With less than a year remaining until water systems are required to meet the loweredarsenic maximum contaminant limit (MCL) of 10 g/L, a number of utilities are currently deciding how to meet thisrequirement. Luckily, several technologies are capable of treating arsenic to low levels.Yet the performance of all of these technologies is influenced by co-occurringcontaminants. While several attempts have been made to nationally quantify the levels atwhich various contaminants co-occur with arsenic (USEPA 1999), these efforts havebeen limited in scope and not focused on parameters which are known to impacttreatment performance. This paper reports on the results of an American WaterWorks Association Research Foundation (AwwaRF) sponsored study which determinednational arsenic occurrence and evaluated the composition of the water quality matrix inwhich arsenic occurs. Using this data, the range of water quality matrices which shouldbe used to evaluate arsenic treatment technologies has been developed and the suitabilityof the existing National Science Foundation (NSF) challenge water has been evaluated.The objective of the analysis was to develop a first order estimate of arsenic occurrencein groundwater and determine the co-occurrence of contaminants which can influence theperformance of arsenic treatment systems. Includes 5 references, tables, figures.
Keywords: Arsenic; Performance; Water Quality; Groundwater
