Full Description

The realization of the value of reclaimed water as a substitute for potable waterfor reuse applications such as turf irrigation has changed the wastewatermanagement philosophy of the Sub-Regional Operating Group (SROG) Cities in thegreater metropolitan Phoenix, Arizona area. This philosophy has shifted from eachSROG city sending all their wastewater for treatment at the regional SROG-owned91st Avenue Wastewater Treatment Plant (WWTP) to treating a greater quantity oftheir wastewater at smaller, decentralized water reclamation plants (WRPs)located near the point of reuse. A number of small to medium size WRPs have beenconstructed and more are planned in the next 10 years by the SROG members. Forreasons of economics and/or aesthetics, these WRPs do not have on-site facilitiesto treat the residuals from the wastewater treatment process. The WRPs presentlydischarge concentrated residual streams to the SROG sewer interceptorsdischarging to the 91st Avenue WWTP. Regional planning indicates the practice ofWRP residuals conveyance to the 91st Avenue WWTP will continue and increase. SROGrealized that the potential adverse impacts of these residuals on the existingtreatment processes at the 91st Avenue WWTP needed to be considered. In 1995,SROG retained Greeley and Hansen to perform a study to quantify the impact of WRPresiduals on the 91st Avenue WWTP. The study investigated the impacts of WRPresiduals on 91st Avenue WWTP wastewater treatability, treatment plant capacity,and treatment costs associated with flow and strength. The results of the studyshowed that there are additional costs that need to be taken into considerationwhen implementing a large scale water reclamation system. Those additional costconsiderations are presented and discussed. Another important aspect of the studywas the capital cost apportionment to the SROG cities to meet their WRP residualimpact and treatment needs. Prior to the study, capital cost apportionment forimprovements at the treatment plant were based solely on flow capacity. The studyrecommended that a new cost apportionment methodology based on flow and strengthloading be adopted. Includes reference, tables, figure.

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Edition: Vol. - No. Published: 01/01/2000 Number of Pages: 9File Size: 1 file , 110 KB