Cary Rd - 929_StricklandADD_BLD20070675_1.pdf
City of Edmonds
TH
121 5 AVENUE NORTH • EDMONDS, WA 98020 • (425) 771-0220 FAX(425) 771-0221
Website: www.ci.edmonds.wa.us
DEVELOPMENT SERVICES DEPARTMENT
Planning • Building • Engineering
Plan Review Corrections
BLD20080675
May15,2008
Permit:Date:
#
StricklandADD/929CaryRoad
Project Name/Address:
Contact Person/Address/Fax:
__________________________________________________________________________________________
__________________________________________________________________________________________
RobertStasney/STASNYARCH@AOL.com
Engineering
EdwardSibrel
Reviewer: Division:
During review of the subject submittal it was found that the following information, corrections, or
clarifications will need to be addressed:
Thesubmittalforthegrinderpumpisinsufficientforreview:
PleaserefertoHandoutE62,RegulationsforPrivateResidentialSewagePumpsinEdmonds
(SingleFamilyResidentialOnly)fortheminimumsubmittalrequirements.Acopyofthehandoutis
attachedforyourconvenience.
Please resubmit three copies of the revised plans/documents to a Development Services Coordinator. You
may contact me at 425-771-0220 if you have specific questions regarding these plan corrections.
8
5/15/081
DATE mailed/faxed/emailed PAGE OF.
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Regulations for Private
Residential Sewage Pumps in Edmonds
(Single Family Residential Only)
GENERAL
These regulations
The following regulations apply only to single family, residential dwellings.
do not apply to multi-family or industrial use.
All other applications shall be reviewed on an
individual basis. Any extension of the City’s Sanitary Sewer System shall be completed in
accordance with the terms of a Side Sewer Permit. All extensions must conform to the State of
Washington Department of Ecology (Ecology) and City of Edmonds requirements. Side sewers
that require sewer pumps are subject to Engineering approval in all cases and shall require
Building Division approval if the sewer pump is built within the confines of the structure.
Ejector systems may be used within the dwelling when any portion of the dwelling sewer system
cannot gravity drain and in all cases shall require Building Division approval. See separate
handout for ejector system requirements.
It is the City’s policy that conveying sewage by gravity is the best system. Sewage pump stations
will be permitted only in those circumstances when a gravity sewer service would be impractical,
If a portion of
unreasonably expensive, environmentally destructive, or otherwise not feasible.
the dwelling cannot gravity drain, an ejector system may be used to pump those systems to
the house gravity line.
In all cases, the ejector system shall be approved by the Building
Official. Sewage pump stations shall be complete and operational package grinder pump
stations. All equipment shall be factory installed, except for the externally mounted control
panel, electrical power connections, gravity sewer inlet hubs, and the pump assembly, which are
to be installed in the field.
The Engineer of Record must be registered in the State of Washington and have had prior
experience in designing similar systems to the satisfaction of the City Engineer. Qualifications
shall be included within the design report.
DESIGN STANDARDS
Pump station design shall conform to the current edition of the Ecology Criteria for Sewage
Works Design, the Uniform Plumbing Code, and City of Edmonds requirements. The Ecology
criteria include design standards and guidelines for lift station location, pump sizing and
selection, wet well sizing criteria, alarm system, emergency response criteria, lighting, and
ventilation.
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S:\\ENGR\\HANDOUTS & POLICIES\\GrinderPump.SingleFamily E62.doc
Revised 5/15/2008
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Design flow rates shall be based on peak water demands of all fixtures and roughed in plumbing,
as outlined in the current edition of the Uniform Plumbing Code, Appendix A. Future additions
and remodeling construction that affect the number and type of fixtures shall submit revised
calculations showing the revised peak flow rates. Exterior hose bibs should not be included in
these calculations.
CONSTRUCTION STANDARDS
All materials, installation, and workmanship shall be in accordance with City standards and shall
be in compliance with OSHA, UL, ASTM, NEC, and other applicable codes and regulations. In
addition, the grinder pump station standards, materials, and installation shall comply with the
manufacturer’s engineering data and specifications.
PUMP STATIONS
Pump stations will not be allowed in areas where gravity sewer service is currently available or
where sewer service would be available through the construction of trunk or lateral gravity sewer
lines.
Pre-Design Report
A pre-design report to justify the installation of a pump station must be submitted to the City
Engineer prior to design. The City Engineer must give approval of a pump station prior to
issuance of a Side Sewer Permit. The report shall include the following information. A checklist
of the pre-design report items is included at the end of these regulations for the applicant’s use.
1.Service area map that includes a topographical representation of the proposed grinder pump
station with the entire potential collection system to the pump station. This includes property
boundaries, existing services, and the 100-year flood plain line. The nearest collection
system and the proposed connection of the force main to the sewer lateral shall also be shown
on this map.
