Description: This is a static dataset representing the Arizona streams that were assessed for the 2018 Water Quality Assessment Reports. Dataset is owned by the Surface Water Quality Improvement Section. Per the EPA, "Every two years states are required to submit Water Quality Assessment Reports under Sections 305(b) and 303(d) of the Clean Water Act describing the condition of waters in the state. Waters are assessed as impaired when an applicable water quality standard is not being attained. Impaired waters require a total maximum daily load (TMDL) or alternative restoration plan to reduce pollutant loadings and restore the waterbody." Attributes in this dataset indicate which of the following assessment categories each waterbody is listed:Category 1 – Attaining all designated usesCategory 2 – Attaining some designated uses, and insufficient or no data information to determine if remaining uses are attainedCategory 3 – Insufficient or no data and information to determine if any use is attainedCategory 4- Impaired or threatened for one or more uses but not needing a TMDL because –a) TMDL has been completedb) Expected to meet standardsc) Not impaired by a pollutantCategory 5 – Impaired or threatened by pollutant(s) for one or more designated uses and requiring a TMDL. These are the waters entered onto a states’ 303(d) list.Data provided in this indicator help demonstrate:The extent to which a state is assessing its waters for nutrient-related parameters,The extent of nitrogen and phosphorus pollution in the state, andThe extent to which the state is working towards restoring nutrient-impaired waters by developing TMDLs or alternative restoration plans.For more information see: https://www.epa.gov/nutrientpollution/waters-assessed-impaired-due-nutrient-related-causes
Copyright Text: Arizona Department of Environmental Quality (ADEQ), Water Quality Division, US Environmental Protection Agency (EPA)