Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-41 - REGULATION NO. 41 - THE BASIC STANDARDS FOR GROUND WATER
Section 5 CCR 1002-41.12 - STATEMENT OF BASIS AND PURPOSE

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

Statement of Basis and Purpose for adopting the Regulations entitled: "The Basic Standards for Ground Waters". In accordance with 24-4-103(4), CRS (1982 and 1985 Supp.), the Commission adopts this Statement of Basis and Purpose.

PURPOSE

"The Basic Standards for Ground Waters" establishes a system of classifications (classes) for determining the appropriate degree of protection (standards) necessary to maintain beneficial uses of ground waters. These standards and classes are intended to complement regulations 3.1.0, "The Basic Standards and Methodologies" which are primarily applicable to surface waters. Together, regulations 3.1.0 and 3.11.0 protect all state waters as defined in Section 25-8-203, CRS (1982). Separate regulations for surface and ground waters are appropriate, because the surface water classification system is not easily adopted to ground waters.

These regulations are the first step in developing a comprehensive, statewide ground water protection program. The complete program will include control regulations which will enforce the water quality standards. These additional regulations may include amending the current CDPS permit regulations and adopting activity-specific control regulations.

It is not the intent of the Commission to control existing or future uses of ground water (i.e., domestic, agricultural, or industrial uses). The intent is to protect ground water quality from uncontrolled degradation and thereby protect existing and future uses of ground water.

It is not the intent of the Commission or the Division by virtue of adoption of these regulations or subsequent control regulations, to duplicate ground water regulations adopted by other state or federal programs. When an activity that impacts ground water appears to be unregulated or inadequately regulated with respect to those impacts, the Division will conduct a thorough review of any applicable authorities prior to proposing a control regulation.

NEED FOR REGULATIONS

Ground water is the primary water source for seventy-five percent of the public water supply systems of the state (defined in the Colorado Primary Drinking Water Regulations).

There are approximately 825,000 people in Colorado that rely either wholly or partially on ground water. Ground water use to support new urban areas is increasing as surface water supplies become more difficult to obtain in some metropolitan areas. Agriculture also relies heavily on ground water for the production of crops and livestock. An estimated 1.5 million acres are presently being irrigated with ground water and approximately 12,500 well permits have been issued for livestock watering.

Currently, public water supply systems using ground water are not required to treat the water prior to distribution except for disinfection. In 1974, the federal "Safe Drinking Water Act" (SDWA) was passed which required regular testing of public water supplies to ensure compliance with the maximum contaminant levels (MCLs). However, the regulations do not require testing for even 1% of the synthetic chemicals in use in the nation today. The 1986 amendments to the Safe Drinking Water Act will increase the number of chemicals to be tested by public water systems. However, neither the SDWA nor the 1986 amendments required testing of private or agricultural supply wells.

Although the state's lack of a comprehensive data base prevents demonstrating a widespread contamination problem, there are many reasons for adopting a regulation which creates a framework for further ground water quality protection. These reasons are:

PUBLIC INPUT AND COMMISSION GOAL

The Commission and Division appointed an AD Hoc Ground Water Advisory Committee in 1982. The Committee represented the various entities who would be most affected by a ground water protection program. On May 15, 1984, the Committee recommended, and the Colorado Water Quality Control Commission adopted, the following statement pertaining to ground water protection:

"The goal of the Water Quality Control Commission is to provide maximum beneficial use of ground water resources, while assuring the safety of the users by preventing or controlling those activities which have the potential to impair existing or future beneficial uses of ground water or to adversely affect the public health. The necessary program is to be instituted in a manner that is consistent with and complementary to the provisions of the Colorado Water Quality Control Act."

This Basic Standards Regulation for ground water, which is adopted after exhaustive public rulemaking hearings, is consistent with this goal. The focus of the Basic Standards Regulation for ground water is the identification of ground water use or uses and the quality level to be maintained to assure its usefulness. This is a framework around which existing and future licensing and permitting regulations revolve in authorizing, conditioning, limiting and denying activities which could impair existing or future beneficial uses of ground water.

DISCUSSION OF REGULATIONS

Classification System

The classification system is a framework of uses of ground water which are to be assigned on a site-specific basis by the Commission so that standards for chemical pollutants can be assigned on a site-specific basis by the Commission so that standards for chemical pollutants can be assigned at levels necessary to protect the use.

