In addition, the problems caused by mercury and selenium are generally only found in localized areas and are heavily influenced by the water chemistry and physical conditions of the specific systems. The State Health Director has the authority to close waters that may be at risk for toxic contamination. In addition, the N.C. DENR oversees a routine monitoring program that evaluates permitted effluents to ensure the safety of the waters. If there is a catastrophic event such as a spill, the state closes a waterbody immediately. Otherwise, criteria are in place for the protection of aquatic life.
Humans only have minimal contact with surface waters during recreation.
Therefore, if we protect our waterways for the aquatic life that lives there and has constant exposure, we can ensure safety for human exposure. The sampling and analysis of water, sediment, fish and shellfish for toxic contaminants is expensive and time consuming. Therefore, the N.C. DENR and the N.C. DHHS work together to determine if metals or other toxic contaminants are at levels that will adversely affect human health. The N.C. DHHS ultimately issues the fish and shellfish consumption advisories for recreationally caught fish species. These advisories inform the public that high concentrations of a specific contaminant have been found in fish or wildlife from a given area, and make recommendations for limiting or avoiding consumption of this species.