AWWA WQTC69466

The objectives of this project were to identify surrogate parameters and indicator compounds for wastewater-derived chemical contaminants that might be useful in the assessment of indirect potable reuse systems; and, to validate the ability of chosen surrogates and indicators to predict the occurrence and removal of wastewater-derived contaminants in indirect potable water reuse systems. The approach for monitoring wastewater-derived contaminants developed in this study utilized a combination of surrogate parameters and indicator compounds tailored to monitor the removal efficiency of individual unit processes comprising an overall treatment train. Selecting multiple indicators representing a broad range of properties will allow accounting for compounds currently not identified ("unknowns"), and new compounds synthesized and entering the environment in the future (i.e., new pharmaceuticals) provided they fall within the range of properties covered. The underlying concept is that absence or removal of an indicator compound during a treatment process would also assure absence or removal of unidentified compounds with similar properties. Thus, a system failure will be indicated by poor removal of the indicator compound while normal operating conditions will be indicated by partial or complete compound removal. This concept was validated through monitoring efforts at pilot- and full-scale water reuse facilities. Indicator compounds and surrogate parameters identified were classified into categories of different treatability and for each treatment process, a master list of indicator compounds was provided by recruiting compounds, for which analytical methods existed, from the final list of viable indicator compounds present in secondary or tertiary treated wastewater effluents. As expected, results of these efforts also revealed that surrogate parameters are not strongly correlated with the removal of indicator compounds occurring at ng/L-level concentrations. Includes reference, table.