Northlake 635(7)-CS021025Oct 25 02 03:20p TITRti Engineering, Inc. [2141 390-1442 p.2
® TITAN Engineering, Inc.
Environmental Consulting and Management
VIA FACSIMILE
October 25, 2002
Mr. Ken Griftin
City of Coppell
P.O. Box 478
Coppell, TX 75019
Re: Drainage Issues ut 7333 Crestside Drive
Dear Mr. Griftin:
Pursuant to your discussions with Mr. Mark Harrington of Structure "Cone, Lnc. retarding the drainage
issues at the tenerator yard of the above referenced site, Structure "Cone retained TITAN I?n~~ineerint,
Inc. to inspect the site, review site drawings, and provide a brief evaluation of storm water discharges
from the generator yard. Currently, the City of Coppell ltas not allowed the tie-in of the area drain inlets
[o the storm sewer system and as a result, during a storm event the inlets back up and stonnwater ponds
in the area causing a safety hazard and general nuisance.
Based on a site visit and review of the drawings, TITAN provides the following information for review
and consideration:
The storm water inlets serving the generator yard are designed to drain storm water to the
on-site storm sewer system and subsequently to the city storm sewer system. Under
normal operating conditions, storm water runoff from this area will have no exposure to
industrial activity. The fuel tanks of the backup generators are double walled tanks for
spill containment and prevention. Storm water will only have contact with the outside of
the tanks and the surrounding concrete pavement structures. 'T'his area would satisfy the
no expvsure criteria of Texas Commission on Environmental. Quality's (TCEQ's) No
E.cposure Certifrcatiat. Furthermore, it is our understanding that this drain is for storm
water only and no process related wastewater is connected. Therefore, this drainage
system is stone water only and is not considered an industrial wastewater discharge.
The oil water separator that currently serves the storm drain inlet serves as a best
management practice for storm water management. Oil water separators (such as
Stormceptors®) are being installed more frequently on commercial and industrial sites
(e.t. parking lots, bus depots, railyards, etc.) and are designed to remove small quantities
of oil and sediment that are inherent in storm water discharges from these areas. At the
Crestside site, no sibmificant quantities of oil and or sediments are expected and
therefore, no adverse impacts on water quality are anticipated. It is T1TAN's
understanding that the oil water separator at this site was not oritinally specified but was
later installed to satisfy the city's concern that the drain was serving a tenerator yard
with fuel tanks. However, it is important to note that the generator iucl tanks and piping
are double contained for leak prevention measures.
2340 E. Trinity Mills Road • Suite 250 Carrollton, Texas 75006
Phone (214) 390-1400 Fax (214) 390-1442
Oct 25 02 03:20p TITfIH Engineering, Inc. (2141 390-1442 p.3
Mr. Ken Griffen
October 25, 2002
Page 2
Based on the above evaluation, TITAN believes that connecting the drain inlet of the generator yard to
the storm sewer system is necessary to alleviate ponded water conditions and storni water ninoff from the
generator yard will not be adversely impacted from normal operating activities.
TITAN appreciates the opportunity to provide this evaluation. If you have any questions, please call me
at 214-390-1400 ext. 106.
Sincerely,
TITAN Engineering, Inc.
Cl~~
Christopher S. Browning, P.E.
Principal
cc: Mr. Mark Harrington -Structure Tone, Inc.
t o/ zS~oZ
Oct 25 02 03:19p
[214] 390-1442 p.l
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Facsimile Cover ~`~~~
TITRn Engineering, Inc.
To: Mr. Ken Griffin -City of Coppell - 972-304-7041
Mr. Mark Harrington -Structure Tone - 214-599-9210
Pages: 3, including this cover sheet.
Date: October 2~, 2002
Subject: 1333 Crestside Dr. Facility -Drainage Issues
Please call me if you have any questions. Thank you.
Chris Browning
chrislii?titanen~~ineerine.com
From the desk of...
TITAN Engineering, Inc. Christopher S. Browning, P.E.
_ Environmental Consulting and Management
2340 E. Trinity Mills Rd., Suite 250
Carrollton, Texas 75006
214-390-1400 x106
Fax: 214-390-1442