1104.1 The surface waters of the District shall be free from substances in amounts or combinations that do any one of the following:

1. (a) Settle to form objectionable deposits;
2. (b) Float as debris, scum, oil, or other matter to create a nuisance;
3. (c) Produce objectionable odor, color, taste, or turbidity;
4. (d) Cause injury to, are toxic to, or produce adverse physiological or behavioral changes in humans, plants, or animals;
5. (e) Produce undesirable or nuisance aquatic life or result in the dominance of nuisance species; or
6. (f) Impair the biological community that naturally occurs in the waters or depends upon the waters for its survival and propagation.

1104.2 For the waters of the District with multiple designated uses, the most stringent standards or criteria shall govern.

1104.3 Class A waters shall be free of discharges of untreated sewage, litter and unmarked submerged or partially submerged man-made structures that would constitute a hazard to the users of Class A waters.

1104.4 The aesthetic qualities of Class B waters shall be maintained. Construction, placement or mooring of facilities not primarily and directly water oriented is prohibited in, on, or over Class B waters unless:

1. (a) The facility is for the general public benefit and service, and
2. (b) Land based alternatives are not available.

1104.5 Class C streams shall be maintained to support aquatic life and shall not be placed in pipes.

1104.6 Within tidally influenced Class C waters, concentrations of chlorophyll a in free-floating microscopic aquatic plants (algae) shall not exceed levels that result in ecologically undesirable consequences such as reduced water clarity, low dissolved oxygen, food supply imbalances, proliferation of species deemed potentially harmful to aquatic life or humans or aesthetically objectionable conditions or otherwise render tidal waters unsuitable for designated uses.

1104.7 Class E waters shall be free of unmarked submerged or partially submerged man-made objects that pose a hazard to users of these waters.

1104.8 Unless otherwise stated, the numeric criteria that shall be met to attain and maintain designated uses are as follows in Tables 1 through 3:

Table 1: Conventional Constituents Numeric Criteria

Constituent	Class A	Class B	Class C
Chlorophyll aa,b (µg/L)(seasonal segment average)
July 1 through September 30	—	—	25
Dissolved Oxygen (mg/L)
Instantaneous minimum (year-round)c	—	—	5.0
February 1 through May 31a,b
7-day mean	—	—	6.0
Instantaneous minimum	—	—	5.0
June 1 through January 31a,b
30-day mean	—	—	5.5
7-day mean	—	—	4.0
Instantaneous minimumd	—	—	3.2
E. colie (MPN/100 mL)
Single Sample Value	410	—	—
Geometric mean (Geometric mean of 5 samples over a maximum period of 30 days)	126	—	—
Hydrogen sulfide (maximum µg/L)	—	—	2.0
Oil and grease (mg/L)	—	—	10.0
pH
Greater than	6.0	6.0	6.0
And less than	8.5	8.5	8.5
Secchi deptha,b (m)(seasonal segment average)
April 1 through October 31	—	—	0.8
Temperature (°C)
Maximum	—	—	32.2
Maximum change above ambient	—	—	2.8
Total dissolved gases (maximum % saturation)	—	—	110
Turbidity Increase above Ambient (NTU)f	20	20	20

Notes:

^a Attainment of the dissolved oxygen, water clarity and chlorophyll a water quality criteria that apply to tidally influenced Class C waters will be determined following the guidelines documented in the 2003 Environmental Protection Agency publication: Ambient Water Quality

Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and its Tidal Tributaries, EPA 903-R-03-002 (April 2003, Region III Chesapeake Bay Program Office, Annapolis, Maryland); 2004 Addendum, EPA 903-R-04-005 (October 2004); 2007 Addendum, EPA 903-R-07-003 CBP/TRS 285/07 (July 2007); 2007 Chlorophyll Criterion Addendum, EPA 903-R-07-005 CBP/TRS 288-07 (November 2007); 2008 Addendum, EPA 903-R-08-001 CBP/TRS 290-08 (September 2008); and 2010 Criterion Addendum, EPA 903-R-10-002 CBP/TRS-301-10 (May 2010).

