Statutes, codes, and regulations
Colorado Administrative Code
Department 1000 - Department of Public Health and EnvironmentDivision 1002 - Water Quality Control Commission (1002 Series)
Rule 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

5 Colo. Code Regs. § 1002-11.45

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Current through Register Vol. 47, No. 20, October 25, 2024
Section 5 CCR 1002-11.45 - MCLs, MCLGs, SMCLs, MRDLs, MRDLGs, TRIGGER LEVEL, AND ACTION LEVELS
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.

5 CCR 1002-11.45

38 CR 07, April 10, 2015, effective 4/30/2015
41 CR 11, June 10, 2018, effective 6/30/2018
41 CR 23, December 10, 2018, effective 12/30/2018
43 CR 07, April 10, 2020, effective 4/30/2020
43 CR 17, September 10, 2020, effective 9/30/2020
45 CR 24, December 25, 2022, effective 1/14/2023
46 CR 18, September 25, 2023, effective 10/15/2023