Proposed Text
9VAC25-260-140. Criteria for surface water.
A. Instream water quality conditions shall not be acutely1 or chronically2 toxic except as allowed in 9VAC25-260-20 B (mixing zones). The following are definitions of acute and chronic toxicity conditions:
"Acute toxicity" means an adverse effect that usually occurs shortly after exposure to a pollutant. Lethality to an organism is the usual measure of acute toxicity. Where death is not easily detected, immobilization is considered equivalent to death.
"Chronic toxicity" means an adverse effect that is irreversible or progressive or occurs because the rate of injury is greater than the rate of repair during prolonged exposure to a pollutant. This includes low level, long-term effects such as reduction in growth or reproduction.
B. The following table is a list of numerical water quality criteria for specific parameters.
Table of Parameters 6, 7
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PARAMETER |
USE DESIGNATION |
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AQUATIC LIFE |
HUMAN HEALTH |
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FRESHWATER |
SALTWATER |
Public Water Supply3 |
All Other Surface Waters4 |
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Acute1 |
Chronic2 |
Acute1 |
Chronic2 |
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Acenapthene (μg/l) |
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Acrolein (μg/l) |
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Acrylonitrile (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Aldrin (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
3.0 |
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1.3 |
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Ammonia (μg/l) Chronic criterion is a 30-day average concentration not to be exceeded more than once every three (3) years on the average.(see 9VAC25-260-155) |
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Anthracene (μg/l) |
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|
400 |
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Antimony (μg/l) |
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|
5.6 |
640 |
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Arsenic (μg/l)5 |
340 |
150 |
69 |
36 |
10 |
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Bacteria |
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Barium (μg/l) |
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2,000 |
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Benzene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
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5.8 |
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Benzidine (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
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Benzo (a) anthracene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
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Benzo (b) fluoranthene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
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Benzo (k) fluoranthene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
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0.12 |
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Benzo (a) pyrene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
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Bis2-Chloroethyl Ether Known or suspected carcinogen; human health criteria at risk level 10-5 |
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0.30 |
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Bis (chloromethyl) Ether 542881 Known or suspected carcinogen; human health criteria at risk level 10-5 |
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|
0.0015 |
0.17 |
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Bis2-Chloroisopropyl Ether (Bis
(2-Chloro-1-methylethyl) Ether) (μg/l) |
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Bis2-Ethylhexyl Phthalate (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. Synonym = Di-2-Ethylhexyl Phthalate. |
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Bromoform (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Butyl benzyl phthalate (μg/l) |
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Cadmium (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate (CaCO3) mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) e (0.9789[ln(hardness)]-3.866) (CFa) Freshwater chronic criterion (μg/l) e (0.7977[ln(hardness)]-3.909) (CFc) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CFa = 1.136672-[(ln hardness)(0.041838)] CFc = 1.101672-[(ln hardness)(0.041838)] |
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5 |
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Carbon tetrachloride (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Chlordane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
2.4 |
0.0043 |
0.09 |
0.0040 |
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|
Chloride (μg/l) Human Health criterion to maintain acceptable taste and aesthetic quality and applies at the drinking water intake. Chloride criteria do not apply in Class II transition zones (see subsection C of this section). |
860,000 |
230,000 |
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|
250,000 |
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|
Chlorine, Total Residual (μg/l) In DGIF class i and ii trout waters (9VAC25-260-390 through 9VAC25-260-540) or waters with threatened or endangered species are subject to the halogen ban (9VAC25-260-110). |
19 See 9VAC25-260-110 |
11 See 9VAC25-260-110 |
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Chlorine Produced Oxidant (μg/l) |
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|
13 |
7.5 |
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Chlorobenzene (μg/l) |
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Chlorodibromomethane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Chloroform (μg/l) |
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2-Chloronaphthalene (μg/l) |
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2-Chlorophenol (μg/l) |
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Chlorpyrifos (μg/l) |
0.083 |
0.041 |
0.011 |
0.0056 |
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Chromium III (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate CaCO3 mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion μg/l WER [e{0.8190[In(hardness)]+3.7256}] (CFa) Freshwater chronic criterion μg/l WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140.F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CFa= 0.316 CFc=0.860 |
570 |
74 |
|
|
100 (total Cr) |
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Chromium VI (μg/l)5 |
16 |
11 |
1,100 |
50 |
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Chrysene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Copper (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate CaCO3 mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER [e {0.9422[In(hardness)]-1.700}] (CFa) Freshwater chronic criterion (μg/l) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F. e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CFa = 0.960 CFc = 0.960 Acute saltwater criterion is a 24-hour average not to be exceeded more than once every three years on the average. |
13 |
9.0 |
9.3 |
6.0 |
1,300 |
|
|
Cyanide, Free (μg/l) |
22 |
5.2 |
1.0 |
1.0 |
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DDD (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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DDE (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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DDT (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. Total concentration of DDT and metabolites shall not exceed aquatic life criteria. |
1.1 |
0.0010 |
0.13 |
0.0010 |
|
0.00030 |
|
Demeton (μg/l) |
|
0.1 |
|
0.1 |
|
|
|
Diazinon (μg/l) |
0.17 |
0.17 |
0.82 |
0.82 |
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Dibenz (a, h) anthracene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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1,2-Dichlorobenzene (μg/l) 95501 |
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1,3-Dichlorobenzene (μg/l) 541731 |
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1,4 Dichlorobenzene (μg/l) |
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3,3 Dichlorobenzidine Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Dichlorobromomethane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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1,2 Dichloroethane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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1,1 Dichloroethylene (μg/l) |
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1,2-trans-dichloroethylene (μg/l) |
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2,4 Dichlorophenol (μg/l) |
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2,4 Dichlorophenoxy acetic acid (Chlorophenoxy
Herbicide) (2,4-D) (μg/l) |
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|
12,000 |
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1,2-Dichloropropane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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1,3-Dichloropropene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
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Dieldrin (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
0.24 |
0.056 |
0.71 |
0.0019 |
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Diethyl Phthalate (μg/l) |
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2,4 Dimethylphenol (μg/l) |
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Dimethyl Phthalate (μg/l) |
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Di-n-Butyl Phthalate (μg/l) |
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2,4 Dinitrophenol (μg/l) |
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Dinitrophenols (μg/l) 25550587 |
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|
10 |
1,000 |
|
2-Methyl-4,6-Dinitrophenol (μg/l) |
|
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2,4 Dinitrotoluene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
|
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Dioxin 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (μg/l) |
|
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|
5.0 E-8 |
5.1 E-8 |
|
1,2-Diphenylhydrazine (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
|
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|
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|
2.0 |
|
Dissolved Oxygen (μg/l) |
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Alpha-Endosulfan (μg/l) Total concentration alpha and beta-endosulfan shall not exceed aquatic life criteria. |
0.22 |
0.056 |
0.034 |
0.0087 |
|
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|
Beta-Endosulfan (μg/l) Total concentration alpha and beta-endosulfan shall not exceed aquatic life criteria. |
0.22 |
0.056 |
0.034 |
0.0087 |
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|
Endosulfan Sulfate (μg/l) |
|
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|
|
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|
Endrin (μg/l) |
0.086 |
0.036 |
0.037 |
0.0023 |
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Endrin Aldehyde (μg/l) |
|
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Ethylbenzene (μg/l) |
|
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Fecal Coliform |
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Fluoranthene (μg/l) |
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Fluorene (μg/l) |
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Foaming Agents (μg/l) |
|
|
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|
500 |
|
|
Guthion (μg/l) |
|
0.01 |
|
0.01 |
|
|
|
Heptachlor (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
0.52 |
0.0038 |
0.053 |
0.0036 |
|
|
|
Heptachlor Epoxide (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
0.52 |
0.0038 |
0.053 |
0.0036 |
|
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Hexachlorobenzene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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Hexachlorobutadiene (μg/l) |
|
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|
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Hexachlorocyclohexane Alpha-BHC (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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|
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Hexachlorocyclohexane Beta-BHC (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
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|
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Hexachlorocyclohexane (μg/l) (Lindane) Gamma-BHC
|
0.95 |
|
0.16 |
|
|
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|
Hexachlorocyclohexane (HCH)-Technical (μg/l) 608731 Known or suspected carcinogen; human health criteria at risk level 10-5.
