20-101386-CO-Response Letter-04-29-2022-V1
April 29, 2022 Job No. 1886-001-016-0015
Mr. Leonard Spadoni
City of Federal Way
33325 8th Avenue S
Federal Way, WA 98003
RE: Permit #20-101386-CO
Woodbridge Building A; 3120 South 344th Street, Federal Way
PW Development Comments for Onsite - RESPONSE
Dear Mr. Spadoni:
ESM Consulting Engineers, LLC, is submitting the following responses to the comment
letter we received from you dated April 25, 2022.
In an effort to provide concise and direct responses, we have copied the review comments
below in italics and our responses are in bold.
General Plan and Formatting
1. Add the city’s inspection notification phone number (253-835-2700), and the “One
Call” utility locate number to the civil plan set.
The City’s inspection notification phone number has been added to the cover
sheet. The one call 811 utility locate number is already on the plan set.
2. Please remember that final acceptance of improvements will require the following:
a. The correction of all defects as noted on the final punch list.
b. Material submittals, shop drawings, and acceptable test/inspection reports.
c. As-Built Plans – See PW Section 1.4.10
d. Statutory Warranty Deed – The developer shall submit a complete statutory
warranty deed for all right-of ways and other lands to be dedicated to the
public. Per PW Section 2.1.14
These comments have been noted and will be addressed prior to final acceptance.
3. The City’s standard general notes that apply to the plan shall be provided on the
plans.
The standard notes have been shown on sheets CV-01, GR-08 and DT-04.
Mr. Leonard Spadoni
April 29, 2022
Page 2
4. Construction Stormwater General permit with DOE 1/2021, is required.
The NPDES permit information for both Woodbridge Buildings A and B has been
submitted to the City.
5. Per SEPA MDNS condition response letter, item 5(I) a wheel wash is required.
Construction general permit SWPP plan must be revised to address this condition.
To be shown on T.E.S.C. plans.
The SWPPP and plans have been revised to include the wheel wash.
6. SEPA MDNS condition for construction to be followed – Item 1, 2, 3, 4, 5, 6, 7, 8, 9
& 10.
This information has been addressed as outlined in the compliance matrix
submitted to the City on April 22, 2021.
7. Standard details to be most current PW Development Standards. Please include
ROW Standard Drawings are not included. 3-02G, 4-10, 4-11, 4-20
a. Please add the Surveyor name and phone number to the Project Contacts
on Plan Sheet 1.
The details and survey information have been added on the relevant sheets.
8. Full build out of the retention ponds and water quality infrastructure to be completed
and accepted by PW for either Building A, or B prior to C of O granted for either
building.
This comment has been noted and will be addressed as necessary prior to
issuance of C of O.
9. Full build out of road frontage improvements and channelization improvements
must be completed and accepted by PW for either Building A or B prior to C of O
granted for either building.
This comment has been noted and will be addressed as necessary prior to
issuance of C of O.
10. A Forester must be present to supervise the activities in environmentally sensitive
areas and forest buffer zones.
A note has been added to reflect this information on sheet TR-01.
Site Plan and Roadway Elements
11. All retaining walls that are over 4-feet and/or support a surcharge load will require
a separate Building Permit.
Mr. Leonard Spadoni
April 29, 2022
Page 3
This comment has been noted and wall building permits will be applied for as
required.
12. Show property lines, right-of-way lines and widths for proposed road and
intersecting roads on plan view and show street cross-sections and reference
applicable City Roadway section.
This information has been shown on the frontage sheets. The applicable City
Roadway section has been added under the road name.
13. Show all existing and proposed roadway features such as centerline, edge of
pavement and shoulder, ditch line curbs and/or sidewalks. In addition, points of
access to abutting properties and roadway continuations shall be shown.
Reference SEPA MDNS response letter items 8,9, & 10.
This information has been addressed as outlined in the compliance matrix
submitted to the City on April 22, 2021.
14. Use PW Development most current Standard details for streets and features. It
appears you have not included 3-02G, 4-10, 4-11, 4-20. Please correct.
The details have been added as requested.
15. Provide channelization/Signage Table detail and station location.
The channelization and illumination plans for Weyerhaeuser Way South have been
completed and were submitted to the City on April 22, 2021.
16. The Geotechnical Recommendations to be followed for specific construction.
This comment has been noted and will be addressed, as necessary.
Drainage Conveyance
17. Again, storm system/detention pond full build out (As shown for Building A & B) will
be required to be completed prior to certificate of occupancy is granted.
This comment has been noted and will be addressed as necessary prior to C of O.
18. The City’s most current standard Drainage notes that apply to the plan shall be
provided on the plans.
The notes have been verified to be the most current standard drainage notes.
19. If PVC is used as storm drain material then a PVC adapter required at CB/MH's
(for PVC pipe only. Applies to all locations.
