bld20131341_SprayPark-1.docx
City of Edmonds
Dave Earling, Mayor
TH
121 5 AVENUE NORTH • EDMONDS, WA 98020 • (425) 771-0220 FAX(425) 771-0221
Website: www.edmondswa.gov
PUBLIC WORKS DEPARTMENT
Engineering Division
Plan Review Comments
Plan Check : Date:
# BLD20131341 October 7, 2014
rd
Project Name/Address:
Spray Park City Project 600 3 Ave S
Contact Person/Address/Fax
: Carrie Hite Parks Department carrie.hite@edmondswa.gov
Reviewer: JoAnne ZulaufDivision:Engineering
During review of the subject submittal, it was found that the following information, corrections, or
clarifications would need to be addressed. All Handouts and Standard Details referred to in these
comments can be accessed at our website: www.edmondswa.gov by choosing Permit Assistance:
Engineering Comments:
1. Please address the following call out issues to provide clarity to the plans and assist with clearer referencing during the
construction process:
a) SD #07 connects to an existing catch basin to the northwest, that existing catch basin then connects to a second existing
catch basin to the west. The callouts for the second catch basin are located on the west side of the asphalt road, quite a
way away from the actual catch basin. The leader is the same weight as the other pipe lines. Please revise to avoid
confusion.
b) Assign identifiers to the existing catch basins.
2. Please revisit rim elevation for SD #07. If 5 ft between invert and rim then a type 2 catch basin should installed. The grade
lines as shown on the plan indicate that the rim may be closer to 28. Please make revisions as needed.
3. The second existing catch basin referenced in comment “1a” has a length of pipe directed to the north and another length
directed northwest that do not connect to anything. Will they be abandoned? Do they connect somewhere that is not shown?
Also the cb callout has two NW inverts; which is the pipe that extends to the far west existing cb?
4. The existing catch basin located just a bit to the southwest of SDCO #6 is noted to be filled with dirt. Please add to the note
“Clean out catch basin….” the phrase “replace with new type 1 catch basin if damaged”.
Utility Engineer Comments:
Project Calculations
Sewer Lift Station
- No data/calculations/report/sizing/pump curves has been provided for the sewer lift station for the
project site. The consultant was asked to follow Engineering Handout E61 for the design of the pump station, so there is no
way for us to check sizing, type of pump, buoyancy calcs, etc. (as detailed in the handout), As discussed in the meeting,
modifications to the flow/storage rates would be allowed to account for the fact that this is just draining the spray ground.
Bouyancy for storage tank –
It is understood that the tank will have an underdrain system. The geotechnical report (HWA
9/18/2014), however, recommends that that the design groundwater level for buoyancy purposes should be one foot above
the existing ground surface. Verify that the designer believes that the proposed underdrain system and associated concrete
anchor are sufficient in these artisan groundwater conditions to prevent the detention pipe from floating without additional
ballast. Underdrains can fail due to clogging. Also based on previous meeting comments by Rich Lindsey, during the
winter, portions of the park parking lot are subject to flooding due to the rain events and the proximity of the nearby
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marsh. Has the consultant determined this flood stage water level to verify that the drainage system could still function and
keep the empty tank from floating up? Or worse yet having the underdrain system act as a conduit for the flood waters to go
in?
Plans
Sheets C2.0 & M4.00
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Provide grades so that tank inverts/connection points are known. Detail 2 on M4.00 has dimensions from top of
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grade, but site is sloped. At least one NAVD88 reference grade needs to be supplied. Also detail 2 on M4.00 shows
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a step between finish grade and the concrete collar, but detail 3 shows it flushWhat is the depth of the slab, thi
ckness, etc. so that contractor knows how much concrete to pour, with what dimensions, how to tie it in and what
straps are made of?
Sheet C3.0
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Water service piping shown as PE, plain PE is not allowed. City standard is copper. Municipex crosslinked PE pipe
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with associated 14 gauge PVC coated copper locator wire is the only other alternative. Also depth and alignment
information needs to be supplied so that it can be as-built properly. Location of where water service enters the
building does not match mechanical dwg on M2.00. Location on mech plans is better since you will not need to
cross all the water supply lines to the spray park. Coordinate with mechanical and realign.
Sewer FM profile missing. Horizontal alignment information missing as well. Also bends are shown in the FM
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pipe. These need to be sweeps/arcs. Verify that HDPE has a 200 psi rating.
Sheet C3.1
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Sewer FM profile missing. Horizontal alignment information missing as well. Also bends are shown in the FM
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pipe. These need to be sweeps/arcs. Verify that HDPE has a 200 psi rating.
Based on orientation of lid for the new manhole being placed in the ROW, an interior drop into the MH structure
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cannot be built as detailed, since the invert penetration for the FM will be somewhere between the cone transition or
the riser. The MH opening will need to be rotated 180 degrees to have the drop detail work as shown. Also at best,
the FM at MH connection has about 1.1’ of cover at connection, but lift station detail shows 2’ cover
min. Recommend rotating the manhole 180 degrees and also shifting it 3 feet east of the current location so that the
lid is at the back of sidewalk and the cone portion is facing the roadway. This should solve the cover issue and the
inside drop issue.