|
|
|
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|
0.066 |
0.1 |
|
Hexachlorocyclopentadiene (μg/l) |
|
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Hexachloroethane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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Hydrogen sulfide (μg/l) |
|
2.0 |
|
2.0 |
|
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Indeno (1,2,3,-cd) pyrene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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|
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Iron (μg/l) Criterion to maintain acceptable taste, odor or aesthetic quality of drinking water and applies at the drinking water intake. |
|
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|
300 |
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Isophorone (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
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|
|
|
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Kepone (μg/l) |
|
zero |
|
zero |
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|
Lead (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate CaCO3 mg/l and the water effect ratio. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) Freshwater chronic criterion (μg/l) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm |
120 |
14 |
240 X WER |
9.3 X WER |
15 |
|
|
Malathion (μg/l) |
|
0.1 |
|
0.1 |
|
|
|
Manganese (μg/l) Criterion to maintain acceptable taste, odor or aesthetic quality of drinking water and applies at the drinking water intake. |
|
|
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|
50 |
|
|
Mercury (μg/l) 5 |
1.4 |
0.77 |
1.8 |
0.94 |
|
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Methyl Bromide (μg/l) |
|
|
|
|
|
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3-Methyl-4-Chlorophenol 59507 |
|
|
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|
500 |
2,000 |
|
Methyl Mercury (Fish Tissue Criterion mg/kg) 8 |
|
|
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|
0.30 |
0.30 |
|
Methylene Chloride (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 Synonym = Dichloromethane |
|
|
|
|
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Methoxychlor (μg/l) |
|
0.03 |
|
0.03 |
|
0.02 |
|
Mirex (μg/l) |
|
zero |
|
zero |
|
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|
Nickel (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate CaCO3 mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion μg/l Freshwater chronic criterion (μg/l) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CFa = 0.998 CFc = 0.997 |
180 |
20 |
74 X WER |
8.2 X WER |
610 |
4,600 |
|
Nitrate as N (μg/l) |
|
|
|
|
10,000 |
|
|
Nitrobenzene (μg/l) |
|
|
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|
|
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N-Nitrosodimethylamine (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
0.0069 |
30 |
|
N-Nitrosodiphenylamine (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
33 |
160 60 |
|
N-Nitrosodi-n-propylamine (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
0.050 |
5.1 |
|
Nonylphenol |
28 |
6.6 |
7.0 |
1.7 |
|
|
|
Parathion (μg/l) |
0.065 |
0.013 |
|
|
|
|
|
PCB Total (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5 |
|
0.014 |
|
0.030 |
0.00064 |
0.00064 |
|
Pentachlorobenzene (μg/l) 608935 |
|
|
|
|
0.1 |
0.1 |
|
Pentachlorophenol (μg/l) Known or suspected carcinogen; human health criteria risk level at 10-5 Freshwater acute criterion (μg/l) Freshwater chronic criterion (μg/l) |
8.7 |
6.7 |
13 |
7.9 |
|
|
|
pH |
|
|
|
|
|
|
|
Phenol (μg/l) |
|
|
|
|
|
|
|
Phosphorus Elemental (μg/l) |
|
|
|
0.10 |
|
|
|
Pyrene (μg/l) |
|
|
|
|
|
|
|
Radionuclides |
|
|
|
|
|
|
|
Gross Alpha Particle Activity (pCi/L) |
|
|
|
|
15 |
|
|
Beta Particle & Photon Activity (mrem/yr) (formerly man-made radionuclides) |
|
|
|
|
4 |
|
|
Combined Radium 226 and 228 (pCi/L) |
|
|
|
|
5 |
|
|
Uranium (μg/L) |
|
|
|
|
30 |
|
|
Selenium (μg/l)5 WER shall not be used for freshwater acute and chronic criteria. Freshwater criteria expressed as total recoverable. |
20 |
5.0 |
290 X WER |
71 |
170 |
4,200 |
|
Silver (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate (CaCO3) mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CFa = 0.85 |
3.4; CaCO3 = 100 |
|
1.9 X WER |
|
|
|
|
Sulfate (μg/l) |
|
|
|
|
250,000 |
|
|
Temperature See 9VAC25-260-50 |
|
|
|
|
|
|
|
1,2,4,5-Tetrachlorobenzene 95943 |
|
|
|
|
0.03 |
0.03 |
|
1,1,2,2-Tetrachloroethane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5) |
|
|
|
|
|
|
|
Tetrachloroethylene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5) |
|
|
|
|
|
|
|
Thallium (μg/l) |
|
|
|
|
0.24 |
0.47 |
|
Toluene (μg/l) |
|
|
|
|
|
|
|
Total Dissolved Solids (μg/l) |
|
|
|
|
500,000 |
|
|
Toxaphene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
0.73 |
0.0002 |
0.21 |
0.0002 |
|
|
|
Tributyltin (μg/l) |
0.46 |
0.072 |
0.42 |
0.0074 |
|
|
|
1, 2, 4 Trichlorobenzene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
|
|
|
1,1,1-Trichloroethane 71556 |
|
|
|
|
10,000 |
200,000 |
|
1,1,2-Trichloroethane (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
|
|
|
Trichloroethylene (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
|
|
|
2, 4, 5 Trichlorophenol 95954 |
|
|
|
|
300 |
600 |
|
2, 4, 6-Trichlorophenol Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
|
|
|
2-(2, 4, 5-Trichlorophenoxy propionic acid (Silvex)
(μg/l) |
|
|
|
|
50 |
|
|
Vinyl Chloride (μg/l) Known or suspected carcinogen; human health criteria at risk level 10-5. |
|
|
|
|
|
|
|
Zinc (μg/l)5 Freshwater values are a function of total hardness as calcium carbonate (CaCO3) mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum, hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion μg/l Freshwater chronic criterion μg/l WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = base e exponential function. ln = log normal function CFa = 0.978 CFc = 0.986 |
120 CaCO3 = 100 |
120 CaCO3 = 100 |
90 |
81 |
7,400 |
26,000 |
1One hour average concentration not to be exceeded more than once every 3 years on the average, unless otherwise noted.
2Four-day average concentration not to be exceeded more than once every 3 years on the average, unless otherwise noted.
3Criteria have been calculated to protect human health from toxic effects through drinking water and fish consumption, unless otherwise noted and apply in segments designated as PWS in 9VAC25-260-390-540.
4Criteria have been calculated to protect human health from toxic effects through fish consumption, unless otherwise noted and apply in all other surface waters not designated as PWS in 9VAC25-260-390-540.
5Acute and chronic saltwater and freshwater aquatic life criteria apply to the biologically available form of the metal and apply as a function of the pollutant's water effect ratio (WER) as defined in 9VAC25-260-140 F (WER X criterion). Metals measured as dissolved shall be considered to be biologically available, or, because local receiving water characteristics may otherwise affect the biological availability of the metal, the biologically available equivalent measurement of the metal can be further defined by determining a Water Effect Ratio (WER) and multiplying the numerical value shown in 9VAC25-260-140 B by the WER. Refer to 9VAC25-260-140 F. Values displayed above in the table are examples and correspond to a WER of 1.0. Metals criteria have been adjusted to convert the total recoverable fraction to dissolved fraction using a conversion factor. Criteria that change with hardness have the conversion factor listed in the table above.
6The flows listed below are default design flows for calculating steady state waste load allocations unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.
Aquatic Life:
|
Acute criteria |
1Q10 |
|
Chronic criteria |
7Q10 |
|
Chronic criteria (ammonia) |
30Q10 |
Human Health:
|
Noncarcinogens |
30Q5 |
|
Carcinogens |
Harmonic mean |
The following are defined for this section:
"1Q10" means the lowest flow averaged over a period of one day which on a statistical basis can be expected to occur once every 10 climatic years.
"7Q10" means the lowest flow averaged over a period of seven consecutive days that can be statistically expected to occur once every 10 climatic years.
"30Q5" means the lowest flow averaged over a period of 30 consecutive days that can be statistically expected to occur once every five climatic years.
"30Q10" means the lowest flow averaged over a period of 30 consecutive days that can be statistically expected to occur once every 10 climatic years.
"Averaged" means an arithmetic mean.
"Climatic year" means a year beginning on April 1 and ending on March 31.
7The criteria listed in this table are two significant digits. For other criteria that are referenced to other sections of this regulation in this table, all numbers listed as criteria values are significant.
8The fish tissue criterion for methylmercury applies to a concentration of 0.30 mg/kg as wet weight in edible tissue for species of fish and/or shellfish resident in a waterbody that are commonly eaten in the area and have commercial, recreational, or subsistence value.
C. Application of freshwater and saltwater numerical criteria. The numerical water quality criteria listed in subsection B of this section (excluding dissolved oxygen, pH, temperature) shall be applied according to the following classes of waters (see 9VAC25-260-50) and boundary designations:
|
CLASS OF WATERS |
NUMERICAL CRITERIA |
|
I and II (Estuarine Waters) |
Saltwater criteria apply |
|
II (Transition Zone) |
More stringent of either the freshwater or saltwater criteria apply |
|
II (Tidal Freshwater), III, IV, V, VI and VII |
Freshwater criteria apply |
The following describes the boundary designations for Class II, (estuarine, transition zone and tidal freshwater waters) by river basin:
1. Rappahannock Basin. Tidal freshwater is from the fall line of the Rappahannock River to the upstream boundary of the transition zone including all tidal tributaries that enter the tidal freshwater Rappahannock River.
Transition zone upstream boundary 38° 4' 56.59"/-76° 58' 47.93" (430 feet east of Hutchinson Swamp) to 38° 5' 23.33"/-76° 58' 24.39" (0.7 miles upstream of Peedee Creek).
Transition zone downstream boundary - 37° 58' 45.80"/-76° 55' 28.75" (1,000 feet downstream of Jenkins Landing) to 37° 59' 20.07/-76° 53' 45.09" (0.33 miles upstream of Mulberry Point). All tidal waters that enter the transition zone are themselves transition zone waters.
Estuarine waters are from the downstream boundary of the transition zone to the mouth of the Rappahannock River (Buoy 6), including all tidal tributaries that enter the estuarine waters of the Rappahannock River.
2. York Basin. Tidal freshwater is from the fall line of the Mattaponi River at N37° 47' 20.03"/W77° 6' 15.16" (800 feet upstream of the Route 360 bridge in Aylett) to the upstream boundary of the Mattaponi River transition zone, and from the fall line of the Pamunkey River at N37° 41' 22.64" /W77° 12' 50.83" (2,000 feet upstream of Totopotomy Creek) to the upstream boundary of the Pamunkey River transition zone, including all tidal tributaries that enter the tidal freshwaters of the Mattaponi and Pamunkey Rivers.
Mattaponni River transition zone upstream boundary N37° 39' 29.65"/W76° 52' 53.29" (1,000 feet upstream of Mitchell Hill Creek) to N37° 39' 24.20"/W76° 52' 55.87" (across from Courthouse Landing). Mattaponi River transition zone downstream boundary N37° 32' 19.76"/W76° 47' 29.41" (old Lord Delaware Bridge, west side) to N37° 32' 13.25"/W76° 47' 10.30" (old Lord Delaware Bridge, east side).
Pamunkey River transition zone upstream boundary N37° 32' 36.63"/W76° 58' 29.88" (Cohoke Marsh, 0.9 miles upstream of Turkey Creek) to N37° 32' 36.51"/W76° 58' 36.48" (0.75 miles upstream of creek at Cook Landing). Pamunkey River transition zone downstream boundary N37° 31' 57.90"/ 76° 48' 38.22" (old Eltham Bridge, west side) to N37° 32' 6.25"/W76 48' 18.82" (old Eltham Bridge, east side).
All tidal tributaries that enter the transition zones of the Mattaponi and Pamunkey Rivers are themselves in the transition zone.
Estuarine waters are from the downstream boundary of the transition zones of the Mattaponi and Pamunkey Rivers to the mouth of the York River (Tue Marsh Light) including all tidal tributaries that enter the estuarine waters of the York River.
3. James Basin. Tidal Freshwater is from the fall line of the James River in the City of Richmond upstream of Mayo Bridge to the upstream boundary of the transition zone, including all tidal tributaries that enter the tidal freshwater James River.
James River transition zone upstream boundary N37° 14' 28.25"/W76° 56' 44.47" (at Tettington) to N37° 13' 38.56"/W76° 56' 47.13" 0.3 miles downstream of Sloop Point.
Chickahominy River transition zone upstream boundary N37° 25' 44.79"/W77° 1' 41.76" (Holly Landing).
Transition zone downstream boundary N37° 12' 7.23"/W76° 37' 34.70" (near Carters Grove Home, 1.25 downstream of Grove Creek) to N37° 9' 17.23"/W76° 40' 13.45" (0.7 miles upstream of Hunnicutt Creek). All tidal waters that enter the transition zone are themselves transition zone waters.