A five (5) class system was developed for these regulations. This system is based on existing and potential future uses and actual water quality data.

Ground water may be assigned more than one class because it may have more than one existing or potential use.

While selection of any of these classes for a specific site is to protect the quality of the water for that beneficial use, because the classification may be based on a potential use, the classification is no warranty that the existing quality is entirely fit for that use by one who does or intends to put it to such use.

The selection of classifications for particular ground water within a specified area shall be by the Commission. The selection of particular classes shall be based upon specific criteria found in the regulations which describe each class.

The regulations provide that ground water may be classified "Domestic Use - Quality" or "Agricultural Use - Quality" if the ground water is either "used" or reasonably likely to be used for domestic or agricultural purposes within the specified area, or if the most recent state engineer's well records or applicable court decrees reveal that ground water is "permitted" or "decreed" for such uses within the specified area. For purposes of classification of ground water pursuant to these two provisions, the Commission presumes (1) that the "use" of ground water is after a legal withdrawal, and (2) that the pertinent state engineer's well record reveals a valid permit, and that the applicable court decree is perfected. If a domestic or agricultural use classification is based solely upon well records or court decrees, that classification may be rebutted by information demonstrating that domestic or agricultural use of ground water is not being made and is not likely to be made in the future.

Selection of applicable classes for a specified area shall occur when there is an activity which affects or has the potential to affect ground water quality within a specified area, and when a specified area for that activity is determined. Upon identification of the activity and determination of the specified area by the Commission, the owner/operator of the activity gathers information within the specified area. The owner/operator of the activity then submits this information to the Commission, pursuant to Section 3.11.7.

SPECIFIED AREA

The specified area is that area within which the ground water is classified. The Commission must determine the appropriate shape, depth, boundaries, and extent of a specified area such that existing and potential uses of ground waters are identified and protected from discharges to ground water by activities.

A specified area will be determined as early as possible after an activity has been identified. The Commission assumes that the specified area may be modified as more hydrologic and geologic information is acquired. The Commission may determine a specified area in the absence of an activity.

A conservative area of two lateral miles around the activity in question will presumptively be used as the initial specified area. The Commission finds this area to be reasonable for the following reasons:

GROUND WATER QUALITY STANDARDS

The promulgated Water Quality Standards include narrative and numeric standards.

NARRATIVE STANDARDS

The narrative standards consider all man-induced alterations of ground water. Since the Commission cannot, and will not, control the withdrawal and use of ground water, the narrative standards are designed to protect all potential uses of the waters. The narrative standards prohibit the introduction of non-natural chemicals where best available information indicates a potential threat to the public health, safety or welfare.

The Colorado Primary Drinking Water Regulations (CPDWR) do not include MCLs (maximum contaminent levels) for many chemicals such as dioxin, TCE, and EDB. There are often health advisories and other scientific studies indicating that a specific chemical is carcinogenic, mutagenic, toxic, or poses a danger to public health, safety, or welfare. The Commission will have the ability to make a specific determination of a limit for that constituent in ground water. This section allows the Commission to make such a determination in the absence of an MCL for the chemical. The toxic and hazardous pollutant lists developed pursuant to sections 301 (a)(1) and 311 (b)(2)(A) of the federal Clean Water Act and contaminants (pollutants) that have had an EPA Health Advisory developed for them will be used as a basis for determining what specific compounds will be included.

NUMERIC STANDARDS

The numeric standards are contained in Tables 1, 2, 3, and 4. These standards apply to classified ground water.

The majority of the numeric standards listed in Table 1 are the maximum contaminant levels (MCLs) for public drinking water supplies, as established by the National Primary Drinking Water Regulations. The remainder are derived from the Colorado Basic Surface Water Standards. These human health levels are set to protect the public from acute poisoning and from long-term "chronic" effects. The MCLs are also contained in the CPDWR. The limits for radioactive constituents; Cesium, Plutonium, Thorium and Tritium are those which would limit human exposure to four (4) millirems/year. Table 1 will be expanded as MCLs for additional parameters are developed under the National Primary Drinking Water Regulations. The numeric standards listed in Table 1 are applicable to ground waters classified "Domestic Use-Quality".

