1983-10-26 Workshop Meeting - Laserfiche WebLink

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e e ~ -- , . TurnerCollieC6Braden Inc. PO BOX 13089 HOUSTON. TEXAS 77219 5757 WOODWAV 713 78().4100 TELEX 774185 TCB HOU July 29, 1983 .,. Mr. Jerry L. Hodge Director of Public Works City of La Porte P. O. Box 1115 La Porte, Texas 77571 Re: Wastewater Treatment Plant Engineering Analysis Turner Collie & Braden Job No. 13-02000-003 Dear Mr. Hodge, In accordance with your letter of authorization dated June 21, 1983 to perform detailed hydraulic and mechanical analyses of several problem~ at the wastewater treatment plant, we have completed our evaluation and are presenting our findings and recommendations in this letter report. We plan to meet with you on Tuesday, August 2 to present this report and discuss our recommendations. 1. HEADWORKS - confirm adequacy of l8-inch sluice gate for bypass of aerated grit chamber ~. We ~ave analyzed the hydraulics of the bypass channel in the headworks based on the following assumptions. a. future average daily flow = 3.75 mgd b. future peak flow = 2.5 times ADF = 9.375 mgd c. return sludge flow rate = 3.75 mgd d. five remaining gates in headworks (one at entrance to grit chamber, two in each of the two bar screen channels) are changed from l8-inch square sluice gates to 36-inch wide full height openings with slide gates At the future average daily flow rate of 3.75 mgd and with the five other gates modified as described above, our cal- culations indicate that the maximum water surface elevation in the head~orks will be 24.35 if the grit chamber is out of service and all the flow is being bypassed. With the top of wall elevation of 27.00, there will be 2.65 feet of freeboard under average daily flow conditions. We consider this to be acceptable. o ;;; '" -,..,.-' .I (O!l;~LlTl"'c. lNGINURS . TlllAS AlJSTINDALlAS'(l I-ASO'HOUS10'-' I.".; Ilk 'iL'!.: COLORI\DO DCN\'lR/('RAN[t 1l'1I;UIO"