Estuarine waters are from the downstream transition zone boundary to the mouth of the James River (Buoy 25) including all tidal tributaries that enter the estuarine waters of the James River.
4. Potomac Basin. Tidal Freshwater includes all tidal tributaries that enter the Potomac River from its fall line at the Chain Bridge (N38° 55' 46.28"/W77° 6' 59.23") to the upstream transition zone boundary near Quantico, Virginia.
Transition zone includes all tidal tributaries that enter the Potomac River from N38° 31' 27.05"/W77° 17' 7.06" (midway between Shipping Point and Quantico Pier) to N38° 23' 22.78"/W77° 1' 45.50" (one mile southeast of Mathias Point).
Estuarine waters includes all tidal tributaries that enter the Potomac River from the downstream transition zone boundary to the mouth of the Potomac River (Buoy 44B).
5. Chesapeake Bay, Atlantic Ocean, and small coastal basins. Estuarine waters include the Atlantic Ocean tidal tributaries, and the Chesapeake Bay and its small coastal basins from the Virginia state line to the mouth of the bay (a line from Cape Henry drawn through Buoys 3 and 8 to Fishermans Island), and its tidal tributaries, excluding the Potomac tributaries and those tributaries listed above.
6. Chowan River Basin. Tidal freshwater includes the Northwest River and its tidal tributaries from the Virginia-North Carolina state line to the free flowing portion, the Blackwater River and its tidal tributaries from the Virginia-North Carolina state line to the end of tidal waters at approximately state route 611 at river mile 20.90, the Nottoway River and its tidal tributaries from the Virginia-North Carolina state line to the end of tidal waters at approximately Route 674, and the North Landing River and its tidal tributaries from the Virginia-North Carolina state line to the Great Bridge Lock.
Transition zone includes Back Bay and its tributaries in the City of Virginia Beach to the Virginia-North Carolina state line.
D. Site-specific modifications to numerical water quality criteria.
1. The board may consider site-specific modifications to numerical water quality criteria in subsection B of this section where the applicant or permittee demonstrates that the alternate numerical water quality criteria are sufficient to protect all designated uses (see 9VAC25-260-10) of that particular surface water segment or body.
2. Any demonstration for site-specific human health criteria shall be restricted to a reevaluation of the bioconcentration or bioaccumulation properties of the pollutant. The exceptions to this restriction are for site-specific criteria for taste, odor, and aesthetic compounds noted by double asterisks in subsection B of this section and nitrates.
3. Procedures for promulgation and review of site-specific modifications to numerical water quality criteria resulting from subdivisions 1 and 2 of this subsection.
a. Proposals describing the details of the site-specific study shall be submitted to the board's staff for approval prior to commencing the study.
b. Any site-specific modification shall be promulgated as a regulation in accordance with the Administrative Process Act. All site-specific modifications shall be listed in 9VAC25-260-310 (Special standards and requirements).
E. Variances to water quality standards.
1. A variance from numeric criteria may be granted to a discharger if it can be demonstrated that one or more of the conditions in 9VAC25-260-10 H limit the attainment of one or more specific designated uses.
a. Variances shall apply only to the discharger to whom they are granted and shall be reevaluated and either continued, modified or revoked at the time of permit issuance. At that time the permittee shall make a showing that the conditions for granting the variance still apply.
b. Variances shall be described in the public notice published for the permit. The decision to approve a variance shall be subject to the public participation requirements of the Virginia Pollutant Discharge Elimination System (VPDES) Permit Regulation, 9VAC25-31 (Permit Regulation).
c. Variances shall not prevent the maintenance and protection of existing uses or exempt the discharger or regulated activity from compliance with other appropriate technology or water quality-based limits or best management practices.
d. Variances granted under this section shall not apply to new discharges.
e. Variances shall be submitted by the department's Division of Scientific Research or its successors to the Environmental Protection Agency for review and approval/disapproval.
f. A list of variances granted shall be maintained by the department's Division of Scientific Research or its successors.
2. None of the variances in this subsection shall apply to the halogen ban section (9VAC25-260-110) or temperature criteria in 9VAC25-260-50 if superseded by § 316(a) of the Clean Water Act requirements. No variances in this subsection shall apply to the criteria that are designed to protect human health from carcinogenic and noncarcinogenic toxic effects (subsection B of this section) with the exception of the metals, and the taste, odor, and aesthetic compounds noted by double asterisks and nitrates, listed in subsection B of this section.
F. Water effect ratio.
1. A water effects ratio (WER) shall be determined by measuring the effect of receiving water (as it is or will be affected by any discharges) on the bioavailability or toxicity of a metal by using standard test organisms and a metal to conduct toxicity tests simultaneously in receiving water and laboratory water. The ratio of toxicities of the metal(s) in the two waters is the WER (toxicity in receiving water divided by toxicity in laboratory water = WER). Once an acceptable WER for a metal is established, the numerical value for the metal in subsection B of this section is multiplied by the WER to produce an instream concentration that will protect designated uses. This instream concentration shall be utilized in permitting decisions.
2. The WER shall be assigned a value of 1.0 unless the applicant or permittee demonstrates to the department's satisfaction in a permit proceeding that another value is appropriate, or unless available data allow the department to compute a WER for the receiving waters. The applicant or permittee is responsible for proposing and conducting the study to develop a WER. The study may require multiple testing over several seasons. The applicant or permittee shall obtain the department's Division of Scientific Research or its successor approval of the study protocol and the final WER.
3. The Permit Regulation at 9VAC25-31-230 C requires that permit limits for metals be expressed as total recoverable measurements. To that end, the study used to establish the WER may be based on total recoverable measurements of the metals.
4. The Environmental Protection Agency views the WER in any particular case as a site-specific criterion. Therefore, the department's Division of Scientific Research or its successor shall submit the results of the study to the Environmental Protection Agency for review and approval/disapproval within 30 days of the receipt of certification from the state's Office of the Attorney General. Nonetheless, the WER is established in a permit proceeding, shall be described in the public notice associated with the permit proceeding, and applies only to the applicant or permittee in that proceeding. The department's action to approve or disapprove a WER is a case decision, not an amendment to the present regulation.
The decision to approve or disapprove a WER shall be subject to the public participation requirements of the Permit Regulation, 9VAC25-31-260 et seq. A list of final WERs will be maintained by the department's Division of Scientific Research or its successor.
5. A WER shall not be used for the freshwater and saltwater chronic mercury criteria or the freshwater acute and chronic selenium criteria.
9VAC25-260-155. Ammonia surface water quality criteria.
A. The Department of Environmental Quality, after consultation with the Virginia Department of Game and Inland Fisheries and the U.S. Fish and Wildlife Service, has determined that the majority of Virginia freshwaters are likely to contain, or have contained in the past, freshwater mussel species in the family Unionidae and contain early life stages of fish during most times of the year. Therefore, the ammonia criteria presented in subsections B and C of this section are designed to provide protection to these species and life stages. In an instance where it can be adequately demonstrated that either freshwater mussels or early life stages of fish are not present in a specific waterbody, potential options for alternate, site-specific criteria are presented in subsection D of this section. Acute criteria are a one-hour average concentration not to be exceeded more than once every three years1 on the average, and chronic criteria are 30-day average concentrations not to be exceeded more than once every three years on the average2.