2.Design Calculations: This would include present, design, and ultimate water fixture counts
and their associated flows. Pump and system curves shall be developed and presented using
actual proposed equipment. Hydraulic computations presented shall include pump cycling
time, wet well capacity, flushing velocity, force main hydraulic losses, minor losses, net
positive suction head, sump basin flotation, electrical power requirements, and other
applicable calculations.
3.List of acceptable manufacturers of packaged grinder pump station, unless otherwise
approved by the City Engineer:
Myers
Barnes
Hydromatic
Zoeller 840 Series
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General Design
Pump stations are subject to review and approval by the City Engineer. Pump stations shall be
simplex or duplex grinder pump units consisting of a sump basin, grinder pump assembly, guide
rail system, discharge piping, control panel, and sump level controls. Plans and details shall
include the following:
Site Requirements
1.Grinder pump station shall be located externally of the residential dwelling, unless
otherwise approved by the City Engineer.
2.The location of the grinder pump system shall be chosen to reduce negative pressure and
air entrapment.
3.The pump station, including electrical panel box, shall be protected from the 100-year
flood.
4.Pump station shall be installed no closer than 5 feet from any structure, rockery, etc.
5.Pump station lid shall be installed no less than 2 inches above the surrounding grade in
dirt, grass, or garden areas. Lids shall be installed flush in concrete or asphalt surface
areas. If located in an area subject to vehicular traffic, lids shall be traffic rated and shall
be installed flush to concrete, asphalt, or surrounding ground surface.
6.No potentially large shrubs or trees shall be placed along the force main alignment.
Sewer lines shall not be installed directly under large trees or shrubs.
7. Hose bibs on the house shall be within 15 feet of the grinder pump.
Structural Requirements
1.The pump station shall be designed and located to allow easy access to the sump basin
and installed equipment. Hatches and other openings shall be provided to permit access
for inspection, repairs, equipment removal, and cleaning. Wet well covers shall include
provision for padlocks.
2.Pump stations shall be equipped with ventilation that complies with NFPA code.
3.Unless otherwise approved by the City Engineer, the sump basin shall be filament wound
non-tapered fiberglass or high density polyethylene basin with a minimum wall thickness
of 1/4 inch. An anti-flotation flange or steel plate shall be molded into the bottom of the
basin. A concrete anti-flotation base shall be poured around the sump basin base and
encapsulate the anti-flotation flange/plate to prevent buoyant forces from displacing the
sump basin while empty. Calculations shall assume that the groundwater table is at grade
with the pump station lid and include a 20 percent factor of safety. Submit floatation
calculations to the City Engineer for review and approval.
4.The sump basin shall provide for the volute of the pumps to be fully submerged.
5.For sump basins greater than 3 feet in diameter, the sump floor shall be sloped for proper
installation and function of the pump inlet. The sump basin and piping system shall
minimize vortexing, debris buildup, and other inlet problems. No down spouts, footing
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drains, or floor drains shall be connected to any sanitary sewer line either through a
gravity or forced sewer line.
6.Pump station sump basin shall be installed on a firm earth base or washed gravel.
Calculations must show that the soil bearing pressure is adequate for a sump basin full of
water.
7.Backfill material around the pump station and sewer lines shall be free of debris, rocks
greater than 1½ inches in diameter, concrete, etc.
8.Sumps and receiving tanks shall be watertight and shall be constructed of fiberglass or
high density polyethylene, unless otherwise approved by the City Engineer. Minimum
sump basin capacity shall be 165 gallons. In addition, the sump basin capacity between
pump on and off levels shall be sized to limit pump cycle time to not exceed 10 starts per
hour.
9.Sumps and receiving tanks shall be provided with substantial covers having a bolt and
gasket-type manhole or equivalent opening to permit access for inspection, repairs, pump
removal, and cleaning. Provide a vent pipe to extend back to the dwelling and terminate
through the roof.
Mechanical Requirements
1.All components used within the pump station or as part of the pressure main shall have a
source of supply and/or repair located within a 24-hour delivery time. Documentation of
these sources shall be provided to the City Engineer at the time of submittal.
2.Pumps shall have double mechanical seals. Pumps shall have a replaceable impeller and
replaceable volute wear ring.
3.The pump grinder unit shall be capable of cutting solid material found in normal
domestic sewage, including reasonable amounts of foreign objects, such as plastic,
rubber, sanitary napkins, and disposable diapers into a fine slurry that will pass freely
through the pump, service line, and force main.
4.The pump motor shall be of the submersible type rated for minimum 2 horsepower,
unless otherwise approved by the City Engineer.
