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D.C. Municipal Regulations (Last Updated: September 13, 2017) |
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Title 21. WATER AND SANITATION |
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Chapter 21-11. WATER QUALITY STANDARDS |
Section 21-1104. STANDARDS
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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 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:
(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.
1104.6Within 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.
1104.8Unless 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 – NUMERIC CRITERIA
Constituent
Criteria for Classes
A
B
C
Bacteriological (MPN/100 mL)
E. coli1
Geometric Mean (Maximum 30 day
126
geometric mean for 5 samples)
Single Sample Value
410
Physical
Dissolved Oxygen (mg/L)
Instantaneous minimum (Year-round) 2
5.0
February 1 through May 31 3,5
7-day mean
6.0
Instantaneous minimum
5.0
June 1 through January 31 3,5
30-day mean
5.5
7-day mean
4.0
Instantaneous minimum 4
3.2
Temperature (oC)
Maximum
32.2
Maximum change above ambient
2.8
pH
Greater than
6.0
6.0
6.0
And less than
8.5
8.5
8.5
Turbidity increase above ambient (NTU)
20
20
20
Secchi Depth 3,5 (m)(seasonal segment average)
April 1 through October 31
0.8
Total dissolved gases (maximum % saturation)
110
Hydrogen Sulfide (maximum μg/L)
2.0
Oil & grease (mg/L)
10.0
Biological
Chlorophyll a 3,5 (μg/L)(seasonal segment average)
July 1 through September 30
25
Notes:
1 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.
² This criterion applies to nontidal waters.
3 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, June 2008; and 2010 Criterion Addendum EPA 903-R-10-002 CBP/TRS-301-10, April 2010.
4 At temperatures greater than 29oC, in tidally influenced waters, an instantaneous minimum dissolved oxygen concentration of 4.3 mg/L shall apply.
5 Shall apply to tidally influenced waters only.
TABLE 2 – NUMERIC CRITERIA
Constituent1
Criteria for Classes
Trace metals and inorganics in μg/L, except where stated otherwise (see Notes below)
C
D2
CCC
4-Day Avg
CMC
1-Hour Avg
30-Day Avg
Ammonia, total mg N/L
See Note 7
See Note 8
Antimony, dissolved
640
Arsenic3, dissolved
150
340
0.14c
Cadmium4,5, dissolved
[I]CF
[I.A]CF
Chlorine, total residual
11
19
Chromium4, hexavalent, dissolved
11 CF
16 CF
Chromium4,5, trivalent, dissolved
[II]CF
[II.A]CF
Copper4,5, dissolved
[III]CF
[III.A]CF
Cyanide, free
5.2
22
140
Iron, dissolved
1000
Lead4,5, dissolved
[IV]CF
[IV.A]CF
Mercury4, total recoverable
0.77
1.4
0.15
Methylmercury (mg/kg, fish tissue residue)
0.3
Nickel4,5, dissolved
[V]CF
[V.A]CF
4600
Selenium, total recoverable
5
20
4200
Silver4,5, dissolved
[VI]CF
65000
Thallium, dissolved
0.47
Zinc4,5, dissolved
[VII]CF
[VII]CF
26000
Notes:
1 For 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.
2 The Class D Human Health Criteria for metals will be based on Total Recoverable metals.
3 The letter “c” after the Class D Human Health Criteria numeric value means that the criteria is based on carcinogenicity of 10-6 risk level.
4 The superscript “CF” means that the criterion derived from the formula under Note 5 is multiplied by the conversion factor in Table 2a as specified in Subsection 1105.10:
TABLE 2A. CONVERSION FACTORS
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
5 The formulas for calculating the criterion for the hardness dependent constituents indicated above are as follows:
[I] The numerical CCC criterion for cadmium in μg/L shall be given by:
e(0.7409[ln(hardness)]-4.719)
[I.A]The numerical CMC criterion for cadmium in μg/L shall be given by:
e(1.0166[ln(hardness)]-3.924)
[II] The numerical CCC criterion for trivalent chromium in μg/L shall be given by:
e(0.8190[ln(hardness)]+0.6848)
[II.A] The numerical CMC criterion for trivalent chromium in μg/L shall be given by:
e(0.8190[ln(hardness)]+3.7256)
[III] The numerical CCC criterion for copper in μg/L shall be given by:
e(0.8545[ln(hardness)]-1.702)
[III.A]The numerical CMC criterion for copper in μg/L shall be given by:
e(0.9422[ln(hardness)]-1.700)
[IV] The numerical CCC criterion for lead in μg/L shall be given by:
e(1.2730[ln(hardness)]-4.705)
[IV.A]The numerical CMC criterion for lead in μg/L shall be given by:
e(1.2730[ln(hardness)]-1.460)
[V]The numerical CCC criterion for nickel in μg/L shall be given by:
e(0.8460[ln(hardness)]+0.0584)
[V.A] The numerical CMC criterion for nickel in μg/L shall be given by:
e(0.8460[ln(hardness)]+2.255)
[VI]The numerical CMC criterion for silver in μg/L shall be given by:
e(1.7200[ln(hardness)]-6.590)
[VII]The numerical CCC criterion for zinc in μg/L shall be given by:
e(0.8473[ln(hardness)]+0.884)
[VII.A] The numerical CMC criterion for zinc in μg/L shall be given by:
e(0.8473[ln(hardness)]+0.884)
6 Hardness in the equations (I) through (VII.A) in Note 5 above shall be measured as mg/L of Calcium Carbonate (CaCO3). The minimum hardness allowed for use in those equations 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 those equations shall not exceed 400 mg/L, as CaCO3, even if the actual ambient water hardness is greater than 400 mg/L as CaCO3.
