AWWA WQTC62506

United Water New Jersey (UWNJ) is a privately-owned water utility that providesservice to about 800,000 residents in 60 municipalities within Bergen and HudsonCounties in Northern New Jersey. UWNJ owns and operates the water system whichincludes water supply reservoirs, treatment facilities, storage and pumping facilities, andtransmission and distribution system piping. Water is supplied primarily from theHaworth Water Treatment Plant (WTP) located in Haworth, New Jersey, which is adirect filtration plant with pre-ozonation for disinfection and oxidation. The plant iscomprised of alum and polymer addition for coagulation, ozone for oxidation, followedby flotation, direct filtration and ultimately chloramination for disinfection beforeentering the distribution system.The Oradell Reservoir serves as the source of supply for the Haworth Water TreatmentPlant. The quality of the water in the Oradell Reservoir has been deteriorating over the past 5 years. Runoff from surrounding developed areas and the introduction ofsupplemental water from the Wanaque South project has led to extensive eutrophicationof the reservoir. The reservoir is also subject to periodic episodes of extremely poorwater quality. These conditions generally manifest themselves during dry periods in thesummer and in times of drought. It is these episodes that present a very significantchallenge to the treatment process. Consequently, UWNJ has pursued alternatives tomanage the Oradell Reservoir supply to enhance the raw water quality and to minimizethe challenges to the Haworth treatment processes. The following reservoir management options were identified and evaluated for theOradell Reservoir:construction of a redundant intake structure in the Oradell Reservoir;construction of a pipeline for direct transmission of Wanaque South water to theHaworth Treatment Plant;aluminum sulfate inactivation of phosphorus in the Wanaque South water prior todischarge to the reservoir;implementation of alternative algaecide/modified algaecide applicationtechniques;construction of a curtain wall at the Wanaque South inlet to the reservoir; and,installation of a reservoir aeration system.Based on evaluations of these alternatives, a reservoir aeration system was recommended to stabilize raw water quality in theOradell Reservoir. More specifically, the system was designed to:stabilize pH fluctuations;maintain separation of the surface and bottom layers by thermal stratification tofacilitate depth-selective withdrawal, while managing the consequences of anoxiain the deep layer;reduce the release of nutrients, metals and organics from reservoir sediments; reduce the intensity of blue-green algal blooms by disrupting their habitationpatterns;enhance competition within the algal community so as to favor beneficialorganisms (zooplankton) and non-nuisance algae (diatoms and green algae); and, reduce reliance on algaecide applications for control of nuisance algae. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2005

Number of Pages:

8

File Size:

1 file , 410 KB