Big Cedar-CS 910906The City With A Beautiful Future
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P.O. Box 478
Coppell, Texas 75019
214-462-0022
September 6, 1991
Mr. D. Mathew Goodwin, P.E.
Goodwin and Marshall, Inc.
6001 Bridge Street, Suite 100
Ft. Worth, Texas 76112
RE: Big Cedar Addition / Existing 10-Inch Sanitary Sewer Capacity
Dear Mr. Goodwin:
We have reviewed your letter dated August 2, 1991, regarding the capacity
of the existing 10-inch sanitary sewer along tribUtary G-1 of Grapevine
Creek. We agree that the capacity of existing sanitary sewer is
approximately 710,000 gallons per day, provided that it was constructed to
plan grade and is in good condition (i.e. no failed sections or other
obstructions). However, when determining the total number of households
that can be served by this line, we used a peaking factor of 4.5 (Figure
4. - Curve "A", ASCE Manual No. 37) and included an infiltration rate of
500gpd/inch dia./mile. This results in a maximum of approximately 475
houses which can be served by the existing 10-inch sanitary sewer. Based
on our records, there appears to be adequate capacity in this line to
serve the 37 lots proposed in the Big Cedar Addition.
Eowever, as we indicated in our review comments of your preliminary plans
and communicated to you during our development review committee meetings,
the proposed relocation of the existing 10-inch sanitary sewer across this
addition should be reconstructed at this time in accordance with the
city's proposed Sanitary Sewer Facilities Master Plan, which calls for a
15-inch sanitary sewer in this area. As we discussed, we will work with
you in determining the method in which the City participates in the
oversized portion of the cost associated with this line.
If you have any questions or comments regarding this response, please do
not hesitate to call.
Sincerely, ~
Acting City Engineer
MSD/GCH/pen
cc: Gary Sieb - Dir. of Planning & Comm. Serv.
Howard Pafford - Water Superintendent
Gary Hendricks, P.E. - Plan Review Engineer
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