5 Colo. Code Regs. § 1002-31.26
The provisions of section 25-8-202(1)(a),(b),(d) and (2); 25-8-203; 25-8-204; and 25-8-501 to 25-8-504 C.R.S., provide the specific statutory authority for adoption of the attached regulatory amendments. The Commission also adopted, in compliance with section 24-4-103(4) C.R.S., the following statement of basis and purpose.
The Commission adopted major revisions to the antidegradation provisions in 1988. The experience gained by the Commission and Division in implementing those provisions since that time indicates that this new structure is generally workable, but that a few refinements would be helpful.
Section 3.1.8 provides that antidegradation review requirements are presumptively applicable to certain waters for which no water quality-based designation has been established. The previous version of this section allowed this presumption to be overcome if existing water quality for one or more parameters is worse than the "table values" set forth in Tables I, II and III. This provision has now been revised to provide that existing quality must be worse than table values for at least three of these parameters in order for the presumptive antidegradation review requirement to be overcome.
This change is being made in part to be consistent with parallel changes that are being adopted in section 3.1.8 . The previous regulatory provisions resulted in a regulatory "no man's land" for segments where one or two parameters exceed table values. Such segments did not qualify for designation either as "high quality" or as "use-protected" segments. They were presumptively subject to antidegradation review if the appropriate classifications were applicable, although this presumption could be overcome by data showing that as few as one parameter in fact exceeded table values. The Commission now believes that a simpler, more consistent cut-off between two and three parameters of "poor" quality is preferable. The Division has indicated that the previous test excluded from antidegradation review a number of water bodies that generally would be considered to have very good quality water. This was particularly true for a number of streams that were excluded from review on the basis of elevated levels of iron. The impacts of iron on aquatic life uses are uncertain, and the benefit of iron as a water quality standard is more as an indicator of sediment loading.
The Commission recognizes that this revision will marginally expand the number of streams subject to antidegradation reviews. The Commission believes that this expansion is appropriate as a matter of policy, to further the goal of protecting Colorado's existing high quality water resources. Moreover, the Commission notes and is influenced by the fact that the experience gained since 1988 indicates that fears that the new antidegradation review provisions would be used as a tool to stop development in Colorado were unfounded.
The Commission also has deleted the reference in this segment to recreation classifications, so that presumptive review would now be based solely on the presence of an aquatic life class 1 classification. In recent basin-specific hearings, and in other revisions being made in this hearing, the Commission has based the distinction between recreation class 1 and class 2 classifications on the presence or absence of specific uses, rather than on the presence or absence of water quality consistent with a class 1 classification. Therefore, it now appears that whether a segment is classified recreation class 1 or class 2 is not a good general indicator of the quality of the water in a particular segment. Accordingly, here and in section 3.1.8 , the references to recreation classifications as a determinant of whether an antidegradation review is required have been eliminated.
Section 3.1.8 has been revised to provide that waters are to be designated high quality 2 if less than three of the listed parameters exceed table values. The previous version of this regulation required that existing quality for all of the listed parameters be better than table values in order for the high quality 2 designation to routinely apply. The reasons for this change are the same as those described above, with respect to the revisions of section 3.1.8(1)(b)(iii).
The reference to recreation classifications in section 3.1.8 has been deleted. See the discussion regarding Presumptive Review Provisions, above.
Subsequent to the revision of this regulation in 1988, the Commission revised its Procedural Rules, 2.1.0 (5 CCR 1002-1), to establish procedural provisions regarding public participation and intergovernmental coordination relating to antidegradation review. A new subsection 3.1.8 has been added to this regulation to cross-reference those procedural provisions.
The Commission considered but rejected proposals to delete subsections 3.1.8 , and (ii). The result of these deletions would have been to base high quality designations solely on the 12-parameter test in subsection 3.1.8 . The Commission continues to believe that it is appropriate as a matter of policy to provide the extra layer of protection afforded by antidegration reviews to waters in National Parks, National Monuments, National Wildlife Refuges, and Wilderness Areas, and to designated Wild Rivers. The Commission also believes that the "exceptional reasons" provision in subsection 3.1.8 has proven workable to date. The Commission considered and rejected a proposal to put more specific guidance regarding the application of this latter subsection in the regulation. In determining whether to designate a segment high quality 2 based on "exceptional reasons" , the Commission has in the past considered factors such as:
Factors such as these, or other factors, may be determined to be relevant to high quality designation decisions in the future. However, until more experience with application of this subsection is acquired, the Commission believes it would be premature include such specific criteria in the regulation.
