D.C. Mun. Regs. tit. 21, r. 21-1104

Current through Register Vol. 71, No. 49, December 6, 2024

Rule 21-1104 - STANDARDS

1104.1

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

(a) Settle to form objectionable deposits;

(b) Float as debris, scum, oil, or other matter to create a nuisance;

(c) Produce objectionable odor, color, taste, or turbidity;

(d) Cause injury to, are toxic to, or produce adverse physiological or behavioral changes in humans, plants, or animals;

(e) Produce undesirable or nuisance aquatic life or result in the dominance of nuisance species; or

(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 submergel 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:

(a) The facility is for the general public benefit and service, and

(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 a ^a,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 31^a,b
7-day mean	-	-	6.0
Instantaneous minimum	-	-	5.0
June 1 through January 31^a,b
30-day mean	-	-	5.5
7-day mean	-	-	4.0
Instantaneous minimum^d	-	-	3.2
E. coli^e (MPN/100mL)
Geometric mean (Geometric mean of 5 samples over a maximum period of 30 days)	126	-	-
Single Sample Value	410	-	-
Hydrogen Sulfide (maximum µg/L)	-	-	2.0
Oil and Grease (µg/L)	-	-	10.0
pH
Greater than	6.0	6.0	6.0
And less than	8.5	8.5	8.5
Secchi Depth^a,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)	20	20	20

Footnotes:

^a Attainment of the dissolved oxygen, water clarity and chlorophyll a water quality criteria that apply to tidal influenced Class C waters will be determined following the guidelines documented in the 2003 United States 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).

^bShall apply to only tidally influenced waters.

^cShall apply to only nontidal waters.

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

^eThe 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.

Table 2: Trace Metals and In organics Numeric Criteria

Constituent^a Trace metals and in organics inµg/L, except where stated otherwise (see Notes below)	Class C		Class D^b
	CCC 4-Day Avg	CMC 1-Hour Avg	30-Day Avg
Ammonia, mg total ammonia nitrogen (TAN)/L	See Footnote g	See Footnote h	-
Antimony, total recoverable	-	-	640
Arsenic, dissolved	150	340	0.14^c
Cadmium, dissolved	See Footnotes d and e	See Footnotes d and e	-
Chlorine, total residual	11	19	-
Chromium, hexavalent, dissolved	11^e	16^e	-
Chromium, trivalent, dissolved	See Footnotes d and e	See Footnotes d and e	-
Copper, dissolved	See Footnotes d and e	See Footnotes d and e	-
Cyanide, free	5.2	22	400
Iron, dissolved	1,000	-	-
Lead, dissolved	See Footnotes d and e	See Footnotes d and e	-
Mercury, dissolved	0.77^e	1.4^e	0.15
Methylmercury (mg/kg, fish tissue residue)	-	-	0.3
Nickel, dissolved	See Footnotes d and e	See Footnotes d and e	4,600
Selenium, total recoverable	5	20	4,200
Silver, dissolved	-	See Footnotes d and e	65,000
Thallium, dissolved	-	-	0.47
Zinc, dissolved	See Footnotes d and e	See Footnotes d and e	26,000

Footnotes:

^aFor constituents without numerical criteria, standards have not been developed at this time. However, the National Pollutant Discharge Elimination System (NPDES) permitting authority shall address constituents without numerical standards in NPDES permit actions by using the narrative criteria for toxics contained in these water quality standards.

^bThe Class D human health criteria for metals will be based on total recoverable metals.

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

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

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

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

^eThe criterion is multiplied by the EPA conversion factor in Table 2b as specified in Subsection 1105.10:

Table 2b: Conversion Factors for Dissolved Metals^f

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

^fHardness in in Tables 2a and 2b shall be measured as mg/L of calcium carbonate (CaCO₃).The minimum hardness value allowed for use in these formulas shall not be less than 25 mg/L as CaCO₃, even if the actual ambient hardness is less than 25 mg/L as CaCO₃. The maximum hardness value allowed for use in these formulas shall not exceed 400mg/L as CaCO₃, even if the actual ambient water hardness is greater than 400 mg/L as CaCO₃.

^gCriterion Continuous Concentration (CCC) for Total Ammonia:

(a) The CCC criterion for ammonia (in mg N/L) (i) shall be the thirty (30)-day average concentration for total ammonia computed for a design flow specified in Subsection 1105.5; and (ii) shall account for the influence of the pH and temperature as shown in Table 2b and Table 2c. The highest four (4)-day average within the thirty (30)-day period shall not exceed 2.5 times the CCC.

(b) The CCC criterion in Table 2c for the period March 1^st through June 30^th was calculated using the following formula, which shall be used to calculate unlisted values: CCC = [(0.0577/(1+10^7.688-pH)) + (2.487/(1+ 10^pH-7.688))] X MIN(2.85, 1.45 X 10^0.028^X^(25-T))], where MIN indicates the lesser of the two values (2.85, 1.45 X 10^0.028^X^(25-T)) separated by a comma.

(c) The CCC criterion in Table 2d for the period July 1^st through February 28/29^th, was calculated using the following formula, which shall be used to calculate unlisted values: CCC = [(0.0577/(1+10^7.688-pH)) + (2.487/(1+ 10^pH-7.688))] X [1.45 X 10^0.028^X^(25-MAX(T,7)], where MAX indicates the greater of the two values (T,7) separated by a comma.