5.All hardware in the wet well and other vaults, including pump rails, float hangers, anchor
bolts, etc. shall be 316 stainless steel. Fiberglass reinforced plastic (FRP) float hangers
will also be accepted.
6.The sewer pump discharge line shall be provided with an accessible check valve and gate
valve within the tank.
7.A 4-inch cleanout is required on the gravity sewer line between the building and the
grinder pump.
8.Building sewers that receive discharge from any pump or other mechanical device shall
be adequately sized to prevent overloading.Two fixture units shall be allowed for each
GPM of continuous flow (refer to Uniform Plumbing Code, Chapter 4.)
9.All grinder pumps shall be on a rail system and shall be installed for easy removal of the
pump, unless otherwise approved by the City Engineer.
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Instrumentation Requirements
1.Pump on, off, and alarm levels shall be controlled by three mercury tube float switches or
by ultrasonic level measurement of a manufacturer approved by the City Engineer. A
fourth level control is recommended for redundant off/low water alarm.
2.Provide alarms for high wet well and pump failure. Provide an audible (minimum
100-dB level), as well as visual, alarm panel located inside the residence. A battery
operated backup power supply for the alarm system is required. The high wet well alarm
should activate when more than two-thirds of the wet well tank depth is exceeded.
3.Pump stations shall be provided with a red, flashing alarm lamp mounted to be visible
from the nearest public right-of-way. The red alarm lamp shall be energized only upon
high wet well level or when the test switch is enabled.
4.Controls shall automatically re-start after disruptions in power supply.
Electrical Requirements
1.Pump control panel shall be a NEMA 4X cabinet and located in direct line of sight from
the pump station. The panel shall have a dedicated circuit from the dwelling’s panel
board.
2.All electrical controls except audio alarm must be installed outside of the home and
accessible.
3.All electrical leads to grinder pumps and accessories must be installed in buried,
non-metallic conduit.
4.State electrical permit is required. This can be obtained at the State Department of Labor
& Industries.
5.All electrical connections, conduit, etc. must be inspected by the State Electrical
Inspector.
Force Main Requirements
1.All pipe and fittings for the grinder pump system shall be 2-inch High Mol (200 psi)
polyethylene pipe from the grinder pump to the 6-inch gravity sewer stub at the property
line. The polyethylene pipe shall be joined by brass fittings with stainless steel inserts.
The pipe location shall be identified by installation of a 12-gauge tracer wire wrapped
and taped every 10 feet to the force main. Minimum cover on force mains shall be 3 feet
(or as required to provide minimum clearance from water mains and other utilities).
2.Force main diameter shall be sized for a minimum flushing velocity of 2.5 ft./sec. The
minimum force main diameter shall be 2 inches.
3.All discharge pipes should be located within private property and connect to a side sewer
cleanout at the street right-of-way per City of Edmonds Standard Detail E6.9.
4.Fittings along the force main, such as bends, will not be allowed. Pipe couplings shall be
brass compression with stainless steel inserts.
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Other
1.All sewer lines must be left exposed in the trench for City inspection and location
recorded.
2.Prior to the construction of the grinder pump station and permit issuance, the Engineering
Division must approve the plans and profile. A separate right-of-way permit must be
secured for all work in the City right-of-way. Only licensed and bonded contractors can
obtain this permit. All sanitary side sewer line installations in the City right-of-way must
be constructed of 6-inch or larger PVC or ductile iron pipe. Any deviation from these
rules and regulations must receive the prior approval of the City Engineer.
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Pre-Design Report Checklist (Single Family)
If site is located in LID 210
Note:, the City of Edmonds Public Works provides the grinder
pump station (no need for submittals). A side sewer permit is required and a licensed and
bonded Contractor shall install the grinder pump station.
1. Qualifications of Engineer
2. Topographic Service Area Map
Topographical limits of pump station service area
Property boundaries
100-year flood plain line
Location of nearest sewage collection system piping
Location of sewer stub that the force main will connect to
Location of water service to the house.
3.Design Calculations
Present, design, and ultimate water fixture counts and their associated flows
Proposed grinder pump curve and system curve
Pump station hydraulic computations for the following design elements:
Pump cycling time
Wet well capacity
Flushing velocity
Force main hydraulic losses
Minor hydraulic losses due to valves and fittings
Net positive suction head
Sump basin anti-floatation calculations
Soil bearing pressure
Electrical power requirements
Other applicable calculations
4.Additional Submittal Requirements Checklist
Manufacturer’s data, drawings and details for pre-assembled grinder pump station
and instrumentation clearly indicating compliance with all specified requirements.
Documentation of source of supply and/or repair located within 24 hour delivery
time.
Drawing showing location of pump station , discharge line, connection to sewer main,
cleanouts, fittings, and alarm panel (audio and visual), etc.
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