Ground Water
Quality Standards

What are the Ground Water Quality Standards for Discharges in South Dakota?

Ground water with a concentration of total dissolved solids (TDS) of less than 10,000 mg/L is classified as having the beneficial use of drinking water. Water under this classification has numeric ground water standards under ARSD 74:54:01:04 (opens in new tab) .

These standards list the maximum concentrations of contaminants allowed in ground water. If ambient concentrations are higher than these standards, the ambient ground water quality becomes the maximum concentration allowed. Ambient conditions are determined as outlined under ARSD 74:54:02:18 (opens in new tab) .

The numeric ground water standards are not an exhaustive list of all potential contaminants. If a toxic pollutant (opens in new tab) is present in ground water but does not have a numeric standard, ARSD 74:54:01:05 (opens in new tab) applies. This rule requires the pollutant to be non-detectable until a maximum contaminant level or health advisory level is established by the United States Environmental Protection Agency (EPA).