creek Critical Aquifer Recharge Area
Literature and Desktop Review
PFAS Source Identification
Prepared for
City of Edmonds
121 Fifth Avenue North
Edmonds, Washington 98020
Prepared by
EA Engineering, Science, and Technology, Inc., PBC
600 Stewart Street, Suite 800
Seattle; Washington 98101
Version: FINAL
EA Project No.: 1664401
August 2026
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Version: Final
Page i
EA Engineering, Science, and Technology, Inc., PBC August 2026
Deer Creek Critical Aquifer Recharge Area Literature and Desktop Review
Edmonds, Washington
Contents
List of Figures .................................................................................................................. iii
List of Tables .................................................................................................................. iv
List of Abbreviations ........................................................................................................ v
1. Summary ................................................................................................................ 1-1
2. Literature and Guidance Review ............................................................................. 2-1
2.1. Purpose and Scope ........................................................................................ 2-1
2.2. PFAS in Urban and Residential Stormwater .................................................. 2-1
2.3. Atmospheric Deposition and Rainwater as PFAS Sources ............................ 2-2
2.4. Built-Environment and Product-Related PFAS Sources ................................. 2-3
2.4.1. Roofing, Sealants, Coatings, and Waterproofing Products ................. 2-5
2.4.2. Pavement, Asphalt, and Construction Materials ................................. 2-6
2.4.3. Playground Surfaces, Turf, and Landscaping Materials ..................... 2-6
2.4.4. Household and Commercial Product Pathways.................................. 2-8
2.5. Screening-Level Source Prioritization and Regulatory-Relevance
Framework .............................................................................................................. 2-9
2.6. Deer Creek CARA: Available Information and Site Context ......................... 2-13
2.6.1. Land Use, Development Patterns, and Stormwater Exposure
Pathways ...................................................................................................... 2-13
2.6.2. Madrona K-8 and Other Publicly Available PFAS Concern
Information .................................................................................................... 2-19
2.6.3. Washington-Specific Analog Studies and Guidance ......................... 2-20
2.6.4. Interpretation of Local PFAS Information in Context of Published
Literature ...................................................................................................... 2-20
2.7. PFAS Sampling Considerations and QA/QC Limitations .............................. 2-21
2.8. Key Data Gaps, Uncertainties, and Implications for Source Identification .... 2-22
3. Mitigation and Aquifer-Protection Alternatives ........................................................ 3-1
3.1. Conditional Framework for Class V UIC Wells and Infiltration
Appropriateness ...................................................................................................... 3-8
3.2. Multi-Media Monitoring Strategy ................................................................... 3-10
4. Recommendations for PFAS Source Control, Stormwater Management, and Aquifer
Protection ..................................................................................................................... 4-1
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Version: Final
Page ii
EA Engineering, Science, and Technology, Inc., PBC August 2026
Deer Creek Critical Aquifer Recharge Area Literature and Desktop Review
Edmonds, Washington
4.1. Tier 1: Measures Based on Existing Evidence ............................................... 4-3
4.2. Tier 2: Conditional Measures Where Site-Specific Information Is Available ... 4-6
4.3. Tier 3: Monitoring and Adaptive Management Recommendations ................. 4-9
5. References ............................................................................................................. 5-1
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List of Figures
Figure 1. Conceptual model of potential PFAS sources and stormwater transport .... 2-18
Figure 2. Conceptual ex-situ/on-site engineered pretreatment train for PFAS
management before infiltration in a critical aquifer recharge area. ............................... 3-7
Figure 3. Conceptual ex-situ foam fractionation treatment train for collected PFAS-
impacted stormwater before conditional recharge, reuse, or controlled discharge. ...... 3-7
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List of Tables
Table 1. Screening-level PFAS source prioritization and regulatory relevance ........... 2-10
Table 2. Summary of publicly available documents .................................................... 2-15
Table 3. Structured comparison of mitigation and aquifer-protection alternatives. ....... 3-2
Table 4. Information in a site-specific hydrogeologic and PFAS-risk evaluation. .......... 3-9
Table 5. Recommended multi-media monitoring strategy........................................... 3-11
Table 6. Big-picture recommended approach for the Deer Creek CARA. .................... 4-1
Table 7. Summary of recommended PFAS risk-reduction measures ......................... 4-12
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List of Abbreviations
AFFF Aqueous Film-Forming Foam
CARA Critical Aquifer Recharge Area
EA EA Engineering, Science, and Technology, Inc., PBC
Ecology Washington State Department of Ecology
EPA U.S. Environmental Protection Agency
ITRC Interstate Technology & Regulatory Council
OECD Organisation for Economic Co-operation and Development
PFAS Per- and polyfluoroalkyl substance
PFOA Perfluorooctanoic acid
PFOS Perfluorooctane sulfonate
NADP National Atmospheric Deposition Program
NIEHS National Institute of Environmental Health Sciences
NPDES National Pollutant Discharge Elimination System
ng/L Nanograms per liter
QA Quality assurance
QC Quality control
TAPE Technology Assessment Protocol – Ecology
UIC Underground injection control
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1. Summary
EA Engineering, Science, and Technology, Inc., PBC (EA) conducted this desktop study
to evaluate published literature, regulatory guidance, and publicly available local
information relevant to potential per- and polyfluoroalkyl substance (PFAS) sources and
transport pathways in the Deer Creek Critical Aquifer Recharge Area (CARA). The
review focused on PFAS occurrence in urban and residential stormwater, atmospheric
deposition and precipitation, built-environment materials, consumer and commercial
products, and stormwater infiltration pathways that may be relevant to aquifer recharge
settings.
The literature indicates PFAS can occur in urban stormwater and may be transported
through developed watersheds via runoff from roads, roofs, paved areas, landscaped
surfaces, school properties, recreational areas, and stormwater conveyance systems. In
aquifer recharge settings, stormwater infiltration may represent a plausible pathway for
PFAS movement toward groundwater; however, the significance of this pathway is
highly site-specific and depends on stormwater concentrations, pretreatment, infiltration
design, vadose-zone conditions, aquifer properties, dilution, travel time, and compound-
specific PFAS behavior. Therefore, PFAS presence in stormwater should be treated as
a pathway of concern but not as direct evidence of aquifer impact without supporting
groundwater or vadose-zone data.
Atmospheric deposition is also a relevant potential input pathway. Published studies
and agency materials indicate PFAS can be transported through the atmosphere and
deposited through rainfall and dry deposition, including in areas without an obvious
single point source. As a result, PFAS detected in developed recharge areas may
reflect a combination of regional/background atmospheric inputs, stormwater runoff
mobilization, and localized material or land-use sources rather than one dominant
source category.
The review also found that PFAS use is broadly documented in built-environment and
consumer-product categories relevant to residential and mixed-use urban settings.
Potential source categories include roofing materials, exterior coatings, sealants,
waterproofing products, treated textiles, carpets, consumer products, artificial turf,
playground surfaces, and other outdoor polymeric or weather-exposed materials. The
strength of evidence varies by material class. The evidence is strongest for documented
PFAS use in coatings, textiles, carpets, consumer goods, exterior building products, and
certain artificial turf components. Direct field-scale runoff data for specific residential
materials, ordinary pavement products, and some landscaping materials remain more
limited. Accordingly, these materials should be considered plausible diffuse PFAS
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source categories during source-screening efforts, while recognizing their relative
contribution in Deer Creek cannot be quantified from the current desktop record alone.
Publicly available Deer Creek-specific technical information appears limited. The
available record primarily consists of city permitting and planning materials, Washington
State Department of Ecology (Ecology) guidance, public issue-history materials,
litigation-related documents, and Washington analog studies rather than detailed, Deer
Creek-specific PFAS fate-and-transport investigations. City materials confirm Deer
Creek is a mapped CARA and projects within the Deer Creek and 228th Street CARA
require city coordination before stormwater design, confirming the area is already
treated as aquifer-sensitive in local permitting. Planning materials also indicate
projected growth within Edmonds is concentrated in the Edmonds Marsh, Deer Creek,
and Shell Creek watersheds, making development patterns and stormwater
management directly relevant to the Deer Creek pathway evaluation.
Madrona K-8 School has become a focal point in the local PFAS concern context.
Publicly available issue-history and litigation materials report PFAS detections in
stormwater and bioretention planter soils at or near the school site and identify concerns
regarding stormwater discharge through underground injection control wells above the
Deer Creek aquifer. Reported stormwater concentrations in the litigation materials
include values up to 32.2 nanograms per liter (ng/L) perfluorooctanoic acid (PFOA) and
18.9 ng/L perfluorooctane sulfonate (PFOS); however, those materials do not present
the reported detections as direct aquifer groundwater results. These materials are
important for understanding the local concern and potential pathway questions, but they
should be treated as public-issue history and litigation context rather than final technical
determinations of source attribution, groundwater impact, or aquifer contamination.
When compared with published urban stormwater literature, the reported Madrona
stormwater PFAS concentrations appear broadly consistent with values reported in
other urban runoff studies, although the reported PFOA concentration is near the upper
end of some comparable datasets. This supports the conclusion that the reported
stormwater detections warrant attention in a recharge-sensitive setting but do not, by
themselves, prove a unique source mechanism or aquifer impact.
Stormwater-management alternatives within the Deer Creek CARA should also be
evaluated in the context of the ultimate disposition of stormwater. Most of the CARA lies
within closed drainage basins, where stormwater that is not managed through
engineered infiltration may pond and ultimately infiltrate naturally unless it is collected
and conveyed elsewhere. Other portions of the CARA may discharge toward Deer
Creek, creating a distinct surface-water pathway. Consequently, prohibiting an
engineered infiltration facility does not necessarily eliminate subsurface recharge or
PFAS transport; it may instead change where infiltration occurs or redirect PFAS-
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bearing stormwater to another receptor. The relative protectiveness of engineered
infiltration, natural infiltration, and non-infiltration alternatives therefore depends on site-
specific hydrology, infiltration configuration, source-water quality, available controls, and
receptor relationships.
Overall, the current record supports a multiple-lines-of-evidence conceptual model for
the Deer Creek CARA. Plausible PFAS inputs include atmospheric deposition, diffuse
urban stormwater, weather-exposed built-environment materials, landscaping and
recreational materials, and household or commercial product-related sources.
Stormwater may then transport PFAS through engineered infiltration, natural infiltration,
stormwater conveyance, or surface-water discharge pathways depending on local
drainage and site conditions.
The available information is sufficient to support targeted source-control measures and
a tiered, risk-differentiated approach to stormwater and infiltration management, but it is
not sufficient to identify a single dominant PFAS source, quantify the relative
contribution of individual sources or pathways, or determine whether reported
stormwater detections have resulted in aquifer impacts. Accordingly, source control
should be emphasized where controllable PFAS inputs can be reduced before runoff is
generated, while infiltration and other stormwater-management decisions should
consider system configuration, hydrogeologic conditions, source-water quality,
pretreatment where they are relied upon as a protective measure, monitoring, and the
ultimate receiving pathway.
Key data gaps include the limited availability of Deer Creek-specific PFAS sampling
data, incomplete source-area characterization, uncertainty regarding stormwater routing
and drainage boundaries, limited information regarding engineered and natural
infiltration pathways, incomplete characterization of surface-water and groundwater
connectivity, limited hydrogeologic and vadose-zone information, and the need for
complete PFAS-specific quality assurance (QA)/quality control (QC) documentation.
These limitations currently prevent quantitative comparison of PFAS loading associated
with engineered infiltration, natural infiltration, and surface-water discharge pathways.
Future work should prioritize well-documented stormwater and source-area sampling,
drainage and infiltration-infrastructure mapping, characterization of closed-basin and
direct-discharge areas, review of existing groundwater and surface-water information,
and targeted evaluation of higher-priority source materials. Where warranted by project
scale or pathway risk, additional hydrogeologic, groundwater, vadose-zone,
pretreatment-performance, or receiving-water monitoring could be used to evaluate
hydraulic and chemical connections and refine the City’s tiered source-control and
stormwater-management framework.
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2. Literature and Guidance Review
2.1. Purpose and Scope
This review summarizes published information relevant to PFAS occurrence in urban
and residential stormwater, atmospheric deposition and precipitation, and mitigation
approaches applicable to developed recharge settings. The emphasis is on diffuse-
source urban environments rather than point-source industrial discharges because the
literature most relevant to the Deer Creek CARA concerns mixed land-use runoff,
precipitation inputs, and the potential for multiple concurrent PFAS pathways. Current
agency materials indicate this remains an evolving management area. U.S.
Environmental Protection Agency (EPA) is using existing National Pollutant Discharge
Elimination System (NPDES) authorities to reduce PFAS discharges and improve
monitoring, while broader PFAS effluent and criteria frameworks continue to develop
(EPA 2022). Washington State has published PFAS investigation and remediation
guidance; however, current stormwater-management frameworks do not establish
PFAS-specific treatment-performance criteria or a comprehensive municipal PFAS
framework for residential runoff and infiltration settings.
2.2. PFAS in Urban and Residential Stormwater
Published literature indicates urban stormwater can act as a transport pathway for
PFAS in developed areas. In a review focused specifically on sustainable water
recycling through aquifers, Page et al. 2019 noted urban stormwater runoff and other
urban waters may contain PFAS at levels relevant to managed aquifer recharge and
infiltration schemes and further observed the implications for groundwater depend on
source concentrations, aquifer properties, and treatment configuration rather than on
source presence alone. This framing is important because it places PFAS in stormwater
within a broader recharge-risk context and avoids oversimplified assumptions that either
all infiltration is benign or all infiltration is inherently unacceptable (Page et al. 2019).
Studies of infiltrated stormwater also show groundwater effects are site-dependent.
Edwards et al. 2022 evaluated stormwater infiltration through dry wells at suburban
residential and suburban commercial locations and found the likelihood of contaminants
reaching groundwater was strongly influenced by pretreatment and subsurface
conditions. Their work concluded that infiltration through dry wells with pretreatment
may pose relatively low groundwater-quality risk under some settings, while also
emphasizing dry wells can bypass portions of the vadose zone; therefore, require
careful evaluation. Although that study addressed a broad range of stormwater
chemicals rather than PFAS alone, it is directly relevant to the question of how infiltrated
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urban runoff can affect shallow groundwater and aquifer recharge systems (Edwards et
al. 2022).
