1984-05-22 - Laserfiche WebLink

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I I , 2 A SURCHARGE FOR WASTE WHICH ARE KNOWN TO HAVE A STRENGTH HIGHER THAN NORMAL FOR WASTEWATER. IT IS IMPORTANT TO DETERMINE ACCURATELY THE VOLUME OF WASTEWATER FLOW DISCHARGED BY EACH MUNICIPALITY IN THE ~1ETROPOLITAN {J,REA. IN M)ST CASES.. INDUSTRIES ARE BILLED DIRECTLY FOR THIS SURCHARGE, As I HAVE PREVIOUSLY STATED.. THERE ARE PRESENTLY 101 MUNICIPALITIES SERVED BY THE COMMISSION FACILITIES, THESE FACILITIES VARY IN SIZE AND WASTEWATER FLOW VOLUME FR()f'~ A FEW MILLION GALLONS PER YEAR TO THE CITY OF MINNEAPOLIS W1ICH DISCHARGES ABOUT 25% OF THE TOTAL WASTEWATER FLOW OF 93..781 MILLION GALLONS PER YEAR. THE COMMISSION HAS METERS IN 160 LOCATIONS TO MEASURE INTERCOMMUNITY WASTEWATER FLOW VOLUMES. THESE METERS ARE LOCATED IN ~CC INTERCEPTORS AT TREATI1ENT PLANTS A.ND LOCAL TRUNK SEWERS AT OR NEAR THE CORPORATE LIMITS OF A MUNICIPALITY. A FLOW MEASUREMENT IS TvlADE AT EACH METER EVERY 15 SECONDS AND THE RATE OF FLOW IS TRANS- MITTED VIA TELEPHONE TO OUR COMPUTER OR DATA LOGGER AT THE SENECA VfASTS'/ATER TREAT- MENT PLANT WHICH IS LOCATED IN EAGAN. THE J5 SECOND SIGNALS ARE COt~PUTED EACH 15 MINUTES C 60 SIGNALS OF WH I CH THE 10 HIGHEST AND 10 LOWEST ARE DISCARDED) TO PROV IDE A PERMANENT RECORD OF FLOW VOLUME EACH DAY DUR ING THE YEAR . To ASSURE THE ACCURACY OF THE MEASURED FLOW" EACH METER IS CALIBRATED QUARTERLY ORMJRE OFTEN IF NEEDED BY CREWS WHO HAVE EXPERTI SE IN SERVI C ING FLOW ~RS. WASTEWATER FLOW I S NOT UN I FORM I N QUANTITY OR QUALI TY AND ITS RATE OF FLOW AND TOTAL VOLUME IS DIFFICULT TO MEASURE. PEAK WASTEWATER FLOWS VARY FROM 1.7 TO 4.0 TIMES THAT OF THE AVERAGE DAILY WASTEWATER FLOW, THEREFORE.. IT IS NECESSARY TO PROVIDE METERS WHICH CAN MEASURE THE RANGE OF MItJI~1U~1 AND Ml\XIMUM FLO\^!S IN THE SYSTEM. IN GRAVITY FLOW SEWERS IT IS VERY DIFFICULT OT MEASURE LOW FLOvlS C2CX},(0) GPD" GALLONS PER DAY OR LESS) ACCURATELY WITH A CONTINUOUS FLOW MEASURING DEVICE. THERE ARE NEARLY 100 OF SUCH LOW VOLUt-1E INTERCOM'-1JNITY FLOWS w-lICH MUST BE ESTI- MATED BASED ON savE PERIODIC FLOW MEASUREMENT" WATER DATA" AND NlJv1BER AND TYPE OF CONNECTIONS IN THE AREA OF SERVICE. IT IS NECESSARY TO HAVE THE ASSISTANCE OF COMMUNITIES TO FURNISH DATA ON WATER USE AND THE NUMBER AND TYPE OF SEWER CONNECT- IONS TO DETERMINE THIS UNMETERED FLOW VOLUME.