Description: This layer provides the polygonal areas for all impoundments in the state of Maryland for mercury assessments from the 2016 Integrated Report. Assessment information includes all assessments captured within Maryland's 2016 Integrated Report and are generally displayed according to Categories: impaired and require a TMDL (Category 5), impaired and have a TMDL approved by the Environmental Protection Agency (EPA) (Category 4a), impaired but have exemptions from needing a TMDL (Categories 4b-4c), insufficient data is available to determine if water is meeting all standards (Category 3), are meeting some standards (Category 2), and waters that are meeting all standards (Category 1).
Service Item Id: 4ddbf8fec31f4637963884363be2b092
Copyright Text: The Maryland Department of the Environment (MDE) acknowledges the U.S. Geological Survey (USGS) which created the National Hydrography Dataset (NHD). The NHD serves as the derivedpolygonal areas for this file and was used to geospatially describe most of Maryland's impoundments; however, MDE had to manually create the boundaries for some impoundments due to the inaccuracies within the NHD. The Maryland Department of the Environment Science Services Administration linked the Integrated Report assessment information to the NHD and then preserved this pollutant-specific layer.