DEPARTMENT OF AGRICULTURE AND NATURAL RESOURCES

WATER POLLUTION CONTROL PROGRAM

TOTAL AMMONIA CRITERIA

Chapter 74:51:01

APPENDIX A

SEE: § 74:51:01:22

APPENDIX A to Chapter 74:51:01

Equation 1: Acute criterion for waters where salmonid fish are present.

MIN(((0.275/(1+10^7.204-pH))+(39/(1+10^pH-7.204))),(0.7249*((0.0114/(1+10^^7.204-pH))+(1.6181/(1+10^^pH-7.204)))*(23.12*10^^0.036*(20-T))))

MIN = use either the value of (((0.275/(1+10^7.204-pH))+(39/(1+10^pH-7.204))) or the value of (0.7249*((0.0114/(1+10^^7.204-pH))+(1.6181/(1+10^^pH-7.204)))*(23.12*10^^0.036*(20-T)))), whichever is the smaller value.

T = the water temperature of the sample in degrees Centigrade.

pH = the pH of the water quality sample in standard units.

Equation 2: Acute criterion for waters where salmonid fish are not present.

0.7249*(((0.0114/(1+10^7.204-pH))+(1.6181/(1+10^pH-7.204)))*MIN(51.93,23.12*10^0.036*(20-T))

MIN = use either 51.93 or the value of 23.12*10^0.036*(20-T), whichever is the smaller value.

T = the water temperature of the sample in degrees Centigrade.

pH - the pH of the water quality sample in standard units.

Equation 3: Chronic criterion

0.8876*(((0.0278/(1+10^7.688-pH))+(1.1994/(1+10^pH-7.688)))*(2.126*10^{0.028*(20-MAX(T,7)}))

T = the water temperature of the sample in degrees Centigrade.

pH - the pH of the water quality sample in standard units.

MAX = use either the water temperature (T) for the sample, or 7, whichever is the greater value.

Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia – Freshwater 2013, EPA 822-R-13-001, April 2013.

Source: Effective November 14, 1980; transferred from Chapter 74:03:02, Appendix A, July 1, 1996; transferred from Chapter 74:51:01, Appendix C, 24 SDR 10, effective July 20, 1997; 31 SDR 29, effective September 13, 2004; 35 SDR 253, effective May 12, 2009 ; 47 SDR 110, effective April 27, 2021 .

Prior versions effective: 2009-05-12.