^b This criterion shall apply to only tidally influenced waters.

^c This criterion shall apply to only non-tidal waters.

^d An instantaneous minimum dissolved oxygen concentration of 4.3 mg/L shall apply in tidally influenced waters at temperatures greater than 29°C.

^e The geometric mean criterion shall be used for assessing water quality trends and for permitting. The single sample value criterion shall be used for assessing water quality trends only.

^f The ambient turbidity equivalent for Piedmont river mainstems and tributaries (Potomac River northwest of the Theodore Roosevelt Bridge and its tributaries, and Rock Creek) is 1 NTU. The ambient equivalent for Coastal Plain river mainstems and tributaries (Potomac River east of the Theodore Roosevelt Bridge and Anacostia River and its tributaries) is 6 NTU.

Table 2: Trace Metals and Inorganics Numeric Criteria

Constituenta Trace metals and inorganics in µg/L, except where stated otherwise (see Notes below)	CAS Number	Class C		Class Db 30-Day Avg
		CMC 1-Hour Avg (Acute)	CCC 4-Day Avg (Chronic)
Ammonia, total ammonia nitrogen (in mg N/L)	7664417	See Footnote g	See Footnote h	—
Antimony, total recoverable	7440360	—	—	640
Arsenic, dissolved	7440382	340	150	0.14c
Cadmium, dissolved	7440439	See Footnotes d and e	See Footnotes d and e	—
Chlorine, total residual	7782505	19	11	—
Chromium, hexavalent, dissolved	18540299	16e	11e	—
Chromium, trivalent,	16065831	See Footnotes d and	See Footnotes d	—

dissolved		e	and e
Copper, dissolved	7440508	See Footnotes d and e	See Footnotes d and e	—
Cyanide, free	57125	22	5.2	400
Iron, dissolved	7439896	—	1,000	—
Lead, dissolved	7439921	See Footnotes d and e	See Footnotes d and e	—
Manganese	7439965	—	—	100
Mercury, dissolved	7439976	1.4e	0.77e	0.15
Methylmercury (mg/kg, fish tissue residue)	22967926	—	—	0.3
Nickel, dissolved	7440020	See Footnotes d and e	See Footnotes d and e	4,600
Selenium, total recoverable	7782492	20	5	4,200
Silver, dissolved	7440224	See Footnotes d and e	—	65,000
Thallium, dissolved	7440280	—	—	0.47
Zinc, dissolved	7440666	See Footnotes d and e	See Footnotes d and e	26,000

Notes:

^a If there are no numeric criteria listed for a constituent, the criteria to attain and maintain designated uses shall be the narrative criteria for toxics contained in these water quality standards.

^b The Class D human health criteria for metals are based on total recoverable metals.

^c The criteria is based on carcinogenicity of 10^-6 risk level.

^d The formulas for calculating the criterion for the hardness dependent constituents indicated above are as follows:

Table 2a: Formulas for Hardness-Dependent Constituents^e

Constituent	CMC (Acute)	CCC (Chronic)
Cadmium	$$e(0.9789[\ln(hardness)] - 3.866)$$	$$e(0.7977[\ln(hardness)] - 3.909)$$
Chromium III	$$e(0.8190[\ln(hardness)] + 3.7256)$$	$$e(0.8190[\ln(hardness)] + 0.6848)$$
Copper	$$e(0.9422[\ln(hardness)] - 1.700)$$	$$e(0.8545[\ln(hardness)] - 1.702)$$
Lead	$$e(1.2730[\ln(hardness)] - 1.460)$$	$$e(1.2730[\ln(hardness)] - 4.705)$$
Nickel	$$e(0.8460[\ln(hardness)] + 2.255)$$	$$e(0.8460[\ln(hardness)] + 0.0584)$$
Silver	$$e(1.7200[\ln(hardness)] - 6.590)$$	—
Zinc	$$e(0.8473[\ln(hardness)] + 0.884)$$	$$e(0.8473[\ln(hardness)] + 0.884)$$

e The criterion is multiplied by the EPA conversion factor which converts the total recoverable metal to dissolved metal in Table 2b as specified in §1105.10:

