5 Colo. Code Regs. § 1002-11.50
Adoption of Section 7.4 - Enhanced Treatment for Cryptosporidium, Section 7.7 - Initial Distribution System Evaluations (IDSE) and Section 7.8 - Additional Requirements for Disinfection Byproducts Compliance with Amendments to Articles 1, 2, 7, 9, 10 and 12(c) of the Colorado Primary Drinking Water Regulations.
The provisions of the Colorado Revised Statutes (CRS), § 25-1.5-202, provides specific statutory authority for adoption of these regulatory amendments. The Commission also adopted, in compliance with § 24-4-103(4), CRS, the following statement of basis and purpose.
BASIS AND PURPOSE
All suppliers of drinking water in Colorado are subject to regulations adopted by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act, (42 U.S.C. 300f et seq.) as well as by the Colorado Primary Drinking Water Regulations under the direction of the Water Quality Control Division (Division). Colorado has been granted primary enforcement responsibility (primacy) for the public water system supervision program under the federal Safe Drinking Water Act; however, in order to maintain primacy, states must promulgate regulations that are no less stringent than those adopted by the federal government. By retaining primacy, the Division is able to protect the public health by ensuring that public water systems provide safe drinking water to Colorado citizens and visitors and remains eligible both for program grants of $1.3 million and for federal revolving funds to assist water systems construct facility improvements of $13 million per year.
The Commission amends Articles 1, 2, 7, 9, 10, and 12(c) of the Colorado Primary Drinking Water Regulations to include:
- The provisions of the federal regulations as published in the Federal Register, Volume 71, Number 2, January 4, 2006, pages 388 through 493, National Primary Drinking Water Regulations: Stage 2 Disinfectants and Disinfection Byproducts Rule incorporated as sections 7.7 and 7.8.
- The provisions of the federal regulations as published in the Federal Register, Volume 71, Number 3, January 5, 2006, pages 654 through 786, National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Rule incorporated as section 7.4.
- Changes referencing the Commission throughout the regulation instead of the Board of Health in accordance with § 25-8-202(1)(n), C.R.S.
- Numerous minor changes removing obsolete references and definitions that are not used within the regulation, and correction of spelling and typographical errors, including a number of nonsubstantive amendments to Article 10 in an effort to provide clarity (such as spelling out abbreviations), and to provide consistency in the citing of materials incorporated by reference (i.e. EPA and other nationally-recognized test methods). Many of the references to these test methods contained unnecessary information about the places where copies could be obtained.
The Commission also updated the numbering of footnotes throughout the regulation for consistency.
Sections 7.7 and 7.8 amend the existing regulatory requirements for disinfection byproducts for all public water systems in Colorado that add a disinfectant to the water in any part of the drinking water treatment process. Section 7.4 amends existing treatment requirements for all public water systems in Colorado that use surface water or groundwater under the direct influence of surface water as drinking water sources.
These amendments and additions provide for increased public health protection against the potential risks for cancer and adverse reproductive and developmental health effects associated with disinfection byproducts and they provide further public health protection against Cryptosporidium and other microbial pathogens in drinking water.
The provisions of sections 7.7 and 7.8, Stage 2 Disinfectants and Disinfection Byproducts Rule, are summarized as follows:
- Adds recordkeeping requirements for turbidity and monitoring plans.
- Establishes maximum contaminant level goals for chloroform, monochloroacetic acid and trichloroacetic acid.
- Finalizes maximum contaminant levels for disinfection byproducts.
- Changes compliance from system-wide running annual average to locational running annual average at each monitoring location.
- Revises the requirements for reduced monitoring for bromate.
- Specifies the best available technologies for control of disinfection byproducts in drinking water.
- Revises the public notification requirements for total trihalomethanes and haloacetic acids.
- Approves additional analytical methods for the determination of disinfectants and disinfection byproducts in drinking water.
The Stage 2 Disinfectants and Disinfection Byproducts Rule is designed to further minimize the formation of disinfection byproducts in the finished water in an effort to reduce the associated long-term cancer risks and reproductive and developmental health effects associated with disinfection byproducts while ensuring continued protection from microbiological contaminants that may pose an acute health threat.
The Commission is simultaneously amending the Colorado Primary Drinking Water Regulations to include the provisions of the National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule to ensure that drinking water is microbiologically safe while considering the limits set for disinfection byproducts.
The provisions of section 7.4 , Long Term 2 Enhanced Surface Water Rule, are summarized as follows:
- Requires public water systems using surface water or groundwater under the direct influence of surface water to monitor their source water to determine an average Cryptosporidium level.
- Specifies criteria for sampling frequency and schedule, sampling location, use of previously collected data, providing treatment instead of monitoring, sampling by systems that use surface water for only part of the year, and monitoring of new plants and sources.
- Establishes requirements for reporting monitoring results, using approved analytical methods, and using certified laboratories for all analysis.
- Supplements current regulations by establishing risk-targeted treatment technique requirements to control Cryptosporidium in public water systems using surface water or groundwater under the direct influence of surface water. (Existing regulations remain in effect.)
- Based on the results of the source water Cryptosporidium monitoring, systems will be classified in one of four (4) treatment categories or "bins." The bin classification determines the degree of additional Cryptosporidium treatment, if any, the system must provide.
- Adds the Microbial Toolbox options that systems must use if required to meet the additional Cryptosporidium treatment required based on bin classification.
- Adds recordkeeping requirements specific to the changes.
- Adds requirements for a "Special notice for repeated failure to conduct monitoring of the source water for Cryptosporidium and for failure to determine bin classification or mean Cryptosporidium level" to the Public Notification requirements.
- Specifies the Public Notification tier level of notice for violations related to these amendments.
Implementing the Long Term 2 Enhanced Surface Water Rule will substantially lower rates of endemic cryptosporidiosis, the illness caused by Cryptosporidium, which can be severe and sometimes fatal in sensitive subpopulations (e.g., infants, people with weakened immune systems). In addition, the treatment technique requirements will increase protection against other microbial pathogens like Giardia lamblia.
In addition to the inclusion of sections 7.4, 7.7 and 7.8, the Colorado Primary Drinking Water Regulations are amended as follows:
Section 2.4 is amended to include the new maximum contaminant level goals (MCLG) for chloroform, monochloroacetic acid and trichloroacetic acid.
"Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the average of all samples taken in the year (for systems which must monitor quarterly) or the result of the sample (for systems which must monitor no more frequently than annually) is no more than 0.060 mg/L and 0.045 mg/L for TTHMs and HAA5, respectively."
This language was inadvertently omitted in the Federal Register when Stage 1 Disinfectants, Disinfection Byproducts Rule was printed. The Stage 2 Disinfection Byproducts Rule includes the reinstatement of this language to the Stage 1 DDBP Rule.
Article 10 is amended to include additional approved analytical methods for drinking water analyses for disinfection byproducts and disinfection byproduct precursors.
Section 12.2 is amended to replace references to the State Board of Health with the Water Quality Control Commission.
Aspects of the Long Term 2 Enhanced Surface Water Rule that were not included in the Colorado Primary Drinking Water Regulations:
Parties to Rulemaking Hearing
5 CCR 1002-11.50