AWWA WQTC63989

The New Jersey Department of Environmental Protection (NJDEP) recognized the need for proactive and innovative steps to safeguard the water supplies in New Jersey when the state experienced a record-breaking drought in 2002. Utilizing the State 2005 fiscal year budget, the Legislature made $35 million in funding monies available from a 1981 Water Supply Bond Fund in 2004. A call for funding proposals was released to water purveyors, wastewater dischargers and agricultural users throughout the state for Water Supply Demonstration Projects. Due to increasing pressures on potable water resources in its service area, Logan Township Municipal Utilities Authority (LTMUA) hired Metcalf & Eddy (M&E) to develop a proposal to design an indirect potable reuse treatment and injection system to replenish an aquifer system which serves as the primary potable water source for the region. This was also based on an upgrade to the existing wastewater treatment plant (WWTP) the LTMUA was planning. Based on the proposal LTMUA received, one of the 23 grants was awarded; a $4.1 million grant for the first indirect potable reuse (IPR) project in the northeastern US. The treatment train for the Advanced Water Treatment Facility (AWTF) at LTMUA was selected based on an evaluation of the alternatives, with finished water quality goals set to meet or exceed drinking water standards. The train incorporated membrane bioreactors (MBR) which provide a high sludge age and a physical barrier to microbes and organics; reverse osmosis (RO) to remove dissolved contaminants and provide a second microbial barrier; and, an advanced oxidation process (AOP) with ultraviolet (UV) light and hydrogen peroxide to provide final disinfection as well as oxidation of any ultra-low molecular weight compounds. The product will be 750,000 gallons per day (gpd) of water that meets or exceeds drinking water quality standards prior to injection. The injected product will blend with native groundwater for approximately three years. The proposed treatment train was pilot tested at LTMUA from August through November 2005 to confirm performance, develop design criteria and build operator understanding of the proposed processes. During the pilot testing period M&E conducted extensive sampling for a wide range of water quality parameters as flow passed through the treatment train. Performance was monitored continuously for each of the treatment processes through pilot plant data acquisition and control systems. Most water quality parameters were monitored daily. In addition, several large-scale water quality testing programs were performed throughout the study, including testing the treated water for the full range of Primary and Secondary Drinking Water Regulations and NJDEP's Testing Requirements for Organic Toxic Pollutants for discharges to groundwater. It also included sampling by M&E, in partnership with the US Geological Survey (USGS), of both the pilot plant and the existing full-scale WWTP for chemical and in vitro analyses of a broad suite of trace organic wastewater contaminants including natural and synthetic hormones, household and industrial chemicals and commonly used pharmaceutical and personal care products. A description of the proposed system upgrade and the pilot study findings are the primary focus of this paper. Includes tables, figures.