SS service lateral connection shall be per COE std detail E6.4.
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Sheet C4.3
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Pump Detail –
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1 hp pumps shown. Standard per E61 is 2hp. Please revise so that it matches all our other lift
stations. Ops staff does not want to have even more materials on hand for maintenance.
How are the valve extension handles for the gate valve secured so that they don’t drop in the
structure? Why were they not placed outside? (Was it because of all the supply pipes leading to the spray
park?) Gate valves need to be non rising stem. Also, what is the pipe in the structure made out of and also
how long is the piece of pipe after the gate valve? Can valve extensions be made so that they operate at
such angles in relation to the lid? Also, verify clearances for all valves (gate/check valves) so that there is
actually enough space in the structure to perform maintenance/access on the structure and valves so that
there is adequate space and clearances can be removed for maintenance. A to scale x,y,z dimension check
of this needs to be done.
What is the purpose of the pump encasement pipe? From previous meetings, there should not be any
debris. What is it made out of? How is it secured? How many holes are needed and what distance on
center and how many rows? How many holes are needed so that performance of pump is not affected?
Pump needs to be on rail system per E61.
Provide Buoyancy calcs, since no underdrain system has been provided. Add ballast as needed.
Is lid of structure a MH lid? If so, please specify. Larger opening would be better, especially if the gate
valves are to stay in the structure.
Where is the vent pipe?
3” HDPE is shown with 2’ min depth. Please show minimum clearance of HDPE in relation to the soffit of
the structure, because as shown, the HDPE could literally be at the soffit of the structure (making
maintenance difficult) and still make the 2’ minimum burial depth. HDPE needs to have a 200 psi rating.
All pipe penetrations shall have Calpico link seals with the tightening bolts installed so that they can be
tightened from the inside of the structure.
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Storm Drain Cleanout –
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Provide locking lid and revise to reference COE std E6.2.
Sheet M1.01
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Material type for all piping not shown. Please supply so that city can verify that city standard materials are being
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used.
Sheet M2.00
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All cleanouts need to have locking lids and be per COE std. E6.2.
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Michele (Mike) F. De Lilla, P.E., LEED AP
Senior Utilities Engineer
Engineering Division | City of Edmonds
th
121 5 Ave N. | Edmonds, WA 98020
425-771-0220 x 1320 | Fax: 425-672-5750
mike.delilla@edmondswa.gov
Stormwater Engineer Comments:
Stormwater Site Plan, 9/15/2014, LPD Engineering
Buoyancy –It is understood that the detention system has an underdrain system. The geotechnical report (HWA 9/18/2014),
however, recommends that that the design groundwater level for buoyancy purposes should be one foot above the existing
ground surface. Verify that the designer believes that the proposed underdrain system is sufficient in these artesian
groundwater conditions to prevent the detention pipe from floating without additional ballast. Underdrains can fail due to
clogging. In addition, anecdotal information for Park’s employees indicate that during large storm events the western part of
the park’s parking lot is flooded meaning the proposed underdrain system may not have anywhere to drain or be
backwatered.
Section 5.4, page 7-
The text states that 1,275 SF of impervious area (0.029 acres) was modeled as bypass. The WWHM4 report in
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Appendix B does not have this basin (Basin 2) as a bypass basin. Please reconcile and show a screenshot of the
WWHM schematic showing the basins with the accompanying basin areas and the detention pipe icon with the
appropriate mode input information.
The allowable release rates from the Edmonds Stormwater Code Supplement listed in Table 2 are correct. These
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values, however, assume all disturbed pervious areas on a site have compost-amended soils so these area essentially
generate zero runoff. This is not the case here where the wood chip play area is assumed to be 50 percent
impervious and 50 percent pervious (assume lawn). The model should include 0.027 acres of lawn for sizing the
detention system.
Appendix B, WWHM4 Report – Why is orifice 1 at an elevation of 0.5 ft?
Project Drawings
Sheet C4.3 – Notes and Details
Replace the City of Bellevue reference in the “Detention Pipe Structural Notes” with the City of Edmonds.
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Detail 8 references the City of Edmonds drawing No, E5.4. Add this detail drawing to the plan set; an AutoCAD
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version is available on our website.
Jerry Shuster, P.E.
Stormwater Engineering Program Manager
Jerry.Shuster@edmondswa.gov
425-771-0220 x1323
Public Works Comments:
1. Install RPBA at water meter, and hot box. Install RPBA or Airgap at water tank.
Please resubmit 3 copies of the revised plans/documents to a Development Services Coordinator. Please
contact me at 425-771-0220 if you have specific questions regarding these plan corrections.
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