The PFAS-specific recharge literature points in the same direction. Page et al. 2019
described PFAS as a relevant concern for urban aquifer infiltration and water recycling
because stormwater and treated waters may introduce persistent fluorinated
compounds to groundwater systems. A more recent systematic review of contaminants
of emerging concern in managed aquifer recharge similarly identified PFAS as part of
the contaminant suite that may enter groundwater where source waters are insufficiently
controlled or treated. Taken together, these studies support a neutral but important
conclusion: PFAS in stormwater is a plausible concern in recharge areas, but the
significance of that concern depends on source strength, pretreatment, infiltration
design, and subsurface transport conditions (Mumberg et al. 2024a; Page et al. 2019).
2.3. Atmospheric Deposition and Rainwater as PFAS
Sources
Atmospheric deposition is also a documented PFAS input pathway. EPA materials
recognize PFAS may affect environmental media through atmospheric releases and
deposition, and the National Atmospheric Deposition Program (NADP) now includes a
PFAS precipitation subnetwork to support evaluation of atmospheric transport and wet
deposition. This reflects a broader scientific consensus that PFAS can be transported
through the atmosphere and deposited by rainfall, even in areas lacking an obvious
local discharge source (NADP, 2024; U.S.EPA, 2020).
Recent global-scale analyses suggest PFAS in precipitation may be widespread, with
some authors proposing atmospheric PFAS contamination has reached levels of global
concern, even in remote regions (Cousins et al., 2022). Peer-reviewed precipitation
studies provide direct evidence of this pathway. Kim and Kannan reported PFAS in
urban air, rain, snow, surface runoff, and lakes, demonstrating early on that atmospheric
deposition and runoff can act as linked pathways within urban watersheds (Kim and
Kannan, 2007). Shimizu et al. 2021 later documented both legacy PFAS and
replacement PFAS in wet and dry deposition in North Carolina, providing direct
evidence newer fluorinated compounds, including replacement chemistries, can also be
transported atmospherically and deposited to the land surface (Shimizu et al., 2021). In
Wisconsin, Pfotenhauer et al. 2022 analyzed 89 precipitation samples across 8
monitoring sites and found summed PFAS concentrations in rainwater ranging from 0.7
to 6.1 ng/L, with regional differences in compound profiles that suggested local or
regional source influences superimposed on a broader background signal (Pfotenhauer
et al., 2022). Great Lakes precipitation studies likewise reported measurable PFAS
concentrations and deposition at multiple sites, reinforcing precipitation can provide
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both a regional background input and a spatially variable source indicator (Gewurtz et
al., 2019; Xia et al., 2024).
Viewed together, the stormwater and atmospheric deposition literature suggests PFAS
detections in developed recharge areas may reflect more than one input pathway.
Stormwater runoff can mobilize PFAS from urban surfaces and land uses, while
precipitation can independently deliver PFAS from atmospheric transport and
deposition. The relative contribution of each pathway likely varies by land use, material
sources, precipitation patterns, and hydrogeologic setting. Therefore, PFAS occurrence
in recharge settings should be evaluated using a multiple-lines-of-evidence approach
that considers diffuse background deposition, runoff mobilization, and site-specific
transport conditions rather than assuming a single dominant source category from the
outset (Edwards et al., 2022; Page et al., 2019; Pfotenhauer et al., 2022).
From a management perspective, available guidance currently emphasizes source
reduction, monitoring, and targeted controls. EPA’s 2022 PFAS NPDES memorandum
states the agency is leveraging permitting authorities to reduce PFAS discharges at the
source and obtain more comprehensive information on PFAS sources and quantities
while broader effluent limitation and criteria frameworks continue to be developed (Fox,
2022). Ecology’s PFAS guidance similarly reflects a broader investigation-and-
management approach rather than a narrowly defined stormwater-specific municipal
PFAS rule set for residential recharge areas. In practical terms, the current guidance
landscape supports careful monitoring, source characterization, and evaluation of
treatment or pretreatment options where warranted, while acknowledging the regulatory
structure remains under active development ((Washington State Department of
Ecology, 2023).
2.4. Built-Environment and Product-Related PFAS Sources
Published literature indicates PFAS use extends well beyond industrial facilities and
firefighting applications and includes a broad range of materials relevant to the built
environment. Glüge et al. 2020 compiled a large global inventory of PFAS uses and
identified more than 200 use categories and subcategories, including uses in building
and construction, textiles, coatings, paper, and numerous consumer-product
applications (Glüge et al., 2020). That review, together with later summaries focused on
occupational and industrial use, indicates that PFAS have historically been incorporated
into products to provide water repellency, stain resistance, grease resistance, weather
resistance, lubrication, and related functional properties that are directly relevant to
urban and residential land uses (Gaines, 2023).
Within the building sector, PFAS use has been reported in roofing materials, paints and
coatings, flooring, sealants, caulks, adhesives, carpets, and other building products. A
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recent survey chapter focused specifically on building products described PFAS
applications across roofing, coatings, flooring, sealants, and related materials, while
broader use inventories similarly identify construction materials and coating applications
as important PFAS use categories (Bruton and Ray, 2023; Glüge et al., 2020). These
findings are relevant to stormwater studies because many of these materials are
installed on or near weather-exposed surfaces; therefore, they may interact directly with
rainfall, runoff generation, or both.
Although the stormwater literature has more commonly documented runoff contributions
from metals and conventional urban pollutants than from PFAS-specific building
products, studies of roof runoff show roofing materials can materially influence runoff
quality. That broader runoff literature supports the premise that stormwater contacting
roofs, facades, and other construction materials should not be assumed to be
chemically uniform or source-free (De Buyck et al., 2021). In the PFAS context, the
importance of roofing, coatings, waterproofing products, and sealants lies less in a
single definitive runoff study for each material type than in the converging evidence
such materials can contain fluorinated chemistries and are exposed to weathering and
runoff over long service lives (Bruton and Ray, 2023; Udvary et al., 2025).
Consumer products represent another relevant source category. EPA states PFAS are
found in a wide array of consumer and industrial products, and Ecology identifies
common PFAS-containing product categories, including carpets, waterproof products,
and other stain-, oil-, or grease-resistant materials (EPA., 2025; Washington State
Department of Ecology, 2023). The Interstate Technology & Regulatory Council (ITRC)
PFAS guidance further notes that degradation of PFAS-treated consumer products,
such as textiles, carpets, and paper, can release PFAS to surrounding environments
(ITRC, 2026). While some of that evidence comes from indoor exposure studies, the
same product classes are relevant to outdoor urban settings where weathering,
abrasion, littering, washing, or disposal may create pathways to stormwater.
Carpets and coated textiles are among the best documented PFAS-containing product
classes. Wu et al. found strong associations between PFAS concentrations in paired
carpet and dust samples, indicating carpets can act as both a source and a sink for
PFAS (Wu et al., 2020b). Additional work on indoor air similarly concluded carpets can
be significant sources of neutral and volatile PFAS in indoor environments (Morales-
McDevitt et al., 2021a). These studies do not directly quantify stormwater loading, but
they do show treated polymeric and textile surfaces can retain and release PFAS over
time, which is relevant when considering analogous outdoor materials or disposal-
related pathways.
Weathering studies provide especially useful evidence for outdoor-source discussions.
Van Der Veen et al. reported weathering affects both PFAS profiles and measured
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concentrations in durable water-repellent outdoor clothing (van Der Veen et al., 2020a).
Schellenberger et al. later demonstrated PFAS release from functional textiles under
outdoor aging conditions involving sunlight, precipitation, wind, and heat
(Schellenberger et al., 2022). Together, these studies show treated materials can
change chemically during use and can release measurable PFAS or PFAS precursors
during environmental exposure. This mechanism is directly relevant to outdoor built
environments where coated fabrics, weatherproof materials, or PFAS-treated surfaces
may be exposed to repeated rainfall.
Landscaping and recreational materials may also warrant consideration. Artificial turf
systems, playground materials, and related outdoor polymeric surfaces have received
increasing attention as possible PFAS-containing materials. A 2022 study of artificial turf
fields in Stockholm reported widespread occurrence of non-extractable fluorine in field
components, suggesting fluorinated substances were common in backing, blades, and
filling materials (Lauria et al., 2022b). Review literature has also noted turf backing can
contain PFAS, although release behavior remains less well characterized than
occurrence (Goulding, 2025; Zuccaro et al., 2022). These studies do not establish that
all recreational surfaces are important PFAS runoff sources, but they do support
including turf- and polymer-based outdoor materials within a broader source-screening
framework for developed areas.
Overall, the available literature supports a neutral but important conclusion: building
materials, infrastructure, landscaping materials, and consumer products constitute a
credible class of potential PFAS sources in developed areas. The significance of any
one material class will vary by land use, product composition, age, weathering history,
maintenance practices, and hydrologic connectivity. However, the breadth of
documented PFAS use across construction materials, treated products, textiles, and
outdoor polymeric surfaces indicates these source categories should be considered in
source identification efforts alongside atmospheric deposition and stormwater transport
processes rather than excluded at the outset.
2.4.1. Roofing, Sealants, Coatings, and Waterproofing Products
The literature strongly supports treating roofing-related materials, sealants, coatings,
and waterproofing products as plausible PFAS sources. The Consumer Product Safety
Commission’s PFAS white paper identifies PFAS-containing paints, varnishes, and
sealants as relevant product categories and notes that PFAS can be released
throughout product life cycles, including use, washing, weathering, and end-of-life
disposal. The same report also notes these materials can contribute to landfill leachate
and runoff once discarded, reinforcing that building products can remain
environmentally relevant after installation and use (Commission, 2023).
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Recent product-testing work strengthens this conclusion. A 2025 study on Canadian
building products analyzed 145 samples of paints, sealers, and textiles, mostly intended
for exterior use, and directly investigated both nonpolymeric PFAS and side-chain
fluorinated polymers in those materials. The study was designed specifically to assess
whether exterior building products may act as environmental PFAS sources, making it
highly relevant to source-screening in developed runoff settings (Liu et al., 2025).
Broader coatings literature is also relevant. Organisation for Economic Co-operation
and Development (OECD) has documented PFAS use and alternatives in coatings,
paints, and varnishes, showing fluorinated chemistries have been used in protective
coatings because of their surface-active and repellent properties. Taken together, the
building-products and coatings literature supports inclusion of roofing, coatings,
sealants, and waterproofing-related materials as plausible diffuse PFAS sources, even
though direct field runoff measurements from every individual product type remain
limited (OECD, 2022).
2.4.2. Pavement, Asphalt, and Construction Materials
A 2023 review on PFAS-contaminated asphalt and concrete concluded PFAS
interactions with these materials are important enough to raise significant management
and characterization questions and identified 24 knowledge gaps and management
challenges related to concrete and asphalt (Douglas et al., 2023). However, much of the
direct PFAS literature for pavement and concrete concerns contaminated sites,
especially locations impacted by Aqueous Film-Forming Foam (AFFF) or known PFAS
releases, rather than ordinary residential streets or routine urban paving products
(Mayer et al., 2024). Vo et al. 2023 tested commercially available sealants for mitigating
PFAS release from AFFF-impacted concrete and found that sealant effectiveness
differed by product type and PFAS behavior. This type of work demonstrates that PFAS
leaching from paved materials is a recognized issue in the scientific and remediation
literature, although most directly studied cases involve previously contaminated
infrastructure rather than ordinary neighborhood pavement (Vo et al., 2023).
Accordingly, pavement treatments, asphalt modifiers, and related construction materials
can reasonably be considered in PFAS source screening, but the strength of evidence
is not the same as for broader building-product or consumer-product use categories. A
balanced interpretation is that paved materials may act as PFAS reservoirs or release
surfaces under some conditions, but the magnitude of their contribution in typical
residential runoff settings remains uncertain.
2.4.3. Playground Surfaces, Turf, and Landscaping Materials
Artificial turf and similar recreational surfaces have received increasing attention as
possible PFAS-containing materials. Lauria et al. 2022a reported widespread
occurrence of non-extractable fluorine in artificial turf field components from Stockholm,
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Sweden, including backing, blades, and filling materials. The authors concluded that
fluorinated substances were common in the sampled turf systems, although targeted
extractable PFAS concentrations were generally low. This distinction is important
because it supports the presence of fluorinated materials while also indicating release
behavior is not yet fully characterized (Lauria et al., 2022a). The artificial-turf literature
is, therefore, useful for source identification, but it does not establish that all playground
or turf materials are major PFAS runoff sources. Rather, it supports inclusion of these
materials within a broader screening framework for developed areas. For landscaping
materials more generally, direct PFAS field studies are relatively sparse. However,
broader PFAS use inventories and building-product surveys support considering
outdoor polymeric materials, treated fabrics, and related weather-exposed specialty
materials as plausible source categories where such products are present (Glüge et al.,
2020).
Compost and other organic soil amendments represent a distinct landscaping-material
category because they are commonly applied directly to the land surface or
incorporated into shallow soils, where they may interact with precipitation, runoff, and
infiltrating water. Recent studies have documented PFAS in commercially available
compost and related soil-amendment products. Compost may represent one of several
landscaping-related PFAS source categories that warrants consideration where
substantial quantities are used. (Saffari Aman et al., 2026) analyzed five commercial
composts and reported a mean concentration of 9.07 ± 12.22 µg/kg dry weight for the
sum of 13 measured PFAS. An earlier study of commercially available composts,
garden soils, and potting mixes reported total concentrations for 38 targeted PFAS
ranging from 1.26 to 11.84 µg/kg dry weight across the tested products and also
identified evidence of PFAS precursors (Sivaram et al., 2022). These studies
demonstrate that PFAS occurrence in compost and organic amendments can vary
substantially among products and feedstocks and should not be assumed to be uniform.
