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In Maryland, most of the northern Rock Creek watershed has good to excellent water quality, according to studies conducted by the county government. In 2004, to preserve water quality in partially developed areas, the county imposed restrictions on development (i.e., designation of "Special Protection Areas") in parts of this sub-watershed. [6]
Aquifers of the United States Withdrawal rates from the Ogallala Aquifer.. This is a list of some aquifers in the United States.. Map of major US aquifers by rock type. An aquifer is a geologic formation, a group of formations, or a part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to groundwater wells and springs.
In 2015, the USGS unveiled the topoView website, a new way to view their entire digitized collection of over 178,000 maps from 1884 to 2006. The site is an interactive map of the United States that allows users to search or move around the map to find the USGS collection of maps for a specific area.
The Safe Drinking Water Act requires the US EPA to set standards for drinking water quality in public water systems (entities that provide water for human consumption to at least 25 people for at least 60 days a year). [3] Enforcement of the standards is mostly carried out by state health agencies. [4]
In general, water quality has improved nationwide since 1972, but not all pollution has been eliminated. Between 1972 and 2001 there was a 12 percent increase in the number of waterways that are safe for fishing. [102] Data supporting this finding is limited; only 19 percent of the United States’ waterways had been tested for contamination. [104]
The organization was created by merging the three existing NOAA National Data Centers with the goal of streamlining the collection and preservation of environmental data. The merger, which came in response to increasing demand for environmental information, was intended to make NOAA's data more useful through the application of consistent data ...
Aquifers of the United States are organized by national principal aquifer codes and names assigned by the National Water Information System (NWIS). Aquifers are identified by a geohydrologic unit code (a three-digit number related to the age of the formation) followed by a 4 or 5 character abbreviation for the geologic unit or aquifer name. [10]
All rivers with average discharge more than 15,000 cubic feet per second are listed. Estimates are approximate, because data are variable with time period measured and also because many rivers lack a gauging station near their point of outflow.