Table 2b: Conversion Factors from Total Recoverable to Dissolved Metalsf

Constituent	CMC (Acute)	CCC (Chronic)
Cadmium	1.136672 – [(ln hardness)(0.041838)]	1.101672 – [(ln hardness)(0.041838)]
Chromium III	0.316	0.860
Chromium VI	0.982	0.962
Copper	0.960	0.960
Lead	1.46203 – [(ln hardness)(0.145712)]	1.46203 – [(ln hardness)(0.145712)]
Mercury	0.85	0.85
Nickel	0.998	0.997
Silver	0.85	—
Zinc	0.978	0.986

f Hardness in Tables 2a and 2b shall be measured as mg/L of calcium carbonate (CaCO₃). The allowed hardness value range shall be 25 – 400 mg/L as CaCO₃, even if the actual ambient water hardness is outside of that range.

g Criterion Maximum Concentration (CMC) for total ammonia nitrogen (in mg N/L):

1. (a) Shall be the one (1)-hour average concentration for total ammonia nitrogen, computed for a design flow specified in §1105.5.
2. (b) Shall account for the influence of the pH as shown in Table 2c.
3. (c) Is calculated using the following formula, which shall be used to calculate unlisted values: CMC = [(0.411/(1+10⁷·²⁰⁴·pH)] + [58.4/(1+ 10⁹·⁷·²⁰⁴)].

Table 2c: Total Ammonia Nitrogen (in mg N/L) CMC for Various pH

pH	CMC	pH	CMC	pH	CMC	pH	CMC
6.50	48.8	7.20	29.5	7.90	10.1	8.60	2.65
6.60	46.8	7.30	26.2	8.00	8.40	8.70	2.20
6.70	44.6	7.40	23.0	8.10	6.95	8.80	1.84
6.80	42.0	7.50	19.9	8.20	5.72	8.90	1.56
6.90	39.1	7.60	17.0	8.30	4.71	9.00	1.32
7.00	36.1	7.70	14.4	8.40	3.88
7.10	32.8	7.80	12.1	8.50	3.20

h Criterion Continuous Concentration (CCC) for total ammonia nitrogen (in mg TAN/L):

(a) Shall be the thirty (30)-day average concentration for total ammonia computed for a design flow specified in §1105.5.

(b) Shall account for the influence of the pH and temperature as shown in Table 2d and Table 2e. The highest four (4)-day average within the thirty (30)-day period shall not exceed 2.5 times the CCC.

(c) Is, for the period March 1 through June 30, calculated using the following formula, which shall be used to calculate unlisted values: CCC = [(0.0577/(1+10⁷·⁶⁸⁸ᵖʰ⁾) + (2.487/(1+ 10ᵖᴴ⁻⁷·⁶⁸⁸))] × MIN(2.85, 1.45 × 10⁰·⁰²⁸ × (²⁵·ᵀ))], where MIN indicates the lesser of the two values (2.85, 1.45 × 10⁰·⁰²⁸ × (²⁵·ᵀ)) separated by a comma, as shown in Table 2c

(d) Is, for the period July 1 through February 28/29, calculated using the following formula, which shall be used to calculate unlisted values: CCC = [(0.0577/(1+10⁷·⁶⁸⁸ᵖʰ⁾) + (2.487/(1+ 10ᵖᴴ⁻⁷·⁶⁸⁸))] × [1.45 × 10⁰·⁰²⁸ × (²⁵·ᴹᴀˣ(T,7))], where MAX indicates the greater of the two values (T,7) separated by a comma, as shown in Table 2d.