The Commission also considered but rejected proposals to make several other changes to the antidegradation provisions. The Commission does not believe that it is necessary or appropriate to further define "available representative data" at this time. Exercise of case-by-case best professional judgment will continue to be necessary in applying this concept. The Commission does agree that the Division should be encouraged to explain the basis for its application of this concept in specific situations (e.g. is an extrapolation from data in other adjacent or similar segments being relied upon?) as early as possible in individual rulemaking hearing proceedings.
The Commission also declined to make changes in the significance determination, economic reasonableness and public participation provisions, or in the provisions defining the applicability of antidegradation provisions to regulated activities. The substance of the public participation provisions is set forth in the Commission's Procedural Rules and was not at issue in this hearing. With respect to other provisions, the Commission does not believe that there is sufficient evidence available at this time that there is a need to revise the provisions adopted in 1988.
In 1989, the Commission adopted certain interim organic pollutant standards, applicable to water segments statewide based on the presence of domestic water supply or aquatic life classifications. Several revisions and additions to those interim standards are now being adopted. In general, the primary purpose of these changes is to provide a more thorough system to assure protection of Colorado's water resources with respect to potential adverse impacts from organic chemicals. In addition, these revisions should address remaining questions regarding Colorado's compliance with the requirements of section 303(c)(2)(B) of the federal Clean Water Act.
One change adopted is to combine previous Tables A, B, and C into a new, consolidated Basic Standards for Organic Chemicals Table. The Commission believes that this format will be easier to read, and helps to assure elimination of potential inconsistencies between the separate tables.
The Commission has added to the new consolidated Basic Standards for Organic Chemicals Table additional organic chemical standards for class 1 aquatic life water segments. These standards have been added to help ensure protection of human health, taking into consideration the fish ingestion or consumption pathway. In 1989, the Commission declined to adopt such standards for all state waters classified for aquatic life (class 1 or class 2). The Commission still believes that that blanket application is unnecessary. However, the Commission does believe that presence of a class 1 aquatic life classification is in general a good indicator of streams where significant fishing may occur.
In 1989, the Commission also questioned whether the assumptions underlying EPA's criteria regarding fish ingestion were appropriate for use in Colorado. EPA's criteria assume an average consumption of 6.5 grams of fish per person per day. The evidence indicates that where other states that have adopted similar standards have used a different average consumption rate, they have generally assumed a consumption rate three times that used by EPA. In the absence of resources to do a more exhaustive analysis of Colorado fish consumption habits, the Commission believes that use of the EPA assumption is a reasonable policy choice.
The Commission does not believe that the evidence indicates that the pollutants contained in the Basic Standards for Organic Chemicals Table are currently present at levels of concern for most Colorado waters. By adopting these standards at this time, the Commission intends to help implement a preventive system to assure that problems do not develop in the future. The experience of other states indicates that issuance of health advisories regarding consumption of locally caught fish can have a significant negative impact on the recreational fishing industry. It is the Commission's goal to prevent such circumstances from developing in Colorado to the maximum degree possible.
In taking this step, the Commission also is influenced by the experience to date in implementing the organics standards adopted in 1989. During the proceeding that led up to the 1989 action, substantial concern was expressed that adoption of standards for a long list of organic chemicals would result in substantial and unnecessary monitoring expenses for the regulated community. The Commission attempted to address this concern by the adoption of section 3.1.14 , which instructs the Division to require monitoring only where toxic conditions are present or the individual constituent is likely to be present in the effluent of a particular discharger on a continuous or recurring basis in quantities which could cause the water quality standards to be violated. The Commission believes that this approach is workable, and that the adoption of the additional standards should not significantly increase monitoring costs, except where there is reason to believe that these pollutants may be present. In such circumstances, additional monitoring-and, and if necessary, effluent limitations-is appropriate.
