74:51:01:44Criteria

for domestic water supply waters. The criteria of parameters for domestic water supply waters and their allowable variations that are not included under § 74:51:01:55 and Appendix B, unless set under § 74:51:01:24, are as found in the following table: Parameter Criteria Unit of Measure Special Conditions Total dissolved solids < 1,000 mg/L 30-day average < 1,750 mg/L daily maximum Nitrates as N < 10 mg/L daily maximum pH > 6.5 - < 9.0 units Total Coliform < 5,000 /100 mL geometric mean of a minimum of 5 samples during separate 24-hour periods for a 30-day period and may not exceed this value in more than 20 percent of the samples examined in the same 30-day period < 20,000 /100 mL in any one sample Barium < 1.0 mg/L daily maximum Chloride < 250 mg/L 30-day average < 438 mg/L daily maximum Fluoride < 4.0 mg/L daily maximum Sulfate < 500 mg/L 30-day average < 875 mg/L daily maximum Total Petroleum Hydrocarbons < 1.0 mg/L daily maximum

Source: SL 1975, ch 16, § 1; 4 SDR 32, effective December 4, 1977; transferred from § 34:04:02:33, effective July 1, 1979; 10 SDR 145, effective July 4, 1984; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 14 SDR 86, effective December 24, 1987; 19 SDR 111, effective January 31, 1993; transferred from § 74:03:02:33, July 1, 1996; 24 SDR 10, effective July 20, 1997; 35 SDR 253, effective May 12, 2009; 47 SDR 110, effective April 27, 2021.