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ST9301-CS 960718oou L; r' uTIlffles ENGINEERING 320 East Jefferaon Dallas, Taxaa 75203 (214) 948-4560 July 18, 1996 Abel Saldana, P.E. Dallas County Public Works 411 Elm Street, 4th Floor Dallas, Texas 75202 Re: Sandy Lake Rd from McArthur Blvd to Coppell E. City Limits Dear Mr. Saldana: Proposed paving and drainage plans for the subject project in the City of Coppell have been reviewed. We offer the following comments regarding impact on Dallas Water Utilities Department facilities: 1. Sheet 6: The proposed paving cut of 4.5' leaves only 2.5' of cover over the existing 30" water main, which is excessively shallow. Please raise the grade between sta. 17+00 & 19+00 by a minimum of one foot. 2. Sheet 12: The 30" water main horizontal gate valve access manhole and bypass valve (at sta. 46+20, 20' left) will require a routine adjustment and an appurtenance adustment to the final paving grade. 3. Sheet 12: The ongoing 60" Irving water main construction shown in the profile appears to conflict with the existing 30" DWUD water main. However, their (Irving's) plans show this 60" water main to be at a much lower elevation. Please review and provide the necessary correction. 4. Sheet 13: The 60" water main pitot manhole at paving sta. 49+70, 60' left will require an appurtenance adjustment to match the fill slope grade outside of pavement. 5. Sheet 14: The 60" water main air valve manhole and vent (at pav. sta. 55+40, 40' left) will require an appurtenance adjustment to match the fill slope grade. 6. Sheet 16: The recessed inlet at pav. sta. 65+30, 45' left conflicts with the access manhole for the operating nut on the 66" horizontal gate valve. Please move the sag point or use a regular inlet rather than a recessed inlet. The water manhole will require an appurtenance adjustment to final grade. A city utility providing Dallas with water purification and distribution, waste water collection and treatment 7. Sheet 33: The proposed 72"RCP storm drain at pav. sta. 46+00, 15'right clears the existing 60" steel water main by only 0.38 feet. On your plans, please annotate the elevation of the top of the water main as 437.6+; also add a caution note to this sheet to warn the contractor of the close vertical proximity of this water transmission main. 8. Ail paving sheets: Please show all proposed street light locations in the median so we can determine their impact on the existing 30" water main. It is our understanding that the street lights in the adjacent Sandy Lake Road project (from Denton Tap to MacArthur) utilize 24" diameter drill shafts ten feet deep, which conflict with the existing 30" water main. Unless the County redesigns or adjusts to clear the design conflicts as noted under items #1 & 6 and possibly #8, a contract will be utilized for the water main relocations necessary to alleviate conflicts. Also, the County will provide funding for any water relocations due to drainage conflicts. In the event that all conflicts are resolved, Dallas Water Utilities Department Construction Services will perform the routine and appurtenance adjustments listed under items #2, 4, 5 & 6, rather than implementing a contract to perform these minor items. Should you have any questions, feel free to contact Jun Battad at 948-4591. Brian H. Cowan, P.E. Project Manager Relocations J. Milstead J. Battad A. Blair-Robinson C. Long File 96200MF2.SandyEast