07-106681CITY OF
�A�k Fbderal
February 13, 2008
CITY HALL
33325 8th Avenue South
Mailing Address: PO Box 9718
Way Federal Way, WA 98063-9718
(253) 835-7000
www.cityoffederalway.com
Marty McAndrews, P.E.
CHS Engineers, LLC
12507 Bel -Red Road, Suite 101
Bellevue, WA 98005-2500
RE; Permit No. 07-106681 -00-EN
HONG RETA21 - 21st Ave SW
Public Works First Review
Dear Mr. McAndrews:
The engineering plans for Hong Retail submitted on December 12, 2007 have been reviewed.
Please make the following revisions and additions:
DOCUMENTS
Forms for the statutory warranty deed and bond are enclosed. Please complete
them and return to me or email them to anndower @C:1bL0ffedera1wayxom. These
items are time -sensitive and delays in processing could affect issuance of the
building permit. Please note that all easements that are located within the area to
be dedicated must be relinquished. The applicant is responsible for obtaining these
relinquishments.
2. A three-year maintenance agreement must be provided for the Stormfilter.
3. An NPDES permit may be required for this project. It is the applicants
responsibility to notify all other agencies and to obtain the proper permits. Provide
the City with a copy of the approved SWPPP associated with the NPDES permit.
4. List the NPDES permit in Section 7.
5. New impervious area created by required frontage improvements must be detained
and treated. If it is not possible to send this runoff into the new detention and
treatment facilities, then the facilities must be sized to effectively over -detain and
over -treat the onsite runoff. Please add this to the discussion and calculations, and
adjust the plans as necessary.
L: \CSDC\DOCS\SAVE\5837312080. DOC
Marty McAndrews. P.E.
CHS Engineers, LLC
RE: Permit No. 07-106681-00-EN
February 13, 2008
Page 2 of 4
& In Section 8, TESC Analysis and Design, either explain why this site is exempt from
providing a sedimentation pond or trap, or provide a design and locate it on the
plans.
5IREETLIGHTING PLANS
7. Streetlighting plans, line loss calculations, and photometric design are required.
Please see the enclosed checklist for items that must appear in the plan set.
LA_NDSCAPE PLAN
8. Within the planter strip on 21" Avenue SW, please select from either Acer
Saccharurn "Green Mountain" (Sugar Maple), Fraxinus pennsylvanica lanceolata
"Marshall" (Green Ash), or Tilia tomentosa (Silver Linden). Size and spacing is
correct. Please add the City of Federal Way Street Tree planting detail, 3-29.
CIVIL PLANS
General
9. Provide a profile view of the 21st Avenue SW frontage improvements.
10. One of the plans must,show parking stall and drive aisle dimensions.
11. Provide a minimum pavement section for onsite paving.
Sheet 2, _Demolition and Grading Plan
L
12. In addition to removing the power poles, please state that overhead utilities will be
placed underground.
13. Add curb and planter strip to the items to be removed.
Sheet 3,Storm Dra* ----jnage Plan
14. Show the individual tanks to -scale on the plan, with access risers and dimensions
between tanks. The TIR states that 2,025 feet of tank is required. Please verify
that this is provided. The 1998 KCSWDM requires that no location within the tank
be over 50'from an access opening.
15. Note that the existing catch basin lids in 21' Avenue SW must be replaced with
solid, round, locking lids. The control structure, CB #5, must also have a solid,
locking lid.
L: \CSDC\DOCS\SAVE\583 7312080. DOC
Marty McAndrews. P.E.
CHS Engineers, LLC
RE: Permit No. 07-106681-00-EN
February 13, 2008
Page 3 of 4
16. Proposed storm drainage lines must be shown as solid lines.
17. Catch basin #14 should be Type IL
18. Note that the 8" and 12' HDPE pipe within the right-of-way must be lined.
19. Add the direction of the inverts to the plan view of the Stormfilter vault.
Sheet 7. Street Improvements in 21" Avenue SW
20. Provide a detail of the sidewalk and paving transition area on the north end of the
improvements. Clarify what is being shown. Is there a reason the tapered
sidewalk edge is shown bolder than the rest of the sidewalk? Why does the new
curb end at the planter strip instead of the existing curb? Several stray lines
shown on the neighboring property must be labeled.
21. Please consider revising the graphics for the new sidewalk and planter strip area as
it is very hard to read. The planter strip pattern could be eliminated. The existing
sidewalk and planter strip could be removed from this plan, since it is shown on the
demolition plan.
22. Show the proposed and existing catch basins on the paving plan for reference.
23. Provide dimension lines for the existing right-of-way (30' width is shown but the
limits are not specified).
