waterquality-universityofnorthcarolinawilmington：水的質(zhì)量-北卡羅來那大學(xué)wilming(已修改)
2025-01-24 09:01 本頁面
【正文】 Water Quality Intro by Erick Bjorkland Chesapeake Bay Case Study Brandon Powers Created Wetlands by Carol Ann Dulin Saltwater Case Study by Meghan Barron Clean Water Act In 1972 congress adopted the Clean Water Act, to restore and maintain the chemical, physical and biological integrity of the nation’s waters. Water Quality Allows States,Tribes and Jurisdictions to set their own water quality standards, but requires that they met and include the “fishable and swimmable” goals of the act. Water Quality ?Provides for the protection and propagation of fish, shellfish and wildlife. ?It provides for recreation in and on the water. ?These are the “fishable and swimmable” goals of the Clean Water Act. Water Quality Water quality has three elements. ? Designed uses ? Criteria developed to protect each use ? Antidegradation policy Designated Uses Water Quality Criteria ? Numerical establish thresholds for the physical, chemical and biological attributes required to support a beneficial use. ? Narrative describe, rather than quantify, conditions that must be maintained to support a designated use. Antidegradation policies ? Narrative statements intended to protect existing uses and prevent waterbodies from deteriorating even if their water quality is better than the fishable and swimmable goals of the Act. Summary of Use Support for . Waters ? States reported that 49% of their assessed estuarine waters have good water quality that fully supports designated uses. ? The remaining 51% has some form of pollution or habitat degradation. States Reported That Pollutants: ? Impact aquatic life in 11,391 square miles (about 52%) of estuarine waters. ? Restrict fish consumption in 6,255 square miles ( about 48%) of estuarine waters. ? Restrict shellfish harvesting in 5,288 square miles ( about 25%) of estuarine waters. ? Violate swimming criteria in 3,245 square miles ( about 15%) of estuarine waters. Pollutants ? Pollutants e from point and nonpoint sources (NPS). ? NPS include stormwater, diffuse agricultural runoff from pastures and rowcrops, concentrated agricultural wastes from feedlots, runoff from building sites, forestry activities, drainage from mining activities. ? NPS contribute 65% of the total pollution load to . inland surface waters (Olson). Pollutants ? Most often there is more than one pollutant impacting a single estuarine waterbody. ? There are more square miles of estuarine waters polluted by metals than any other pollutant or stressor. Mercury is the primary metal pollutant. ? The largest number of impaired streams and rivers is in the Appalachian region. This is caused by the leaching of heavy metals. Pollutants in Estuaries ? Pesticides pollute 5,985 square miles. ? Oxygen depletion from anic wastes impact 5,324 square miles. ? Pathogens impair4,764 square miles. Pesticide pollution ? The greatest potential for pesticide contamination is on the eastern seaboard. ? Runoff is the major mode of transportation but 1030% e from aerosol drift. ? Still getting DDT from S. America via this mode. ? Pesticides are even being detected in groundwater (atrazine, aldicarb and alachor) Nitrogen and Phosphorous ? Large amounts of N and P can cause to much vegetation growth and decay, leading to water chemistry changes and limited vegetation diversity. ? Depending on the wetland, one or the other can act as a limiting agent for algal growth. State Reported
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