Because these materials may be applied in relatively large quantities and have direct
contact with recharge soils, compost and similar organic amendments are appropriate
for inclusion in PFAS source screening within the Deer Creek CARA. The available
literature does not establish that all compost represents a significant PFAS source, nor
does it provide a direct basis for predicting PFAS concentrations in stormwater or
groundwater from a measured compost concentration. However, the documented
occurrence of PFAS in commercial compost products provides a technical basis for
considering product documentation or analytical verification where these materials are
proposed for use in recharge-sensitive areas.
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2.4.4. Household and Commercial Product Pathways
Household and commercial products represent one of the strongest literature-backed
PFAS source categories. The National Institute of Environmental Health Sciences
(NIEHS) states PFAS have been used in many everyday products, including clothes,
carpets, stain-resistant materials, cookware, and packaging. ITRC similarly documents
PFAS use in textiles, upholstery, carpets, leather, and apparel, including fluoropolymer
and side-chain fluorinated polymer coatings used to impart oil, water, and stain
repellency. These sources are especially important because they connect PFAS
occurrence to ordinary residential and mixed urban land uses rather than only to
specialized industrial settings (ITRC, 2023; NIEHS, 2025). The environmental-release
literature supports the relevance of these products. Wu et al. 2020a found strong
associations between PFAS concentrations in paired carpets and dust samples from
childcare centers, concluding carpets can act as both sources and sinks of PFAS.
Morales-McDevitt et al. likewise found that concentrations of volatile PFAS in indoor air,
carpet, and dust were closely related, indicating carpets and dust are major indoor
PFAS sources. Although these are indoor studies, they are valuable because they
demonstrate treated surfaces and consumer materials can retain and release PFAS
over time (Morales-McDevitt et al., 2021b; Wu et al., 2020a).
Studies of treated outdoor textiles make the outdoor relevance even clearer. Van der
Veen et al. found that weathering affected both PFAS profiles and measured
concentrations in durable water-repellent clothing, while Schellenberger et al. 2022
showed outdoor aging under sunlight, precipitation, wind, and heat led to PFAS
emissions from functional textiles. These studies provide a direct mechanism by which
PFAS-treated consumer or commercial materials exposed to environmental conditions
may contribute to environmental loading (Schellenberger et al., 2022; van der Veen et
al., 2020b).
Recent reviews of literature also reinforces the breadth of the consumer-product issue.
Yang et al. 2025 reviewed PFAS occurrence in consumer products and summarized
evidence across textiles, leather, paper, food-contact materials, and related consumer
goods, concluding consumer products remain an important PFAS reservoir and
exposure source. Consumer Product Safety Commission white paper similarly
emphasizes PFAS, and precursors can be released during production, use, washing,
disposal, and recycling, and PFAS-containing materials can re-enter the environment
through waste handling pathways (Commission, 2023; Yang et al., 2025). From a runoff
perspective, literature does not support a single dominant product class; rather,
household and commercial products provide multiple plausible pathways for PFAS
release to the urban environment, including weathering, washing, abrasion, disposal,
dust generation, and runoff contact. As a result, these pathways are appropriately
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treated as diffuse source categories that may contribute to PFAS occurrence in
developed watersheds.
2.5. Screening-Level Source Prioritization and Regulatory-
Relevance Framework
The current desktop review does not support definitive quantitative ranking of individual
PFAS sources within the Deer Creek Critical Aquifer Recharge Area (CARA) because
representative source-area, stormwater, vadose-zone, and groundwater data are
limited. However, the available literature supports a screening-level prioritization of
source categories based on multiple factors, including documented PFAS occurrence or
use, potential material quantity or exposed surface area, likelihood of rainfall or runoff
contact, potential release or leaching, hydrologic connection to stormwater or recharge
soils, and relevance to residential or mixed-use development within the CARA.
Where reasonably comparable concentration information was identified in the literature,
Table 1 includes that information to provide additional context regarding potential
source strength. Concentration data should be interpreted cautiously because available
studies use different material matrices, analyte lists, analytical methods, reporting limits,
and study designs. Concentrations measured directly in solid products or materials,
such as compost or building materials, are not directly comparable to PFAS
concentrations measured in stormwater, and product concentrations alone do not
establish the mass ultimately released to runoff or groundwater. For several built-
environment source categories, the literature establishes PFAS occurrence or use but
does not provide sufficiently comparable field-runoff data to assign a representative
concentration range.
Accordingly, the screening priority in Table 1 should not be interpreted as a quantitative
PFAS mass-loading ranking for the Deer Creek CARA or as evidence that every
product within a listed category contains PFAS. Rather, the framework identifies source
categories that warrant differing levels of attention based on the combined strength of
evidence, potential exposure and hydrologic relevance, and ability to control the source
through development review or other management measures. Site-specific product
documentation, source-area sampling, and runoff data would be needed to refine the
framework and quantitatively compare the relative contribution of individual PFAS
sources within the CARA.
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Table 1. Screening-level PFAS source prioritization and regulatory relevance for the Deer Creek CARA.
Note: Table 1 is a conceptual, screening-level prioritization and should not be interpreted as a quantitative source-strength ranking. The categories reflect the
relative strength of published evidence for PFAS use or release potential, likely exposure to rainfall and runoff, and hydrologic relevance to the Deer Creek CARA.
The desktop review did not identify sufficient Deer Creek-specific data or directly comparable material-specific runoff studies to assign quantitative source-strength
values or rank individual materials by PFAS mass contribution. Future source-area sampling, product documentation, or site-specific runoff data could be used to
refine this screening framework.
Screening Priority Source Category Basis for Inclusion Available Concentration Information Regulatory / Source-Control Relevance
Higher Exterior coatings, sealants, waterproofing products, and treated building materials
Strong literature basis for PFAS use in coatings and treated building products; likely outdoor exposure and direct rainfall/runoff contact.
PFAS have been measured in exterior building products, but the reviewed literature does not provide a directly comparable field-runoff concentration range suitable for assigning a Deer Creek-specific source strength.
Strong candidates for material documentation, certification, product substitution, or restrictions for major weather-exposed components.
Moderate/material-dependent Artificial turf, playground surfacing, and outdoor polymeric recreational materials
Evidence of fluorinated substances in some artificial turf and recreational-surface components, with direct relevance to schools, parks, and redevelopment settings. PFAS occurrence and potential release appear to be product-specific, and direct runoff data remain limited.
Targeted PFAS and non-extractable fluorine have been reported in turf components, but directly comparable PFAS runoff concentration data remain limited.
Consider manufacturer documentation, PFAS-related specifications, or alternative materials where runoff is hydrologically connected to infiltration or sensitive receiving waters.
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Screening Priority Source Category Basis for Inclusion Available Concentration Information Regulatory / Source-Control Relevance Moderate Roofing materials,
façade treatments, membranes, and weather-resistant products
Plausible outdoor
PFAS source category with large, exposed surface area and direct rainfall/runoff contact; product-specific evidence varies by formulation.
The reviewed literature supports PFAS occurrence in
some building products, but a representative PFAS runoff concentration range for roofing materials was not identified.
High relevance for documentation
because roofing has extensive direct rainfall contact. Manufacturer specification information could be incorporated into certification requirements.
Moderate Pavement sealants, asphalt/concrete treatments, construction chemicals, and specialty surface treatments
PFAS interactions with pavement materials and some specialty products are documented, although much of the literature concerns contaminated infrastructure rather than ordinary residential paving.
Insufficient directly comparable runoff data are available to assign a representative concentration range for routine residential paving or construction materials.
Focus controls on specialty treatments or products with documented/intentionally added PFAS rather than treating all pavement or concrete as equivalent PFAS sources.
Moderate / material-dependent
Compost and other bulk organic soil amendments
PFAS have been reported in commercial composts and other waste-derived soil amendments. These materials may be applied in substantial quantities directly to soils where they can interact with rainfall and infiltrating water.
A recent study of five commercial composts reported a mean Σ13 PFAS concentration of 9.07 ± 12.22 µg/kg dry weight. Concentrations vary by feedstock and product, and material concentrations are not directly comparable to stormwater concentrations in ng/L (Aman et al., 2026).
Reasonable candidate for source screening or verification before use within the CARA. A rebuttable-presumption approach could be considered, provided the City defines acceptable analytical or documentation criteria.
Moderate Household and commercial diffuse sources
Strong evidence of PFAS use in consumer and commercial products, but
No single representative concentration range is appropriate because this category includes numerous products and release mechanisms.
Better addressed through education, waste management, procurement, housekeeping, and targeted source identification
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Screening Priority Source Category Basis for Inclusion Available Concentration Information Regulatory / Source-Control Relevance source-to-
stormwater pathways are diffuse and less directly controlled through development review.
rather than material restrictions
alone.
Background / contextual Atmospheric deposition and rainwater
Documented regional/background PFAS input pathway that can contribute PFAS even where no discrete local source is present.
Pfotenhauer et al. (2022) reported summed PFAS concentrations of approximately 0.7–6.1 ng/L in precipitation samples collected across Wisconsin; concentrations vary geographically and by analyte list and method.
Use as background/context for interpreting stormwater results rather than as a locally controllable source category.
Site-specific / data-dependent UIC wells, dry wells, infiltration galleries, and infiltration BMPs
These features are not PFAS sources but may transmit PFAS-bearing stormwater toward the subsurface.
Not applicable as a source concentration. Relevant concentrations are those in the stormwater entering the system and, where treatment is used, the water following pretreatment.
Manage as pathway features through risk-differentiated review, source-water characterization, hydrogeologic evaluation, pretreatment where appropriate, O&M, and monitoring.
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2.6. Deer Creek CARA: Available Information and Site
Context
2.6.1. Land Use, Development Patterns, and Stormwater
Exposure Pathways
Publicly available Deer Creek-specific technical information appears limited. Materials
identified during this desktop review consist primarily of city permitting and planning
pages confirming the Deer Creek CARA designation, Ecology guidance, and broader
stormwater and groundwater-protection references. A substantial body of Deer Creek-
specific peer-reviewed or agency case-study literature on PFAS transport through
stormwater infiltration to the aquifer was not identified. Accordingly, the available local
record is useful for framing land use, development pressure, infrastructure type, and
plausible exposure pathways, but it is not sufficient by itself to resolve PFAS source
attribution.
Available city materials indicate Deer Creek is a mapped CARA and projects within the
Deer Creek and 228th Street CARA require coordination with city staff before
stormwater systems are designed. This confirms Deer Creek is already treated as an
aquifer-sensitive planning area in local permitting. City stormwater planning materials
also indicate projected growth within city limits is concentrated in the Edmonds Marsh,
Deer Creek, and Shell Creek watersheds, which makes development pressure in the
Deer Creek watershed directly relevant to stormwater management and groundwater-
recharge questions (City of Edmonds, 2026a; b).
The key publicly available documents and information sources identified during this
desktop review and their relevance to land use, development patterns, and potential
stormwater exposure pathways in the Deer Creek CARA are summarized in Table 2. As
shown in Table 2, the available Deer Creek-specific record is limited and consists
primarily of permitting materials, state guidance, public issue-history documents, and
broader Washington analog sources rather than detailed, site-specific technical studies.
Stormwater-management conditions within the Deer Creek CARA are not uniform. Most
of the CARA lies within closed drainage basins where no direct surface-water outlet is
available and stormwater that is not managed through engineered infiltration must pond
and ultimately infiltrate naturally unless it is collected and conveyed outside the basin.
Other portions of the CARA drain toward Deer Creek and primarily discharge to the
creek without infiltrating, including areas upstream of and near the wellhead. These
drainage settings create different potential PFAS transport pathways and should be
considered separately when evaluating stormwater-management alternatives.
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In closed-basin areas, the relevant technical comparison may be between managed
engineered infiltration and less-controlled natural infiltration rather than between
infiltration and complete elimination of subsurface recharge. In areas draining to Deer
Creek, a non-infiltration approach may instead transfer PFAS-bearing stormwater to a
surface-water pathway. The relative significance of these pathways depends on
stormwater flow and PFAS concentrations, infiltration characteristics, hydrogeologic
connectivity, travel time, dilution, and receptor relationships. The current desktop review
does not include the hydraulic or mass-flux information necessary to quantitatively rank
these pathways.
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Table 2. Summary of publicly available documents and their relevance to land use, development patterns and
potential stormwater exposure pathways in the Deer Creek CARA
Data Source What It Tells Us Relevance to PFAS Source/Pathway Screening Key Uncertainty/ Limitation
Deer Creek CARA drainage and stormwater-management information
Most of the CARA lies within closed drainage basins where stormwater may ultimately infiltrate unless it is collected and conveyed outside the basin. Other portions of the CARA drain toward Deer Creek, including areas upstream of and near the wellhead.
Establishes two distinct stormwater-management settings that should be considered in the PFAS pathway analysis: closed-basin areas where engineered and natural infiltration may represent alternative subsurface pathways, and areas where stormwater may be conveyed to a surface-water receptor.
Planning-level drainage context. This desktop review did not independently perform basin hydraulic modeling, quantify stormwater volumes, evaluate conveyance capacity, or calculate comparative PFAS mass loading to groundwater and surface-water receptors.
City of Edmonds Permit Assistance/ Permit Information Pages
Confirms Deer Creek is a mapped CARA and projects in the Deer Creek or 228th Street CARA require city coordination before stormwater design.
(edmondswa.gov)
Establishes that Deer Creek is already treated as an aquifer-sensitive planning area where stormwater design is a special issue
Administrative pages; do not provide hydrogeologic detail, contaminant data, or source characterization
Edmonds Stormwater Management Action Planning Materials
States projected growth within city limits is concentrated in the Edmonds Marsh, Deer Creek, and
Shell Creek watersheds. (ArcGIS StoryMaps)
Supports review of land use and development pressure as part of the Deer Creek pathway analysis
Planning-level information; not a PFAS investigation
Ecology Cara Guidance
Explains the purpose of CARAs and emphasizes protection of both groundwater quality and recharge
function. (apps.ecology.wa.gov)
Provides the technical basis for why infiltration, land use, and contaminant pathways matter in this setting
Statewide guidance; not Deer Creek-specific and not PFAS-specific
Ecology PFAS Guidance
States PFAS contamination in Washington surface waters occurs mainly through stormwater and wastewater pathways.