Table 2 contains additional numeric standards for "Domestic Use - Quality" ground waters. Much debate and discussion revolved around the need for these standards. These parameters are the National Secondary Drinking Water Standards and are instituted to maintain a ground water as a drinking water source requiring very little treatment. In the judgement of the USEPA Administrator, these limits are a requisite to protect the public welfare.

Contaminants (pollutants) contained in Table 2 are those which may adversely affect the aesthetic quality of a drinking water such as taste, odor, color, and appearance and which thereby may deter public acceptance of and confidence in that ground water source as a drinking water supply.

Numeric standards meant to protect a water source for agricultural uses are listed in Table 3. Table 3 numeric values were developed through Commission review of Water Quality Criteria in 1972, EPA/R/73/033 (March 1973). The value of the molybdenum was developed from information provided by AMAX and the Cottor Corporation. These values are set at levels to protect livestock and crops. All "Agricultural Use - Quality" ground waters must meet these standards when implemented by any agency.

Much public input and debate revolved around Table 4, "TDS Water Quality Standards." Some parties wanted less or no degradation of ground water, while other parties felt that more was warrented. The division proposed this version which allows for limited degradation.

The TDS numeric standard is implemented on a sliding scale and is applicable to all classes of ground water, except "Domestic Use - Quality" and "Limited Use and Quality" ground waters. TDS Table 4 values are applicable to "Agricultural Use - Quality", "Surface Water Quality Protection" and "Potentially Usable Quality" ground waters, because these three classes are not subject to Table 2 for sulfates and chlorides; a TDS limitation for these three classes assumes some level of anti-degradation.

By maintaining a TDS concentration within a range, an existing or potential use should not be impacted. The sliding scale allows for a twenty-five percent increase for all ground waters with a background TDS concentration greater than 500 mg/l. If the background concentration is less than 400 mg/l then the maximum allowable concentration of TDS is 500 mg/l. This value is the secondary drinking water standards and is instituted to maintain a high quality water. Total dissolved solids concentrations of less than 500 mg/l are not expected to impair any ground water use. The twenty-five percent allowable incremental increase for waters with a background between 500 and 10,000 mg/l would afford a greater degree of protection to ground water with lower TDS concentrations. Ground waters with TDS concentrations greater than 10,000 mg/l would not have a numeric limit.

The term "representative" contained within the definition for background level implies standard acceptable monitoring, sampling, and analytical procedures, which are available.

The criteria for determining background levels will be established by the Commission. It is important that the regulated entity work closely with the agency requiring the background level determination.

It is intended that the monitoring and sampling protocols shall be those procedures best capable for obtaining ground water samples which are representative of the water quality being monitored.

The following documents may provide useful guidance:

The analytical method selected for a parameter should be that which can measure the lowest detection limit for the parameter, unless a standard is within the range of another approved method. Approved analytical methods include those contained in the "Standard Methods for the Examination of Water and Wastewater," 16th or most recent edition, or "Methods for Chemical Analysis of Water and Wastes," EPA, Office of Technology Transfer, or 40 CFR "Guidelines Establishing Test Procedures for the analysis of Pollutants under the Clean Water Act (CWA)."

The owner/operator reporting the results of the laboratory studies shall identify the detection limit and method used for the analysis of each parameter.

POINT OF COMPLIANCE

The Commission intends to allow for flexibility in locating the point or points of compliance within the specified area. After the point or points of compliance are determined, applicable ground water quality standards are to be met at these locations.

Mining activities are recognized to occur within ground water bodies and that water quality within the disturbed area will obviously change. The point(s) of compliance established outside the area anticipated to be disturbed may protect the water body while allowing the mining activity.

The Commission envisions that future and/or amended regulations will specify the design criteria and/or monitoring requirements necessary at the point or points of compliance. Down-gradient ground water monitoring locations may correspond to the point of compliance for the regulated activity.

