ST9401-CS 980731C: )40��3
CITY OF DALLAS
July 31, 1998
Kenneth M. Griffin, P.E.
City Engineer
City of Coppell
RE: Denton Tap Road - from Cottonwood Creek to City Limits Coppell.
Dear Mr. Griffin:
This is regarding the ongoing construction involving your proposed 60 -inch RCP storm sewer
and DWU's existing 30 -inch transmission main in Denton Tap Road at Denton Creek (Paving
Station 207 +50 to 208 +50).
As you are aware, the shift in your proposed storm sewer alignment and a change of size from
48 -inch to the current proposed 60 -inch RCP resulted in a mere clearance of 0.56 feet between
the wall of the proposed storm sewer and the concrete encasement on the 30 -inch water main.
Our operations personnel have stated that they need approximately 5 feet of working space on
either side of the 30 -inch main for maintenance and repair. Due to the closeness of the 60 -inch
RCP to the 30 -inch main, working on the 30 -inch main without affecting the 60 -inch RCP is
impossible. The storm sewer would need to be removed and then replaced to allow for work to
be done on the 30 -inch water, if it were required in the future.
We would prefer that you provide additional clearance between the two pipes. We recommend
issuing a strong caution note and advice to the contractor to exercise extreme care and the
application of acceptable shoring and /or bracing to ensure the stability of the existing 30 -inch
water main.
This transmission main is a major water supply to the City of Flower Mound. Any damage to this
main will jeopardize the water supply and fire protection to the City of Flower Mound.
Please call if you have any questions.
H `$aha, P.E.
roject Manager
Development Services
C: P. Boyd, J. Milstead, S. Hardy, M. Rickman, J. Battad
Water Utilities Department
Development Services • 320 E. Jefferson, Room 218 • Dallas, Texas 75203 •214 / 948 -4590
A city utility providing regional water and wastewater services vital to public health and safety.