24. Show existing and proposed topographic contours within 21st Avenue S.
25. Provide station and offset for all paving limits, catch basins, tapers, driveway
centerline, streetlights, etc. Stationing must be tied to an existing monument.
26. Correct the pavement cross-section to 0.67' Class A over 0.5' CSTC.
27. Provide dimensions and striping for the driveway.
28. Show proposed striping for 21st Avenue SW..
Sheet %_gpAd Improvement Details
29. All current development standards and details for streetlights, landscaping, storm
sewer, and streets are available on the City of Federal Way website,
www.cityoffederalway.com. Use current streetlighting details. Add details for
catch basin, grate, and barricades.
L:\CSDC\DOCS\SAVE\5837312080. DOC
Marty McAndrews. P.E.
CH5Engineers, LL[
RE.,Pernnt Nu87-106681'00-EN
February 13,ZOU8
Page 4cf4
31. Show any significant trees to remain onsite, and any significant trees offsite that
are within twice the distance of their drip line to the subject property.
32. Include applicable wet season provisions, Appendix D, pg. D-42, in the 1998
A set of redlined plans has been emailed to CHS Engineers (Kristen White). Please provide
three pape sets of revised civil and streetlighting plans as we do not have online review
capability at this time. Do not include architectural plans. Send them to my attention with the
enclosed green resubmittal form and an itemized response letter. If you have any questions,
please contact me at (253) 835-2732.
Ann Dower
Engineering Plans Reviewer
eu:oc
Enclosures: Bond Form
Statutory Warranty DeedNorksheet
Streetlight Checklist
cc: William Appleton, P.E, Development Services Manager
Janet Shull, Senior Planner
Mike Ba|4\L0GArchitects, 1319Dexter Ave NLSuite 245,Seattle, VVAA81Og
Ann Dower - Hong Retail
From: Ann Dower
To: Kristen White; mwarner@stormtech.com
Date: 5/1/20088:45AM
Subject: Hong Retail
Hi Kristen
Ivvas able bmtalk with Marty Warner ofStorntech
The City iswilling hoapprove the Stormtechchamber system, provided the design includes a distribution system
between all ofthe chambers. Since we don't have alot ofexperience with this system, vvemay require
pretreatment in addition to the isolator row to assure that the system doesn't plug.
[)nanother issue, are the owners willing bodotheir hg dedication now? Idon't think Iever had afinal
Let meknow ifyou have
Ann Dower
ann.dower@cityoffederalway.com
253-835-2732
333258thAve S
P[)Box 9710
Federal Way, \NA 98063'9718
•' r
r- •T
Department
DATE: February 25, 2008
TO: Ann Dower
FROM: Janet Shull'
SUBJECT: HONG RETAIL - (07-106681-00-EN)
35411 21ST AVE SW
I have reviewed the submittal received 12-12-07, and have the following comment:
CIVIL PLANS
Sheet 3, Storm Drainage Plan
a:• �r _ � �w� w
Page 1 of 3
Ann DRetail
From: Ann Dower
To:
Kristen White
Date:
2/20/2008 11:24 AM
Subject:
RE: Hong Retail markups
CC:
Matt Herrera
Kristen,
I realized in looking at your plans again that you are proposing this detention system directly under several
parking lot planter islands. The system is so shallow that I suspect you will only be able to install shrubs, not
trees, over the top of it. You will need to either work this out with your planner, Matt Herrera, or revise the
system to miss the planter islands.
I also realized that you did show the Contech detention system in a detail. However, the detail is vague. I
don't see what the flow path is through the system and I only count 14 pipes. If you decide to use Contech, I
will need a better detail.
With a standard tank system we would require you to meet the maximum 50' between access points, due to
maintenance concerns. If there is a chamber system involved here, please send me clear details of it and we
will review it. I am not seeing that on the details for the Contech system so I have nothing to base an answer
on. I'd like you to tell me the item number, size, or whatever specific information you can give me and provide
a brochure or website reference that shows the specific system you want to use. Your Stormtech rep has
contacted me, but I will not schedule a meeting unless it's absolutely necessary, so please send me some
information.
We will not allow you to use an infiltration system that has been lined instead of an actual detention system.
You will need to use a detention system, or have your geotechnical engineer approve an infiltration system and
provide us an infiltration rate.
If you decide to go with the Stormtech system instead of the one shown on the plans, I will need accurate
details on the plan set.
Let me know if you have further questions.