Some comment was submitted recommending that the Commission should apply the new standards only to streams classified for aquatic life and water supply, since the underlying criteria are based on a combination of water and fish ingestion. The Commission has rejected this alternative. Persons eating fish from Colorado streams can still be expected to drink water from some source, even if not the same segment. Both ingestion pathways should be protected, even if they do not occur at the same location. Therefore, the assumption that a portion of the potential total exposure is through drinking water is still valid.
Finally, the Commission intends to consider the application of the fish and water ingestion standards to class 2 aquatic life segments on a case-by-case basis, where there is evidence that fishing is a significant activity for the waters in question. The Division staff has begun to request information regarding fishing for particular streams, as the basin-by-basin triennial review hearings occur. The Commission specifically requests that in future basin-specific hearings the Division solicit information, at a minimum, from the Colorado Division of Wildlife and any applicable section 208 agency to determine those class 2 aquatic life segments on which significant fishing occurs.
When the Commission adopted interim organic chemical standards in 1989, the Commission adopted standards based on maximum contaminant levels (MCLs) for all pollutants for which MCLs had been established under the Safe Drinking Water Act. The Commission has now reevaluated this policy and adopted health-based standards for these constituents instead of standards equal to the MCLs, whenever health-based criteria are available. Several considerations have led to this new approach.
The vast majority of the standards adopted in 1989 were already set equal to health-based criteria. MCLs generally are more lenient than health-based criteria, and have been developed taking into account laboratory detection limits and the economic ability of water suppliers to treat for removal of these constituents. For most dischargers, the availability of low flow dilution credits in calculating effluent limitations has resulted in a second level of relaxation-i.e. movement away from underlying health-based-levels-when applying non-health-based MCL standards. The Commission already has attempted to temper the application of stringent health-based standards for non-MCL organic pollutants by providing for the application of the practical quantitation limit (PQL) concept in determining compliance with the standards. Use of low flow dilution credits in calculating effluent limitations provides for a further tempering of these very stringent standards in application. Therefore, the Commission has determined that it is a more appropriate policy to base these water quality standards on health-based criteria, rather than MCLs. Revisions have been made to the standards as now contained in the consolidated Basic Standards for Organic Chemicals Table.
Standards for a number of additional organic chemicals have been added to the Basic Standards for Organic Chemicals Table to help complete Colorado's compliance with section 303(c)(2)(B) of the federal Clean Water Act. The chemicals added are ones listed as priority toxic pollutants, and for which EPA has developed human health or aquatic life criteria under the Clean Water Act.
The Commission decided not to include in the consolidated Table standards for total trihalomethanes or for polynuclear aromatic hydrocarbons (PAHs) as a class. The Commission believes that it is more practical to regulate individual chemicals in these groups. Some evidence was submitted indicating that not all PAHs should have the same standard. For now the Commission has adopted these standards based on the available EPA criteria, although if more specific evidence on this issue is brought to the Commission in the future, revisions can be considered.
Several minor clarifications have been adopted in the Basic Standards for Organic Chemicals Table. A footnote has been added for the human health-based standards to indicate that these are chronic water quality standards. The "detection levels" column has been relabeled "PQLs" , to clarify that the values indicated are practical quantitation limits. In addition, the PQLs for a few parameters were revised to be consistent with the current information from the Colorado Department of Health laboratory. Inconsistencies in PQLs for individual chemicals have been avoided by adopting a consolidated table. The Commission declined to adopt a definition of "PQL" based on a fixed multiple of the method detection limit (MDL), since that would not accurately reflect current scientific practice.
The Commission chose not to list EPA laboratory analytical methods in the Basic Standards for Organic Chemicals Table. Dictating a specific analytical method in the regulation would unnecessarily constrain flexibility. Currently, the Division has discretion to approve the use of alternative methods. However, the Commission encourages the Division to make information regarding the standard analytical techniques available in a guidance document, so that this information will be easily accessible to the regulated community and the general public.