(apps.ecology.wa.gov)
Strong state-level support for including stormwater as a recognized PFAS pathway in Washington
Not Deer Creek-specific and not focused on CARA infiltration design
Olympic View PFAS Public Materials
Describes PFAS detections in stormwater and soils at the school site and frames concern around groundwater risk to the Deer Creek
aquifer. (Olyview)
Identifies a local concern area and a claimed stormwater-to-groundwater pathway that should be acknowledged in the desktop review
Party-position source; should be treated as issue history rather than independent technical proof
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Data Source What It Tells Us Relevance to PFAS Source/Pathway Screening Key Uncertainty/ Limitation
Local news coverage of moratorium and study
Reports that the city paused
development while conducting a PFAS study in Deer Creek and states city staff view infiltration as a key stormwater management issue
in the basin. (HeraldNet.com)
Useful background for the policy and development context driving the study News reporting; not a technical study
2024 Stormwater Management Manual for Western Washington
Provides the regional technical framework for stormwater quantity and quality control.
(apps.ecology.wa.gov)
Useful for identifying likely facility types and stormwater design context in Edmonds Not PFAS-specific and not Deer Creek-specific
Ecology Artificial Turf Runoff Study
Designed to assess whether Washington artificial turf installations release PFAS and other chemicals into stormwater
runoff. (apps.ecology.wa.gov)
Relevant analog for screening school, playground, and recreational surfaces as possible PFAS runoff contributors
Statewide analog; not Deer Creek-specific
Ecology Greater Lake Washington PFAS Survey
Assesses PFAS sources and pathways in a developed Washington watershed.
(apps.ecology.wa.gov)
Useful Washington urban-watershed analog for pathway framing Different watershed and not a CARA-specific case study
Older regional groundwater references for Snohomish County
Provide broad groundwater and hydrogeologic context for western Snohomish County.
(apps.ecology.wa.gov)
Potential supporting regional context for aquifer sensitivity and groundwater vulnerability
Old and too regional for Deer Creek-specific conclusions
Notes:
CARA = Critical Aquifer Recharge Area
Ecology = Washington State Department of Ecology
PFAS = per- and polyfluoroalkyl substance
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At the state level, Ecology’s CARA guidance provides a broader technical context for
why land use and stormwater pathways matter in this setting. The guidance emphasizes
protection of both groundwater quality and recharge quantity and supports evaluation of
hydrogeologic sensitivity, contaminant fate and transport, and land-use controls in
recharge areas. Ecology’s PFAS guidance for Washington also states PFAS
contamination of surface water in Washington occurs mainly through stormwater and
wastewater pathways, which supports inclusion of stormwater infrastructure and runoff-
generating land uses in the Deer Creek source/pathway review (Washington State
Department of Ecology, 2021; 2023).
Based on the available information, potential PFAS inputs and transport pathways in the
Deer Creek CARA include runoff from developed and weather-exposed surfaces,
stormwater conveyance, engineered and natural infiltration, and, where a surface-water
outlet is present, discharge toward Deer Creek or another receiving water. Figure 1
provides a screening-level conceptual representation of these potential sources,
transport pathways, and receptors and is intended to support pathway evaluation rather
than depict confirmed Deer Creek-specific source mechanisms.
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Figure 1. Conceptual model of potential PFAS sources and stormwater transport
pathways in the Deer Creek CARA, including engineered and natural
infiltration in closed-basin areas and surface-water discharge pathways in
direct-drainage areas.
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2.6.2. Madrona K-8 and Other Publicly Available PFAS
Concern Information
Within this broader conceptual framework, the Madrona K-8 site represents the most
prominent publicly documented local example of how PFAS-related source and pathway
concerns have been framed in the Deer Creek CARA. Publicly available issue-history
materials indicate PFAS detections at or near the Madrona K-8 School site have
become a significant part of the Deer Creek CARA concern context. Public statements
by Olympic View Water & Sewer District describe PFAS detections in stormwater and
soils at the school site and identify concern regarding infiltration through underground
injection systems above the Deer Creek aquifer. Recent local news coverage likewise
indicates the city’s current study was commissioned in the context of a development
moratorium and ongoing concern over PFAS and stormwater infiltration in the Deer
Creek CARA (Olympic View Water & Sewer District, 2026; Peterson, 2026; Wippel,
2026). These materials are not independent technical findings and should be treated as
issue-history sources rather than conclusive evidence, however, they identify the types
of pathway questions already being raised locally.
Publicly available litigation materials related to the Madrona K-8 School further indicate
the site has become a focal point for local PFAS-related concern (Godwin, 2025). In a
2025 Safe Drinking Water Act complaint, filed by Olympic View Water & Sewer District
against Edmonds School District Number 15, the plaintiff alleged stormwater discharged
through 16 underground injection control (UIC) wells at Madrona K-8 may endanger the
Deer Creek drinking water aquifer. The complaint states PFAS were detected in
stormwater samples collected in 2022, 2023, and 2024 and in bioretention planter soils
sampled in 2025; however, the filing does not present these reported concentrations as
direct aquifer groundwater results.
Reported stormwater values in the filing include concentrations up to 32.2 ng/L PFOA
and 18.9 ng/L PFOS. The filing also reports PFAS detections in bioretention planter
soils and compares those reported values to federal Maximum Contaminant Levels and
Washington State Action Levels; however, because the litigation materials present soil
results in the same parts per trillion format used for water, the original laboratory
reporting units for soil are not clear from the filing itself. The complaint further states
Ecology issued a letter of concern in August 2024, indicating PFAS concentrations
entering the UIC wells may violate the non-endangerment standard. Because these
statements are drawn from litigation materials and public issue-history sources, they are
best treated in this review as relevant site context and evidence of documented local
concern. They should not be interpreted as final adjudicated findings regarding source
attribution, aquifer groundwater concentrations, or aquifer impact.
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2.6.3. Washington-Specific Analog Studies and Guidance
Washington-specific analog information is available even though Deer Creek-specific
case studies are sparse. Ecology’s 2024 Stormwater Management Manual for Western
Washington provides the regional technical framework for stormwater quantity and
quality management in western Washington. Ecology’s statewide PFAS assessment
planning documents also explicitly include stormwater outfalls, runoff from developed
surfaces, and stormwater facilities in PFAS pathway investigations, supporting the
broader relevance of stormwater infrastructure and developed-surface runoff in
Washington PFAS assessments (Washington State Department of Ecology, 2024a;
2025b).
In addition, Ecology is conducting a Washington study on toxic chemicals in runoff from
artificial turf installations that specifically includes PFAS, which is relevant to screening
school and recreational surfaces as possible contributors in developed areas
(Washington State Department of Ecology, 2024a). Ecology’s Greater Lake Washington
watershed PFAS survey is also useful as a Washington urban watershed analog
because it evaluates sources and pathways of PFAS in a developed watershed,
although it is not a CARA-specific study (Salamone, 2025; Washington State
Department of Ecology, 2024a; b; 2025b; Wong, 2022). These Washington-specific
sources provide useful regional context for evaluating potential PFAS source categories
and stormwater-related transport pathways in Deer Creek. However, they should be
treated as analogs and guidance rather than direct evidence of conditions at the Deer
Creek CARA.
2.6.4. Interpretation of Local PFAS Information in Context
of Published Literature
Published literature supports PFAS-bearing stormwater can represent a plausible
pathway to groundwater in infiltration and recharge settings; however, the literature
reviewed does not provide a reliable basis to infer a specific aquifer concentration from
the stormwater concentrations reported at the Madrona K-8 site. Quantitative translation
from stormwater concentration to groundwater concentration is strongly site-specific and
depends on hydrogeology, vadose-zone attenuation, infiltration design, PFAS
composition, and travel time (Edwards et al., 2022; Mumberg et al., 2024b).
Published stormwater literature also indicates the PFAS concentrations reported in the
Madrona litigation materials are generally within the range of urban stormwater
concentrations reported elsewhere, although the reported PFOA concentration appears
to be at the upper end of several comparable studies. The litigation materials report
stormwater concentrations up to 32.2 ng/L PFOA and 18.9 ng/L PFOS at the Madrona
K-8 site. By comparison, Xiao et al. (2012) reported urban stormwater runoff
concentrations up to 30.6 ng/L PFOA and 42.5 ng/L PFOS, while Houtz and Sedlak
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(2012) reported urban runoff ranges of 2.1 to 16 ng/L for PFOA and 2.6 to 26 ng/L for
PFOS. These comparisons suggest the Madrona stormwater values are not anomalous
relative to published urban stormwater literature, although the reported PFOA
concentration is somewhat elevated relative to some urban runoff datasets and above
the residential-area values summarized by Xiao et al (Houtz and Sedlak, 2012;
Washington State Department of Ecology, 2025a; Xiao et al., 2012). At the same time,
broader urban studies have reported substantially higher total PFAS concentrations in
stormwater, particularly where short-chain PFAS dominate.
The publicly raised concern regarding PFAS in stormwater within the Deer Creek CARA
is reasonable considering the reported PFAS detections in stormwater and soil at the
Madrona K-8 site, the presence of UIC systems, and the recharge-sensitive setting.
However, the currently available information does not by itself establish direct aquifer
contamination, identify a unique PFAS source mechanism, or quantify the relative
contribution of engineered infiltration, natural infiltration, surface-water discharge, or
other plausible PFAS transport pathways.
Accordingly, the reported stormwater detections should be interpreted as evidence that
PFAS-bearing runoff warrants management within the CARA, rather than as evidence
that a single stormwater-management pathway is inherently more or less protective.
The relative significance of each pathway depends on stormwater PFAS concentrations
and mass loading, infiltration configuration, hydrogeologic conditions, travel time, source
controls, pretreatment where applicable, and the hydraulic relationship between
stormwater, Deer Creek, groundwater, and drinking-water receptors.
2.7. PFAS Sampling Considerations and QA/QC Limitations
A key consideration in PFAS investigations is that sample collection and handling
require especially stringent QA/QC procedures to minimize the risk of cross-
contamination (Arcadis, 2022; ITRC, 2022). Multiple guidance documents note cross-
contamination can occur from sampling equipment, ineffective decontamination,
incidental contact with PFAS-containing materials, personal care products, food
packaging, field clothing, and sample handling and shipment (Kidd et al., 2022; Pulster
et al., 2024). For this reason, PFAS investigations typically rely on matrix-specific
sampling precautions and multiple QC samples, such as trip blanks, equipment or rinse
blanks, and field blanks, to help distinguish site-related detections from contamination
introduced during collection, handling, transport, or analysis (Washington State
Department of Ecology, 2023). Accordingly, PFAS detections reported in site
investigations are most defensible when interpreted together with the associated
QA/QC record, including the types of blanks collected, whether contamination was
observed in blanks, and whether sampling materials and procedures were consistent
with PFAS-specific guidance.
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2.8. Key Data Gaps, Uncertainties, and Implications for
Source Identification
The literature review and desktop assessment indicate that multiple plausible PFAS
source categories and transport pathways may be relevant to the Deer Creek CARA,
including atmospheric deposition, urban stormwater, building materials, recreational
surfaces, and household or commercial product-related pathways. At present, however,
the available information is not sufficient to identify a single dominant PFAS source or
pathway for the Deer Creek setting. Rather, the existing record supports a multiple-
lines-of-evidence interpretation in which several diffuse inputs may contribute to PFAS
occurrence in developed recharge areas.
One of the most significant limitations is the scarcity of Deer Creek-specific technical
information. Publicly available materials identified during this review consist primarily of
planning and permitting documents, state guidance, litigation-related materials, and
broader Washington analog studies, rather than detailed site-specific investigations of
PFAS occurrence, fate, and transport in the Deer Creek CARA. As a result, current
understanding of source areas, release mechanisms, and exposure pathways is based
largely on plausibility, analogy, and conceptual pathway assessment rather than on a
comprehensive local dataset. This limitation is particularly important because the
published literature indicates PFAS occurrence and transport in recharge settings are
strongly influenced by site-specific factors, including land use, stormwater routing,
infrastructure design, hydrogeologic conditions, and vadose-zone characteristics.
A second major uncertainty concerns source attribution. Publicly available materials
related to the Madrona K-8 site report PFAS detections in stormwater and bioretention
soils; however, those materials do not present direct aquifer groundwater results and do
not conclusively establish the original PFAS source. More broadly, the literature
reviewed in this study indicates that PFAS concentrations in urban stormwater can
reflect multiple overlapping inputs, including atmospheric deposition, weathered built-
environment materials, treated products, and other diffuse urban sources. Accordingly,
the currently available information does not support assigning the reported PFAS
detections to a unique source category without additional site-specific evidence.
There is also substantial uncertainty in relating reported stormwater concentrations to
potential aquifer impacts. Although published studies support the conclusion that PFAS-
bearing stormwater can represent a plausible pathway to groundwater in infiltration and
recharge settings, the literature reviewed does not provide a reliable basis for inferring
specific groundwater concentrations from the stormwater concentrations reported in
publicly available Deer Creek-related materials. Quantitative relationships between
PFAS in stormwater and PFAS in groundwater depend on multiple site-specific
variables, including vadose-zone attenuation, pretreatment, infiltration configuration,
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hydraulic connectivity, travel time, dilution, and compound-specific transport behavior.
Consequently, the presence of PFAS in stormwater should be interpreted as evidence
of a plausible pathway of concern, but not as direct evidence of aquifer impact
(Adamson et al., 2026; Edwards et al., 2022; Mumberg et al., 2024a)
An additional source of uncertainty relates to data quality and interpretation of low-level
PFAS detections. As discussed previously, PFAS sampling requires particularly
stringent quality assurance and quality control measures because cross-contamination
can occur from field materials, equipment, packaging, clothing, personal care products,
and sample handling procedures. Interpretation of PFAS detections is therefore most
robust when supported by complete QA/QC documentation, including blanks, rinsates,
and matrix-specific sampling precautions. Where such information is incomplete,
unavailable, or not clearly documented in public-facing materials, confidence in source-
specific interpretation is correspondingly reduced.
