HomeMy WebLinkAboutCOM2007-00108 Stormwater Review - COM Engineering / Geo-Tech Reports - 12/12/2007 MASON COUNTY
PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER
Shelton, Washington 98584
TO BE KEPT IN THE
DATE: December 12, 2007 PARCEL FILE
C
INTER-DEPARTMENTAL COMMUNICATIONS (-
TO: Pam Bennett- Cumming PARCEL # 42012-21-90102
FROM: John Sliva, Programs Engineer-PW PERMIT #: COM2007-00108
SUBJECT: Stormwater Review NAME: Extreme Holdings
PAGES 2
Pam:
The engineered stormwater site plan (SSP) for the proposed auto body shop at 1383 E Shelton
Springs Road Shelton was received and reviewed by Public Works.
The stormwater site plan was presented as an insert in the Phase I Environmental Assessment.
The proposal is to build a 7200 square foot auto repair shop with associated parking next to the
existing facilities. The site is fairly level and will require very little grading. The current stormwater
facilities include an oil/water separator, bioswales, and ponds. The stormwater facilities were sized
for the proposed expansion in the Stormwater and Erosion and Sediment Control Site Plan dated
April 18, 2000. The proposal provides an erosion and sediment control plan and a permanent
stormwater plan.
An addendum letter dated April 4, 2007, from the original design engineer, supplements the 2000
SSP. The original plan was to reserve the westerly 35 feet of the property from Shelton Springs
Road to the north side of the ponds for drain fields. The remaining portion of the property lying
north of the big shop was considered impervious. The letter notes that it is OK for the stormwater
from the proposed new building site area to be piped into the catch basin #3 and discharge to the
westerly pond. It is also planned that the future parking area would flow free south along the
access road and enter the easterly pond. Both ponds have been sized to handle the proposed
improvements.
Silt fences, straw and Hay Bale Barriers, are a few Best Management Practices provided in the
temporary erosion and sediment control plan (TESC).
The Stormwater Site Plan with addendum letter will be acceptable to Public Works if the applicant
accepts the following conditions. The stormwater drainage plan should be incorporated into the site
development plans.
CONDITIONS:
1. Stormwater from the new building site area will be piped to the catch basin #3 that
discharges into westerly pond.
2. What does not go to the westerly pond will free flow south along the access road and enter
the easterly pond.
3. An oil water separator will be installed in the system for parking and floor drains that are
piped to the ponds.
4. A Maintenance and Operations Covenant should be executed unless one already exists for
the site.
Please feel free to contact me at 724 if you have any questions regarding these comments, or if
you feel any features need further discussion or attention.
Si nc rely,
ohn iva
rograms Engineer