One party suggested that the Commission should specify that dischargers would not be subject to effluent limitations based on the aquatic or fish and water ingestion standards if they had passed whole effluent toxicity (WET) tests. WET tests only address potential toxicity to aquatic life and are therefore not an appropriate substitute for limits based on fish and water ingestion standards. Moreover, the Division already has discretion to determine the appropriate combination of chemical-specific effluent limitations and WET testing requirements to assure that potential toxicity to aquatic life is controlled. Therefore, the suggested change was not made.
The Commission has adopted a new subsection 3.1.11 , to enumerate factors that may be addressed in considering the adoption of site-specific standards to override statewide numerical standards. These provisions are intended to broaden the scientific base of information considered, not to limit protection. For example, these provisions do not mean that an area with a few people should receive a lower level of protection than a heavily populated area. Rather, certain sensitive populations may need to be considered in site-specific situations, e.g. children. The burden of demonstrating the relevance of these factors in a site-specific application would be that of the proponent of site-specific standards.
The Commission declined to make revisions that would broaden the applicability of section 3.1.11 , since these provisions were adopted solely to clarify the interrelation of the statewide standards with the unique provisions of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).
The Commission has been concerned that the current regulation does not contain as much flexibility as the Commission believes appropriate to address currently contaminated water segments where the Commission believes that some improvement in water quality is desirable and feasible. The Commission has expressed a general discomfort with the extreme options of choosing either ambient quality-based standards or table value standards in segments where some improvement is expected but the degree of improvement is difficult to predict. The Commission often is left with the dilemma of either sending a message that it finds the status quo of existing contamination acceptable by setting ambient quality-based standards, or that it expects the water segment to reach table value standards within twenty years, when the actual degree of cleanup may be difficult to identify with certainty.
An additional concern of the Commission's has been that the water quality standards system has generally been reactive, rather that proactive. The Commission believes that the standards system should, where feasible, help facilitate the statutory goal "to protect, maintain, and improve " Colorado's water resources. In this regard, a more proactive, goal-based approach would also help establish priorities for determining upon which water segments nonpoint source cleanup efforts might best be focused.
To address these concerns, the Commission considered the adoption of a new section 3.1.4 , entitled "Water Quality Improvement Targets." The provisions of this section would have been intended to operate in a manner independent from, but complementary to, the water quality classification and standards system. The key aspect of this section would have been the adoption of "numerical protection targets" , which would be used to help guide efforts at point and nonpoint source pollution control. In addition, in keeping with the statutory focus on beneficial use protection, this section would have provided for the adoption of "use attainment targets" , which would then be used as the basis for determining appropriate numerical protection targets.
Numerous concerns were expressed in the rulemaking process regarding this proposed new section, particularly with respect to uncertainties regarding the relationship of targets to the water quality standards system, and the practical effects of implementing targets in discharge permits. Upon consideration of all the evidence submitted, the Commission has decided not to adopt the proposed targets provisions at this time. However, the Commission continues to believe that pursuing opportunities for water quality improvement is an important priority that needs to be addressed further in the future. The Commission will continue to explore opportunities in this regard, and encourages any interested persons to advance to the Commission any recommendations that they may have.
The Commission has revised the description of the class 1 recreation classification. Although the previous definition was broad enough to encompass uses other than swimming, recent basin-specific hearings have resulted in controversy regarding how broadly that definition can or should be applied. The Commission believes that the operative factor for classifying waters recreation class 1 should be whether there are any activities that are likely to involve ingestion of water. This may include certain recreational activities that generally occur on the water, such as rafting, kayaking and water-skiing. This list of activities potentially involving ingestion is not intended to be exclusive. Other activities may warrant a class 1 classification in specific situations.
By clarifying the class 1 recreation definition in this manner, the Commission is not condoning or encouraging the ingestion of any untreated water. Rather, the Commission is recognizing the reality that ingestion occurs from these activities. In fact, experience indicates that these activities may involve a higher likelihood of ingestion of water than does swimming. Therefore, the definition in section 3.1.13 has been revised to further clarify the Commission's intent.
