R18-11-215. Numeric Water Quality Standards for Non-

WOTUS Protected Surface Waters A. E. coli bacteria. The following water quality standards for Escherichia coli (E. coli) are expressed in colony-forming units per 100 milliliters of water (cfu / 100 ml) or as a Most Probable Number (MPN): E. coli FBC AZ PBC AZ Geometric mean (minimum of four samples in 30 days) 126 126 Statistical threshold value 410 576 B. pH. The following water quality standards for non-WOTUS protected surface waters pH are expressed in standard units: FBC AZ, PBC AZ, A&Ww AZ, AgI AZ AgL AZ Maximum 9.0 9.0 9.0 9.0 Minimum 5.0 6.5 4.5 6.5 pH DWS AZ A&Wc AZ C. The maximum allowable increase in ambient water temperature, due to a thermal discharge is as follows: A&Ww AZ A&Wc AZ 3.0° C 1.0° C D. Suspended sediment concentration. 1. The following water quality standards for suspended sediment concentration, expressed in milligrams per liter (mg/L), are expressed as a median value determined from a minimum of four samples collected at least seven days apart: 2. The Director shall not use the results of a suspended sediment concentration sample collected during or within 48 hours after a local storm event to determine the median value. A&Wc AZ A&Ww AZ Table 1. Water Quality Criteria by Designated Use (see footnote) DWS AZ FC AZ (µg/L) FBC AZ 25 80 E. Dissolved oxygen. A non-WOTUS protected surface water meets the water quality standard for dissolved oxygen when either: 1. The percent saturation of dissolved oxygen is equal to or greater than 90 percent, or 2. The single sample minimum concentration for the designated use, as expressed in milligrams per liter (mg/L) is as follows: Single sample minimum Designated Use concentration in mg/L A&Ww AZ 6.0 A&Wc AZ 7.0 The single sample minimum concentration is the same for the designated use in a lake, but the sample must be taken from a depth no greater than one meter. F. Tables 1 through 17 prescribe water quality criteria for individual pollutants by designated use.