Table 2d: Total Ammonia Nitrogen (in mg N/L) CCC for Various pH and Temperatures for March 1 through June 30

pH	Temperature (°C)
	0	14	16	18	20	22	24	26	28	30
6.50	6.67	6.67	6.06	5.33	4.68	4.12	3.62	3.18	2.80	2.46
6.60	6.57	6.57	5.97	5.25	4.61	4.05	3.56	3.13	2.75	2.42
6.70	6.44	6.44	5.86	5.15	4.52	3.98	3.42	3.00	2.64	2.32
6.80	6.29	6.29	5.72	5.03	4.42	3.89	3.42	3.00	2.64	2.32
6.90	6.12	6.12	5.56	4.89	4.30	3.78	3.32	2.92	2.57	2.25
7.00	5.91	5.91	5.37	4.72	4.15	3.65	3.21	2.82	2.48	2.18
7.10	5.67	5.67	5.15	4.53	3.98	3.50	3.08	2.70	2.38	2.09
7.20	5.39	5.39	4.90	4.31	3.78	3.33	2.92	2.57	2.26	1.99
7.30	5.08	5.08	4.61	4.06	3.57	3.13	2.76	2.42	2.13	1.87
7.40	4.73	4.73	4.30	3.97	3.49	3.06	2.69	2.37	2.08	1.83
7.50	4.36	4.36	3.97	3.49	3.06	2.69	2.37	2.08	1.83	1.61
7.60	3.98	3.98	3.61	3.18	2.79	2.45	2.16	1.90	1.67	1.47
7.70	3.58	3.58	3.25	2.86	2.51	2.21	1.94	1.71	1.50	1.32
7.80	3.18	3.18	2.89	2.54	2.23	1.96	1.73	1.52	1.33	1.17
7.90	2.80	2.80	2.54	2.24	1.96	1.73	1.52	1.33	1.17	1.03
8.00	2.43	2.43	2.21	1.94	1.71	1.50	1.32	1.16	1.02	0.897
8.10	2.10	2.10	1.91	1.68	1.47	1.29	1.14	1.00	0.879	0.773
8.20	1.79	1.79	1.63	1.43	1.26	1.11	0.973	0.855	0.752	0.661
8.30	1.52	1.52	1.39	1.22	1.07	0.941	0.827	0.727	0.639	0.562
8.40	1.29	1.29	1.17	1.03	0.906	0.796	0.700	0.615	0.541	0.475

8.50	1.09	1.09	0.990	0.870	0.765	0.672	0.591	0.520	0.457	0.401
8.60	0.920	0.920	0.836	0.735	0.646	0.568	0.499	0.439	0.386	0.339
8.70	0.778	0.778	0.707	0.622	0.547	0.480	0.422	0.371	0.326	0.287
8.80	0.661	0.661	0.601	0.528	0.464	0.408	0.359	0.315	0.277	0.208
8.90	0.565	0.565	0.513	0.451	0.397	0.349	0.306	0.269	0.237	0.208
9.00	0.486	0.486	0.442	0.389	0.342	0.300	0.264	0.232	0.204	0.179

Table 2e: Total Ammonia Nitrogen (in mg N/L) CCC Criterion for Various pH and Temperatures for July 1 through February 28/29

