8327 Civ Eng No 2 122402December 24, 2002
Robert Tauscher
JWM & A Inc.
1700 Cooper Point Rd SE #B2
Olympia, Washington 98502
RE: Civil Engineering Review No. 2
Central Reddi-Mix Grading and Drainage Plans
City of Yelm Project No. CIV-02-8327-YL
Dear Mr. Tauscher:
The proposed stormwater drainage plans have been reviewed in accordance with the Department of Ecology Stormwater Management Manual for the Puget Sound Basin. At this time the City
of Yelm has made the determination that the proposed stormwater improvements shown on the above referenced plans do not meet the manuals minimum technical requirements or intent of these
requirements.
Currently this developed industrial site has over 5,000 square feet of impervious area. This area consists of concrete surface area that has been added without upgrading the stormwater
system or being in compliance with the City of Yelm Development Guidelines. Before any approvals are issued the site will need to be brought up to current stormwater code.
I have reviewed the stormwater plans, letter from Steven High of TESI and Department of Ecology’s sand and gravel permit for Central Reddi-Mix. This information was submitted on December
09, 2002. The following are comments from the above referenced plans and need to be addressed on the future submittal.
The stormwater traveling across the gravel areas will need to be treated before being released to the infiltration facilities. In your report, this area is referred to as “non contact
area”. This may be the case with regards to the sand and gravel permit and the use of Portland Concrete Cement. However the stormwater manual requires this area to be treated before
release to the infiltration facility. This area should also be considered impervious for the stormwater calculations. It is currently shown as landscape area.
Much of the existing concrete currently sheet flows into the surrounding gravel areas. Your report indicates that this flow will not be redirected to the new stormwater facility or
the reuse holding pond. How will this surface water be contained and treated?
Currently a significant amount stormwater is released undetained to Rhoton Road. This stormwater is flowing out of the batch plants concrete entrance. How will this stormwater be treated
and released in accordance with the DOE storm manual?
The current proposed infiltration facility will need to meet the requirements of the stormwater manual for side slopes, access and the setback from property lines. The setback can be
reduced to 10’ from the top of slope.
The future plans are not limited to the above comments. Until the stormwater plan is submitted based on the Department of Ecology Stormwater Manual a full review may not be possible.
The City of Yelm does understand that you are trying to meet the standards set by the Department of Ecology Sand and Gravel Permit issued 8/6/99. However the City of Yelm also has requirements
for stormwater control and treatment, which will have to be met before you are permitted to add additional impervious surfaces to this site.
Please review and revise your engineering drawings. When you resubmit your package, please send 4 revised sets and two drainage reports. If you have any questions or comments, please
call me at (360) 458-8438 and I will be happy to further assist you.
Respectfully
City of Yelm Community Development
Jim Gibson
Development Review Engineer
Cc: John Pearch, Dept of Ecology
Steven High, TESI
Mike Hanson, Central Reddi-Mix