Ann Dower
ann.dower@cityoffederalway.com
253-835-2732
33325 8th Ave S
PO Box 9718
Federal Way, WA 98063-9718
>>> "Kristen White" <kristenw@chsengineers.com> 2/18/2008 12:41 PM >>>
Ann,
A question on the StormTech system as it relates to your review letter, comment #14. The 1998 KCSWDM
requires that no location within the tank be over 50' from an access opening. Is this requirement still applicable
to the chamber systems? StormTech tells me this requirement does not apply to their chamber system and this
has been discussed and is acceptable with King Co and Pierce Co, among others. If access risers are required,
they recommend no more than 2 risers per isolator row (the one row dedicated to settling out TSS) and perhaps
one other port somewhere else to evaluate the water level. What will the City require for access to the
file://C:\Documents and Settings\Default\Local Settings\Temp\XPgrpwise\47BCOE05CHP... 2/20/2008
Page 2 of 3
StormTech system?
Also, if we go with the Contech system, as currently proposed on the construction drawings, will 2 risers be
required per row? The pipe segments are currently about 120' long and therefore would technically require two
risers per row, totaling 32. This seems excessive considering how shallow the pipe is. With one set of risers per
row, there would be 16 risers and no location would be over 55' from an access opening.
-----Original Message -----
From: Kristen White [ma iIto: kristenw@chsengineers.com]
Sent: Tuesday, February 12, 2008 12:06 PM
To: Ann Dower
Subject: RE: Hong Retail markups
We would want to still use the StormTech system as a detention system and not for any infiltration. If
we used an impermeable geotextile liner would that be acceptable or do we still need geotechnical
engineering input?
-----Original Message -----
From: Ann Dower [mailto:Ann.Dower@cityoffederalway.com]
Sent: Tuesday, February 12, 2008 11:45 AM
To: Kristen White
Subject: RE: Hong Retail markups
Kristen,
We are ok with the StormTech product in general, however, you haven't designed it to be an
infiltration system so there are some issues you iwould need to resolve.
First, I'd want your geotechnical engineer to review and approve that option. The geotech report
expressed some concern over the soils on this site becoming overly wet. I'm not sure if that is
just standard language or if it's site specific. �That:would concern me if you use a system that both
detains and infiltrates.
Second, If you want any credit for infiltration, the geotech would have to provide an infiltration
rate based on his test pit information, and you would have to redesign based on that rate. It looks
like the soils are not particularly well -drained, but he didn't actually make a statement regarding
infiltration rates.
Third, since you have designed to meet Contech's criteria, I would have to see all of the
StormTech information and you would have to prove that you've met all the Stormtech design
criteria. I may call for additional calcs, adding the details to the plans, etc. I don't know at this
point.
If you decide to pursue this, send me the Stormtech information along with a letter stating your
intent (to infiltrate, detain, etc.) and an addendum from your geotechnical engineer.
Ann
Ann Dower
ann.dower@cityoffederalway.com
253-835-2732
33325 8th Ave S
PO Box 9718
Federal Way, WA 98063-9718
>>> "Kristen White" <kristenw@chsengineers.com> 2/12/2008 11:20 AM >>>
file://CADocuments and Settings\Default\Local Settings\Temp\XPgrpwise\47BCOE05CHP... 2/20/2008
zM
Another quick thought nnthe detention tank...
We received obid alternate from a comparable detention tank manufacturer, StormTech. Are you
familiar with Stornn7ech? They have those yellow plastic arch pipe systems laid in a bed of
gravel ... they work as both detention and infiltration systems as a result. I'm wondering ifthis is
an acceptable technical alternative to the City. Also vvnu|d it be sufficient to add a note to our
plans indicating that the contractor may used an approved equivalent for the detention tank? Or
do we need to replace the Contech details with StormTech details?
----- Original Message ---
Fmmmm: Ann Dower [nnaiko:Ann.Dovver@kway.com]
Sent: Tuesday, February 12, 2008 10:28AM
To: Kristen White
Subject: Hong Retail markups
Hi Kristen
We're trying this out, so let mmknow if you have suggestions.Attachedare 10odf files.
Inaperfect world, you would fece�ethennw�hnoppob�nls. However, �you don't
nace�ethem all let nmehnovvandI'll start over with fewer attachments. Sorry, Idon't have
color scanner capabilities. Let me know ifit's too hard bofind the comments.
I've just had Autodesk Design Review installed. on..my computer too, so maybe we'll get up
and running onthat soon, atleast for changes bmthe approved plans.
� ^ We do not have the capability of reviewing full plan sets via email at this point. There are
processing issues, along with thefac±that nmy computer screen is too small. '
Iwill besending ahard copy of the review letter by tomorrow.
Ann Dower
ann.dower@cityoffederalway.com
253-835-2732
333258thAve S
P]Box 9718
Federal Way, VVA 98063-9718