IMPLEMENTATION

The Commission has considered several approaches to implementation of these regulations. The proposed rule initially included a provision for automatic applicability, with appeals to the Commission for reclassification. The parties raised strong objections to this proposal based on due process and statutory grounds. In its deliberations the Commission deleted this approach and proposed to the delegate classification and standard setting authority to other state agencies. The Attorney General's office indicated that the approach would constitute an unlawful delegation of the Commission's statutory duties. Next the Commission proposed to include a procedure for appeals to the Commission, but the delegation issue continued to be raised by the Attorney General's office and at least one party. The implementation provisions adopted in this rule are a response to objections raised by parties and the Attorney General.

The Commission assumes full responsibility for classification and standard setting at this time. Ample opportunity for comment has been provided at each juncture in the process, and the Commission has afforded the parties two additional four day comment periods.

In the absence of some delegation of responsibility to other agencies, the Commission anticipates a potential workload beyond its capabilities to absorb. The final rule establishes a list of factors to be considered in acting upon petitions for rulemaking hearings, in recognition of the time and resource limitations placed upon the Commission.

Reconsideration of classifications and standards by the Commission is permissible in the final rule. However, the Commission has determined that C.R.S. 25-8-207 was intended to apply only to surface waters and is not applicable to ground water.

A variance provision has been included in the final rule. The burden of proof is on the proponent of a variance to demonstrate that Table Values need not be adopted in order to protect classified uses. Variances can be granted at the time that standards are initially adopted or in a proceeding under Section 3.11.7(D).

When the Commission has adopted classifications and standards, such regulations should be applied by the Commission, the Division and other state agencies in carrying out their ground water protection responsibilities. The Commission has favored the delegation of responsibilities to other agencies, but has eliminated that approach based upon the objections of the Attorney General. However, the Commission hopes that other agencies with the authority to do so will follow the classification and standards system established by the regulations even in the absence of rulemaking by the Commission to establish classifications and standards for a specified area.

Ground water in a specified area shall not be deemed classified under C.R.S. 25-8-203, and standards shall not be deemed to be set under C.R.S. 25-8-204, in the absence of rulemaking by the Commission.

FISCAL IMPACT STATEMENT FOR THE BASIC STANDARDS FOR GROUND WATER

The Colorado Water Quality Control Commission promulgates this regulation entitled "The Basic Standards for Ground Water" under the authority to classify waters of the state and to establish water quality standards to support those classifications, Section(s) 25-8-202, 203, and 204 CRS.

The regulation establishes a system for classifying ground water and describing those classifications by use and quality. The standards, when applied to specific classes of ground water, become the baseline by which one can establish if water quality has been degraded or water use has been impaired or precluded. At this point there is no economic impact with respect to these regulations, except the cost associated with adopting the regulations. As control or other regulations are proposed which will implement the classification and standards system, the actual costs and benefits for each such proposal will be developed and considered. These regulations as originally proposed would have been automatically applicable to all sources of ground water contamination. This concept has been eliminated in the final rule.

This statement discusses potential economic impacts form future regulations that may be adopted to implement this regulation. All statements regarding values and costs are subject to change during the future adoption of specific control regulations.

COSTS

The fiscal impacts may occur at two different points in the regulatory system. If the regulations are implemented through source controls, then the entities responsible for the source (activity) will bear the cost. In socio-economic terms, this is the most equitable way to pay for the cost of prevention. The responsible entity may either pass the costs on to their consumers and have a relatively small percent increase in costs of service over a large user base, or absorb the costs without changing the price of their goods or services.

If the regulations are implemented by pathway elimination (i.e., alternate water supplies or point-of-use water treatment), then the question is who bears the costs? If the owner or operator of the source (activity) pays for pathway elimination, then the cost remains spread over the users of the product. If the pathway is eliminated and the cost is borne by the ground water users who are not responsible for the source, then the cost may be borne by a larger but less appropriate user base.

Finally, if neither the source nor the pathway are controlled and contaminated ground water is delivered to its ultimate user, then the individual water user carries the burden associated with increased health costs and risks.

Treatment of waste prior to discharge as a result of a control regulation is a viable alternative but the burden is upon the facility to provide the treatment. The elimination or reduction of the discharge includes design criteria such as pond linings, leak collection and/or detection. These costs can be significant but are limited to the life of the facility plus some limited post closure period. Eliminating or reducing the discharge is already required under several state statutes for some facilities such as certain solid waste disposal facilities.

