A pilot-scale study was conducted under field conditions to determine the potential role of soil aquifer treatment (SAT) in renovating wastewater effluent to potable water quality. Instrumented test basins were used to evaluate water quality transformations through the upper vadose zone during effluent recharge. Samples of either chlorinated secondary or reclaimed (tertiary) effluent were obtained from suction samplers situated in two separate test basins at depths of up to 6.1 m (20 ft). Samples were characterized according to dissolved organic carbon (DOC), a measurement of dissolved organic matter, and total organic halide (TOX), a measurement of chlorination byproducts. Average DOC and TOX removals were 50% and 40%, respectively, for secondary source water; slightly higher removals were observed for tertiary source water. Performance was found to be affected by operational factors; variations in DOC and TOX removal were observed within a wetting cycle as well as from cycle to cycle. Significant nitrification occurred during drying cycles between flooding cycles, resulting in an initial wave of high nitrate in the percolating water. Water Environ. Res., 65, 726 (1993).Southwestern municipalities faced with impending water shortages recognize the need to reuse treated effluent. Recharge and recovery of effluent balances out seasonal needs for nonpotable irrigation water. Also, when combined with soil aquifer treatment (SAT), groundwater recharge becomes an adjunct to standard treatment technologies, potentially leading to potable reuse. A major concern in SAT schemes is the fate and transport of trace organics during deep percolation of wastewater. A secondary concern relates to nitrogen species. This paper will review the results of a short-term study of fate and transport processes during deep percolation of chlorinated secondary and tertiary effluent applied to instrumented pilot-scale test basins at Tucson, Arizona, and discuss implications for potable water recovery. ObjectivesThe general objective of the research reported below was to determine the fate of wastewater effluent organic matter, as measured by dissolved organic carbon (DOC), and chlorinated organics, as measured by total organic halide (TOX) through a SAT system. Specific objectives were to:• delineate the potential role of SAT in the potable reuse of effluent;• develop well-characterized, instrumented, pilot-scale test basins to evaluate SAT through the vadose zone;• develop time-dependent depth profiles of DOC and TOX;• evaluate the effects of wetting/drying cycles on performance and, within a given wetting cycle, evaluate the effects of time;• contrast secondary versus tertiary effluent as a source water, and provide a qualitative understanding of sorption versus microbiological phenomena; and• define variations in infiltration rates from cycle to cycle and within a given cycle.

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Aging pipeline infrastructure and limited funding for pipeline maintenance efforts make condition assessment an essential function in managing large-diameter pipeline assets for water agencies. Many of these pipelines are prestressed concrete cylinder pipe (PCCP) and, therefore, are subject to an elevated risk of failure attributable to prestressed wire breaks and continued corrosion of steel cylinders. Major water agencies must emphasize assessing and monitoring the PCCP pipelines' condition. Condition assessments should include: (1) determining the pipeline's structural condition by considering the number of wire breaks and the external and internal loads on the pipeline, (2) ranking the pipeline's condition, and (3) prioritizing maintenance needs.Based on past research supported by the PCCP Users Group and the American Concrete Pressure Pipe Association (ACPPA), the use of risk curves in PCCP asset management has been successfully demonstrated in the existing literature. However, given the complex structural analysis procedures required for the design of PCCP and the development of appropriate representations for wire break conditions, analysis tools for creating such risk curves have not been widely developed for practical applications.This paper presents a Microsoft Excel spreadsheet-based risk assessment tool developed by the primary author to perform structural analyses and to create risk curves based on condition assessment findings, including wire breaks detected through electromagnetic data and corrosion damage to cylinders obtained from internal and external pipeline inspection. The spreadsheet tool uses the structural analysis approach outlined in the current American Water Works Association (AWWA) C304 standard and historical C301 and C304 standards. The paper also presents an example of the tool's application to a risk-based condition assessment program.