Mr. Leonard Spadoni
April 29, 2022
Page 4
The drainage notes on sheet DT-04 have been revised to include this note.
20. Cover over PVC pipe (SDR 35) shall be 3' minimum. Applies in all locations.
The cover has been verified to be met as required.
21. Solid waste enclosures require drainage collection and conveyance system and
pollution management per FWRC 19.125.150 (Attachment A).
The proposed trash enclosure has an area of 315 square feet and will be covered
as required by FWRC 19.125.150. A side sewer service and grease interceptor
has been added and is shown in the background of this plan set. A field changed
will be obtained from Lakehaven Water & Sewer District to the approved sewer
plans.
Retention/Detention General
22. Full buildout of detention pond must be completed prior to certificate of occupancy
for either building A or B is granted.
This comment has been noted and will be addressed as necessary prior to C of O.
23. Dam Safety Compliance required. Detention pond is over 10-acre feet:
Detention ponds and other open impoundment facilities must comply with
requirements for dam safety (WAC 173-175). Under current regulations (as of
February 2012), if the impoundment has a storage capacity (including both water
and sediment storage volumes) greater than 10 acre-feet above natural ground
level and a dam height of more than 6 feet, then dam safety design and review are
required by the Washington State Department of Ecology (Ecology). If the storage
capacity is less than 10 acre-feet above natural ground level, then the facility is
exempt from Ecology review. If the dam height is less than 6 feet but capacity is
greater than 10 acre-feet, then Ecology reviews on a case-by-case-basis to
determine the hazard potential downstream in the event of a failure. 13 Acre Feet
- 67,165 SF, 9.5’ deep.
The detention pond required live storage volume is 413,100 cubic feet (9.48 acre-feet)
storing the Level 3 flow control of the 100-year storm event. The detention pond
available volume is 442,438 cubic feet (10.22 acre-feet), providing a 7 percent factor
of safety. The sediment storage volume is 50,150 cubic feet (1.15 acre-feet), for a
total pond volume of 492,588 cubic feet (11.31 acre-feet).
The maximum berm height between existing natural ground and the top of live storage
is 5.7 feet, which is less than the 6 feet. Per WAC 173-175-020 Applicability (1), dated
October 25, 2019: Only water that can be stored above natural ground level or which
could be released by a failure of the dam is considered in assessing the storage
volume.
Mr. Leonard Spadoni
April 29, 2022
Page 5
The volume of water that is stored 5.7 feet above natural ground level (elevations
376.3 to 382.0) is 346,525 cubic feet (7.96 acre-feet), which is the volume that is
required to be under a maximum 10 acre-feet as to not trigger the dam safety
requirement.
In summary, the proposed stormwater detention pond stores less than 10 acre-feet
with a 5.7 feet height berm and does not trigger the dam safety requirement.
24. Rip rap pads for outflow are required. Rip rap pad sized per 2021 KCSWDM
Rip rap pads underlain by sand and gravel filter or filter fabric. Applies in all locations.
Rip rap pad has been added for the proposed discharge location to Stream EA.
25. Support straps shall be 1 in top 1/3 of control tee and 1 in bottom 1/3 of control tee.
Per DWG 4-14.
The support straps have been updated as requested.
26. Storm Filter/Water Quality Vaults
1. Approval letter from manufacturer, including total contributing area,
impervious area, detention release rate, maximum release rate, media,
cartridge flow rate, minimum drop required.
2. Formal quote from manufacturer, for bond information.
3. 2-year maintenance agreement from Stormwater Management Inc.,
including cartridge removal and vault cleaning.
4. Yearly (minimum) Certificate of Compliance stating that maintenance has
been completed by Stormwater Inc. (Direct it to Surface Water Division
Manager).
This information will be provided as soon as obtained from the
manufacturer.
27. Water quality treatment shall be provided for new pollution-generating surfaces,
where surfaces were taken to sub-grade, within the public right-of-way.
Additional water quality treatment has been provided onsite to mitigate for the
replaced pavement reconstruction and new Weyerhaeuser Way South widening
pavement (1.8 acres). The TIR has been updated to reflect this information.
28. Flow control shall be provided for new surfaces, where surface is taken to sub-
grade, in right-of-way and meet most current regulations.
Additional flow control has been provided onsite to mitigate for the replaced
pavement reconstruction and new Weyerhaeuser Way South widening pavement
(1.8 acres). The TIR has been updated to reflect this information.
Mr. Leonard Spadoni
April 29, 2022
Page 6
If there are any questions or a need for further clarification, please feel free to contact me
at (253) 838-6113 and we would be happy to discuss them with you.
Sincerely,
ESM CONSULTING ENGINEERS, LLC
LAURA BARTENHAGEN, P.E., LEED® AP
Principal
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