A. B. The one-hour
average concentration of total ammonia nitrogen (in mg N/L) in freshwater shall
not exceed, more than once every three years on the average1, the
acute criteria for total ammonia (in mg N/L) for freshwaters with
trout absent or present are below:
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Acute Ammonia Freshwater Criteria TROUT ABSENT |
|||||||||||||||||||||
|
Temperature (°C) |
|||||||||||||||||||||
|
pH |
0-10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
|
6.5 |
51 |
48 |
44 |
41 |
37 |
34 |
32 |
29 |
27 |
25 |
23 |
21 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.9 |
|
6.6 |
49 |
46 |
42 |
39 |
36 |
33 |
30 |
28 |
26 |
24 |
22 |
20 |
18 |
17 |
16 |
14 |
13 |
12 |
11 |
10 |
9.5 |
|
6.7 |
46 |
44 |
40 |
37 |
34 |
31 |
29 |
27 |
24 |
22 |
21 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.8 |
9.0 |
|
6.8 |
44 |
41 |
38 |
35 |
32 |
30 |
27 |
25 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.2 |
8.5 |
|
6.9 |
41 |
38 |
35 |
32 |
30 |
28 |
25 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.4 |
8.6 |
7.9 |
|
7.0 |
38 |
35 |
33 |
30 |
28 |
25 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.4 |
8.6 |
7.9 |
7.3 |
|
7.1 |
34 |
32 |
30 |
27 |
25 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.3 |
8.5 |
7.9 |
7.2 |
6.7 |
|
7.2 |
31 |
29 |
27 |
25 |
23 |
21 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.8 |
9.1 |
8.3 |
7.7 |
7.1 |
6.5 |
6.0 |
|
7.3 |
27 |
26 |
24 |
22 |
20 |
18 |
17 |
16 |
14 |
13 |
12 |
11 |
10 |
9.5 |
8.7 |
8.0 |
7.4 |
6.8 |
6.3 |
5.8 |
5.3 |
|
7.4 |
24 |
22 |
21 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.8 |
9.0 |
8.3 |
7.7 |
7.0 |
6.5 |
6.0 |
5.5 |
5.1 |
4.7 |
|
7.5 |
21 |
19 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.2 |
8.5 |
7.8 |
7.2 |
6.6 |
6.1 |
5.6 |
5.2 |
4.8 |
4.4 |
4.0 |
|
7.6 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.3 |
8.6 |
7.9 |
7.3 |
6.7 |
6.2 |
5.7 |
5.2 |
4.8 |
4.4 |
4.1 |
3.8 |
3.5 |
|
7.7 |
15 |
14 |
13 |
12 |
11 |
10 |
9.3 |
8.6 |
7.9 |
7.3 |
6.7 |
6.2 |
5.7 |
5.2 |
4.8 |
4.4 |
4.1 |
3.8 |
3.5 |
3.2 |
2.9 |
|
7.8 |
13 |
12 |
11 |
10 |
9.3 |
8.5 |
7.9 |
7.2 |
6.7 |
6.1 |
5.6 |
5.2 |
4.8 |
4.4 |
4.0 |
3.7 |
3.4 |
3.2 |
2.9 |
2.7 |
2.5 |
|
7.9 |
11 |
9.9 |
9.1 |
8.4 |
7.7 |
7.1 |
6.6 |
3.0 |
5.6 |
5.1 |
4.7 |
4.3 |
4.0 |
3.7 |
3.4 |
3.1 |
2.9 |
2.6 |
2.4 |
2.2 |
2.1 |
|
8.0 |
8.8 |
8.2 |
7.6 |
7.0 |
6.4 |
5.9 |
5.4 |
5.0 |
4.6 |
4.2 |
3.9 |
3.6 |
3.3 |
3.0 |
2.8 |
2.6 |
2.4 |
2.2 |
2.0 |
1.9 |
1.7 |
|
8.1 |
7.2 |
6.8 |
6.3 |
5.8 |
5.3 |
4.9 |
4.5 |
4.1 |
3.8 |
3.5 |
3.2 |
3.0 |
2.7 |
2.5 |
2.3 |
2.1 |
2.0 |
1.8 |
1.7 |
1.5 |
1.4 |
|
8.2 |
6.0 |
5.6 |
5.2 |
4.8 |
4.4 |
4.0 |
3.7 |
3.4 |
3.1 |
2.9 |
2.7 |
2.4 |
2.3 |
2.1 |
1.9 |
1.8 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
|
8.3 |
4.9 |
4.6 |
4.3 |
3.9 |
3.6 |
3.3 |
3.1 |
2.8 |
2.6 |
2.4 |
2.2 |
2.0 |
1.9 |
1.7 |
1.6 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.96 |
|
8.4 |
4.1 |
3.8 |
3.5 |
3.2 |
3.0 |
2.7 |
2.5 |
2.3 |
2.1 |
2.0 |
1.8 |
1.7 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.93 |
0.86 |
0.79 |
|
8.5 |
3.3 |
3.1 |
2.9 |
2.7 |
2.4 |
2.3 |
2.1 |
1.9 |
1.8 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
0.98 |
0.90 |
0.83 |
0.77 |
0.71 |
0.65 |
|
8.6 |
2.8 |
2.6 |
2.4 |
2.2 |
2.0 |
1.9 |
1.7 |
1.6 |
1.5 |
1.3 |
1.2 |
1.1 |
1.0 |
0.96 |
0.88 |
0.81 |
0.75 |
0.69 |
0.63 |
0.58 |
0.54 |
|
8.7 |
2.3 |
2.2 |
2.0 |
1.8 |
1.7 |
1.6 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.94 |
0.87 |
0.80 |
0.74 |
0.68 |
0.62 |
0.57 |
0.53 |
0.49 |
0.45 |
|
8.8 |
1.9 |
1.8 |
1.7 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.93 |
0.86 |
0.79 |
0.73 |
0.67 |
0.62 |
0.57 |
0.52 |
0.48 |
0.44 |
0.41 |
0.37 |
|
8.9 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.93 |
0.85 |
0.79 |
0.72 |
0.67 |
0.61 |
0.56 |
0.52 |
0.48 |
0.44 |
0.40 |
0.37 |
0.34 |
0.32 |
|
9.0 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.93 |
0.86 |
0.79 |
0.73 |
0.67 |
0.62 |
0.57 |
0.52 |
0.48 |
0.44 |
0.41 |
0.37 |
0.34 |
0.32 |
0.29 |
0.27 |
|
Acute Ammonia Freshwater Criteria TROUT PRESENT |
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|
Temperature (°C) |
|||||||||||||||||
|
pH |
0-14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
|
6.5 |
33 |
33 |
32 |
29 |
27 |
25 |
23 |
21 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.9 |
|
6.6 |
31 |
31 |
30 |
28 |
26 |
24 |
22 |
20 |
18 |
17 |
16 |
14 |
13 |
12 |
11 |
10 |
9.5 |
|
6.7 |
30 |
30 |
29 |
27 |
24 |
22 |
21 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.8 |
9.0 |
|
6.8 |
28 |
28 |
27 |
25 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.2 |
8.5 |
|
6.9 |
26 |
26 |
25 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.4 |
8.6 |
7.9 |
|
7.0 |
24 |
24 |
23 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.4 |
8.6 |
8.0 |
7.3 |
|
7.1 |
22 |
22 |
21 |
20 |
18 |
17 |
15 |
14 |
13 |
12 |
11 |
10 |
9.3 |
8.5 |
7.9 |
7.2 |
6.7 |
|
7.2 |
20 |
20 |
19 |
18 |
16 |
15 |
14 |
13 |
12 |
11 |
9.8 |
9.1 |
8.3 |
7.7 |
7.1 |
6.5 |
6.0 |
|
7.3 |
18 |
18 |
17 |
16 |
14 |
13 |
12 |
11 |
10 |
9.5 |
8.7 |
8.0 |
7.4 |
6.8 |
6.3 |
5.8 |
5.3 |
|
7.4 |
15 |
15 |
15 |
14 |
13 |
12 |
11 |
9.8 |
9.0 |
8.3 |
7.7 |
7.0 |
6.5 |
6.0 |
5.5 |
5.1 |
4.7 |
|
7.5 |
13 |
13 |
13 |
12 |
11 |
10 |
9.2 |
8.5 |
7.8 |
7.2 |
6.6 |
6.1 |
5.6 |
5.2 |
4.8 |
4.4 |
4.0 |
|
7.6 |
11 |
11 |
11 |
10 |
9.3 |
8.6 |
7.9 |
7.3 |
6.7 |
6.2 |
5.7 |
5.2 |
4.8 |
4.4 |
4.1 |
3.8 |
3.5 |
|
7.7 |
9.6 |
9.6 |
9.3 |
8.6 |
7.9 |
7.3 |
6.7 |
6.2 |
5.7 |
5.2 |
4.8 |
4.4 |
4.1 |
3.8 |
3.5 |
3.2 |
3.0 |
|
7.8 |
8.1 |
8.1 |
7.9 |
7.2 |
6.7 |
6.1 |
5.6 |
5.2 |
4.8 |
4.4 |
4.0 |
3.7 |
3.4 |
3.2 |
2.9 |
2.7 |
2.5 |
|
7.9 |
6.8 |
6.8 |
6.6 |
6.0 |
5.6 |
5.1 |
4.7 |
4.3 |
4.0 |
3.7 |
3.4 |
3.1 |
2.9 |
2.6 |
2.4 |
2.2 |
2.1 |
|
8.0 |
5.6 |
5.6 |
5.4 |
5.0 |
4.6 |
4.2 |
3.9 |
3.6 |
3.3 |
3.0 |
2.8 |
2.6 |
2.4 |
2.2 |
2.0 |
1.9 |
1.7 |
|
8.1 |
4.6 |
4.6 |
4.5 |
4.1 |
3.8 |
3.5 |
3.2 |
3.0 |
2.7 |
2.5 |
2.3 |
2.1 |
2.0 |
1.8 |
1.7 |
1.5 |
1.4 |
|
8.2 |
3.8 |
3.8 |
3.7 |
3.5 |
3.1 |
2.9 |
2.7 |
2.4 |
2.3 |
2.1 |
1.9 |
1.8 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
|
8.3 |
3.1 |
3.1 |
3.1 |
2.8 |
2.6 |
2.4 |
2.2 |
2.0 |
1.9 |
1.7 |
1.6 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.96 |
|
8.4 |
2.6 |
2.6 |
2.5 |
2.3 |
2.1 |
2.0 |
1.8 |
1.7 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.93 |
0.86 |
0.79 |
|
8.5 |
2.1 |
2.1 |
2.1 |
1.9 |
1.8 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
0.98 |
0.90 |
0.83 |
0.77 |
0.71 |
0.65 |
|
8.6 |
1.8 |
1.8 |
1.7 |
1.6 |
1.5 |
1.3 |
1.2 |
1.1 |
1.0 |
0.96 |
0.88 |
0.81 |
0.75 |
0.69 |
0.63 |
0.59 |
0.54 |
|
8.7 |
1.5 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.0 |
0.94 |
0.87 |
0.80 |
0.74 |
0.68 |
0.62 |
0.57 |
0.53 |
0.49 |
0.45 |
|
8.8 |
1.2 |
1.2 |
1.2 |
1.1 |
1.0 |
0.93 |
0.86 |
0.79 |
0.73 |
0.67 |
0.62 |
0.57 |
0.52 |
0.48 |
0.44 |
0.41 |
0.37 |
|
8.9 |
1.0 |
1.0 |
1.0 |
0.93 |
0.85 |
0.79 |
0.72 |
0.67 |
0.61 |
0.56 |
0.52 |
0.48 |
0.44 |
0.40 |
0.37 |
0.34 |
0.32 |
|
9.0 |
0.88 |
0.88 |
0.86 |
0.79 |
0.73 |
0.67 |
0.62 |
0.57 |
0.52 |
0.48 |
0.44 |
0.41 |
0.37 |
0.34 |
0.32 |
0.29 |
0.27 |
The acute criteria for trout present shall apply to all Class V-Stockable Trout
Waters and Class VI-Natural Trout Waters as listed in 9VAC25-260-390 through
9VAC25-260-540. The acute criteria for trout absent apply to all other fresh
waters.
To calculate total ammonia nitrogen acute criteria values in
freshwater at different pH values than those listed in this subsection, use the
following formulas equations and round the result to two significant
digits:
Where trout are present absent:
Acute Criterion Concentration (mg N/L) =
|
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0.7249 X ( |
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+ |
|
) X MIN |
|||
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1 + 107.204-pH |
1 + 10pH-7.204 |
||||||
Where MIN = 51.93 or 23.12 X 100.036 X (20 T), whichever is less.
T = Temperature in oC
Or where trout are absent present, whichever of
the below calculation results is less:
Acute Criterion Concentration (mg N/L) =
|
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( |
0.275 |
+ |
39.0 |
) |
|
1 + 107.204-pH |
1 + 10pH-7.204 |
Or
|
0.7249 X ( |
0.0114 |
+ |
1.6181 |
) X (23.12 X 100.036X(20 T)) |
|
1 + 107.204-pH |
1 + 10pH-7.204 |
T = Temperature in oC
1The default design flow for calculating
steady state waste load allocations for the acute ammonia criterion is the 1Q10
(see 9VAC25-260-140 B footnote 10) unless statistically valid methods are
employed which demonstrate compliance with the duration and return frequency of
the water quality criteria.