Treatment of waste prior to discharge is an effective option for controlling contamination but is capital-intensive in terms of initial costs. This is a cost of production, manufacturing or operation and is considered a cost of doing business. The treatment of waste prior to discharge is already required for facilities that discharge to surface water.

Treatment of water at the point of use is the most costly option because it requires recapturing a much larger volume of contaminated water and redistribution of the water as well as treatment and maintenance. When this is related to private water supplies and maintenance, the cost rises because the treatment is not centralized.

One example of point-of-use treatment costs is nitrate removal system for the McFarland Mutual Water Company water supply in McFarland, California. The capital cost in 1983 was $900,000 for a one million gallon per day facility. Operating costs are twenty-four cents per 1,000 gallons.

In Colorado, provision of an alternate water supply could arguably be the most expensive option depending on the location of the contaminated resource. For example in the Denver area the cost to replace a water supply for South Adams County Water and Sanitation District (30,000 residents) is approximately $20.9 million for water from the Metro Water Development Authority and $34 million for water from the Burlington Ditch. This does not include the costs of treating the water. In rural areas, the replacement cost may not be as high as in the Denver area but alternate water supplies are not likely to be readily available.

Finally, the costs associated with cleanup of contaminated ground water tends to be the most expensive. Remedial cleanup is not always feasible, it is always costly. The costs associated with implementing these regulations as preventative measures are significantly less than the costs of implementing them as reactive or "cleanup" measures.

When used in the reactive sense, the costs of cleanup and contamination investigation have been described by Geraghty and Miller Ground Water Contamination, 1984, page 16. "Hydrogeologic investigations to define contamination problems can cost from $25,000 to $250,000. Litigation may lead to doubling of this price. The minimum costs of the ground water phase of a partial cleanup and containment project is $500,000."

In Santa Clara, California, IBM has spent $20 million and Fairchild has spent $16 million to cleanup ground water contamination. California has had some nineteen sites put on the Superfund National Priorities List because the small companies which are responsible do not have the funds to pursue cleanup activities.

In Colorado, the costs estimated for the cleanup of the Rocky Mountain Arsenal are estimated in the billions of dollars. The time needed for such cleanup is estimated to be several decades. Indeed, there will be costs associated with these rules that are likely to be large. However, when compared to the benefits or elimination of risk to the public health, those costs are warranted.

In terms of monitoring requirements, the agencies that may have to consider these standards in their permitting actions already require specific monitoring and hydrogeologic analyses to be performed. Therefore, no new monitoring requirements or costs may be associated with these rules when implemented under existing regulatory controls unless frequency of sampling or the number of parameters is increased by the agency.

Monitoring requirements, when implemented under the Commission's future regulations, will be an additional cost to facilities which will be controlled by those regulations. The Colorado Mining Association has estimated that a new investigation designed to comply with monitoring requirements which may result from future control regulations, may cost $500,000 the first year and $68,000 for each additional year. Monitoring programs for other types of activities may be lesser or greater than these figures depending on the nature of the activity and the specific requirements of the future control regulations.

State agencies, including the Division, will incur costs to adopt the future classifications, standards and control regulations and to implement them. It is not now known the magnitude of such costs or whether they will be paid by the taxpayers of the state or by facility owners through cash funding mechanisms such as discharge permit fees.

BENEFITS

There are no specific benefits which can be attributed to this present Commission action since these regulations only set up a framework for additional future regulations and their implementation. Several potential benefits may be realized by such future action. The most obvious possible benefit would be the protection of human health. Prevention of ground water contamination which would otherwise result in long-term illness is a benefit. The prevention of the costs of remedial medical care for the sick, additional health insurance premiums and costs to business for long-term illnesses and the costs to society for caring for chronically ill patients, not to mention the reduction of human suffering, is a distinct benefit.

Possible environmental benefits are related to the preservation of a valuable resource in a water scarce state. In many areas of Colorado, ground water is the only source of water for agriculture. The prevention of contamination of ground water allows the agriculture use to continue through the irrigation of crops or watering of livestock. Such crops and livestock make up a significant segment of the Colorado economy, the protection of which is a benefit.

PARTIES TO THE PROCEEDINGS OF THE PUBLIC RULEMAKING HEARING FOR THE BASIC STANDARDS FOR GROUND WATER