Gateway BP(1.1)-CS 921102 ALBERT H. HALFF ASSOCIATES, INC.
ENGINEERS · SCIENTISTS · SURVEYORS
DALLAS · ARLINGTON · CHICAGO * FORT WORTH
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?4 .'39-0C9a · FAX 2'4 73:2.-0095
November 2, 1992
AVO 11978
Dept. of Public Works ~.~~'
P.O. Box 478
Coppell, Texas 75019
Att: Mr. Kenneth M. Griffin, P.E.
City Engineer
Re: Gateway Business Park Phase IB
Dear Mr. Griffin:
Please find attached two blueline sets of the above referenced construction drawings
for your approval. The plans have been revised per your comments as follows:
1. A header rest was added at Station 0+57.85.
2. A General note was added referencing Note #5 of the Final Plat. "No
sidewalks shall be required for this development at this time. The Director
of Public Works shall decide the requirements for and timing of the
sidewalks."
3. The barricade striping has been revised.
4. No. 6 dowels epoxyed in at 24" O.C. have been added to all new pavement
connections to existing pavement.
5. The radius of the curb return at the northwest comer of Exchange Drive and
Gateway Boulevard was modified to clear the existing manhole.
6. We have added top of curb elevations and points of intersection to the
drawings.
7. The capacity and the existing condition flow rate have been added for the
existing railroad ditch.
ALBERT H. HALFF ASSOCIATES, INC.
ENGINEERS · SCIENTISTS · SURVEYORS
City of Coppell
November 2, 1992
Page 2
8. Drainage areas A-7, A-12, A-14, A-15 and B-2 have been added.
9. A traffic detour plan has been added as Sheet TC-1.
10. A General note has been added to require prefabricated wyes for all pipe
connections.
11. Per our discussions, we have reviewed the hydraulics of Lateral TG-1 in
Sterling Drive with its ability to provide service to its respective drainage area.
Extending the hydraulic grade line into the site provides 3 feet between the
hydraulic grade line and the existing grade of the site. (See attached sketch)
12. A detail for the proposed headwall at the end of l~ine TE-12 has been added
to Sheet D-6.
13-A. Energy dissipating Blocks and rock riprap are included in the headwall detail.
13-B. We reviewed the increase in size for the last 150' to 200 feet of Line TE-12
to accommodate a connection with the existing 66" RCP. The box would
increase in size from an 8 x 5 PRCB to a 12 x 5 PRCB to maintain equivalent
capacities. This modification does not appear to be cost effective when
considering that both the 66" and the 8 x 5 PRCB may be abandoned in the
future in this area and rerouted along the future railroad ali~cmment to
Grapevine Creek as proposed in the Southwestern Boulevard plans for Park
West Commerce Center.
13-C. The headwall has been skewed to redirect the water more in line with the flow
of the channel.
14. The radius of the sanitary sewer has been revised to 850 feet.
15. We have not extended the water and sewer at this time. We called Mr. Steve
Goram with Pubic Works today to discuss this matter. Mr. Goram was
unavailable until Tuesday, November 3, 1992.
ALBERT H. HALFF ASSOCIATES, INC.
ENGINEERS · SCIENTISTS · SURVEYORS
City of Coppell
November 2, 1992
Page 3
As you know, these improvements were advertised for bid by the City of Coppell,
Friday, October 30, 1992. Bids are to be received Friday, November 13, 1992. Bid packages
are being dism~uted through our office. Please notify us immediately of any discrepancies
in the drawings that may require an addendum. Thank you for your time and consideration.
Very truly yours,
AT~ 2~~OCIATES, INC.
Patrick L. Acker, P.E., R.P.L.S.
cc: Mr. Wayland Threadgill, Catellus Development Corp.
Mr. Sim Ragsdill, City of Coppell