Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-11 - REGULATION NO. 11 - COLORADO PRIMARY DRINKING WATER REGULATIONS
Section 5 CCR 1002-11.45 - MCLs, MCLGs, SMCLs, MRDLs, MRDLGs, TRIGGER LEVEL, AND ACTION LEVELS

Universal Citation: 5 CO Code Regs 1002-11 § 45

Current through Register Vol. 47, No. 5, March 10, 2024

11.45(1) MCLs and MCLGs for Microbiological Contaminants

The following MCLs and MCLGs apply to all public water systems regardless of size or type.

TABLE 11.45-I MCLs AND MCLGs FOR MICROBIOLOGICAL CONTAMINANTS
Contaminant	Number of samples	MCL	MCLG	MCL Violation Citation
Cryptosporidium	N/A	Zero	N/A
Giardia lamblia	N/A	Zero	N/A
Viruses	N/A	Zero	N/A
Legionella	N/A	Zero	N/A
Fecal coliform or E. coli repeat sample (following routine total coliform-positive sample) or any total coliform-positive repeat sample following a fecal coliform-positive or E. coli-positive routine sample.	Absent	Zero	11.11 for the Ground Water Rule) and 11.16 for the Revised Total Coliform Rule
Escherichia coli	1. E. coli-positive repeat sample following a total coliform-positive routine sample, 2. total coliform-positive repeat sample following an E. coli-positive routine sample, 3. failure to collect all required repeat samples following an E. coli-positive routine sample, or 4. failure to analyze a total-coliform positive repeat sample for E. coli.	Zero	11.11 for the Ground Water Rule and 11.16 for the Revised Total Coliform Rule

11.45(2) MCLs and MCLGs for Inorganic Chemicals

The following MCLs and MCLGs for inorganic chemicals apply to all community and non-transient, non-community water systems, except:

(a) The MCLs and MCLGs for nitrate, nitrite, and total nitrate and nitrite apply to all public water systems.

(b) The MCL and MCLG for fluoride apply only to community water systems and may be applied to non-community water systems when found by the Department to be necessary to protect public health.

TABLE 11.45-II MCLs AND MCLGs FOR INORGANIC CHEMICALS

Contaminant	MCL (mg/L)	MCLG (mg/L)
Antimony	0.006	0.006
Arsenic	0.010	Zero
Asbestos	7 Million Fibers/liter (Longer than 10 µm)	7 Million Fibers/liter (Longer than 10 µm)
Barium	2	2
Beryllium	0.004	0.004
Cadmium	0.005	0.005
Chromium	0.1	0.1
Cyanide (as free Cyanide)	0.2	0.2
Fluoride	4.0	4.0
Mercury	0.002	0.002
Nitrate	10 (as Nitrogen)	10 (as Nitrogen)
Nitrite	1 (as Nitrogen)	1 (as Nitrogen)
Total Nitrate and Nitrite	10 (as Nitrogen)	10 (as Nitrogen)
Selenium	0.05	0.05
Thallium	0.002	0.0005

11.45(3) MCLs and MCLGs for Organic Chemicals

(a) The following MCLs and MCLGs for volatile organic chemicals (VOCs) apply to all community and non-transient, non-community water systems.

TABLE 11.45-III MCLs AND MCLGs FOR VOCs

Contaminant	MCL (mg/L)	MCLG (mg/L)
Vinyl chloride	0.002	Zero
Benzene	0.005	Zero
Carbon tetrachloride	0.005	Zero
1,2-Dichloroethane	0.005	Zero
Trichloroethylene	0.005	Zero
Para-Dichlorobenzene	0.075	0.075
1,1-Dichloroethylene	0.007	0.007
1,1,1-Trichloroethane	0.2	0.20
cis-1,2 Dichloroethylene	0.07	0.07
1,2-Dichloropropane	0.005	Zero
Ethylbenzene	0.7	0.7
Monochlorobenzene	0.1	0.1
o-Dichlorobenzene	0.6	0.6
Styrene	0.1	0.1
Tetrachloroethylene	0.005	Zero
Toluene	1	1
Trans-1,2 Dichloroethylene	0.1	0.1
Xylenes (total)	10	10
Dichloromethane (methylene chloride)	0.005	Zero
1,2,4-Trichlorobenzene	0.07	0.07
1,1,2-Trichloroethane	0.005	0.003

(b) The following MCLs and MCLGs for synthetic organic chemicals (SOCs) apply to all community and non-transient, non-community water systems:

TABLE 11.45-IV MCLs AND MCLGs FOR SOCs

Contaminant	MCL (mg/L)	MCLG (mg/L)
Alachlor	0.002	Zero
Aldicarb1	0.003	0.001
Aldicarb sulfoxide	0.004	0.001
Aldicarb sulfone	0.002	0.001
Atrazine	0.003	0.003
Carbofuran	0.04	0.04
Chlordane	0.002	Zero
Dibromochloropropane	0.0002	Zero
2,4-D	0.07	0.07
Ethylene dibromide	0.00005	Zero
Heptachlor	0.0004	Zero
Heptachlor epoxide	0.0002	Zero
Lindane	0.0002	0.0002
Methoxychlor	0.04	0.04
Polychlorinated biphenyls	0.0005	Zero

Contaminant	MCL (mg/L)	MCLG (mg/L)
Pentachlorophenol	0.001	Zero
Toxaphene	0.003	Zero
2,4,5-TP (Silvex)	0.05	0.05
Benzopyrene	0.0002	Zero
Dalapon	0.2	0.2
Di(2-ethylhexyl)adipate	0.4	0.4
Di(2-ethylhexyl)phthalate	0.006	Zero
Dinoseb	0.007	0.007
Diquat	0.02	0.02
Endothall	0.1	0.1
Endrin	0.002	0.002
Glyphosate	0.7	0.7
Hexachlorobenzene	0.001	Zero
Hexachlorocyclopentadiene	0.05	0.05
Oxamyl (Vydate)	0.2	0.2
Picloram	0.5	0.5
Simazine	0.004	0.004
2,3,7,8-TCDD (Dioxin)	3 x 10- 8	Zero

1 The aldicarbs are currently under "administrative stay" as a result of litigation. They are therefore treated as unregulated contaminants until further notice.

