In addition to the standards set forth in Rule .0208 of this Section, the following water quality standards shall apply to all Class C waters. Additional standards applicable to other freshwater classifications are specified in Rules .0212, .0214, .0215, .0216, .0218, .0219, .0223, .0224, .0225, and .0231 of this Section.
Fish tissue concentrations are determined as dry weight and water column concentrations are based on the dissolved fraction of selenium. Fish tissue components are expressed as steady-state concentrations and provide instantaneous point measurements that reflect integrative accumulation of selenium over time and space in fish populations at a given site. Fish tissue components supersede the water column component when both fish tissue and water concentrations are measured. Egg-ovary tissue results, where available, supersede all other tissue and water column components. The chronic selenium standards are as follows:
Component | Magnitude | Duration | |
Fish tissue | Fish egg/ovary tissue | 15.1 mg/kg | Instantaneous |
Fish whole body or muscle tissue | 8.5 mg/kg whole body | Instantaneous | |
11.3 mg/kg muscle | Instantaneous | ||
Water column | Lentic or Lotic | 1.5 ug/l lentic | 30-day average |
3.1 ug/l lotic | 30-day average |
Table A: Dissolved Freshwater Standards for Hardness-Dependent Metals
Numeric standards calculated at 25 mg/l hardness are listed below for illustrative purposes. The Water Effects Ratio (WER) is equal to one unless determined otherwise under Sub-Item (11)(b) of this Rule.
Metal | Equations for Hardness-Dependent Freshwater Metals (ug/l) | Standard at 25 mg/l hardness (ug/l) |
Cadmium, Acute | WER.[{1.136672-[ln hardness](0.041838)} . e^{0.9789 [ln hardness]-3.443}] | 0.75 |
Cadmium, Acute, Trout waters | WER.[{1.136672-[ln hardness](0.041838)} . e^{0.9789 [ln hardness]-3.866}] | 0.49 |
Cadmium, Chronic | WER.[{1.101672-[ln hardness](0.041838)} . e^{0.7977[ln hardness]-3.909}] | 0.25 |
Chromium III, Acute | WER. [0.316 . e^{0.8190[ln hardness]+3.7256}] | 180 |
Chromium III, Chronic | WER. [0.860 . e^{0.8190[ln hardness]+0.6848}] | 24 |
Copper, Acute | WER. [0.960 . e^{0.9422[ln hardness]-1.700}] Or, Aquatic Life Ambient Freshwater Quality Criteria-Copper 2007 Revision (EPA-822-R-07-001) | 3.6 NA |
Copper, Chronic | WER. [0.960 . e^{0.8545[ln hardness]-1.702}] Or, Aquatic Life Ambient Freshwater Quality Criteria-Copper 2007 Revision (EPA-822-R-07-001) | 2.7 NA |
Lead, Acute | WER. [{1.46203-[ln hardness](0.145712)} . e^{1.273[ln hardness]-1.460}] | 14 |
Lead, Chronic | WER. [{1.46203-[ln hardness](0.145712)} . e^{1.273[ln hardness]-4.705}] | 0.54 |
Nickel, Acute | WER. [0.998 . e^{0.8460[ln hardness]+2.255}] | 140 |
Nickel, Chronic | WER. [0.997 . e^{0.8460[ln hardness]+0.0584}] | 16 |
Silver, Acute | WER. [0.85 . e^{1.72[ln hardness]-6.59}] | 0.30 |
Zinc, Acute | WER. [0.978 . e^{0.8473[ln hardness]+0.884}] | 36 |
Zinc, Chronic | WER. [0.986 . e^{0.8473[ln hardness]+0.884}] | 36 |
15A N.C. Admin. Code 02B .0211
Eff. February 1, 1976;
Amended Eff. January 1, 2015; May 1, 2007; April 1, 2003; August 1, 2000; October 1, 1995; August 1, 1995; April 1, 1994; February 1, 1993;
Readopted Eff. November 1, 2019;
Amended Eff. September 1, 2022; June 1, 2022.
Eff. 2/1/1976;
Amended Eff. 5/1/2007; April 1, 2003; August 1, 2000; October 1, 1995; August 1, 1995; April 1, 1994; February 1, 1993.