20140625151645771.pdfJune 20, 2014
City of Edmonds Public Works
Engineering Division
Attn: JoAnne Zulauf
15728 Main Street
Edmonds, WA 98020
6621 Foster Slough Rd.
Snohomish, WA 98290
Phone: 425-334-9980
e-mail: DonnaBreske@comcast.net
Subject: Respond to City Review Comments for Jacobsen SFR, 741 Hanna Park Rd.
Reference: Plan Check #BLD20140415
Donna L Breske PE, LLC is in receipt of the City of Edmonds Plan Review Corrections from JoAnne
Zulauf dated June 6, 2014 and an e-mail sent June 9, 2014 from Jerry Shuster, P.E. Stormwater Engineering
Program Manager. Following are listed the responses to each of the review comments. The revised plan sheets
C1 & C2 as well as Revision #Ito the Drainage Report are included with this resubmittal.
Sheet C1 - Stormwater Plan comments from JoAnne Zulauf:
1. Please revise the site classification and the impervious surface map as follows;
a. All impervious surface on this project is "new". There is no impervious surface that
meets the definition for "replaced". Please see handout E72.
Per discussion between this engineer, Jerry Shuster and yourself, it is not necessary to revise the
impervious surfaces information as it is agreed that the exempt impervious area was correct, and
can stay as calculated for this case, since a stream discharge is not involved.
b. The geo report mentions a possible small structure to be constructed in the east area
of the property. Please add to the impervious surface calculations and the plans if
this to be constructed.
There is no structure other than the house proposed for construction as part of this permit
application.
c. Unless specifically approved by the geotech in the form of an addendum, dispersion
shall not be approved as a mitigation measure for runoff. The Geospectrum
Consultant, Inc. report dated December 4, 2013 states on page 11; "no uncontrolled
water flow should be allowed on the site". All impervious surface runoff shall be
mitigated using conventional stormwater management techniques.
An Addendum letter dated June 16, 2014 has been received from Geotechnical Engineer
approving the use of the shown limited areas of dispersion. Said letter is included in the revised
Drainage Report within Appendix E.
1
2. Please replace or revise current control manhole for detention to be consistent with City
Standard Detail E5.3 and add control structure Detail E5.4.
The Control Manhole Detail on Sheet CI has been revised to be consistent with City Standard
Details E5.4 and the Type 2 Control Manhole is consistent with City Standard Detail E5.3.
3. Remove sheer gate detail. (see E5.3 for more information)
The sheer gate detail has been removed.
4. Remove all references to Galvanized Steel piping. This is not an approved pipe material for
construction of detention systems. See E72A for more information.
All referenced to Galvanized Steel piping have been removed and a list of City approved plastic pipe
materials has been added. Also, reference to City Handout #E 72A to Drawing Sheet Cl.
5. Please change footing drain line type to Id". Please change clean out labels to reflect
footing drains.
The footing drain line now shows a ' fd" within it. The clean out labels now read SDCO & FDCO.
6. Please address Geospectrum requirement for existing storm drain. See page 11 of report.
Sheet CI requires that the existing 4 " pvc directed to the bluff slope above the railroad is removed.
7. Note size, length and material of all tightline connections from house to detention system.
All pipe located under driving surfaces shall be sdr 35 or better, or if under 1 '/' of cover
then shall be ductile iron.
The size, length and type of tightline connections from the house to the detention system are shown.
Also a note concerning the pipe located under driving surfaces per the above has been added.
6. Please replace or revise"Construction Sequence" to include the information on the Sample
Construction Sequence attached. Please replace all instances of "town" with "city".
The Construction Sequence has been revised accordingly.
9. Please provide a de -watering plan.
_Dewatering routing and notes have been added to the Temporary Erosion Control Sheet C2.
10. WPPP # 11 not adequately addressed. Please add information regarding timing of
inspections, story i � event response and wet weather inspections and responsibilities for tesc.
A new section of notes titled, "MAINTENANCE OF EROSION CONTROL ELEMENTS" has been
added to Sheet C2.
Water, sewer and dry utility information and purveyor information have been added to Sheet C1.
1. Please show temporary construction entrance and location of stockpile(s) on plan.
The location of the soil stockpiles was already shown on the TESL plan. They are located east of the
on-site driveway. The existing paving is to be used as the temporary construction entrance and a
note already exists to depict this.
2. Please review and revise Site Grading and T.E.S.C. notes. Many are not consistent
with the geotechnical report recommendations. Attached are some sample grading
and test notes that can be edited to work for this site.
The Site Grading and Erosion Control Notes have been revised to be consistent with the above
comment.
3. "Cover Methods" and "Temporary Cover" are the same and can be combined into
one.
