Power Plant Wastewater Sampling and Analysis Methods Guidance Project, Electric Power Research Institute (EPRI)

In anticipation of the more stringent Effluent Limitations Guidelines (ELG) under the National Pollutant Discharge Elimination System (NPDES) that were to be implemented in 2018, EcoChem collaborated with a group of power plants and laboratories to research best practices for sampling and analysis of flue gas desulfurization (FGD) wastewaters for arsenic and selenium.  Procedures were developed to minimize contamination, ensure sample stability, and measure concentrations both precisely and accurately at the lower levels dictated by the new regulations. Emphasis was placed on field sampling techniques, sample preservation, sample digestion, interference reduction techniques, and QA/QC. A multi-laboratory study was conducted to evaluate the impact of different sample preservation options and various ICP-MS interference reduction techniques. The final report recommended enhanced procedures for the collection and analysis of regulated wastewaters that will improve the accuracy of compliance monitoring.