Water Quality: EDGEMONT, SD

Long-term exposure increases risk of skin, bladder, and lung cancers, as well as cardiovascular and neurological effects.

Common source: Natural rock deposits, agricultural pesticides, industrial waste

EPA limit: 0.010 mg/L (10 ppb)

Cardiovascular damage and reproductive effects with long-term exposure; potential endocrine disruptor.

Common source: Runoff from corn and other crop herbicide applications

EPA limit: 0.003 mg/L (3 ppb)

Increases blood pressure and causes cardiovascular effects with long-term exposure.

Common source: Natural rock deposits, oil drilling operations, coal power plant waste

EPA limit: 2 mg/L

Kidney damage with long-term exposure; classified as a probable human carcinogen.

Common source: Corrosion of galvanized pipes, natural deposits, industrial waste, fertilizers

EPA limit: 0.005 mg/L (5 ppb)

Eye and nose irritation at high levels; long-term exposure above the MCL may cause liver and kidney damage.

Common source: Water treatment disinfectant added to kill harmful microorganisms

EPA limit: 4.0 mg/L (MRDL — Maximum Residual Disinfectant Level)

Hexavalent chromium (Cr-VI) is a known human carcinogen linked to lung and stomach cancers.

Common source: Natural geological deposits, industrial pollution, electroplating discharge

EPA limit: 0.1 mg/L total chromium

At low levels prevents tooth decay; excessive levels cause dental and skeletal fluorosis.

Common source: Natural deposits, water fluoridation programs, some fertilizers

EPA limit: 4.0 mg/L (secondary standard: 2.0 mg/L)

Known human carcinogen strongly associated with leukemia and other blood cell cancers.

Common source: Industrial discharges, gas station leaks, chemical plant emissions

EPA limit: 0.005 mg/L (5 ppb)

Damages kidneys and the central nervous system; causes developmental harm to fetuses and infants.

Common source: Natural deposits, industrial discharges, landfill runoff

EPA limit: 0.002 mg/L (2 ppb)

Hair loss, nail brittleness, and nervous system damage at elevated concentrations.

Common source: Natural geological deposits, mining discharges, oil refinery waste

EPA limit: 0.05 mg/L (50 ppb)

Total trihalomethanes are linked to increased risk of bladder cancer and adverse reproductive outcomes.

Common source: Reaction of chlorine disinfectants with naturally occurring organic matter in water

EPA limit: 0.080 mg/L (80 ppb)

Haloacetic acids are associated with increased cancer risk and potential reproductive and developmental effects.

Common source: Reaction of chlorine disinfectants with organic matter in treated water

EPA limit: 0.060 mg/L (60 ppb)