pH	Temperature (°C)
	0-7	8	9	10	11	12	13	14	15*	16*
6.50	10.8	10.1	9.51	8.92	8.36	7.84	7.35	6.89	6.46	6.06
6.60	10.7	9.99	9.37	8.79	8.24	7.72	7.24	6.79	6.36	5.97
6.70	10.5	9.81	9.20	8.62	8.08	7.58	7.11	6.66	6.25	5.86
6.80	10.2	9.58	8.98	8.42	7.90	7.40	6.94	6.51	6.10	5.72
6.90	9.93	9.31	8.73	8.19	7.68	7.20	6.75	6.33	5.93	5.56
7.00	9.60	9.00	8.43	7.91	7.41	6.95	6.52	6.11	5.73	5.37
7.10	9.20	8.63	8.09	7.58	7.11	6.67	6.25	5.86	5.49	5.15
7.20	8.75	8.20	7.69	7.21	6.76	6.34	5.94	5.57	5.22	4.90
7.30	8.24	7.73	7.25	6.79	6.37	5.97	5.60	5.25	4.92	4.61
7.40	7.69	7.21	6.76	6.33	5.94	5.57	5.22	4.89	4.59	4.30
7.50	7.09	6.64	6.23	5.84	5.48	5.13	4.81	4.51	4.23	3.97
7.60	6.46	6.05	5.67	5.32	4.99	4.68	4.38	4.11	3.85	3.61
7.70	5.81	5.45	5.11	4.79	4.49	4.21	3.95	3.70	3.47	3.25
7.80	5.17	4.84	4.54	4.26	3.99	3.74	3.51	3.29	3.09	2.89
7.90	4.54	4.26	3.99	3.74	3.51	3.29	3.09	2.89	2.71	2.54
8.00	3.95	3.70	3.47	3.26	3.05	2.86	2.68	2.52	2.36	2.21
8.10	3.41	3.19	2.99	2.81	2.63	2.47	2.31	2.17	2.03	1.91
8.20	2.91	2.73	2.56	2.4	2.25	2.11	1.98	1.85	1.74	1.63
8.30	2.47	2.32	2.18	2.04	1.91	1.79	1.68	1.58	1.48	1.39
8.40	2.09	1.96	1.84	1.73	1.62	1.52	1.42	1.33	1.25	1.17
8.50	1.77	1.66	1.55	1.46	1.37	1.28	1.20	1.13	1.06	0.990
8.60	1.49	1.40	1.31	1.23	1.15	1.08	1.01	0.951	0.892	0.836
8.70	1.26	1.18	1.11	1.04	0.976	0.915	0.858	0.805	0.754	0.707
8.80	1.07	1.01	0.944	0.885	0.829	0.778	0.729	0.684	0.641	0.601
8.90	0.917	0.860	0.806	0.756	0.709	0.664	0.623	0.584	0.548	0.513
9.00	0.790	0.740	0.694	0.651	0.610	0.572	0.536	0.503	0.471	0.442

*At 15°C and above, the criterion for July 1 through February 28/29 is the same as the criterion for March 1 through June 30.

Table 3: Organic Constituents Numeric Criteria

Organic Constituenta (µg/L)	CAS Number	Class C		Class D
		CMC 1-Hour Avg (Acute)	CCC 4-Day Avg (Chronic)	30-Day Avg
Acrolein	107028	3.0	3.0	400
Acrylonitrile	107131	—	700.0	7.0,b
Aldrin	309002	3.0	0.4	0.00000077,b
Benzene	71432	—	1000	16,b
Benzidine	92875	—	250	0.011,b
Carbamates	—	—	—	—
Carbaryl (Sevin)	63252	2.1	2.1	—
Carbon Tetrachloride	56235	—	1000	5,b
Chlordane	57749	2.4	0.0043	0.00032,b
Chlorinated Benzenes (except Di)	—	—	25.0	—
Chlorobenzene	108907	—	—	800
1,2-Dichlorobenzene	95501	—	200	3,000
1,3-Dichlorobenzene	541731	—	200	10
1,4-Dichlorobenzene	106467	—	200	900
Hexachlorobenzene	118741	—	—	0.000079,b
Pentachlorobenzene	608935	—	—	0.1
1,2,4,5-Tetrachlorobenzene	95943	—	—	0.03
1,2,4-Trichlorobenzene	120821	—	—	0.076
Chlorinated Ethanes	—	—	50	—
1,2-Dichloroethane	107062	—	—	650,b
Hexachloroethane	67721	—	—	0.1,b
1,1,2,2-Tetrachloroethane	79345	—	—	3,b
1,1,1-Trichloroethane	71556	—	—	200,000
1,1,2-Trichloroethane	79005	—	—	8.9,b
Chlorinated Naphthalenes	—	—	—	—
2-Chloronaphthalene	91587	—	200	1000
Chlorinated Phenols	—	—	—	—
2-Chlorophenol	95578	—	100	800
2,4-Dichlorophenol	120832	—	200	60
Pentachlorophenol	87865	Footnote c	Footnote c	0.04,b
2,4,5-Trichlorophenol	95954	—	—	600
2,4,6-Trichlorophenol	88062	—	—	2.8,b
3-Methyl-4-Chlorophenol	59507	—	—	2,000
Chloroalkyl Ethers	—	—	1000	—
Bis(2-Chloroethyl) Ether	111444	—	—	2.2,b