Language has been added to section 3.1.14 to clarify that the Water Quality Control Division has authority to establish numerical effluent limitations for parameters for which no statewide or site-specific numerical standards have been adopted, when necessary to comply with the narrative standards in section 3.1.11 . Such action by the Division does not constitute standard-setting. The effluent limitations developed are applicable only to an individual discharger. Moreover, this appears to be the only meaningful way to implement the narrative standards in practice. Application of such effluent limitations when necessary reflects the past and current practice of the Division. This language has been added to this regulation merely to recognize the appropriateness of this practice.
Language also has been added to section 3.1.14 to clarify that it is the Commission's intent that the Water Quality Control Division is authorized to utilize compliance schedules when appropriate in implementing water quality standards into discharge permits. Again, this revision merely confirms existing Division practice. This provision is being added to this regulation because of recent indications from EPA that states that may need to authorize the use of compliance schedules in their water quality standards regulations in order for such schedules to be included in discharge permits. Other compliance schedule issues raised by EPA in this proceeding are more appropriately addressed in the Discharge Permit Regulations.
Section 3.1.14 has been revised to clarify the appropriate analytical methodologies for metals monitoring. This revision is necessary since there are water segments which have both total recoverable and dissolved metals standards.
The provisions of section 3.1.14 previously referred merely to the imposition of monitoring requirements with respect to organic chemicals standards. The language in this section has now been revised to apply to monitoring related to water quality standards in general. This change has been adopted because the Commission believes that, although this section was originally drafted with organic chemical standards in mind, the provisions contained therein are appropriate with respect to water quality standards generally.
As described with respect to the preceding revision, the Commission has revised section 3.1.14 to broaden its applicability to water quality standards in general, rather than merely organic chemicals standards.
A new subsection 3.1.14 has been added, to clarify the relationship between chronic and acute effluent limitations, when implementing water quality standards.
The Commission considered revisions to the dissolved oxygen values for aquatic life. The Division withdrew this proposal at this time, since it appears that EPA's position on this issue is still evolving. The Commission did adopt a new footnote to Table I, to help clarify the application of dissolved oxygen standards to lakes.
In 1988, the Commission considered and rejected a proposal to change the indicator parameter used for bacteriological standards. Although the issue was raised again in this hearing, the Commission does not believe that any new information has become available since 1988 to warrant a different conclusion.
The total residual chlorine values for aquatic life have been revised, to be consistent with the 1986 EPA criteria. The Commission also has adopted a new table value for asbestos, to assure that criteria for all appropriate priority toxic pollutants are available for adoption on a site-specific basis if necessary.
The Table III table values for aluminum, mercury, and zinc have been revised to reflect more current information that was unavailable when the Commission revised this regulation in 1988. With respect to zinc, limited information was submitted in the hearing questioning the appropriateness of the new criteria at low hardness levels. This issue can be considered further in the future, if more specific evidence is submitted to the Commission. With respect to mercury, the Commission has revised footnote 6 to Table III.
For the vast majority of stream segments in the state, the Commission has adopted the FRV (final residue value) of 0.01 ug/liter mercury as the numeric stream standard. The Commission has clarified that this standard applies to the "total" form. For a few segments, the Commission has adopted ambient-based standards or temporary modifications where site-specific studies have shown methylmercury concentrations in fish to be less than the FDA action level. New information contained in the 1990 Colorado Department of Health's Advisory for Consumption of Fish Contaminated with Methylmercury, indicates that methylmercury concentrations in sport-caught fish as much as one-fifth lower (0.2 ppm) than the FDA action level may pose a health risk to sensitive subpopulations such as the fetus, infants and children.
In consideration of this health risk assessment it becomes apparent that the FDA action level is not the only basis for evaluating concentrations of mercury in sport-caught fish. It may be possible to recalculate the FRV based on the health risk information, but the Commission decided not to, because the current FRV and any subsequent adjustments would place the resulting stream standard below the CDH detection limit for mercury in water of 0.25 ug/liter. From a practical standpoint, achievement of FRV or any adjusted FRV would still be based on instream values being below the detection limit.
