Review and Development of Water Quality Criteria

Many of the Environmental Protection Agency (EPA) criteria were developed up to 20 years ago. Prior to deriving site-specific standards, it is necessary to review and especially to update the national toxicity databases, given the potential for new data to exist since the EPA criteria documents were originally published. GEI has conducted many such reviews as part of our development of site-specific standards for metals and other parameters. In fact, updated criteria developed by GEI for key metals such as zinc and cadmium, have replaced older EPA criteria in Colorado and other states.