11.45(4) MCLs and MCLGs for Radionuclides

The following MCLs and MCLGs for radionuclides apply to all community water systems. TABLE 11.45-V MCLs AND MCLGs FOR RADIONUCLIDES

Contaminant	MCL	MCLG
Combined radium-226 and radium-2281	5 pCi/L	Zero
Gross alpha particle activity (including radium-226 but, excluding radon and uranium)	15 pCi/L	Zero
Beta particle and photon radioactivity2	4 mrem/yr3	Zero
Uranium	30 µg/L	Zero

1 The combined radium-226 and radium-228 value is determined by the addition of the results of the analysis for radium-226 and the analysis for radium-228.

2 The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year (mrem/year).

3 Except for the radionuclides listed in Table 11.22-II of section 11.22 , the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents must be calculated on the basis of 2 liter per day drinking water intake using the 168 hour data list in "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure," NBS (National Bureau of Standards) Handbook 69 as amended August 1963, U.S. Department of Commerce. If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year.

11.45(5) MRDLs and MRDLGs for Disinfectants

The following MRDLs and MRDLGs for disinfectant residuals apply to all community and non-transient, non-community water systems, except:

(a) The MRDL and MRDLG for chlorine dioxide apply to all public water systems.

TABLE 11.45-VI MRDLs AND MRDLGS FOR DISINFECTANTS

Disinfectant residual	MRDL (mg/L)	MRDLG (mg/L)
Chlorine	4.0 (as Cl2)	4.0 (as Cl2)
Chloramines	4.0 (as Cl2)	4.0 (as Cl2)
Chlorine dioxide1	0.8 (as ClO2)	0.8 (as ClO2)

1 The MRDL and MRDLG for chlorine dioxide only apply to those systems that use chlorine dioxide as a disinfectant or oxidant somewhere in the treatment process.

11.45(6) MCLs and MCLGs for Disinfection Byproducts

The following MCLs and MCLGs for disinfection byproducts apply to all community and non-transient, non-community water systems.

TABLE 11.45-VII MCLs AND MCLGs FOR DISINFECTION BYPRODUCTS

Disinfection byproduct	MCL (mg/L)	MCLG (mg/L)
Total trihalomethanes (TTHM)	0.0801
Bromodichloromethane	Zero
Bromoform	Zero
Chloroform	0.07
Dibromochloromethane	0.06
Haloacetic acids (five) (HAA5)	0.0601
Bromoacetic acid	N/A
Dibromoacetic acid	N/A
Dichloroacetic acid	Zero
Monochloroacetic acid	0.07
Trichloroacetic acid	0.02
Bromate2	0.010	Zero
Chlorite3	1.0	0.8

1 All systems must comply with these MCLs as an LRRA.

2 The MCL and MCLG for bromate only apply to those systems that use ozone as a disinfectant or oxidant somewhere in their treatment process.

3 The MCL and MCLG for chlorite only apply to those systems that use chlorine dioxide as a disinfectant or oxidant somewhere in the treatment process.

11.45(7) Trigger Level, Action Levels, and MCLGs for Lead and Copper

The following trigger level for lead and action levels for lead and copper apply to all community and non-transient, non-community water systems.

TABLE 11.45-VIII TRIGGER LEVEL, ACTION LEVELS, AND MCLGs FOR LEAD AND COPPER

Contaminant	Trigger Level (mg/L)	Action level (mg/L)	MCLG (mg/L)
Copper	N/A	1.3	1.3
Lead	0.010	0.015	Zero

11.45(8) Secondary Maximum Contaminant Levels

(a) These contaminants in drinking water primarily affect the aesthetic qualities relating to the public acceptance of drinking water. At considerably higher concentrations of these contaminants, health implications may also exist as well as aesthetic degradation. The secondary maximum contaminant levels are not enforceable, but are intended as guidelines that represent reasonable goals for drinking water quality.

TABLE 11.45-IX SECONDARY MAXIMUM CONTAMINANT LEVELS

Contaminant	Level
Aluminum	0.05 to 0.2 mg/L
Chloride	250 mg/L
Color	15 color units
Copper	1.0 mg/L
Corrosivity	Non-corrosive
Fluoride	2.0 mg/L1
Foaming agents	0.5 mg/L
Iron	0.3 mg/L
Manganese	0.05 mg/L
Odor	3 threshold odor number
pH	6.5-8.5
Silver	0.1 mg/L
Sulfate	250 mg/L
Total dissolved solids (TDS)	500 mg/L
Zinc	5 mg/L

1 When the fluoride level exceeds the SMCL of 2.0 mg/L public notification in accordance with 11.19 is required.

(b) It is recommended that the contaminants specified in Table 11.45-IX be monitored at intervals no less frequently than the sampling performed for inorganic chemicals as applicable to community water systems. More frequent monitoring would be appropriate for specific parameters such as pH, color, odor, or others under certain circumstances.

Disclaimer: These regulations may not be the most recent version. Colorado may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.

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