B. [ C. ] The 30-day average
concentration of chronic criteria for total ammonia nitrogen (in mg
N/L) where freshwater mussels and early life stages of fish are present
in freshwater shall not exceed, more than once every three years on the
average2, the chronic criteria are below:
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Chronic Ammonia Freshwater Criteria Total Ammonia Nitrogen (mg N/L) |
||||||||||||||||||||||||
|
Temperature (°C) |
||||||||||||||||||||||||
|
pH |
0-7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
|
6.5 |
4.9 |
4.6 |
4.3 |
4.1 |
3.8 |
3.6 |
3.3 |
3.1 |
2.9 |
2.8 |
2.6 |
2.4 |
2.3 |
2.1 |
2.0 |
1.9 |
1.8 |
1.6 |
1.5 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
|
6.6 |
4.8 |
4.5 |
4.3 |
4.0 |
3.8 |
3.5 |
3.3 |
3.1 |
2.9 |
2.7 |
2.5 |
2.4 |
2.2 |
2.1 |
2.0 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.3 |
1.2 |
1.1 |
|
6.7 |
4.8 |
4.5 |
4.2 |
3.9 |
3.7 |
3.5 |
3.2 |
3.0 |
2.8 |
2.7 |
2.5 |
2.3 |
2.2 |
2.1 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.2 |
1.1 |
|
6.8 |
4.6 |
4.4 |
4.1 |
3.8 |
3.6 |
3.4 |
3.2 |
3.0 |
2.8 |
2.6 |
2.4 |
2.3 |
2.1 |
2.0 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.1 |
|
6.9 |
4.5 |
4.2 |
4.0 |
3.7 |
3.5 |
3.3 |
3.1 |
2.9 |
2.7 |
2.5 |
2.4 |
2.2 |
2.1 |
2.0 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.2 |
1.1 |
1.0 |
|
7.0 |
4.4 |
4.1 |
3.8 |
3.6 |
3.4 |
3.2 |
3.0 |
2.8 |
2.6 |
2.4 |
2.3 |
2.2 |
2.0 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.1 |
0.99 |
|
7.1 |
4.2 |
3.9 |
3.7 |
3.5 |
3.2 |
3.0 |
2.8 |
2.7 |
2.5 |
2.3 |
2.2 |
2.1 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.2 |
1.1 |
1.0 |
0.95 |
|
7.2 |
4.0 |
3.7 |
3.5 |
3.3 |
3.1 |
2.9 |
2.7 |
2.5 |
2.4 |
2.2 |
2.1 |
2.0 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.3 |
1.2 |
1.1 |
1.0 |
0.96 |
0.90 |
|
7.3 |
3.8 |
3.5 |
3.3 |
3.1 |
2.9 |
2.7 |
2.6 |
2.4 |
2.2 |
2.1 |
2.0 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.3 |
1.2 |
1.1 |
1.0 |
0.97 |
0.91 |
0.85 |
|
7.4 |
3.5 |
3.3 |
3.1 |
2.9 |
2.7 |
2.5 |
2.4 |
2.2 |
2.1 |
2.0 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.3 |
1.2 |
1.1 |
1.0 |
0.96 |
0.90 |
0.85 |
0.79 |
|
7.5 |
3.2 |
3.0 |
2.8 |
2.7 |
2.5 |
2.3 |
2.2 |
2.1 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.2 |
1.1 |
1.0 |
0.95 |
0.89 |
0.83 |
0.78 |
0.73 |
|
7.6 |
2.9 |
2.8 |
2.6 |
2.4 |
2.3 |
2.1 |
2.0 |
1.9 |
1.8 |
1.6 |
1.5 |
1.4 |
1.4 |
1.3 |
1.2 |
1.1 |
1.1 |
0.98 |
0.92 |
0.86 |
0.81 |
0.76 |
0.71 |
0.67 |
|
7.7 |
2.6 |
2.4 |
2.3 |
2.2 |
2.0 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.1 |
1.0 |
0.94 |
0.88 |
0.83 |
0.78 |
0.73 |
0.68 |
0.64 |
0.60 |
|
7.8 |
2.3 |
2.2 |
2.1 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.2 |
1.1 |
1.0 |
0.95 |
0.89 |
0.84 |
0.79 |
0.74 |
0.69 |
0.65 |
0.61 |
0.57 |
0.53 |
|
7.9 |
2.1 |
1.9 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.2 |
1.1 |
1.0 |
0.95 |
0.89 |
0.84 |
0.79 |
0.74 |
0.69 |
0.65 |
0.61 |
0.57 |
0.53 |
0.50 |
0.47 |
|
8.0 |
1.8 |
1.7 |
1.6 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.1 |
1.0 |
0.94 |
0.88 |
0.83 |
0.78 |
0.73 |
0.68 |
0.64 |
0.60 |
0.56 |
0.53 |
0.50 |
0.44 |
0.44 |
0.41 |
|
8.1 |
1.5 |
1.5 |
1.4 |
1.3 |
1.2 |
1.1 |
1.1 |
0.99 |
0.92 |
0.87 |
0.81 |
0.76 |
0.71 |
0.67 |
0.63 |
0.59 |
0.55 |
0.52 |
0.49 |
0.46 |
0.43 |
0.40 |
0.38 |
0.35 |
|
8.2 |
1.3 |
1.2 |
1.2 |
1.1 |
1.0 |
0.96 |
0.90 |
0.84 |
0.79 |
0.74 |
0.70 |
0.65 |
0.61 |
0.57 |
0.54 |
0.50 |
0.47 |
0.44 |
0.42 |
0.39 |
0.37 |
0.34 |
0.32 |
0.30 |
|
8.3 |
1.1 |
1.1 |
0.99 |
0.93 |
0.87 |
0.82 |
0.76 |
0.72 |
0.67 |
0.63 |
0.59 |
0.55 |
0.52 |
0.49 |
0.46 |
0.43 |
0.40 |
0.38 |
0.35 |
0.33 |
0.31 |
0.29 |
0.27 |
0.26 |
|
8.4 |
0.95 |
0.89 |
0.84 |
0.79 |
0.74 |
0.69 |
0.65 |
0.61 |
0.57 |
0.53 |
0.50 |
0.47 |
0.44 |
0.41 |
0.39 |
0.36 |
0.34 |
0.32 |
0.30 |
0.28 |
0.26 |
0.25 |
0.23 |
0.22 |
|
8.5 |
0.80 |
0.75 |
0.71 |
0.67 |
0.62 |
0.58 |
0.55 |
0.51 |
0.48 |
0.45 |
0.42 |
0.40 |
0.37 |
0.35 |
0.33 |
0.31 |
0.29 |
0.27 |
0.25 |
0.24 |
0.22 |
0.21 |
0.20 |
0.18 |
|
8.6 |
0.68 |
0.64 |
0.60 |
0.56 |
0.53 |
0.49 |
0.46 |
0.43 |
0.41 |
0.38 |
0.36 |
0.33 |
0.31 |
0.29 |
0.28 |
0.26 |
0.24 |
0.23 |
0.21 |
0.20 |
0.19 |
0.18 |
0.16 |
0.15 |
|
8.7 |
0.57 |
0.54 |
0.51 |
0.47 |
0.44 |
0.42 |
0.39 |
0.37 |
0.34 |
0.32 |
0.30 |
0.28 |
0.27 |
0.25 |
0.23 |
0.22 |
0.21 |
0.19 |
0.18 |
0.17 |
0.16 |
0.15 |
0.14 |
0.13 |
|
8.8 |
0.49 |
0.46 |
0.43 |
0.40 |
0.38 |
0.35 |
0.33 |
0.31 |
0.29 |
0.27 |
0.26 |
0.24 |
0.23 |
0.21 |
0.20 |
0.19 |
0.17 |
0.16 |
0.15 |
0.14 |
0.13 |
0.13 |
0.12 |
0.11 |
|
8.9 |
0.42 |
0.39 |
0.37 |
0.34 |
0.32 |
0.30 |
0.28 |
0.27 |
0.25 |
0.23 |
0.22 |
0.21 |
0.19 |
0.18 |
0.17 |
0.16 |
0.15 |
0.14 |
0.13 |
0.12 |
0.12 |
0.11 |
0.10 |
0.09 |
|
9.0 |
0.36 |
0.34 |
0.32 |
0.30 |
0.28 |
0.26 |
0.24 |
0.23 |
0.21 |
0.20 |
0.19 |
0.18 |
0.17 |
0.16 |
0.15 |
0.14 |
0.13 |
0.12 |
0.11 |
0.11 |
0.10 |
0.09 |
0.09 |
0.08 |
To calculate total ammonia nitrogen chronic criteria values
in freshwater when fish freshwater mussels and early life stages of
fish are present at different pH and temperature values than those listed
in this subsection, use the following formulas equation and round the
result to two significant digits:
Chronic Criteria Concentration =
|
|
|
|
|
|
|
|
|
|
Where MIN = 2.85 or 1.45 x 100.028(25-T),
whichever is less.
|
0.8876 X ( |
0.0278 |
+ |
1.1994 |
) X (2.126 X 100.028 X (20 - MAX(T,7))) |
|
1 + 107.688-pH |
1 + 10pH-7.688 |
Where MAX = 7 or temperature in degrees Celsius, whichever is greater.
T = temperature in °C
2The default design flow for calculating
steady state waste load allocations for the chronic ammonia criterion where
early life stages of fish are present is the 30Q10 (see 9VAC25-260-140 B
footnote 10) unless statistically valid methods are employed which demonstrate
compliance with the duration and return frequency of the water quality
criteria.
D. Site-specific considerations and alternate criteria. If it can be adequately demonstrated that freshwater mussels or early life stages of fish are not present at a site, then alternate site-specific criteria can be considered using the information provided in this subsection. Recalculated site-specific criteria shall provide for the attainment and maintenance of the water quality standards of downstream waters.
1. Site-specific modifications to the ambient water quality criteria for ammonia to account for the absence of freshwater mussels or early life stages of fish shall be conducted in accordance with the procedures contained in this subdivision. Because the department presumes that most state waterbodies have freshwater mussels and early life stages of fish present during most times of the year, the criteria shall be calculated assuming freshwater mussels and early life stages of fish are present using subsections B and C of this section unless the following demonstration that freshwater mussels or early life stages of fish are absent is successfully completed. Determination of the absence of freshwater mussels requires special field survey methods. This determination must be made after an adequate survey of the waterbody is conducted by an individual certified by the Virginia Department of Game and Inland Fisheries (DGIF) for freshwater mussel identification and surveys. Determination of absence of freshwater mussels will be done in consultation with the DGIF. Early life stages of fish are defined in subdivision 2 of this subsection. Modifications to the ambient water quality criteria for ammonia based on the presence or absence of early life stages of fish shall only apply at temperatures below 15°C.
a. During the review of any new or existing activity that has a potential to discharge ammonia in amounts that may cause or contribute to a violation of the ammonia criteria contained in subsection B of this section, the department may examine data from the following approved sources in subdivisions 1 a (1) through (5) of this subsection or may require the gathering of data in accordance with subdivisions 1 a (1) through (5) on the presence or absence of early life stages of fish in the affected waterbody.
