Arsenic is a toxic chemical element that is found naturally in the Earth's crust in soil, rocks, and minerals. The levels of arsenic found in drinking water systems and private water supplies across the United States vary widely. Some people could experience skin damage or problems with their circulatory system and may have an increased risk of getting cancer if they drink water that contains arsenic in excess of the EPA standard over many years.

The maximum contaminant level (MCL) for arsenic is 10 mcg/L.

Measure Description:

  • Arsenic Tests is the number of Arsenic tests conducted on private water well.
  • Elevated Arsenic Tests >= 10 mcg/L is the number of Arsenic tests conducted on private water wells with a result greater than or equal to 10 micrograms per liter.
  • Percent Elevated Arsenic Tests is the percent of Arsenic tests conducted on private water wells that were elevated.
  • The Average Arsenic Level is the median result of the Arsenic tests conducted on private water wells.
  • The 95th Percentile Arsenic Level is the level at which 95% of the Arsenic tests conducted on private water wells will fall below.
  • The Maximum Arsenic Level is the highest Arsenic test result conducted on private water wells.

View data visualization