An additional uncertainty concerns the ultimate disposition of stormwater within different
portions of the Deer Creek CARA. Most of the CARA lies within closed drainage basins,
where stormwater that is not managed through engineered infiltration may pond and
ultimately infiltrate naturally unless it is collected and conveyed elsewhere. Other
portions of the CARA may discharge toward Deer Creek, creating a distinct surface-
water pathway. These hydrologic settings are important to PFAS management because
eliminating an engineered infiltration facility does not necessarily eliminate subsurface
recharge and, where stormwater is conveyed to a surface-water outlet, may instead
redirect PFAS loading to another receptor.
The currently available information is not sufficient to quantitatively compare PFAS
loading associated with engineered infiltration, natural infiltration, or direct surface-water
discharge. Such a comparison would require additional information regarding drainage
boundaries and routing, stormwater flow and volume, representative PFAS
concentrations and profiles, infiltration characteristics, groundwater and surface-water
connectivity, travel time, and receptor relationships. Consequently, the relative
protectiveness of these pathways should be evaluated using site-specific hydrologic and
PFAS information rather than assuming that avoidance of one stormwater pathway
necessarily results in an overall reduction in PFAS risk.
Collectively, the available information and associated uncertainties have important
implications for source identification and PFAS management in the Deer Creek CARA.
First, the current record supports a screening-level conceptual model that includes
multiple plausible PFAS source categories and transport pathways rather than
assuming that a single source or pathway is responsible for observed detections.
Second, the available information is sufficient to support targeted source-control and
pathway-management measures, but it is not sufficient to establish direct aquifer
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contamination, quantify the relative contribution of individual PFAS sources, or
quantitatively rank engineered infiltration, natural infiltration, and surface-water
discharge pathways.
These limitations support use of a risk-differentiated management approach rather than
a uniform assumption regarding PFAS sources or stormwater pathways. Section 3
evaluates the relative strengths and limitations of available mitigation and aquifer-
protection alternatives within that framework.
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3. Mitigation and Aquifer-Protection Alternatives
The available literature on PFAS-specific stormwater mitigation remains limited, and
most stormwater BMPs were not developed specifically to remove dissolved PFAS.
However, the current science supports a structured comparison of aquifer-protection
alternatives based on whether a measure reduces PFAS inputs, reduces or redirects
PFAS transport, treats stormwater before infiltration, or improves the City’s ability to
manage uncertainty through monitoring and adaptive decision-making. For the Deer
Creek CARA, that comparison must also consider the hydrologic setting and the
ultimate disposition of stormwater rather than evaluating an engineered infiltration
facility in isolation.
Most of the Deer Creek CARA lies within closed drainage basins with no direct surface-
water outlet. In these areas, stormwater that is not managed through engineered
infiltration may pond and ultimately infiltrate naturally unless it is collected and pumped
or conveyed outside the basin. Portions of the CARA outside the closed-basin areas
drain toward Deer Creek upstream of and near the wellhead. These settings create
different pathway considerations. In closed-basin areas, prohibiting an engineered
infiltration facility may not eliminate subsurface recharge; instead, it may change where
infiltration occurs and the degree to which pretreatment, hydraulic loading, operation
and maintenance, and monitoring can be controlled. In areas with a feasible surface-
water outlet, a non-infiltration approach may redirect PFAS-bearing stormwater to Deer
Creek or another receiving water and therefore requires consideration of the receiving-
water pathway as well.
Accordingly, the alternatives in Table 3 are compared at two levels: (1) their ability to
control or avoid intentional subsurface discharge at the project scale, and (2) their likely
effect on the ultimate PFAS transport pathway at the basin and receptor scale. This
distinction is important because preventing use of an engineered infiltration facility does
not necessarily eliminate infiltration or PFAS transport from the watershed. The
comparison is intended as a planning-level assessment based on currently available
information; it does not constitute a basin-scale hydraulic analysis or a quantitative
comparison of PFAS mass loading to groundwater versus surface-water receptors.
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Table 3. Structured comparison of mitigation and aquifer-protection alternatives.
Alternative Description Relative PFAS Risk Reduction Key Limitations Applicability to Deer Creek CARA
Continue categorical or area-wide prohibition on engineered stormwater infiltration.
Prevents use of engineered infiltration facilities in designated areas. In closed-basin portions of the CARA, this does not necessarily
prevent stormwater from entering the subsurface because unmanaged water may pond and infiltrate naturally unless it is collected and pumped or conveyed elsewhere.
Variable. High for avoiding intentional discharge through a regulated infiltration facility but potentially limited at the basin scale where stormwater
still infiltrates naturally or is redirected to a different receptor.
Protective benefit depends on the feasible ultimate disposition of stormwater. A prohibition may remove the
opportunity to require pretreatment, controlled hydraulic loading, enforceable operation and maintenance, and monitoring at an engineered infiltration facility. It may also require storage, pumping, conveyance, basin analyses, and downstream capacity.
Potentially defensible for discrete higher-risk sites where infiltration cannot be shown to be protective or where a feasible non-
infiltration pathway exists. The available information does not establish a technical basis for treating categorical prohibition as uniformly the most protective strategy across the entire CARA.
Allow engineered infiltration under a tiered or conditional framework with enhanced pretreatment.
Allows shallow infiltration or selected UIC use where source controls, PFAS-relevant pretreatment, site-specific hydrogeologic review, enforceable operation and maintenance, and monitoring are incorporated. In closed-basin areas, engineered infiltration may provide a more controllable pathway than unmanaged ponding and natural infiltration because pretreatment, hydraulic loading, maintenance, and monitoring can be incorporated into the facility design and operation.
Moderate to high where source-water quality is controlled and treatment and hydrogeologic safeguards are demonstrated; uncertain where PFAS treatment performance or pathway conditions are not adequately characterized.
PFAS removal performance in stormwater remains an evolving area. Dissolved and shorter-chain PFAS can be difficult to remove, and performance may be affected by stormwater flow variability, sediment and organic matter loading, media breakthrough, maintenance, and replacement requirements. No pretreatment approach should be assumed to provide consistent PFAS removal without supporting performance data and operation and maintenance controls.
Potentially appropriate where infiltration is hydrologically necessary or preferred and site-specific review can support protective conditions. This approach may be particularly relevant in closed-basin areas and where shallow infiltration can be differentiated from deeper UIC configurations based on hydrogeologic setting and pathway risk.
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Alternative Description Relative PFAS Risk Reduction Key Limitations Applicability to Deer Creek CARA Use source-control material
restrictions, certification, or documentation.
Reduces or documents the
use of materials containing intentionally added PFAS, particularly major weather-exposed or high-surface-area materials with direct rainfall, runoff, or soil contact. Potential measures may include certification or manufacturer documentation for major building, roofing, paving, landscaping, turf, and other components with a plausible direct connection to stormwater or recharge soils.
Moderate to potentially high
for controllable future sources, although the magnitude of reduction cannot be quantified from the current Deer Creek dataset.
Product-specific PFAS
information may be incomplete or reported using different definitions and analytical approaches. Implementation would require clear definitions of covered materials, an appropriate product-content or analytical acceptance criterion, acceptable documentation, treatment of minor components, verification procedures, and consideration of product availability and administrative burden.
Strong near-term option
because source control acts upstream of both infiltration and surface-water pathways and can be combined with either engineered infiltration or non-infiltration stormwater management. A focused certification and documentation program may provide a practical way to prioritize major weather-exposed materials without requiring testing of every individual component.
Use site-specific hydrogeologic and PFAS-risk review for higher-risk infiltration proposals.
Evaluates hydrostratigraphy, depth to groundwater, seasonal water-level conditions, infiltration rate, travel time, preferential pathways, UIC configuration, source-water quality, and proximity or hydraulic connection to drinking-water receptors.
Moderate to high where the review is supported by representative site-specific data and is tied to enforceable design, pretreatment, operation and maintenance, and monitoring requirements.
A hydrogeologic report does not by itself demonstrate that infiltration is protective. The technical value of the review depends on the quality and representativeness of the site data and whether PFAS source-water quality, infiltration design, preferential pathways, pretreatment performance, and receptor connectivity are adequately evaluated. The level of effort may also be disproportionate for small projects.
Most appropriate for larger redevelopment, deeper or higher-risk UIC configurations, substantial impervious areas, or projects near sensitive receptors. A site-specific review can also provide the technical basis for determining whether a proposed infiltration system should be allowed conditionally, modified, or restricted.
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Alternative Description Relative PFAS Risk Reduction Key Limitations Applicability to Deer Creek CARA Use lined, detained, conveyed,
or treated non-infiltration systems.
Collects stormwater and
manages it without intentional onsite subsurface discharge through storage, pumping, conveyance, treatment, reuse, or controlled surface-water discharge.
Variable. High for avoiding
intentional onsite infiltration, but overall PFAS risk depends on the ultimate receiving pathway and whether PFAS-bearing stormwater is redirected to Deer Creek or another receptor.
May require substantial
storage, pumping, conveyance infrastructure, downstream hydraulic capacity, land area, maintenance, and permitting. In closed-basin portions of the CARA, a feasible surface-water discharge point may not exist without additional infrastructure.
Most applicable where a
technically and environmentally defensible receiving pathway is available. In closed-basin areas, feasibility may be limited unless new pumping or conveyance infrastructure is developed, and the receiving-water pathway should be evaluated rather than assuming that avoiding onsite infiltration necessarily reduces overall PFAS risk. Use monitoring-based adaptive management. Uses rainwater, stormwater, source-area, treatment-media, infiltration-system, vadose-zone, and groundwater data, as appropriate, to evaluate source strength, treatment performance, pathway behavior, and changing conditions over time.
Indirect but important for reducing uncertainty, verifying whether source controls and treatment measures are functioning as intended, and determining whether management requirements should be adjusted.
Monitoring does not reduce PFAS loading by itself and requires sustained sampling, data review, and clearly defined decision criteria. Because generally applicable PFAS action levels for municipal stormwater have not been established for the Deer Creek CARA, monitoring results should be interpreted using trends, treatment performance, applicable criteria for the relevant environmental medium, and multiple lines of evidence rather than a single universal stormwater threshold.
Important across the CARA because Deer Creek-specific PFAS source, stormwater, treatment-performance, and groundwater-pathway data remain limited. Monitoring can support a tiered management approach by providing information to maintain, modify, or strengthen source-control, pretreatment, infiltration, or other protective measures as additional data become available.
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Alternative Description Relative PFAS Risk Reduction Key Limitations Applicability to Deer Creek CARA Use standard stormwater
BMPs without additional PFAS-specific controls.
Continues conventional
stormwater management without PFAS-specific source controls, treatment-performance requirements, monitoring, or site-specific PFAS pathway evaluation.
Low to uncertain for PFAS-
specific risk reduction. Conventional BMPs may reduce solids and particle-associated contaminants, but their effectiveness for dissolved PFAS is not well established.
Standard stormwater
BMPs were generally not developed or validated specifically for PFAS removal. Their performance may vary substantially depending on PFAS composition, suspended solids, organic matter, hydraulic loading, and facility type. Absence of PFAS-specific controls also provides limited ability to verify whether PFAS loading or transport is being reduced.
Standard BMPs may
remain an important component of stormwater management but are not sufficient, by themselves, to demonstrate PFAS protectiveness in a recharge-sensitive setting. They are best used as part of a broader framework that may include source control, site-specific review, monitoring, and PFAS-relevant pretreatment where warranted.
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Viewed against the City’s two recent regulatory approaches, the current prohibition on
infiltration BMPs for new development provides certainty that new projects will not
intentionally discharge stormwater through engineered infiltration facilities. In closed-
basin portions of the CARA, however, this approach may not eliminate subsurface
recharge if stormwater ultimately ponds and infiltrates naturally, and a true non-
infiltration alternative may require collection, pumping, or conveyance to another
discharge location. By comparison, the City’s prior risk-differentiated approach, which
distinguished deeper Class V UICs from shallow Class V UICs and required enhanced
pretreatment for allowed infiltration, provided greater opportunity to manage where and
how infiltration occurred through design requirements, pretreatment, operation and
maintenance, and other project controls. However, the available information does not
establish that the prior approach would consistently provide adequate PFAS protection
because PFAS removal performance of stormwater treatment systems remains
uncertain and subsurface transport is strongly dependent on site-specific hydrogeologic
conditions. Accordingly, neither approach can be assumed to be categorically more
protective across the entire CARA. A tiered approach that combines source control,
risk-differentiated infiltration review, site-specific hydrogeologic evaluation, pretreatment
where practicable, monitoring, and targeted restrictions where pathway risk cannot be
adequately resolved is more consistent with the available technical evidence.
Any area-wide restriction on infiltration should also be evaluated within the City’s
broader stormwater-management and regulatory framework. Where infiltration is limited
or unavailable, alternative stormwater management may require additional storage,
pumping, conveyance, downstream capacity, or discharge infrastructure, particularly in
closed-basin areas without an existing surface-water outlet. Such changes may also
require additional basin-scale drainage and engineering analyses. Accordingly, the
practical feasibility of a broad infiltration restriction depends not only on PFAS pathway
considerations but also on consistency with applicable stormwater requirements,
available infrastructure, and the feasibility of the ultimate discharge pathway.
Figures 2 and 3 illustrate conceptual examples of engineered treatment approaches
that could be considered where PFAS-relevant pretreatment is evaluated as part of a
conditional stormwater-management strategy. These figures are intended to illustrate
potential treatment components rather than recommended or established treatment
trains for the Deer Creek CARA. PFAS treatment of stormwater remains an evolving
application, and treatment selection and performance would need to be evaluated under
representative stormwater flow and water-quality conditions. Ecology’s current
Technology Assessment Protocol – Ecology (TAPE) framework establishes
performance criteria for conventional stormwater treatment objectives such as
suspended solids, oil, metals, and phosphorus, but does not currently establish a PFAS-
specific stormwater treatment performance criterion (Ecology, 2026).