(1) Species and distribution data contained in the Virginia Department of Game and Inland Fisheries Wildlife Information System database.
(2) Species and distribution data contained in Freshwater Fishes of Virginia, 1994.
(3) Data and fish species distribution maps contained in Handbook for Fishery Biology, Volume 3, 1997.
(4) Field data collected in accordance with U.S. EPA's Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers, Second Edition, EPA 841-B-99-002. Field data must comply with all quality assurance and quality control criteria.
(5) The American Society for Testing and Materials (ASTM) Standard E-1241-88, Standard Guide for Conducting Early Life-Stage Toxicity Tests with Fishes.
b. If data or information from sources other than subdivisions 1 a (1) through (5) of this subsection are considered, then any resulting site-specific criteria modifications shall be reviewed and adopted in accordance with the site-specific criteria provisions in 9VAC25-260-140 D, and submitted to EPA for review and approval.
c. If the department determines that the data and information obtained from subdivisions 1 a (1) through (5) of this subsection demonstrate that there are periods of each year when no early life stages are expected to be present for any species of fish that occur at the site, the department shall issue a notice to the public and make available for public comment the supporting data and analysis along with the department's preliminary decision to authorize the site-specific modification to the ammonia criteria. Such information shall include, at a minimum:
(1) Sources of data and information.
(2) List of fish species that occur at the site as defined in subdivision 3 of this subsection.
(3) Definition of the site. Definition of a "site" can vary in geographic size from a stream segment to a watershed to an entire eco-region.
(4) Duration of early life stage for each species in subdivision 1 c (2) of this subsection.
(5) Dates when early life stages of fish are expected to be present for each species in subdivision 1 c (2) of this subsection.
(6) Based on subdivision 1 c (5) of this subsection, identify the dates (beginning date, ending date), if any, where no early life stages are expected to be present for any of the species identified in subdivision 1 c (2) of this subsection.
d. If, after reviewing the public comments received in subdivision 1 c of this subsection and supporting data and information, the department determines that there are times of the year where no early life stages are expected to be present for any fish species that occur at the site, then the applicable ambient water quality criteria for ammonia for those time periods shall be calculated using the table in this subsection, or the formula for calculating the chronic criterion concentration for ammonia when early life stages of fish are absent.
e. The department shall maintain a comprehensive list of all sites where the department has determined that early life stages of fish are absent. For each site the list will identify the waterbodies affected and the corresponding times of the year that early life stages of fish are absent. This list is available either upon request from the Office of Water Quality Programs at 629 East Main Street, Richmond, VA 23219, or from the department website at http://www.deq.virginia.gov/programs/water/waterqualityinformationtmdls/waterqualitystandards.aspx.
2. The duration of the "early life stages" extends from the beginning of spawning through the end of the early life stages. The early life stages include the prehatch embryonic period, the post-hatch free embryo or yolk-sac fry, and the larval period, during which the organism feeds. Juvenile fish, which are anatomically similar to adults, are not considered an early life stage. The duration of early life stages can vary according to fish species. The department considers the sources of information in subdivisions 1 a (1) through (5) of this subsection to be the only acceptable sources of information for determining the duration of early life stages of fish under this procedure.
3. "Occur at the site" includes the species, genera, families, orders, classes, and phyla that are usually present at the site; are present at the site only seasonally due to migration; are present intermittently because they periodically return to or extend their ranges into the site; or were present at the site in the past or are present in nearby bodies of water, but are not currently present at the site due to degraded conditions, and are expected to return to the site when conditions improve. "Occur at the site" does not include taxa that were once present at the site but cannot exist at the site now due to permanent physical alteration of the habitat at the site.
4. Any modifications to ambient water quality criteria for ammonia in subdivision 1 of this subsection shall not likely jeopardize the continued existence of any federal or state listed, threatened, or endangered species or result in the destruction or adverse modification of such species' critical habitats.
5. Site-specific modifications to the ambient water quality criteria for ammonia to account for the absence of freshwater mussels shall be conducted in accordance with the procedures contained in this subdivision. Because the department presumes that most state waterbodies have freshwater mussel species, the criteria shall be calculated assuming mussels are present using subsections B and C of this section unless the demonstration that freshwater mussels are absent is successfully completed and accepted by DEQ and DGIF.
6. Equations for calculating ammonia criteria for four different site-specific scenarios are provided below as follows: (i) acute criteria when mussels are absent but trout are present, (ii) acute criteria when mussels and trout are absent, (iii) chronic criteria when mussels are absent and early life stages of fish are present, and (iv) chronic criteria when mussels and early life stages of fish are absent. Additional information regarding site-specific criteria can be reviewed in appendix N (pages 225-242) of the EPA Aquatic Life Ambient Water Quality Criteria to Ammonia--Freshwater 2013 (EPA 822-R-13-001).
a. Acute criteria: freshwater mussels absent and trout present.
To calculate total ammonia nitrogen acute criteria values (in mg N/L) in freshwater with freshwater mussels absent (procedures for making this determination are in subdivisions 1 through 5 of this subsection) and trout present, use the equations below. The acute criterion is the lesser of the calculation results below. Round the result to two significant digits.
|
( |
0.275 |
+ |
39 |
) |
|
1 + 107.204-pH |
1 + 10pH-7.204 |
Or
|
0.7249 X ( |
0.0114 |
+ |
1.6181 |
) X (62.15 X 100.036X(20 T)) |
|
1 + 107.204-pH |
1 + 10pH-7.204 |
b. Acute criteria: freshwater mussels absent and trout absent.
To calculate total ammonia nitrogen acute criteria values (in mg N/L) in freshwater where freshwater mussels are absent and trout are absent, use the following equation. Round the result to two significant digits.
|
0.7249 X ( |
0.0114 |
+ |
1.6181 |
) X MIN |
|
1 + 107.204-pH |
1 + 10pH-7.204 |
Where MIN = 51.93 or 62.15 X 100.036 X (20 T), whichever is less.
T = Temperature in oC.
c. Chronic criteria: freshwater mussels absent and early life stages of fish present.
C. The 30-day average concentration of The chronic
criteria for total ammonia nitrogen (in mg N/L) where early life stages
of fish freshwater mussels are absent (procedures for making this
determination are in subdivisions 1 through 4 5 of this
subsection) in freshwater shall not exceed , more than once every three
years on the average3, the chronic criteria concentration
values calculated using the equation below :. Round the result to
two significant digits.
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At 15°C and above, the criterion for fish early life
stages absent is the same as the criterion for fish early life stages present.
To calculate total ammonia nitrogen chronic criteria
values in freshwater when fish early life stages are absent at different pH and
temperature values than those listed in this subsection, use the following
formulas:
Chronic Criteria Concentration =
|
|
|
|
|
|
|
|
|
|
MAX = temperature in °C or 7, whichever is greater.
|
0.9405 X ( |
0.0278 |
+ |
1.1994 |
) X MIN |
|
1 + 107.688-pH |
1 + 10pH-7.688 |
Where MIN = 6.920 or 7.547 X 100.028 x (20 T) whichever is less
T = temperature in °C
3The default design flow for calculating
steady state waste load allocations for the chronic ammonia criterion where
early life stages of fish are absent is the 30Q10 (see 9VAC25-260-140 B
footnote 10) unless statistically valid methods are employed that demonstrate
compliance with the duration and return frequency of the water quality
criteria.
1. Site-specific modifications to the ambient water
quality criteria for ammonia to account for the absence of early life stages of
fish shall be conducted in accordance with the procedures contained in this
subdivision. Because the department presumes that most state waterbodies have
early life stages of fish present during most times of the year, the criteria
shall be calculated assuming early life stages of fish are present using
subsection B of this section unless the following demonstration that early life
stages are absent is successfully completed. Early life stages of fish are
defined in subdivision 2 of this subsection. Modifications to the ambient water
quality criteria for ammonia based on the presence or absence of early life
stages of fish shall only apply at temperatures below 15°C.
a. During the review of any new or existing activity that
has a potential to discharge ammonia in amounts that may cause or contribute to
a violation of the ammonia criteria contained in subsection B of this section,
the department may examine data from the following approved sources in subdivisions
1 a (1) through (5) of this subsection or may require the gathering of data in
accordance with subdivisions 1 a (1) through (5) on the presence or absence of
early life stages of fish in the affected waterbody.
(1) Species and distribution data contained in the
Virginia Department of Game and Inland Fisheries Wildlife Information System
database.
(2) Species and distribution data contained in Freshwater
Fishes of Virginia, 1994.
(3) Data and fish species distribution maps contained in
Handbook for Fishery Biology, Volume 3, 1997.
(4) Field data collected in accordance with U.S. EPA's
Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers, Second
Edition, EPA 841-B-99-002. Field data must comply with all quality
assurance/quality control criteria.
(5) The American Society for Testing and Materials (ASTM)
Standard E-1241-88, Standard Guide for Conducting Early Life-Stage Toxicity
Tests with Fishes.
b. If data or information from sources other than subdivisions
1 a (1) through (5) of this subsection are considered, then any resulting
site-specific criteria modifications shall be reviewed and adopted in
accordance with the site-specific criteria provisions in 9VAC25-260-140 D, and
submitted to EPA for review and approval.
c. If the department determines that the data and
information obtained from subdivisions 1 a (1) through (5) of this subsection
demonstrate that there are periods of each year when no early life stages are
expected to be present for any species of fish that occur at the site, the
department shall issue a notice to the public and make available for public
comment the supporting data and analysis along with the department's
preliminary decision to authorize the site-specific modification to the ammonia
criteria. Such information shall include, at a minimum:
(1) Sources of data and information.
(2) List of fish species that occur at the site as
defined by subdivision 3 of this subsection.
(3) Definition of the site. Definition of a "site"
can vary in geographic size from a stream segment to a watershed to an entire
eco-region.
(4) Duration of early life stage for each species in
subdivision 1 c (2) of this subsection.
(5) Dates when early life stages of fish are expected to be
present for each species in subdivision 1 c (2) of this subsection.
