The realization of the value of reclaimed water as a substitute for potable water
for reuse applications such as turf irrigation has changed the wastewater
management philosophy of the Sub-Regional Operating Group (SROG) Cities in the
greater metropolitan Phoenix, Arizona area. This philosophy has shifted from each
SROG city sending all their wastewater for treatment at the regional SROG-owned
91st Avenue Wastewater Treatment Plant (WWTP) to treating a greater quantity of
their wastewater at smaller, decentralized water reclamation plants (WRPs)
located near the point of reuse. A number of small to medium size WRPs have been
constructed and more are planned in the next 10 years by the SROG members. For
reasons of economics and/or aesthetics, these WRPs do not have on-site facilities
to treat the residuals from the wastewater treatment process. The WRPs presently
discharge concentrated residual streams to the SROG sewer interceptors
discharging to the 91st Avenue WWTP. Regional planning indicates the practice of
WRP residuals conveyance to the 91st Avenue WWTP will continue and increase. SROG
realized that the potential adverse impacts of these residuals on the existing
treatment 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 WRP
residuals on the 91st Avenue WWTP. The study investigated the impacts of WRP
residuals on 91st Avenue WWTP wastewater treatability, treatment plant capacity,
and treatment costs associated with flow and strength. The results of the study
showed that there are additional costs that need to be taken into consideration
when implementing a large scale water reclamation system. Those additional cost
considerations are presented and discussed. Another important aspect of the study
was the capital cost apportionment to the SROG cities to meet their WRP residual
impact and treatment needs. Prior to the study, capital cost apportionment for
improvements at the treatment plant were based solely on flow capacity. The study
recommended that a new cost apportionment methodology based on flow and strength
loading be adopted. Includes reference, tables, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 110 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 9 |
| Published : | 01/01/2000 |