I Cover Methods refer to permanent cover after all construction activity is complete, and Temporary
Cover is that to be utilized during construction as a Temporary Erosion Control Measure. Hence, the
notes differ and have not be combined into one.
4. Number 6 SWPPP is shown next to "Cover Methods". There is no reference to cut
and fill slopes. That information is under "Maintenance of Siltration Barriers".
The number 6 SWPPP has been removed from this location.
5. The heading "Maintenance of Siltration Barriers" does not describe all the
information following it.
The non -related information under the heading "Maintenance of Siltation Barriers " has been
removed.
requirements6. Add -noWto-plans: W disturbed areas on and off site shall be compost a nded t#
I meet - Stormwater Manual, Vol V, Chapter 5.
Said note has been added to the plan. - -
7. Top Soil Preservation Notes: How does this work with the above (6) requirement?
Please clarify.
The requirement to maintain 8" minimum topsoil cover has been harmonized into the BMP T5.13
note added to Sheet C2.
9
8. The clearing limits are shown along the entire property line. Please review the
geotechnical report and adjust those lines according to the recommendations in the
report. Also, Low Impact development encourages preservation of as much existing
pervious area as possible.
The clearing limits have been revised accordingly.
9. Please provide detail showing how driveway will be constructed to meet the
geotechnical report requirements on page # 10 Pavement and Slab Subgrade
Preparation.
A detail titled D/W Pavement Subgrade Preparation has been added to Sheet Cl.
Response to Review Comments received from Jerry Shuster sent via e-mail .Tune 9, 2014:
Drainage Report
1. Page 5, Downstream Analysis — Note that the stormwater system on Hanna Park Road is a
privately owned and maintained system. Permission may be needed from the other owners of
the road to connect to this system. At minimum, a conveyance check for the 100 year un -
detained flow plus the existing flows should be included to check this system's capacity. The
City's Geographic Information System map indicates this private system on Hanna Park Road
connects to City catch basin number 8-156 (http://maps.edmondswa.gov/Default.htm). The
outlet to this catch basin is a 6 inch diameter pipe. A conveyance check should be done % mile
downstream of the connection to the City system.
The outlet from City Catch Basin 8-156 is an 8" pvc pipe per this Engineers field
investigation and measurement on Monday June 16, 2014. Hanna Park Road, property
owner Cory Heins assisted and witnessed the measurement of the pipe. The Downstream
Analysis has been revised and includes discussion and a schematic of the 8" downstream
piping system. Permission to use the system is to be provided by the Architect or others.
Since the pipe downstream of the 8" pvc pipe is also an 8" pipe, (concrete), and the short
segment is not a 6" pipe there is no flow conveyance "necking -down " concern and a
conveyance check is not warranted.
- -- -2 P-ag,e-6`SmaII Site -Minimum -Requirement- , n®Site-Stormwater Management and
Impervious Area Exhibit —The text and the exhibit discuss the use of "Flow Dispersion" for two
sections of patio and the "pond overflow." The plans do not indicate a designed flow dispersal
system per the Ecology's 2005 Stormwater Management Manual for_Western
Washington (SWMMWW). Their location is unclear. In addition, the "Drainage Control" section
of the geotechnical report for project (Geospectum Consultants, Inc., December 2013, page 11)
recommends "Roof drains ... and out buildings should be tightlined into the storm drains system
(no discharge to the ground) or to a non-erosive discharge point below the bluff slope."
M
Minimum Requirement #5 has been revised to include reference to the DOE Manual for
flow dispersion LID flow path requirement. Also, An Addendum letter dated June 16,2014
has been received from Geotechnical Engineer approving the use of the shown limited areas of
dispersion. Said letter is included in the revised Drainage Report within Appendix E.
3. Page 6, Small Site Minimum Requirement 7: Flow Control —The WWHM modeling should use
the "Puget East 36" precipitation file per Section 5.7.3.1of the Edmonds Stormwater Code
Supplement.
The WWHM2012 model has been revised and run using the Puget East 36 precipitation
file.
4. Appendix R - The soil management exhibit needs a legend for the various letters.
The Soil Management Exhibit has been revised to include a legend and include the
proposed area of clearing.
Plan Sheet C1
5. Detention System Section - The City has a new detail for detention control structures that does
not a shear gate.
See:http://www.edmondswa.gov/images/COE/Services/Permits_and_Development/Standard_
Details/Storm_Drainage/E5-4_FLOW—CONTROL_STRUCTURE.pdf
Plan Sheet CI depicts the City's new detail for the Detention Control Structure per City
Standard E5.4 and the Shear Gate and details have been removed.
Sincerely,
f
Donna L. Breske, P.E.
Phone: 425-334-9980
_Mobile: 206-715=9582 - - -
0