(6) Based on subdivision 1 c (5) of this subsection,
identify the dates (beginning date, ending date), if any, where no early life
stages are expected to be present for any of the species identified in
subdivision 1 c (2) of this subsection.
d. If, after reviewing the public comments received in
subdivision 1 c of this subsection and supporting data and information, the
department determines that there are times of the year where no early life
stages are expected to be present for any fish species that occur at the site,
then the applicable ambient water quality criteria for ammonia for those time
periods shall be calculated using the table in this subsection, or the formula
for calculating the chronic criterion concentration for ammonia when fish early
life stages are absent.
e. The department shall maintain a comprehensive list of
all sites where the department has determined that early life stages of fish
are absent. For each site the list will identify the waterbodies affected and
the corresponding times of the year that early life stages are absent. This
list is available either upon request from the Office of Water Quality Programs
at P.O. Box 1105, Richmond, Virginia 23218 or from the department website
http://www.deq.virginia.gov/wqs.
2. The duration of the "early life stages"
extends from the beginning of spawning through the end of the early life
stages. The early life stages include the prehatch embryonic period, the
post-hatch free embryo or yolk-sac fry, and the larval period, during which the
organism feeds. Juvenile fish, which are anatomically similar to adults, are
not considered an early life stage. The duration of early life stages can vary
according to fish species. The department considers the sources of information
in subdivisions 1 a (1) through (5) of this subsection to be the only
acceptable sources of information for determining the duration of early life
stages of fish under this procedure.
3. "Occur at the site" includes the species,
genera, families, orders, classes, and phyla that: are usually present at the
site; are present at the site only seasonally due to migration; are present
intermittently because they periodically return to or extend their ranges into
the site; were present at the site in the past or are present in nearby bodies
of water, but are not currently present at the site due to degraded conditions,
and are expected to return to the site when conditions improve. "Occur at
the site" does not include taxa that were once present at the site but
cannot exist at the site now due to permanent physical alteration of the
habitat at the site.
4. Any modifications to ambient water quality criteria
for ammonia in subdivision 1 of this subsection shall not likely jeopardize the
continued existence of any federal or state listed, threatened or endangered
species or result in the destruction or adverse modification of such species'
critical habitat.
d. Chronic criteria: freshwater mussels absent and early life stages of fish absent.
The chronic criteria for total ammonia nitrogen (in mg N/L) where freshwater mussels are absent and early life stages of fish are absent (procedures for making this determination are in subdivisions 1 through 5 of this subsection in freshwater shall not exceed concentration values calculated using the equation below. Round the result to two significant digits.
|
0.9405 X ( |
0.0278 |
+ |
1.1994 |
) X(7.547 X 100.028 X (20 - MAX(T,7))) |
|
1 + 107.688-pH |
1 + 10pH-7.688 |
Where MAX = 7 or temperature in degrees Celsius, whichever is greater.
T = temperature in °C
D. E. The one-hour average concentration of
total ammonia nitrogen (in mg N/L) in saltwater shall not exceed, more than
once every three years on the average, the acute criteria below:
|
Acute Ammonia Saltwater Criteria |
||||||||||||||||
|
|
Temperature °C |
|||||||||||||||
|
pH |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
||||||||
|
7.00 |
231.9 |
159.8 |
110.1 |
75.88 |
52.31 |
36.08 |
24.91 |
17.21 |
||||||||
|
7.20 |
146.4 |
100.9 |
69.54 |
47.95 |
33.08 |
22.84 |
15.79 |
10.93 |
||||||||
|
7.40 |
92.45 |
63.73 |
43.94 |
30.32 |
20.94 |
14.48 |
10.03 |
6.97 |
||||||||
|
7.60 |
58.40 |
40.28 |
27.80 |
19.20 |
13.28 |
9.21 |
6.40 |
4.47 |
||||||||
|
7.80 |
36.92 |
25.48 |
17.61 |
12.19 |
8.45 |
5.88 |
4.11 |
2.89 |
||||||||
|
8.00 |
23.37 |
16.15 |
11.18 |
7.76 |
5.40 |
3.78 |
2.66 |
1.89 |
||||||||
|
8.20 |
14.81 |
10.26 |
7.13 |
4.97 |
3.48 |
2.46 |
1.75 |
1.27 |
||||||||
|
8.40 |
9.42 |
6.54 |
4.57 |
3.20 |
2.27 |
1.62 |
1.18 |
0.87 |
||||||||
|
8.60 |
6.01 |
4.20 |
2.95 |
2.09 |
1.50 |
1.09 |
0.81 |
0.62 |
||||||||
|
8.80 |
3.86 |
2.72 |
1.93 |
1.39 |
1.02 |
0.76 |
0.58 |
0.46 |
||||||||
|
9.00 |
2.51 |
1.79 |
1.29 |
0.95 |
0.71 |
0.55 |
0.44 |
0.36 |
||||||||
|
Salinity = 20 g/kg |
||||||||||||||||
|
|
Temperature °C |
|||||||||||||||
|
pH |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
||||||||
|
7.00 |
247.6 |
170.5 |
117.5 |
80.98 |
55.83 |
38.51 |
26.58 |
18.36 |
||||||||
|
7.20 |
156.3 |
107.7 |
74.21 |
51.17 |
35.30 |
24.37 |
16.84 |
11.66 |
||||||||
|
7.40 |
98.67 |
68.01 |
46.90 |
32.35 |
22.34 |
15.44 |
10.70 |
7.43 |
||||||||
|
7.60 |
62.33 |
42.98 |
29.66 |
20.48 |
14.17 |
9.82 |
6.82 |
4.76 |
||||||||
|
7.80 |
39.40 |
27.19 |
18.78 |
13.00 |
9.01 |
6.26 |
4.37 |
3.07 |
||||||||
|
8.00 |
24.93 |
17.23 |
11.92 |
8.27 |
5.76 |
4.02 |
2.83 |
2.01 |
||||||||
|
8.20 |
15.80 |
10.94 |
7.59 |
5.29 |
3.70 |
2.61 |
1.86 |
1.34 |
||||||||
|
8.40 |
10.04 |
6.97 |
4.86 |
3.41 |
2.41 |
1.72 |
1.24 |
0.91 |
||||||||
|
8.60 |
6.41 |
4.47 |
3.14 |
2.22 |
1.59 |
1.15 |
0.85 |
0.65 |
||||||||
|
8.80 |
4.11 |
2.89 |
2.05 |
1.47 |
1.07 |
0.80 |
0.61 |
0.48 |
||||||||
|
9.00 |
2.67 |
1.90 |
1.36 |
1.00 |
0.75 |
0.57 |
0.46 |
0.37 |
||||||||
|
Salinity = 30 g/kg |
||||||||||||||||
|
|
Temperature °C |
|||||||||||||||
|
pH |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
||||||||
|
7.00 |
264.6 |
182.3 |
125.6 |
86.55 |
59.66 |
41.15 |
28.39 |
19.61 |
||||||||
|
7.20 |
167.0 |
115.1 |
79.31 |
54.68 |
37.71 |
26.03 |
17.99 |
12.45 |
||||||||
|
7.40 |
105.5 |
72.68 |
50.11 |
34.57 |
23.87 |
16.50 |
11.42 |
7.92 |
||||||||
|
7.60 |
66.61 |
45.93 |
31.69 |
21.88 |
15.13 |
10.48 |
7.28 |
5.07 |
||||||||
|
7.80 |
42.10 |
29.05 |
20.07 |
13.88 |
9.62 |
6.68 |
4.66 |
3.27 |
||||||||
|
8.00 |
26.63 |
18.40 |
12.73 |
8.83 |
6.14 |
4.29 |
3.01 |
2.13 |
||||||||
|
8.20 |
16.88 |
11.68 |
8.10 |
5.64 |
3.94 |
2.78 |
1.97 |
1.42 |
||||||||
|
8.40 |
10.72 |
7.44 |
5.18 |
3.63 |
2.56 |
1.82 |
1.31 |
0.96 |
||||||||
|
8.60 |
6.83 |
4.77 |
3.34 |
2.36 |
1.69 |
1.22 |
0.90 |
0.68 |
||||||||
|
8.80 |
4.38 |
3.08 |
2.18 |
1.56 |
1.13 |
0.84 |
0.64 |
0.50 |
||||||||
|
9.00 |
2.84 |
2.01 |
1.45 |
1.06 |
0.79 |
0.60 |
0.47 |
0.39 |
||||||||
To calculate total ammonia nitrogen acute criteria values in saltwater at different pH and temperature values than those listed in this subsection, use the following formulas:
|
I = |
19.9273S |
|
(1000 - 1.005109S) |
Where I = molal ionic strength of water
S = Salinity ppt (g/kg)
The regression model used to relate I to pKa (negative log of the ionization constant) is
pKa = 9.245 + .138I 0.138(I)
pKa as defined by these equations is at 298 degrees Kelvin (25°C). T °Kelvin = °C + 273
To correct for other temperatures:
pKaST = pKaS298
+ .0324(298 - T °Kelvin) 0.0324(298 - T °Kelvin)
The unionized ammonia fraction (UIA) is given by:
|
UIA = |
1 |
|
1 + 10(pKaST-pH) |
The acute ammonia criterion in saltwater is given by:
|
Acute = |
|
|
UIA |
Multiply the acute value by .822 0.822 to get
the ammonia-N acute criterion.