Bis(2-Chloro-1-methylethyl) Ether	108601	—	—	4,000
Bis(Chloromethyl) Ether	542881	—	—	0.017,b
Chlorophenoxy Herbicide (2,4-D)	94757	—	—	12,000
Chlorophenoxy Herbicide (2,4,5-TP) [Silvex]	93721	—	—	400
3,3-Dichlorobenzidine	91941	—	10	0.15,b
Dichloroethylenes	—	—	1000	—
1,1-Dichloroethylene	75354	—	—	20,000
Trans-1,2-Dichloroethylene	156605	—	—	4,000
1,2-Dichloropropane	78875	—	2000	31,b
Dichloropropenes	—	—	400	—
1,3-Dichloropropene	542756	—	—	12,b
Dieldrin	60571	0.24	0.056	0.0000012,b
2,4-Dimethylphenol	105679	—	200	3000
2,4-Dinitrotoluene	121142	—	33	1.7,b
Dioxin (2,3,7,8-TCDD)	1746016	—	—	0.0000000051,b
1,2-Diphenylhydrazine	122667	—	30	0.2,b
Endosulfan	—	0.22	0.056	89
alpha-Endosulfan	959988	0.22	0.056	30
beta-Endosulfan	33213659	0.22	0.056	40
Endosulfan Sulfate	1031078	—	—	40
Endrin	72208	0.086	0.036	0.03
Endrin Aldehyde	7421934	—	—	1
Ethylbenzene	100414	—	40	130
Halomethanes	—	—	1000	—
Bromoform	75252	—	—	120,b
Chloroform	67663	—	3000	2000
Chlorodibromomethane	124481	—	—	21,b
Dichlorobromomethane	75274	—	—	27,b
Methyl Bromide	74839	—	—	10,000
Methylene Chloride	75092	—	—	1,000,b
Heptachlor	76448	0.52	0.0038	0.0000059,b
Heptachlor Epoxide	1024573	0.52	0.0038	0.000032,b
Hexachlorobutadiene	87683	—	10	0.01,b
Hexachlorocyclohexane (HCH)-Technical	608731	—	—	0.010,b
alpha-Hexachlorocyclohexane (HCH)	319846	—	—	0.00039,b
beta-Hexachlorocyclohexane (HCH)	319857	—	—	0.014,b

