HomeMy WebLinkAboutSEP96-00058 - SEP Determinations - 4/9/1996 STATg O ,,
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STATE OF WASHINGTON
DEPARTMENT OF ECOLOGY
P.O. Box 47775 • Olympia, Washington 98504-7775 • (360) 407-6300
April 9, 1996 RECEIVED
APR 1 0 1996
Mr. Gary Yando MASON CO. PLANNING DEPL
Mason County
PO Box 578
Shelton WA 98584
Dear Mr. Yando:
Thank you for the opportunity to comment on the mitigated determination of nonsignificance to excavate a
3 foot wide x 200 foot long x 2 to 3 foot deep ditch to direct runoff in drainage area of an untyped stream
in order to control area of saturated soils and provide an area where a septic drainfield may be located,
located at Northeast 330 Makela Road as proposed by Anna Ahmed. We reviewed the environmental
checklist and have the following comments:
Wetlands:
Based on the description of the plants, and their association with a seasonal drainage, is appears that
wetlands are present. We recommend that a wetlands identification and delineation be completed in order
to assess the impacts of the proposed project.
Excavation of wetlands, such as this proposed ditch,may be regulated by the Corps of Engineers under
Section 404 of the Federal Clean Water Act. We recommend that the applicant contact the Regulatory
Branch of the Corps at (206) 764-3495 for their regulatory determination.
The broad flat area between the toe of the major slopes, appears to be a wetland and/or floodplain of the
stream. Consequently, it is not likely that an excavated ditch,which would interrupt the natural flow of the
stream, will persist as a permanent feature. The proposed drainfield is not likely to be protected from high
flow events since the ditch is sure to fill in over time. We recommend that alternative sites west of the
existing homesite,up on the high ground,be evaluated for the septic relocation.
At the request of the County,we would be happy to provide review and a site visit to provide more detailed
comments and recommendations for correcting the current problem.
Water Resources:
If the trench is constructed as proposed, it should be designed to redirect both surface and shallow
interflow. The downslope side of the trench should be made impervious in order to prevent flow from
continuing downhill.
I
Mr. Gary Yando
April 9, 1996
Page 2
Water OualiW
Proper erosion and sediment control practices must be used on the construction site and adjacent areas to
prevent upland sediments from entering the stream channel. All areas disturbed or newly created by
construction activities must be revegetated, use bioengineering techniques,use clean durable riprap, or
some other equivalent type of protection against erosion when other measures are not practical.
Any work in or adjacent to waterways that will adversely affect water quality must receive specific prior
authorization from the Department of Ecology pursuant to WAC 173-201A-110. A short-term water
quality standards modification may be issued if the proponent agrees to a number of specific construction
practices and techniques designed to minimize water quality impacts. The construction schedule will be
tied to the schedule on the Hydraulic Project Approval(IPA).
If you have questions regarding the wetland comments,please call Mr. Mark Bentley with Ecology's
Wetlands Program at(360) 407-7269. With questions regarding the water resources comments,please call
Ms. Helen Pressley with Ecology's Water Resources Program at(360)407-0290. With questions regarding
the water quality comments, please call Mr. Kahle Jennings with Ecology's Water Quality Program at
(360)407-6269.
Sincerely,
Carlwes ale
Assistant to the Regional Director
(360)407-6309
CG:alw(96-2022)
cc: Abbe White, SWRO
Helen Pressley, SWRO
Kahle Jennings, SWRO
Mark Bentley, SWRO