E. F. The 30-day average concentration of
total ammonia nitrogen (in mg N/L) in saltwater shall not exceed, more than
once every three years on the average, the chronic criteria below:
|
Chronic Ammonia Saltwater Criteria |
|||||||||||||||||||||||
|
|
Temperature °C |
||||||||||||||||||||||
|
pH |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
|||||||||||||||
|
7.00 |
34.84 |
24.00 |
16.54 |
11.40 |
7.86 |
5.42 |
3.74 |
2.59 |
|||||||||||||||
|
7.20 |
21.99 |
15.15 |
10.45 |
7.20 |
4.97 |
3.43 |
2.37 |
1.64 |
|||||||||||||||
|
7.40 |
13.89 |
9.57 |
6.60 |
4.55 |
3.15 |
2.18 |
1.51 |
1.05 |
|||||||||||||||
|
7.60 |
8.77 |
6.05 |
4.18 |
2.88 |
2.00 |
1.38 |
0.96 |
0.67 |
|||||||||||||||
|
7.80 |
5.55 |
3.83 |
2.65 |
1.83 |
1.27 |
0.88 |
0.62 |
0.43 |
|||||||||||||||
|
8.00 |
3.51 |
2.43 |
1.68 |
1.17 |
0.81 |
0.57 |
0.40 |
0.28 |
|||||||||||||||
|
8.20 |
2.23 |
1.54 |
1.07 |
0.75 |
0.52 |
0.37 |
0.26 |
0.19 |
|||||||||||||||
|
8.40 |
1.41 |
0.98 |
0.69 |
0.48 |
0.34 |
0.24 |
0.18 |
0.13 |
|||||||||||||||
|
8.60 |
0.90 |
0.63 |
0.44 |
0.31 |
0.23 |
0.16 |
0.12 |
0.09 |
|||||||||||||||
|
8.80 |
0.58 |
0.41 |
0.29 |
0.21 |
0.15 |
0.11 |
0.09 |
0.07 |
|||||||||||||||
|
9.00 |
0.38 |
0.27 |
0.19 |
0.14 |
0.11 |
0.08 |
0.07 |
0.05 |
|||||||||||||||
|
Salinity = 20 g/kg |
|
||||||||||||||||||||||
|
|
Temperature °C |
|
|||||||||||||||||||||
|
pH |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
|
||||||||||||||
|
7.00 |
37.19 |
25.62 |
17.65 |
12.16 |
8.39 |
5.78 |
3.99 |
2.76 |
|
||||||||||||||
|
7.20 |
23.47 |
16.17 |
11.15 |
7.69 |
5.30 |
3.66 |
2.53 |
1.75 |
|
||||||||||||||
|
7.40 |
14.82 |
10.22 |
7.04 |
4.86 |
3.36 |
2.32 |
1.61 |
1.12 |
|
||||||||||||||
|
7.60 |
9.36 |
6.46 |
4.46 |
3.08 |
2.13 |
1.47 |
1.02 |
0.71 |
|
||||||||||||||
|
7.80 |
5.92 |
4.08 |
2.82 |
1.95 |
1.35 |
0.94 |
0.66 |
0.46 |
|
||||||||||||||
|
8.00 |
3.74 |
2.59 |
1.79 |
1.24 |
0.86 |
0.60 |
0.43 |
0.30 |
|
||||||||||||||
|
8.20 |
2.37 |
1.64 |
1.14 |
0.79 |
0.56 |
0.39 |
0.28 |
0.20 |
|
||||||||||||||
|
8.40 |
1.51 |
1.05 |
0.73 |
0.51 |
0.36 |
0.26 |
0.19 |
0.14 |
|
||||||||||||||
|
8.60 |
0.96 |
0.67 |
0.47 |
0.33 |
0.24 |
0.17 |
0.13 |
0.10 |
|
||||||||||||||
|
8.80 |
0.62 |
0.43 |
0.31 |
0.22 |
0.16 |
0.12 |
0.09 |
0.07 |
|
||||||||||||||
|
9.00 |
0.40 |
0.28 |
0.20 |
0.15 |
0.11 |
0.09 |
0.07 |
0.06 |
|
||||||||||||||
|
Salinity = 30 g/kg |
|
||||||||||||||||||||||
|
|
Temperature °C |
|
|||||||||||||||||||||
|
pH |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
|
||||||||||||||
|
7.00 |
39.75 |
27.38 |
18.87 |
13.00 |
8.96 |
6.18 |
4.27 |
2.95 |
|
||||||||||||||
|
7.20 |
25.09 |
17.29 |
11.91 |
8.21 |
5.67 |
3.91 |
2.70 |
1.87 |
|
||||||||||||||
|
7.40 |
15.84 |
10.92 |
7.53 |
5.19 |
3.59 |
2.48 |
1.72 |
1.19 |
|
||||||||||||||
|
7.60 |
10.01 |
6.90 |
4.76 |
3.29 |
2.27 |
1.57 |
1.09 |
0.76 |
|
||||||||||||||
|
7.80 |
6.32 |
4.36 |
3.01 |
2.08 |
1.44 |
1.00 |
0.70 |
0.49 |
|
||||||||||||||
|
8.00 |
4.00 |
2.76 |
1.91 |
1.33 |
0.92 |
0.64 |
0.45 |
0.32 |
|
||||||||||||||
|
8.20 |
2.53 |
1.75 |
1.22 |
0.85 |
0.59 |
0.42 |
0.30 |
0.21 |
|
||||||||||||||
|
8.40 |
1.61 |
1.12 |
0.78 |
0.55 |
0.38 |
0.27 |
0.20 |
0.14 |
|
||||||||||||||
|
8.60 |
1.03 |
0.72 |
0.50 |
0.35 |
0.25 |
0.18 |
0.14 |
0.10 |
|
||||||||||||||
|
8.80 |
0.66 |
0.46 |
0.33 |
0.23 |
0.17 |
0.13 |
0.10 |
0.08 |
|
||||||||||||||
|
9.00 |
0.43 |
0.30 |
0.22 |
0.16 |
0.12 |
0.09 |
0.07 |
0.06 |
|
||||||||||||||
To calculate total ammonia nitrogen chronic criteria values in saltwater at different pH and temperature values than those listed in this subsection, use the following formulas:
|
I = |
19.9273S |
|
(1000 - 1.005109S) |
Where I = molal ionic strength of water
S = Salinity ppt (g/kg)
The regression model used to relate I to pKa (negative log of the ionization constant) is
pKa = 9.245 + .138I 0.138(I)
pKa as defined by these equations is at 298 degrees Kelvin (25°C). T °Kelvin = °C + 273
To correct for other temperatures:
pKaST = pKaS298
+ 0324(298 - T °Kelvin) 0.0324(298 - T °Kelvin)
The unionized ammonia fraction (UIA) is given by:
|
UIA = |
1 |
|
1 + 10(pKaST-pH) |
The chronic ammonia criterion in saltwater is given by:
|
Chronic = |
|
|
UIA |
Multiply the chronic value by .822 0.822 to
get the ammonia-N chronic criterion.
1The default design flow for calculating steady state wasteload allocations for the acute ammonia criterion for freshwater is the 1Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.
2The default design flow for calculating steady state wasteload allocations for the chronic ammonia criterion for freshwater is the 30Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.
G. Implementation of Ammonia Criteria through VPDES Permits.
The ammonia criteria in subsections A through C shall be addressed during individual VPDES permit reissuance for existing dischargers subject to new or more restrictive water quality-based ammonia effluent limits in accordance with the Department's standard permitting practices except as follows.
- Notwithstanding any other regulatory requirement, a compliance schedule may be established that exceeds the term of the permit, subject to a demonstration by the permittee that a longer period is necessary to allow a reasonable opportunity to attain compliance with the new or more restrictive ammonia discharge requirements. The Department's consideration for such a demonstration shall be made on a case-by-case basis, and shall require compliance as soon as possible, but not later than the applicable statutory deadline under the Clean Water Act.
- Information to be provided under subsection G.1 may include, but is not limited to, such factors as: (i) opportunities to minimize costs to the public or facility owners by phasing in the implementation of multiple projects; (ii) time needed for freshwater mussel habitat determinations; and (iii) other relevant factors.
- If a permit establishes a schedule of compliance which exceeds the term of the permit, the compliance schedule shall set forth interim requirements and the dates for their achievement.
a. The time between interim dates shall not exceed one year.
b. If the time necessary for completion of any interim requirement is more than one year and is not readily divisible into stages for completion, the permit shall specify interim dates for the submission of reports of progress toward completion of the interim requirements and indicate a projected completion date.
c. The permit shall be written to require that no later than 14 days following each interim date and the final date of compliance, the permittee shall notify the Department in writing of its compliance or noncompliance with the interim or final requirements, or submit progress reports if subdivision 3.b is applicable.
d. Any change to an interim compliance date in the schedule of compliance will be deemed to be a Minor Modification of the permit, provided the new date is not more than 120 days after the date specified in the existing permit and does not interfere with attainment of the final compliance date requirement.
9VAC25-260-170. Bacteria; other recreational waters.
A. The following bacteria criteria (colony forming units (CFU)/100 ml) shall apply to protect primary contact recreational uses in surface waters, except waters identified in subsection B of this section:
E. coli bacteria shall not exceed a monthly geometric mean of 126 CFU/100 ml in freshwater and no more than 10% of the samples in the assessment period shall exceed a Statistical Threshold Value (STV) of 410 CFU/100 ml..
Enterococci bacteria shall not exceed a monthly geometric mean of 35 CFU/100 ml in transition and saltwater and no more than 10% of the samples in the assessment period shall exceed a Statistical Threshold Value (STV) of 130 CFU/100 ml.
1. See 9VAC25-260-140 C for boundary delineations for freshwater, transition and saltwater.
2. Geometric means shall be calculated using all data
collected during any calendar month with a minimum of four weekly samples. The
Virginia Department of Health (VDH) shall make determinations regarding beach
advisories or closures.
3. If there are insufficient data to calculate monthly
geometric means in freshwater, no more than 10% of the total samples in the
assessment period shall exceed 235 E. coli CFU/100 ml.
4. If there are insufficient data to calculate monthly
geometric means in transition and saltwater, no more than 10% of the total
samples in the assessment period shall exceed enterococci 104 CFU/100 ml.
5. For beach advisories or closures, a single sample maximum
of 235 E. coli CFU/100 ml in freshwater and a single sample maximum of 104 enterococci
CFU/100 ml in saltwater and transition zones shall apply .
B. The following bacteria criteria per 100 ml (CFU/100 ml)
of water shall apply:
E. coli bacteria shall not exceed a monthly geometric mean
of 630 CFU/100 ml in freshwater.
Enterococci bacteria shall not exceed a monthly geometric
mean of 175 CFU/100 ml in transition and saltwater.
1. See 9VAC25-260-140 C for boundary delineations for
freshwater, transition and saltwater.
2. Geometric means shall be calculated using all data
collected during any calendar month with a minimum of four weekly samples.
3. If there is insufficient data to calculate monthly
geometric means in freshwater, no more than 10% of the total samples in the
assessment period shall exceed 1173 E. coli CFU/100 ml.
4. If there is insufficient data to calculate monthly
geometric means in transition and saltwater, no more than 10% of the total
samples in the assessment period shall exceed 519 enterococci CFU/100 ml.
5. Where the existing water quality for bacteria is below the
geometric mean criteria in a water body designated for secondary contact in
subdivision 6 of this subsection that higher water quality will be maintained
in accordance with 9VAC25-260-30 A 2.
6. Surface waters designated under this subsection are as
follows:
a. (Reserved)
b. (Reserved)
c. (Reserved)