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Figure 2. Conceptual ex-situ/on-site engineered pretreatment train for PFAS
management before infiltration in a critical aquifer recharge area.
Figure 3. Conceptual ex-situ foam fractionation treatment train for collected
PFAS-impacted stormwater before conditional recharge, reuse, or controlled
discharge.
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Based on this comparison, the most technically defensible approach is not reliance on a
single CARA-wide measure. Rather, the City could combine source control, conditional
engineered infiltration where supported by site-specific hydrogeologic information and
appropriate safeguards, targeted restrictions for higher-risk infiltration configurations,
PFAS-relevant pretreatment where practicable, and phased monitoring. A prohibition or
restriction remains technically supportable where a proposed infiltration system could
create a relatively direct pathway to groundwater, where PFAS source-water quality
cannot be adequately controlled, where pretreatment and enforceable operation and
maintenance cannot be demonstrated, or where site-specific information is insufficient
to evaluate risk to a drinking-water receptor. Conversely, in closed-basin areas where
stormwater would otherwise pond and infiltrate naturally, engineered infiltration with
appropriate controls may provide greater ability to manage pretreatment, hydraulic
loading, maintenance, and monitoring than uncontrolled infiltration. This tiered approach
allows the City to apply more protective measures where pathway risk is greater while
preserving flexibility to refine management decisions as additional Deer Creek-specific
PFAS, drainage, and hydrogeologic information becomes available.
3.1. Conditional Framework for Class V UIC Wells and
Infiltration Appropriateness
From a hydrogeologic and PFAS-risk perspective, a site-specific hydrogeologic report
could provide useful scientific justification for evaluating whether a Class V UIC or other
infiltration facility may be appropriate under specific site conditions. Class V UIC is a
regulatory classification that can encompass infiltration systems with substantially
different depths, configurations, and hydraulic relationships to groundwater.
Accordingly, shallow infiltration systems and deeper UIC configurations should not be
assumed to present equivalent PFAS transport risks. Shallow systems may preserve
greater unsaturated-zone separation and residence time between the infiltration feature
and groundwater, whereas deeper systems may bypass portions of the vadose zone
and shorten the potential transport pathway to the aquifer. The significance of these
differences is site-specific and depends on hydrostratigraphy, depth to groundwater,
preferential pathways, infiltration rate, PFAS composition, and other transport
conditions.
A site-specific report could therefore support a technically defensible decision regarding
conditional infiltration, but it should provide representative site data sufficient to evaluate
the potential PFAS migration pathway to the Deer Creek aquifer or drinking-water
receptors and determine whether the proposed system can be managed with
appropriate safeguards. The report should focus on the quality and representativeness
of the hydrogeologic and PFAS data and on the ability to implement appropriate source
controls, pretreatment, operation and maintenance, monitoring, and contingency
measures.
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A conditional framework is therefore recommended in which the level of review is
matched to the potential PFAS pathway risk of the proposed infiltration system.
Relevant factors include the depth and configuration of the infiltration feature,
separation from groundwater, hydrostratigraphic conditions, potential preferential
pathways, drainage-area PFAS source characteristics, representative source-water
quality, pretreatment performance, hydraulic loading, operation and maintenance
requirements, monitoring, and contingency measures. Shallow systems with substantial
vadose-zone separation and lower-risk source areas may warrant a different level of
review than deeper UIC configurations, systems that bypass portions of the unsaturated
zone, or projects located near sensitive drinking-water receptors.
This framework would allow the City to distinguish among projects where available
information supports conditional infiltration, projects where additional safeguards or
technical evaluation are warranted, and projects where infiltration risk cannot be
adequately resolved. The key technical elements for this site-specific evaluation are
summarized in Table 4.
Table 4. Information to consider in a site-specific hydrogeologic and PFAS-risk
evaluation for Class V UIC or infiltration proposals.
Evaluation Element Information to Consider
Hydrostratigraphy Soil borings, lithologic logs, depth to groundwater, confining or semi-confining layers, permeable zones, and potential preferential pathways.
Hydraulic setting Recharge rate, infiltration rate, groundwater gradient, seasonal water-level variability, and groundwater mounding potential.
Travel time and unsaturated-zone residence Estimated vertical and lateral travel time from the infiltration feature to groundwater and potential receptors, including the expected residence time within the unsaturated zone. The evaluation should consider whether the proposed infiltration configuration preserves meaningful vadose-zone separation or bypasses portions of the unsaturated profile, recognizing that longer residence time does not necessarily equate to effective PFAS removal and that attenuation is compound- and site-specific.
UIC configuration and subsurface pathway Depth and configuration of the infiltration feature; presence and depth of horizontal perforated piping, open or screened intervals, or other subsurface discharge components; vertical separation from groundwater; thickness and characteristics of the unsaturated zone; and the potential for the system to bypass portions of the vadose zone or create preferential hydraulic pathways. The evaluation should distinguish shallow Class V UIC configurations from deeper injection structures based on their physical relationship to groundwater rather than regulatory classification alone. Artesian or drilling risk Assessment of artesian conditions, drilling-induced conduits, short-circuiting, and the potential for construction to create new hydraulic connections. PFAS source water quality Representative stormwater PFAS data for the proposed drainage area, not only literature values or assumptions.
PFAS-relevant pretreatment Pretreatment configuration, media or treatment type, available evidence of PFAS removal under representative stormwater conditions, hydraulic loading and flow variability, sediment and organic matter loading, expected media life, breakthrough monitoring, maintenance requirements, and replacement schedule. Because PFAS treatment performance for stormwater remains an evolving area, proposed treatment should be evaluated using available performance data and should not be assumed to provide consistent removal of all PFAS under all operating conditions.
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Evaluation Element Information to Consider
Operation and maintenance enforceability Inspection frequency, maintenance obligations, cartridge or media replacement procedures, sediment removal, and reporting commitments.
Monitoring Influent/effluent stormwater monitoring, treatment-media monitoring, vadose-zone monitoring where feasible, and groundwater monitoring for larger or higher-risk projects.
Contingency and decision criteria Pre-established decision criteria for additional evaluation, maintenance, media replacement, operational changes, temporary suspension of infiltration, retrofit, or other corrective action. Criteria may be based on increasing PFAS trends, treatment breakthrough or declining performance, changes in source-water quality, detections at relevant downgradient monitoring locations, or exceedance of applicable criteria for the environmental medium being evaluated. Because generally applicable PFAS action levels have not been established for municipal stormwater in the Deer Creek CARA, contingency decisions should rely on multiple lines of evidence rather than a single universal stormwater concentration threshold.
Therefore, site-specific hydrogeologic reports may provide a scientifically useful basis
for evaluating Class V UIC or other infiltration proposals where they include adequate
field data, characterize the physical relationship between the infiltration system and
groundwater, evaluate travel time and preferential pathways, consider representative
PFAS source-water quality, and address pretreatment, operation and maintenance,
monitoring, and contingency measures as appropriate. Such reports should not rely on
vadose-zone attenuation as a presumed protective mechanism; rather, any expected
reduction in PFAS transport should be supported by site-specific hydrogeologic
conditions and relevant technical evidence. For smaller residential projects, the cost and
complexity of this level of review may limit practical usefulness unless the City develops
a simplified, risk-tiered review process.
3.2. Multi-Media Monitoring Strategy
Because PFAS occurrence in the Deer Creek CARA may reflect overlapping
atmospheric, stormwater, built-environment, and localized source inputs, no single
monitoring medium is sufficient to resolve source attribution, pathway significance, or
aquifer risk. A phased, multi-media monitoring strategy is therefore recommended.
Near-term monitoring should include the planned rainwater sampling to establish
atmospheric/background context, while representative stormwater and targeted source-
area monitoring can be incorporated in future phases where additional source or
pathway characterization is warranted.
Where engineered infiltration or Class V UIC systems are proposed or already present,
monitoring may be expanded, as appropriate to project scale and risk, to characterize
stormwater entering the infiltration system, evaluate pretreatment influent and effluent
where treatment is used, assess treatment or bioretention media, and evaluate vadose-
zone or groundwater conditions where warranted. Monitoring should be designed to
support pre-established decision criteria and adaptive management rather than rely on
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a single universal PFAS concentration threshold. The recommended monitoring lines of
evidence, their purpose, and their relative priority are summarized in Table 5.
Table 5. Recommended multi-media monitoring strategy for PFAS source and
pathway evaluation.
Monitoring Line of Evidence Purpose Priority / Use Rainwater sampling Establish atmospheric/background PFAS input to the CARA and provide context for stormwater detections.
Near-term; already included in the project scope, pending suitable storm conditions.
Representative stormwater sampling Evaluate PFAS concentrations and profiles in runoff before infiltration, discharge, or treatment.
High priority for understanding pathway risk and comparing with rainwater. Source-area runoff sampling Compare runoff from roofs, paved areas, school or recreational surfaces, landscaped areas, and redevelopment areas.
High priority if source-control or material restrictions are being considered.
Bioretention soil or media sampling Evaluate PFAS accumulation and distribution within treatment or infiltration media and provide information on media condition and potential need for additional performance evaluation.
Moderate to high priority where bioretention receives runoff from developed surfaces.
Engineered infiltration or UIC influent and pretreatment-effluent monitoring
Characterize PFAS concentrations entering the infiltration system and evaluate whether pretreatment is reducing PFAS loading before infiltration. Where treatment is used, paired influent and effluent data can also be used to identify changes in performance, potential media breakthrough, and the need for maintenance or replacement.
High priority for larger, higher-risk, or conditionally approved infiltration systems where PFAS pretreatment is relied upon as a protective measure. Monitoring frequency and duration should be scaled to project risk, treatment configuration, stormwater variability, and the role of pretreatment in supporting continued infiltration.
Vadose-zone monitoring Evaluate vertical migration through unsaturated materials where technically feasible.
Useful for larger or higher-risk projects but may be impractical for small residential sites. Groundwater monitoring Evaluate whether PFAS detected in stormwater or infiltrated water is hydraulically and chemically linked to groundwater conditions and assess whether concentrations or PFAS profiles change over time in locations relevant to potential drinking-water receptors.
Highest priority for larger or higher-risk infiltration systems, existing UIC systems of concern, or locations where hydrogeologic information indicates a plausible connection to sensitive groundwater receptors. Groundwater monitoring may not be warranted for every individual project and should be scaled to pathway risk, project size, existing monitoring infrastructure, and the value of the data for reducing uncertainty. Monitoring should be interpreted using multiple lines of evidence rather than single-
sample comparisons alone. Rainwater data can help distinguish atmospheric
background input from localized runoff contributions; stormwater and source-area data
can identify areas where runoff concentrations or PFAS profiles differ; pretreatment
influent and effluent data can evaluate whether treatment is functioning as intended;
and groundwater data can help determine whether infiltrated stormwater is hydraulically
and chemically linked to groundwater conditions. Where stormwater is managed
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through a surface-water discharge rather than infiltration, monitoring may also be used
to evaluate the receiving-water pathway and determine whether PFAS loading is being
redirected rather than reduced. This multi-media strategy is consistent with the current
uncertainty in the Deer Creek CARA and provides a practical basis for adaptive
management and refinement of source-control, treatment, infiltration, and non-infiltration
strategies over time.
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4. Recommendations for PFAS Source Control,
Stormwater Management, and Aquifer Protection
The recommendations below provide a practical, science-based framework for reducing
potential PFAS inputs and managing PFAS transport pathways within the Deer Creek
CARA. The recommendations are based on the literature review, available local
information, and the limitations of the current Deer Creek-specific dataset. They are
intended to support technical decision-making regarding source control, stormwater
management, infiltration, monitoring, and development review rather than resolve legal
or policy questions regarding specific code requirements.
Consistent with the comparative analysis in Section 3, the recommended approach
emphasizes controls that reduce PFAS before runoff is generated, management of the
ultimate stormwater pathway, risk-differentiated review of engineered infiltration, and
monitoring to reduce uncertainty over time. Source-control measures are particularly
important because they can reduce PFAS loading regardless of whether stormwater
ultimately infiltrates to groundwater or is conveyed to a surface-water receptor. Because
the current desktop record does not support definitive ranking of individual PFAS
sources or quantitative comparison of pathway-specific PFAS loading within Deer
Creek, the recommendations are organized using a tiered approach. Tier 1
recommendations identify measures that are supportable now based on available
evidence and the recharge-sensitive setting. Tier 2 recommendations identify
conditional measures that may be appropriate where site-specific information is
available. Tier 3 recommendations identify monitoring and adaptive-management
actions that can improve future decision-making. The overall recommendation
framework is summarized in Table 6.
Table 6. Big-picture recommended approach for the Deer Creek CARA.
Recommendation Theme Big-Picture Action Reason for Including Reduce PFAS inputs before runoff is generated. Use a focused source-control framework for major weather-exposed and high-surface-area materials, supported by contractor certification, manufacturer documentation, or other verification tools. Priority materials may include roofing, exterior building materials, paving and surface treatments, landscaping materials, turf, and other components with direct rainfall or runoff contact.
Source control reduces potential PFAS loading before stormwater enters either the groundwater or surface-water pathway. It can therefore complement engineered infiltration, non-infiltration stormwater management, and monitoring without requiring the City to first determine the exact contribution of each individual material to PFAS concentrations in the CARA.
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Recommendation Theme Big-Picture Action Reason for Including
Manage untreated infiltration based on pathway risk and site conditions. Use a risk-differentiated approach that considers whether stormwater
would otherwise infiltrate naturally, whether the proposed facility is shallow or deeper, the degree of vadose-zone separation, PFAS source-water quality, hydrogeologic conditions, and proximity or connection to drinking-water receptors. Restrict untreated infiltration where these factors indicate a higher or unresolved PFAS migration risk.