7Criterion 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 2b for the period March 1st through June 30th was calculated using the following formula, which shall be used to calculate unlisted values: CCC = [(0.0577/(1+107.688-pH)) + (2.487/(1+ 10pH-7.688))] X MIN(2.85, 1.45 X 100.028 X (25-T))], where MIN indicates the lesser of the two values (2.85, 1.45 X 100.028 X (25-T)) separated by a comma.
(c) The CCC criterion in Table 2c for the period July 1st through February 28/29th, was calculated using the following formula, which shall be used to calculate unlisted values: CCC = [(0.0577/(1+107.688-pH)) + (2.487/(1+ 10pH-7.688))] X [1.45 X 100.028 X (25-MAX(T,7)], where MAX indicates the greater of the two values (T,7) separated by a comma.
TABLE 2B. TOTAL AMMONIA
(in milligrams of Nitrogen per liter)
CCC CRITERION FOR VARIOUS pH AND TEMPERATURES
FOR MARCH 1ST THROUGH JUNE 30THTemperature (°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 2C. TOTAL AMMONIA
(milligrams of Nitrogen per liter)CCC CRITERION FOR VARIOUS pH AND TEMPERATURES FOR JULY 1ST THROUGH FEBRUARY 28TH/29TH
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 1st through February 28th/29th is the same as the criterion for March 1st through June 30th.
8 Criterion 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 2d.
(b) The CMC criterion was calculated using the following formula, which shall be used to calculate unlisted values: CMC = [(0.411/(1+107.204-pH)] + [58.4/(1+ 10pH-7.204)].
TABLE 2D. TOTAL AMMONIA
(in milligrams of Nitrogen per liter)
CMC CRITERION FOR VARIOUS pHpH
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 COMPOUNDS
Constituent1
Organics (μg/L)
CAS
Number
Criteria for Classes
C
D2
CCC
4-Day Avg
CMC
1-Hour Avg
30-Day
Avg
Acrolein
107028
3.0
3.0
9.0
Acrylonitrile
107131
700.0
0.25,c
Aldrin
309002
0.4
3.0
0.000050,c
Benzene
71432
1000
51.0,c
Carbon Tetrachloride
56235
1000
1.6,c
Chlordane
57749
0.0043
2.4
0.00081,c
Chlorinated benzenes (except Di)
25.0
Chlorobenzene
108907
1600
1,2-Dichlorobenzene
95501
200
1300
1,3-Dichlorobenzene
541731
200
960
1,4-Dichlorobenzene
106467
200
190
Hexachlorobenzene
118741
0.00029,c
Pentachlorobenzene
608935
1.5
1,2,4,5-Tertrachlorobenzene
95943
1.1
1,2,4-Trichlorobenzene
120821
70
Chlorinated ethanes
50
1,2-Dichloroethane
107062
37.0,c
Hexachloroethane
67721
3.3,c
1,1,2,2-Tetrachloroethane
79345
4.0,c
1,1,2-Trichloroethane
79005
16.0,c
Chlorinated naphthalene
2-Chloronaphthalene
91587
200
1600
Chlorinated phenols
2-Chlorophenol
95578
100
150
2,4-Dichlorophenol
120832
200
290.0
Pentachlorophenol3
87865
[I]
[I.A]
3.0,c
2,4,5-Trichlorophenol
95954
3600
2,4,6-Trichlorophenol
88062
2.4,c
Chloroalkyl ethers
1000
Bis(2-Chloroethyl)Ether
111444
0.53,c
Bis(2-Chloroisopropyl)Ether
108601
65,000
Bis(Chloromethyl)Ether
542881
0.00029
3,3-Dichlorobenzidine
91941
10
0.028,c
Dichloroethylenes
1000
1,1-Dichloroethylene
75354
7,100,c
1,2-Trans-Dichloroethylene
156605
10,000
1,2-Dichloropropane
78875
2000
15,c
Dichloropropenes
400
1,3-Dichloropropene
542756
21
Dieldrin
60571
0.056
0.24
0.000054,c
2,4-Dimethylphenol
105679
200
850
2,4-Dinitrotoluene
121142
33
3.4,c
Dioxin (2,3,7,8-TCDD)
1746016
0.0000000051,c
(5.1 E-8)
1,2-Diphenylhydrazine
122667
30
0.20,c
