Case Study Development of Site-Specific Ambient Water Quality Criteria for Cadmium, Copper, Lead, and Zinc in Freshwater, St. Croix River, Maine By Patrick O. Gwinn, Principal, Toxicology, Health, and Ecological Sciences Published January 7, 2022 Key Contact Mr. Patrick Gwinn has more than 30 years of environmental consulting experience, providing a broad base of expertise in the... Full bio