Engineered infiltration is a potential PFAS transport pathway,
but prohibiting an infiltration facility does not necessarily eliminate subsurface recharge in closed-basin areas. The protective value of a restriction therefore depends on the site-specific pathway and the ultimate disposition of stormwater.
Use a tiered, risk-differentiated review framework. Differentiate among shallow infiltration systems, deeper Class V UIC configurations, closed-basin versus direct-discharge settings, project scale, PFAS source-water characteristics, weather-exposed source materials, and proximity or hydraulic connection to sensitive receptors. Match the level of hydrogeologic review, source-control documentation, pretreatment, monitoring, and other safeguards to the potential pathway risk.
Infiltration systems with different depths, configurations, source areas, and hydrogeologic settings do not present equivalent PFAS transport risks. A tiered framework allows the City to apply more stringent requirements where pathway risk or uncertainty is greater while avoiding unnecessary requirements for lower-risk projects.
Evaluate PFAS-relevant pretreatment where infiltration is considered.
Where pretreatment is relied upon as part of a conditional infiltration approach, evaluate treatment options using available PFAS performance data under representative stormwater conditions. Consider treatment configuration, hydraulic loading, sediment and organic matter loading, media life, breakthrough, maintenance, replacement requirements, and the ability to verify performance through monitoring.
Conventional stormwater BMPs can provide important sediment and runoff-quality control but generally have not been validated specifically for removal of dissolved PFAS. PFAS treatment performance in stormwater remains an evolving area, particularly for shorter-chain compounds; therefore, pretreatment should be treated as a project-specific protective measure rather than assumed to provide uniform PFAS removal. Use monitoring and adaptive management to reduce uncertainty over time.
Use rainwater, representative stormwater, source-area, pretreatment-performance, infiltration-system, and groundwater data, as appropriate to project scale and pathway risk, as multiple lines of evidence. Establish pre-defined decision criteria for when monitoring results should trigger additional
evaluation, maintenance, treatment modification, or changes to infiltration or other stormwater-management requirements.
Monitoring can verify whether source-control and pretreatment measures are functioning as intended, help distinguish among potential PFAS pathways, and provide the technical basis for adjusting management requirements as local data and PFAS science evolve. Decision-
making should rely on trends, treatment performance, applicable criteria for the relevant environmental medium, and multiple lines of evidence rather than a single universal stormwater PFAS threshold.
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4.1. Tier 1: Measures Based on Existing Evidence
Recommendation 1: Prioritize PFAS source control as the first line of protection.
The most direct near-term strategy for reducing future PFAS loading is to limit
controllable PFAS inputs before they enter stormwater. This approach is applicable
regardless of whether stormwater is ultimately managed through engineered infiltration,
natural infiltration, or surface-water discharge. The literature supports PFAS use in a
broad range of built-environment and outdoor product categories, including exterior
coatings, sealants, waterproofing products, roofing and façade materials, specialty
surface treatments, artificial turf components, and other weather-exposed materials.
Although the relative contribution of individual material categories to PFAS loading in
the Deer Creek CARA cannot be quantified from the current desktop record, the
documented use of PFAS in these categories provides a technical basis for targeted
source-control measures.
Source-control measures should focus on major weather-exposed or high-surface-area
materials with direct rainfall, runoff, or soil contact. Potential implementation
mechanisms include material certification, manufacturer documentation, procurement
requirements, and targeted verification. Recommendations 2 and 5 provide additional
considerations for prioritizing material categories and establishing a practical
certification and verification framework. Implementation could begin with voluntary
guidance or limited priority materials before broader application.
Recommendation 2: Prioritize weather-exposed materials with direct stormwater
or soil pathways. Not all potential PFAS-containing materials present the same
likelihood of contributing to stormwater or recharge-area loading. Source-control
requirements should therefore focus first on materials that are installed outdoors, have
relatively large, exposed surface areas or are applied in substantial quantities, are
subject to rainfall, weathering, abrasion, or leaching, and are hydrologically connected
to stormwater conveyance, infiltration features, or recharge soils. Examples include
roofing and exterior waterproofing products, façade treatments, specialty pavement and
surface treatments, artificial turf, playground surfacing, and selected landscaping
materials.
Compost warrants separate consideration because it is typically applied directly to the
land surface in relatively large quantities and may have direct contact with precipitation,
runoff, and infiltrating water. Where available information indicates that compost or
similar organic amendments may contain PFAS, the City could consider requiring
documentation demonstrating that the material meets an established PFAS-related
acceptance criterion before use within the CARA. A rebuttable-presumption approach,
under which compost is treated as a potential PFAS source unless acceptable
documentation or analytical information demonstrates otherwise, could provide a
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conservative screening mechanism while allowing use of materials for which PFAS
concerns have been adequately addressed. The specific analytical basis, concentration
criterion, sampling requirements, and acceptable documentation for such a program
would need to be defined before implementation.
Indoor consumer products and minor exterior components may contribute to broader
urban PFAS loading but are generally less suitable for development-review controls
where their quantity, exposed surface area, or hydrologic connection is limited.
Prioritizing materials based on the strength of available evidence, potential material
quantity or exposed surface area, and pathway relevance can reduce administrative
burden while focusing source-control efforts on materials with greater potential to
influence stormwater or recharge.
Recommendation 3: Treat stormwater infiltration as a pathway-management
issue, not as a PFAS source by itself. UIC wells, infiltration galleries, dry wells, and
other infiltration BMPs do not create PFAS; rather, they may provide a pathway by
which PFAS-bearing stormwater is introduced to the subsurface. The significance of
that pathway depends on source-water quality, infiltration depth and configuration,
vadose-zone conditions, preferential pathways, travel time, and hydraulic connection to
groundwater receptors.
Management decisions should therefore distinguish between controls that reduce PFAS
loading and controls that manage where PFAS-bearing stormwater ultimately travels. In
closed-basin portions of the CARA, prohibiting an engineered infiltration facility may not
eliminate infiltration if stormwater subsequently ponds and infiltrates naturally. In areas
where stormwater can be conveyed to a surface-water outlet, avoiding onsite infiltration
may instead redirect PFAS loading to Deer Creek or another receiving water.
Accordingly, source control reduces PFAS loading regardless of the ultimate stormwater
pathway, while infiltration, conveyance, pretreatment, and monitoring requirements are
pathway-management tools that should be selected based on site-specific hydrologic
and receptor conditions.
Recommendation 4: Apply restrictions on untreated infiltration where pathway
risk is elevated or cannot be adequately resolved. Untreated stormwater infiltration
may warrant restriction where site conditions indicate a comparatively direct or
insufficiently characterized pathway to groundwater. Relevant factors include infiltration
depth and configuration, limited separation from groundwater, potential preferential
pathways, higher-risk PFAS source areas, proximity or hydraulic connection to drinking-
water receptors, and insufficient information regarding source-water quality, travel time,
or subsurface transport conditions.
Restrictions should be applied based on these pathway-specific factors rather than as a
uniform assumption that prohibiting engineered infiltration will eliminate PFAS transport.
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In closed-basin portions of the CARA, stormwater may ultimately infiltrate through
ponding or other natural pathways if engineered infiltration is not available, unless an
alternative collection and conveyance system is provided. Under those conditions, an
engineered infiltration system that incorporates source controls, pretreatment where
appropriate, controlled hydraulic loading, enforceable operation and maintenance, and
monitoring may provide greater management control than uncontrolled infiltration.
Conversely, where a proposed infiltration configuration could bypass substantial
portions of the vadose zone, create a preferential pathway, or otherwise result in
unresolved risk to a drinking-water receptor, restriction or prohibition remains a
technically supportable protective measure.
Recommendation 5: Establish a clear certification, documentation, and
verification framework for source-control requirements. If the City implements
material-based PFAS source controls, the compliance framework should clearly define
the materials subject to review, the applicable PFAS criterion, acceptable
documentation, treatment of minor components, and circumstances requiring additional
verification. Focusing requirements on major weather-exposed or high-surface-area
components with direct rainfall, runoff, or soil contact would provide a more targeted
and practicable approach than attempting to regulate or verify every individual product
used in construction or landscaping.
For manufacturing building, paving, and landscaping products, a practical first level of
review could rely on contractor certification supported by manufacturer specification
sheets, manufacturer declarations, safety or technical product information, or
recognized third-party documentation. Roofing and other major weather-exposed
materials are particularly suitable for this approach because of their large surface area
and direct rainfall contact; manufacturer specification information should accompany the
certification where available. Minor components could be addressed through a
simplified or exempted process where their quantity, exposed surface area, or
hydrologic connection indicates a comparatively low potential contribution to PFAS
loading.
The compliance framework should distinguish between a product-content criterion and
an analytical concentration threshold. For manufactured products, a criterion based on
whether PFAS are intentionally added may be more readily implemented through
manufacturer documentation than a numerical concentration threshold applied across
substantially different material types. A single concentration threshold should not be
assumed to have equivalent technical meaning for roofing, coatings, paving products,
turf, landscaping materials, and other matrices. If the City elects to establish numerical
acceptance criteria, the requirements should clearly define the PFAS analytes or
measurement approach, applicable material matrix, sampling and sample-preparation
procedures, analytical method, reporting limits, and interpretation of non-detect results.
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Bulk materials such as compost or other organic soil amendments may warrant a
different verification approach because PFAS content can reflect feedstocks and
manufacturing inputs that may not be adequately characterized through a manufacturer
declaration alone. For these materials, analytical verification may provide a more
appropriate basis for demonstrating compliance. The current desktop review does not
provide a sufficient technical basis for establishing a single health- or risk-based
numerical PFAS concentration threshold applicable to all materials within the CARA;
development of any numerical criteria should therefore consider material type, analytical
capability, regulatory context, and the specific source-control objective.
Verification should be scaled to potential source significance and uncertainty. Routine
laboratory testing of every manufactured product is unlikely to be necessary or practical
where adequate documentation is available. Periodic third-party review, targeted
verification of higher-priority materials, or additional documentation where certifications
are incomplete could provide quality assurance while limiting administrative burden. The
framework should also be designed to accommodate changes in product availability,
manufacturer disclosure practices, analytical capabilities, and PFAS regulation over
time.
The regulatory and product-information landscape for PFAS continues to evolve,
including state initiatives that restrict or require reporting of intentionally added PFAS in
selected product categories (Washington State Department of Ecology, 2025a). These
developments may improve product transparency and reduce PFAS use over time but
do not currently provide comprehensive requirements for the full range of roofing,
paving, landscaping, and construction materials relevant to the Deer Creek CARA.
Accordingly, any local source-control framework should be periodically reviewed and
adjusted as state or federal requirements and market practices evolve. Product
disclosures and PFAS-free claims should be interpreted based on the definitions and
reporting requirements applicable at the time of review.
4.2. Tier 2: Conditional Measures Where Site-Specific
Information Is Available
Recommendation 6: Use site-specific hydrogeologic and PFAS-risk information
to support conditional infiltration decisions. A site-specific hydrogeologic evaluation
can provide a technical basis for determining whether an engineered infiltration system
or Class V UIC configuration may be appropriate under particular site conditions. The
evaluation should be risk-based and should consider the physical configuration of the
proposed infiltration system, the ultimate stormwater pathway, and the relationship
between the infiltration feature and groundwater.
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At a minimum, the evaluation should address hydrostratigraphy, depth to groundwater,
seasonal groundwater variability, infiltration rate, vertical and lateral travel time,
preferential pathways, groundwater flow direction, hydraulic connection to drinking-
water receptors, and the potential for the proposed system to bypass portions of the
unsaturated zone.
Where PFAS is a concern, the evaluation should include representative stormwater
PFAS data for the contributing drainage area, information regarding higher-priority
PFAS source materials, and an assessment of any source-control or pretreatment
measures relied upon to reduce PFAS loading. Operation and maintenance
requirements, monitoring, and contingency measures should also be considered where
they are necessary to support continued infiltration.
A site-specific report should not be considered protective solely because it has been
prepared. Rather, it should provide sufficient information to determine whether the
proposed infiltration pathway can be managed with reasonable safeguards or whether
additional controls, design modifications, monitoring, or restrictions are warranted.
Recommendation 7: Distinguish shallow infiltration and shallow Class V UIC
configurations from deeper UIC systems based on physical pathway characteristics.
Class V UIC is a regulatory classification that may encompass infiltration systems with
substantially different depths, configurations, and relationships to groundwater.
Accordingly, systems should not be assigned the same PFAS pathway risk solely
because they fall within the same regulatory category.
Shallow bioretention, infiltration trenches, or shallow Class V UIC configurations may
preserve greater separation from groundwater and longer residence within the
unsaturated zone than deeper UIC systems. Deeper configurations may bypass
portions of the soil profile or substantially shorten the vertical pathway between
stormwater discharge and groundwater. These differences can affect travel time and the
opportunity for interaction with soil and vadose-zone materials; however, greater
vadose-zone thickness or residence time should not be assumed to provide reliable
PFAS removal because PFAS mobility and retention are compound- and site-specific.
The level of technical review should therefore be based on system depth and
construction, separation from groundwater, hydrostratigraphy, potential preferential
pathways, source-water PFAS characteristics, and proximity or hydraulic connection to
drinking-water receptors. Deeper UIC configurations or systems that bypass substantial
portions of the unsaturated zone generally warrant greater technical scrutiny than
shallow systems that maintain substantial vadose-zone separation, while recognizing
that site-specific conditions ultimately determine pathway risk.
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Recommendation 8: Evaluate PFAS-relevant pretreatment where it is relied upon
to support conditional infiltration. Where pretreatment is used as part of the technical
basis for allowing engineered infiltration, its expected performance should be evaluated
under representative stormwater conditions rather than assumed from drinking-water or
other treatment applications. Conventional stormwater BMPs can provide important
sediment, particulate, and runoff-quality control, but they generally have not been
demonstrated to provide consistent removal of dissolved PFAS, particularly shorter-
chain PFAS.