Endosulfan
0.056
0.22
89
Alpha-Endosulfan
959988
0.056
0.22
89
Beta-Endosulfan
33213659
0.056
0.22
89
Endosulfan sulfate
1031078
89
Endrin
72208
0.036
0.086
0.060
Endrin aldehyde
7421934
0.30
Ethylbenzene
100414
40
2,100
Halomethanes
1000
Bromoform
75252
140,c
Chloroform
67663
3000
470.0,c
Chlorodibromomethane
124481
13.0,c
Dichlorobromomethane
75274
17.0,c
Methyl Bromide
74839
1,500
Methylene chloride
75092
590,c
Heptachlor
76448
0.0038
0.52
0.000079,c
Heptachlor epoxide
1024573
0.0038
0.52
0.000039,c
Hexachlorobutadiene
87683
10
18.0,c
Hexachlorocyclohexane
alpha-BHC
319846
0.0049,c
beta-BHC
319857
0.017,c
gamma-BHC (Lindane)
58899
0.08
0.95
1.8,c
Hexachlorocyclopentadiene
77474
0.5
1,100
Isophorone
78591
1000
960,c
Manganese
7439965
100
Methoxychlor
72435
0.03
Mirex
2385855
0.001
Naphthalene
91203
600
Nitrobenzene
98953
1000
690
Nitrophenols
20
2-Methyl-4,6- Dinitrophenol
534521
280
2,4-Dinitrophenol
51285
5,300
Dinitrophenols
25550587
5,300
Nitrosamines
600
1.24
N-Nitrosodibutylamine
924163
0.22
N-Nitrosodiethylamine
55185
1.24
N-Nitrosodimethylamine
62759
3.0,c
N-Nitrosodi-n-Propylamine
621647
0.51,c
N-Nitrosodiphenylamine
86306
6.0,c
N-Nitrosopyrrolidine
930552
34,c
Nonylphenol
84852153
6.6
28
Carbamates
Carbaryl (Sevin)
63252
2.1
2.1
Organochlorides
4,4’-DDD
72548
0.001
1.1
0.00031,c
4,4’-DDE
72559
0.001
1.1
0.00022,c
4,4’-DDT
50293
0.001
1.1
0.00022,c
Organophosphates
Guthion
86500
0.01
Malathion
121755
0.1
Parathion
56382
0.013
0.065
Phenol
108952
860,000
Phthalate esters
100
Bis(2-Ethylhexyl) Phthalate
117817
2.2,c
Butylbenzyl Phthalate
85687
1,900
Diethyl Phthalate
84662
44,000
Dimethyl Phthalate
131113
1,100,000
Di-n-Butyl Phthalate
84742
4,500
Polychlorinated biphenyls4
0.014
0.000064,c
Polynuclear aromatic hydrocarbons
Acenaphthene
83329
50
990
Acenaphthylene
208968
Anthracene
120127
40,000
Benzidine
92875
250
0.00020,c
Benzo(a)Anthracene
56553
0.018,c
Benzo(a)Pyrene
50328
0.018,c
Benzo(b)Fluoranthene
205992
0.018,c
Benzo(k)Fluoranthene
207089
0.018,c
Chrysene
218019
0.018,c
Dibenzo(a,h) Anthracene
53703
0.018,c
Fluoranthene
206440
400
140.0
Fluorene
86737
5,300
Indeno(1,2,3-cd) Pyrene
193395
0.018,c
Pyrene
129000
4,000
Tetrachloroethylene
127184
800
3.3,c
Toluene
108883
600
15000
Toxaphene
8001352
0.0002
0.73
0.00028,c
Tributyltin (TBT)
--
0.072
0.46
Trichloroethylene
79016
1000
30.0,c
Vinyl chloride
75014
2.4,c
Notes:
1 For constituents without numerical criteria, standards have not been developed at this time. However, permit writers shall address these constituents in NPDES permit actions using the narrative criteria for toxics contained in these water quality standards.
2 The letter “c” after the Class D Human Health Criteria numeric value means that the criterion is based on carcinogenicity of 10-6 risk level.
3 The formulas for calculating the concentrations of substances indicated above are as follows:
[I]The numerical CCC criterion for pentachlorophenol in μg/L shall be given by:
e(1.005(pH) - 5.134)
[I.A]The numerical CMC criterion for pentachlorophenol in μg/L shall be given by:
e(1.005(pH) - 4.869)
4 The polychlorinated biphenyls (PCB) criterion applies to total PCBs (e.g., the sum of all congener or all isomer or homolog or Aroclor analyses.)