Table 2c. Total Ammonia (In Milligrams of Nitrogen Per Liter) Ccc Criterion for Various Ph And Temperatures for March 1^st Through June 30^th

Temperature (°C)
pH	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 2d. Total Ammonia (Milligrams of Nitrogen Per Liter)

Ccc Criterion for Various Ph And Temperatures for July 1^st Through February 28^th/29^th

Temperature (°C)
pH	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^st through February 28^th/29^th is the same as the criterion for March 1^st through June 30^th.

^hCriterion Maximum Concentration (CMC) for Total Ammonia:

(a) The CMC criterion for total ammonia (in mg N/L) (i) shall be the one (1)-hour average concentration for total ammonia, computed for a design flow specified in subsection 1105.5; and (ii) shall account for the influence of the pH as shown in Table 2e.

(b) The CMC criterion was calculated using the following formula, which shall be used to calculate unlisted values: CMC = [(0.411/(1+10^7.204-pH)] + [58.4/(1+ 10^pH-7.204)].

Table 2e. Total Ammonia (In Milligrams of Nitrogen Per Liter) Cmc Criterion 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

Table 3: Organic Constituents Numeric Criteria

Organic Constituent^a (µg/L)	CAS Number	Class C		Class D
Organic Constituent^a (µg/L)	CAS Number	CCC 4-Day Avg	CMC 1-Hour Avg	30-Day Avg
Acrolein	107028	3.0	3.0	400
Acrylonitrile	107131	700.0	-	7.0, ^b
Aldrin	309002	0.4	3.0	0.00000077, ^b
Benzene	71432	1000	-	16, ^b
Carbamates	-	-	-	-
Carbaryl (Sevin)	63252	2.1	2.1	-
Carbon Tetrachloride	56235	1000	-	5, ^b
Chlordane	57749	0.0043	2.4	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 Naphthalene s	-	-	-	-
2-Chloronaphthalene	91587	200	-	1000
Chlorinated Phenols	-	-	-	-
2-Chlorophenol	95578	100	-	800
2,4-Dichlorophenol	120832	200	-	60
Pentachlorophenol^c	87865	[I]^c	[I.A]^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	0.056	0.24	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	-	0.056	0.22	89
alpha-Endosulfan	959988	0.056	0.22	30
beta-Endosulfan	33213659	0.056	0.22	40
EndosulfanSulfate	1031078	-	-	40
Endrin	72208	0.036	0.086	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	0.0038	0.52	0.0000059, ^b
Heptachlor Epoxide	1024573	0.0038	0.52	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	0.08	0.95	4.4
Hexachlorocyclopentadiene	77474	0.5	-	4
Isophorone	78591	1000	-	1,800, ^b
Manganese	7439965	-	-	100
Methoxychlor	72435	0.03	-	0.02
Mirex	2385855	0.001	-	-
Naphthalene	91203	600	-	-
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	-	-	0.22 ^b
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	6.6	28	-
Organochlorides	-	-	-	-
4,4'-DDD	72548	0.001	1.1	0.00012, ^b
4,4'-DDE	72559	0.001	1.1	0.000018, ^b
4,4'-DDT	50293	0.001	1.1	0.000030, ^b
Organophosphates	-	-	-	-
Guthion	86500	0.01	-	-
Malathion	121755	0.1	-	-
Parathion	56382	0.013	0.065	-
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
Benzidine	92875	250	-	0.011, ^b
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
Pyrene	129000	-	-	30
Tetrachloroethylene	127184	800	-	29, ^b
Toluene	108883	600	-	520
Toxaphene	8001352	0.0002	0.73	0.00071, ^b
Tributyltin (TBT)	-	0.072	0.46	-
Trichloroethylene	79016	1000	-	7, ^b
Vinyl chloride	75014	-	-	1.6, ^b

Footnotes:

^aFor constituents with blank numeric criteria, EPA has not calculated criteria at this time. However, permit authorities will address these constituents in NPDES permit actions using the narrative criteria for toxics.

^bThe criteria are based on carcinogenicity of 10- risk level.

^cThe formulas for calculating the concentrations of substances indicated above areas follows:

[[I] The numerical CCC for pentachlorophenol in µg/L shall be given by:

e^{(1.005(pH) - 5.134)}

[I.A] The numerical CMC for pentachlorophenol in µg/L shall be given by:

e^{(1.005(pH) - 4.869)}

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

D.C. Mun. Regs. tit. 21, r. 21-1104

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); amended by Final Rulemaking published at 67 DCR 5372 (5/22/2020)

Authority: District Department of the Environment Establishment Act of 2005, effective February 15, 2006 (D.C. Law 16-51; D.C. Official Code § 8-151.01 et seq. (2012 Repl.)), Sections 5 and 21 of the Water Pollution Control Act of 1984 , effective March 16, 1985 (D.C. Law 5-188; D.C. Official Code §§ 8-103.04 and 8-103.20 (2012 Repl.)), and Mayor's Order 2006-61, dated June 14, 2006.