PFAS-specific stormwater treatment remains an evolving area, and treatment
performance can be affected by stormwater flow variability, suspended solids, dissolved
organic matter, competing constituents, contact time, and hydraulic loading. Advanced
treatment approaches such as sorptive media, granular activated carbon, ion exchange,
specialized filter media, or other PFAS-relevant technologies may reduce PFAS under
appropriate conditions, but their feasibility and effectiveness should be supported by
applicable performance data rather than assumed to be transferable directly from
drinking-water treatment.
Where pretreatment is proposed, the evaluation should address treatment configuration,
available PFAS removal data, design flow and hydraulic loading, sediment and organic
matter management, media life, breakthrough, replacement frequency, operation and
maintenance, and a method for verifying performance over time. Pretreatment should
therefore be treated as one component of a broader protective framework that includes
source control, appropriate infiltration design, hydrogeologic review, and monitoring
where warranted, rather than as a stand-alone assurance of PFAS protection.
Recommendation 9: Use a tiered, risk-based decision framework for development
review. The City could use a structured decision process that matches source-control,
hydrogeologic review, pretreatment, monitoring, and other requirements to the potential
PFAS source and pathway risk of a proposed project. Relevant screening factors may
include the location of the project within a closed-basin or direct-discharge area, the
type and depth of any proposed infiltration system, separation from groundwater, project
size and impervious area, proximity or hydraulic connection to drinking-water receptors,
the presence of higher-priority PFAS source materials, and whether source-control
documentation or certification is available.
Lower-risk projects may require primarily source-control documentation and standard
stormwater requirements where no significant PFAS source materials or higher-risk
infiltration pathways are present. Projects involving major weather-exposed materials
could require contractor certification and supporting manufacturer documentation
consistent with the source-control framework described above. Projects involving
shallow engineered infiltration may warrant additional review of source-water quality,
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pretreatment, operation and maintenance, and site-specific hydrogeologic conditions
where appropriate. Higher-risk projects involving deeper UIC configurations, limited
vadose-zone separation, substantial impervious areas, higher-priority PFAS source
areas, or sensitive receptors may warrant a more detailed hydrogeologic and PFAS-risk
evaluation, pretreatment-performance assessment, and monitoring.
The decision framework should also account for the ultimate disposition of stormwater.
In closed-basin areas, the comparison may be between managed engineered infiltration
and natural ponding and infiltration rather than between infiltration and complete
pathway elimination. In areas with a feasible surface-water outlet, the evaluation should
consider whether non-infiltration management would redirect PFAS-bearing stormwater
to Deer Creek or another sensitive receiving water. This approach would allow the City
to apply requirements proportionate to source and pathway risk while avoiding a uniform
regulatory response to projects with substantially different hydrologic and PFAS
characteristics.
4.3. Tier 3: Monitoring and Adaptive Management
Recommendations
Recommendation 10: Implement a phased, risk-based multi-media monitoring
strategy using multiple lines of evidence. A single sampling medium is unlikely to
resolve PFAS source attribution, pathway significance, or aquifer risk in the Deer Creek
CARA. PFAS occurrence may reflect overlapping inputs from atmospheric deposition,
stormwater runoff, built-environment materials, landscaping materials, and localized
source areas. Monitoring should therefore be phased and scaled to the management
question, project size, and potential source and pathway risk.
Rainwater sampling can establish atmospheric or regional background context.
Representative stormwater sampling can characterize PFAS concentrations and profiles
before infiltration or surface-water discharge. Source-area runoff sampling can help
distinguish contributions from roofs, paved surfaces, landscaping areas, school or
recreational surfaces, and other land uses, particularly where source-control measures
are being evaluated. Where pretreatment is relied upon as part of a conditional
infiltration approach, paired influent and pretreatment-effluent monitoring can be used to
evaluate treatment performance and identify potential breakthrough. Treatment or
bioretention-media sampling may provide additional information regarding PFAS
accumulation and system performance.
Groundwater monitoring should be considered where project scale, UIC configuration,
hydrogeologic conditions, or proximity to sensitive receptors indicate that the
information would materially improve evaluation of the groundwater pathway. It should
not be assumed necessary for every individual project. Where stormwater is conveyed
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to a surface-water outlet rather than infiltrated, monitoring may also be appropriate to
evaluate the receiving-water pathway and determine whether PFAS loading is being
reduced or redirected. Monitoring results should be interpreted collectively and used to
refine source-control, treatment, infiltration, and other stormwater-management
requirements over time.
Recommendation 11: Use monitoring to support adaptive management rather
than one-time decision-making. PFAS science, analytical methods, treatment
performance information, regulations, and product-use practices continue to evolve. The
City should therefore treat PFAS management in the Deer Creek CARA as an adaptive
process in which requirements can be refined as additional local information becomes
available.
Monitoring results should be periodically reviewed to determine whether source-control
requirements, pretreatment measures, infiltration conditions, monitoring programs, or
other stormwater-management controls remain appropriate as new information
becomes available. This adaptive approach is particularly useful where uncertainty
remains regarding source contribution, treatment effectiveness, or the relative
importance of groundwater and surface-water pathways. Recommendation 12
describes the decision criteria that can be used to determine when additional evaluation
or corrective action is warranted.
Recommendation 12: Establish clear decision criteria for additional evaluation or
corrective action. Where monitoring is used to support source control, pretreatment,
engineered infiltration, or other stormwater-management decisions, the City should
establish pre-established decision criteria identifying when additional evaluation,
maintenance, treatment-media replacement, operational changes, enhanced
monitoring, temporary suspension of infiltration, retrofit, or other corrective measures
should be considered.
Decision criteria may include increasing PFAS concentration trends or changes in PFAS
profiles; evidence of treatment breakthrough or declining pretreatment performance;
changes in source-water quality; detections at relevant downgradient groundwater or
receiving-water monitoring locations; or exceedance of applicable criteria for the
environmental medium being evaluated. The appropriate response should depend on
the weight of evidence, the location and significance of the monitoring result, and the
potential pathway to sensitive receptors.
Because generally applicable PFAS action levels have not been established for
municipal stormwater in the Deer Creek CARA, the City should not rely on a single
universal stormwater concentration threshold as the sole basis for corrective action.
Instead, decision criteria should combine trends, treatment performance, applicable
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groundwater or drinking-water criteria where relevant, source and pathway information,
and other lines of evidence appropriate to the management objective.
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Table 7. Summary of recommended PFAS risk-reduction measures for the Deer Creek CARA.
Recommendation Timing Technical Basis Implementation Consideration Prioritize PFAS source control for major weather-exposed and high-surface-area materials.
Near-term PFAS use is documented in multiple built-environment and outdoor product categories, including coatings, sealants, waterproofing products, roofing materials, specialty surface treatments, turf, and other weather-exposed materials. Source control reduces potential PFAS loading before stormwater enters either
groundwater or surface-water pathways.
Could be implemented through contractor certification, manufacturer documentation, product specification sheets, procurement requirements, or project conditions focused on major materials with direct rainfall or runoff contact. Requirements should define covered materials, acceptable documentation,
treatment of minor components, and appropriate verification procedures.
Establish a certification and documentation framework for covered materials.
Near-term Manufacturer and contractor documentation may provide a practical screening mechanism for manufactured products where routine laboratory testing of every product would be impractical.
Define covered materials, acceptable certifications, supporting manufacturer information, treatment of minor components, and verification procedures. For manufactured products, an “intentionally added PFAS” criterion may be more readily implemented than a single numerical concentration threshold across dissimilar material types.
Apply targeted source-control requirements to compost and other bulk organic amendments where appropriate.
Near-term Compost is applied directly to the land surface in relatively large quantities and may have direct contact with precipitation, runoff, and infiltrating water. Where PFAS are present, this creates a relatively direct soil and recharge pathway.
The City could consider treating compost as a potential PFAS source unless acceptable documentation or analytical information demonstrates otherwise. Any analytical acceptance criterion should define the PFAS analytes or measurement approach, sampling method, reporting limits, and applicable material matrix. Manage untreated infiltration based on pathway risk and site conditions.
Near-term Engineered infiltration is a potential PFAS transport pathway, but prohibiting an infiltration facility does not necessarily eliminate subsurface recharge in closed-basin areas. The protective value of restriction depends on infiltration configuration, source-water quality, hydrogeology, and the ultimate disposition of stormwater.
Restrict untreated infiltration where pathway risk is comparatively high or unresolved. In closed-basin settings, also consider whether eliminating engineered infiltration would result in natural ponding and infiltration or require new collection and conveyance infrastructure.
Distinguish shallow infiltration and shallow Class V UIC configurations from deeper UIC systems.
Near-term Systems within the Class V regulatory category may have substantially different physical relationships to groundwater. Deeper systems may bypass greater portions of the unsaturated zone and shorten the potential transport pathway.
Base the level of technical review on system depth and construction, vadose-zone separation, hydrostratigraphy, preferential pathways, source-water quality, and receptor proximity rather than regulatory classification alone. Use site-specific hydrogeologic and PFAS-risk information to support
conditional infiltration decisions.
Conditional Infiltration risk depends on hydrostratigraphy, groundwater depth, travel time, preferential pathways, source-water PFAS concentrations, and hydraulic
connection to drinking-water receptors.
Most appropriate for larger projects, deeper or higher-risk UIC configurations, substantial impervious areas, or projects near sensitive receptors. A hydrogeologic
report should inform the decision but should not be considered protective solely because it has been prepared.
Evaluate PFAS-relevant pretreatment where it is Conditional Conventional stormwater BMPs provide important sediment and runoff-quality control but generally have Evaluate available performance data under representative stormwater conditions, including
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Recommendation Timing Technical Basis Implementation Consideration
relied upon to support conditional infiltration. not been demonstrated to provide consistent removal of dissolved PFAS. PFAS stormwater-treatment
performance remains an evolving area.
hydraulic loading, sediment and organic matter loading, media life, breakthrough, maintenance, replacement,
and monitoring. Pretreatment should not be treated as a stand-alone assurance of PFAS protection.
Use a tiered, risk-based development-review framework.
Near-term / Conditional Projects with different source materials, infiltration configurations, hydrogeologic settings, and receptor relationships do not present equivalent PFAS pathway risks.
Match source-control documentation, hydrogeologic review, pretreatment, monitoring, and other safeguards to project risk. Include closed-basin versus direct-discharge setting, shallow versus deeper infiltration, project scale, source materials, and receptor proximity as screening factors. Conduct rainwater monitoring. Near-term / ongoing Establishes atmospheric deposition and regional/background PFAS input and provides context for interpreting stormwater concentrations.
Already included in the current project scope, pending suitable storm conditions. Interpret in conjunction with stormwater and source-area results rather than as a stand-alone indicator of local source strength. Conduct targeted stormwater and source-area monitoring.
Future phase Needed to refine source attribution, characterize PFAS concentrations and profiles in runoff, and compare potential contributions from different weather-exposed surfaces and land uses.
Could focus on roofing, paved surfaces, landscaping areas, school/recreational surfaces, and other priority source categories. Where stormwater is conveyed to surface water, monitoring can also help evaluate whether PFAS loading is being redirected to Deer Creek or another receiving water.
Monitor pretreatment performance where treatment is relied upon for conditional infiltration.
Future phase / Conditional
Paired influent and pretreatment-effluent data can determine whether treatment is reducing PFAS loading and identify declining performance or media breakthrough.
Highest priority for larger or higher-risk systems where treatment performance is an important basis for continued infiltration. Monitoring frequency should reflect stormwater variability, treatment design, and pathway risk. Use groundwater monitoring where technically warranted.
Future phase / Conditional
Groundwater data can help determine whether infiltrated stormwater is hydraulically and chemically linked to groundwater conditions and sensitive drinking-water receptors.
Highest priority for larger or higher-risk infiltration systems, existing UIC systems of concern, or locations where hydrogeologic information indicates a plausible connection to sensitive receptors. Groundwater monitoring is not necessarily warranted for every individual project.
Use pre-established decision criteria and adaptive management.
Ongoing PFAS science, treatment performance, product use, analytical methods, and regulatory requirements continue to evolve. Monitoring provides a basis for adjusting controls as additional information becomes available.
Decision criteria may consider PFAS trends or profile changes, treatment breakthrough, source-water changes, downgradient detections, and applicable criteria for the relevant environmental medium. Avoid reliance on a single universal municipal-stormwater PFAS threshold where one has not been established.
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Based on the current desktop review, the most technically defensible approach for the
Deer Creek CARA is a tiered framework that combines PFAS source control, risk-based
stormwater pathway management, site-specific review where infiltration risk is elevated
or uncertain, PFAS-relevant pretreatment where relied upon as a protective measure,
and monitoring and adaptive management to reduce uncertainty over time. Source
control is particularly important because it can reduce PFAS loading before stormwater
enters either groundwater or surface-water pathways.
The appropriate stormwater-management approach should account for site-specific
hydrology, infiltration configuration, source-water quality, available controls, and the
ultimate receiving pathway. Additional Deer Creek-specific PFAS, drainage, and
hydrogeologic data would improve the City’s ability to quantify source contributions and
compare pathway-specific risks; however, the available information is sufficient to
support the risk-differentiated source-control and stormwater-management framework
described in this report.
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5. References
Adamson, D.T., Gamlin, J., Jin, Y., Casteel, W., Schaefer, C. and Higgins, C.P. 2026. Understanding the scale and potential contributions of background PFAS in the environment. Journal of Hazardous Materials 503, 141121. Aman, M.S., Daley, D.J., You, Y., Kumar, D. and Yoo, C.G. 2026. PFAS in
commercially available organic amendments and food-contact paper products.
Science of The Total Environment 1014, 181342. Arcadis. 2022. TGI–Per- and polyfluoroalkyl substances (PFAS) field sampling guide (Rev. 10). U.S. Environmental Protection Agency. https://www.epa.gov/system/files/documents/2023-07/App%20B%20-
%20TGI%20for%20PFAS%20Per-
%20and%20Polyfluoroalkyl%20Substances%20Field%20Sampling%20Guide.pdf. Bruton, T. and Ray, H. 2023. PFASs in Building Products: Survey of Uses and Potential Alternatives.
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