Specifications include, but are not limited to: DWQ and cooperators collect water samples from (GSL) to characterize trends and potential ecosystem health risks posed by trace metals in GSL waters. The analytical laboratory will be responsible for providing accurate and precise quantitative measurements of arsenic, cadmium, copper, total mercury, methlymercury, lead, selenium, and zinc in all water samples. Results shall be provided in mass to volume concentration units as per specification in Table 1. The laboratory shall also conduct and provide results for all appropriate quality control/quality assurance procedures as specified by analytical methods. Annual monitoring includes up to 64 water samples including fresh, brackish, and hypersaline (up to and potentially exceeding 20% salinity) waters plus field blanks and replicates. Hypersaline GSL waters can have significant impacts on laboratory preparation, analytical procedures, and results. The laboratory shall have demonstrated experience conducting trace metal analyses in hypersaline GSL waters and demonstrated capability to quantify trace metal concentrations across a wide range of salinities (0-20+ %) under consistent and repeatable methods with adequate quantification limits. Laboratory detection limits must meet the data quality objectives in Table 1. Quotes from laboratories shall include applicable quantification limits for each constituent under proposed analytical methods. The required analysis of hypersaline water samples from GSL include the following: Total Hg by EPA Method 1631E MeHg via EPA Method 1630 Seawater prep and analysis for LL selenium (Se) EPA Method 1640, Mod. with Column Separation Total Rec. As Analysis by ICP-QQQ-MS EPA 1638, Mod. with In-bottle Digestion Seawater prep and analysis for Cd, Cu, Pb, and Zn EPA Method 1640 Mod. with Column Chelation