gamma-Hexachlorocyclohexane (HCH) [Lindane]	58899	0.95	0.08	4.4
Hexachlorocyclopentadiene	77474	—	0.5	4
Isophorone	78591	—	1000	1,800,b
Methoxychlor	72435	—	0.03	0.02
Mirex	2385855	—	0.001	—
Nitrobenzene	98953	—	1000	600
Nitrophenols	—	—	20	—
2-Methyl-4,6- Dinitrophenol	534521	—	—	30
2,4-Dinitrophenol	51285	—	—	300
Dinitrophenols	25550587	—	—	1,000
Nitrosamines	—	—	600	1.24,b
N-Nitrosodibutylamine	924163	—	—	0.22b
N-Nitrosodiethylamine	55185	—	—	1.24,b
N-Nitrosodimethylamine	62759	—	—	3.0,b
N-Nitrosodi-n-Propylamine	621647	—	—	0.51,b
N-Nitrosodiphenylamine	86306	—	—	6.0,b
N-Nitrosopyrrolidine	930552	—	—	34,b
Nonylphenol	84852153	28	6.6	—
Organochlorides	—	—	—	—
4,4'-DDD	72548	1.1	0.001	0.00012,b
4,4'-DDE	72559	1.1	0.001	0.000018,b
4,4'-DDT	50293	1.1	0.001	0.000030,b
Organophosphates	—	—	—	—
Diazinon	333415	0.17	0.17	—
Guthion	86500	—	0.01	—
Malathion	121755	—	0.1	—
Parathion	56382	0.065	0.013	—
Phenol	108952	—	—	300,000
Phthalate Esters	—	—	100	—
Bis(2-Ethylhexyl) Phthalate	117817	—	—	0.37,b
Butylbenzyl Phthalate	85687	—	—	0.10,b
Diethyl Phthalate	84662	—	—	600
Dimethyl Phthalate	131113	—	—	2,000
Di-n-Butyl Phthalate	84742	—	—	30
Polychlorinated Biphenyls (PCB)d	—	—	0.014	0.000064,b
Polynuclear aromatic hydrocarbons (PAH)	—	—	—	—
Acenaphthene	83329	—	50	90
Acenaphthylene	208968	—	—	—
Anthracene	120127	—	—	400

Benzo(a)anthracene	56553	—	—	0.0013,b
Benzo(a)pyrene	50328	—	—	0.00013,b
Benzo(b)fluoranthene	205992	—	—	0.0013,b
Benzo(k)fluoranthene	207089	—	—	0.013,b
Chrysene	218019	—	—	0.13,b
Dibenzo(a,h)anthracene	53703	—	—	0.00013,b
Fluoranthene	206440	—	400	20
Fluorene	86737	—	—	70
Indeno(1,2,3-cd)pyrene	193395	—	—	0.0013,b
Naphthalene	91203	—	600	—
Pyrene	129000	—	—	30
Tetrachloroethylene	127184	—	800	29,b
Toluene	108883	—	600	520
Toxaphene	8001352	0.73	0.0002	0.00071,b
Tributyltin (TBT)	—	0.46	0.072	—
Trichloroethylene	79016	—	1000	7,b
Vinyl chloride	75014	—	—	1.6,b

Notes:

^a For constituents with blank numeric criteria, EPA has not made a criteria recommendation under CWA 304(a) at this time. However, permit authorities will address these constituents in NPDES permit actions using the narrative criteria for toxics.

^b The criteria are based on carcinogenicity of 10^-6 risk level.

^c The formulas for calculating the concentrations of substances indicated above are as follows:

Pentachlorophenol CMC ($\mu$g/L)	Pentachlorophenol CCC ($\mu$g/L)
$e^{(1.005(\text{pH}) - 4.869)}$	$e^{(1.005(\text{pH}) - 5.134)}$

^d The polychlorinated biphenyls (PCB) criterion applies to total PCBs (e.g., the sum of all congener, isomer, homolog, or Aroclor analyses.)

SOURCE: Final Rulemaking published at 41 DCR 1075, 1077 (March 4, 1994); as amended by Final Rulemaking published at 47 DCR 284 (January 21, 2000); as amended by Final Rulemaking published at 49 DCR 3012 (April 5, 2002); as amended by Emergency and Proposed Rulemaking published at 49 DCR 1706 (February 22, 2002); as amended by Final Rulemaking published at 52 DCR 9621 (October 28, 2005); as amended by Final Rulemaking published at 57 DCR 9129, 9135-9146 (October 1, 2010); as amended by Final Rulemaking published at 60 DCR 15231 (November 1, 2013); as amended by Final Rulemaking published at 67 DCR 5371 (May 22, 2020); as amended by Final Rulemaking published at 72 DCR 002805 (March 14, 2025); as amended by Errata Notice published at 72 DCR 011787 (October 24, 2025).