It is the Commission's intent that due to the persistence of mercury in the environment and the new health risk information, mercury in effluent discharges be kept to the lowest levels possible, preferably below detectable concentrations. However, for those segments supporting fish or shell fish populations where there is the potential for human consumption and where an ambient-based approach is sought by a proponent, the Commission believes that a substantial case must be clearly demonstrated for adopting an ambient standard. Accordingly, footnote (6) of Table III for metals in Section 3.1.16 has been changed to reflect new information requirements based on the health risk assessment.
The Commission considered but declined to make revisions in the table value for selenium, based on a new EPA criteria document. Substantial questions were raised regarding the basis for the new EPA criteria, and the Commission believes that this issue should be examined more closely before the existing table values are changed.
The Commission has adopted new drinking water supply table values for antimony, beryllium, and thallium, to assure that criteria for all appropriate priority toxic pollutants are available for adoption on a site-specific basis if necessary. These table values will be applied on a site-specific basis only where there is reason to believe that there is potential concern regarding the pollutant in question. Such circumstances are not expected to arise frequently.
The Commission declined to adopt a proposal to change the table values for agricultural and domestic uses to the dissolved form rather than total recoverable, because no scientific basis for the change was provided.
The Commission declined to adopt a proposal to adopt PQLs for all parameters in Table III. This issue of standards below routine detection levels appears to be an issue for metals only with respect to mercury and silver. Therefore, only in these instances would the adoption of PQLs be significant. No proposals for specific PQLs were advanced by the parties to the hearing. If specific proposals are put forth in the future, the Commission can consider them in a subsequent rulemaking proceeding.
The Commission also declined to adopt regulatory provisions proposed by the Division of Wildlife to address certain sampling and analytical method issues. The Commission does not believe that these issues are appropriately addressed in this regulation, but encourages the Division to consider these recommendations.
Section 3.1.6 has been revised to delete a reference to the effective date of this regulation. First, this reference is somewhat confusing since there have been several revisions in this regulation. More significantly, the Commission believes that as a matter of policy and to be consistent with federal law, the downgrading restrictions should apply to use classifications whenever adopted, not merely to classifications that were in effect at some earlier date. In addition, in response to a recommendation by the Colorado Water Congress, the provisions of this section have been substantially revised to more closely parallel the federal downgrading provisions.
Section 3.1.6 has been revised to clarify the circumstances in which it may be necessary for the Division or other advocate of omitting an aquatic life or recreation classification to perform a new use attainability analysis.
The Commission rejected a proposal to add a new subsection (d) to section 3.1.6 , to clarify the Commission's policy to minimize the number of segments established in its basin-specific classifications and standards whenever possible. Although it was intended to restate existing policy and not to indicate that segments should be combined where there is a reason for distinguishing between them, based on substantial concerns raised regarding the proposal, the Commission has decided that it is unnecessary at this time.
Language has been added to section 3.1.7 to clarify the criteria used by the Commission in determining whether to apply standards based on Tables I, II and III on a site-specific basis. This provision merely confirms existing practice. It is adopted in large part to clarify for EPA the fact that the Commission does apply such criteria in deciding when standards for priority toxic pollutants need to be adopted on a site-specific basis.
Section 3.1.7 has been revised to clarify that when the Commission establishes chronic standards based on existing ambient quality, such standards must be at least as stringent as an acute toxicity standard based on table values. The purpose of this revision is to assure that the adoption of ambient quality-based standards does not result in any acute toxicity in-stream. This revision is not intended to change the current methodology for determining compliance with ambient standards.
Section 3.1.9 has been revised to clarify the Commission's intention with respect to the application of standards during low flow conditions. In particular, the language has been revised to indicate that the 30E3 and 1E3 flow values are to be utilized as minimum dilution assumptions for developing discharge permit effluent limitations. This is consistent with existing practice. However, the language has been revised to clarify that water quality standards apply to streams at all times. In other words, merely because a stream happens to be currently at a flow below its established low flow values, does not mean that someone would be allowed to dump pollutants into the stream in violation of the standards. Again, this is not intended to change the existing practice with respect to the development of discharge permit effluent limitations.
Minor editorial revisions have been made to sections 3.1.1 , 3.1.6 , 3.1.16 , 3.1.16 , footnote 4 to Table II and the Table II entry regarding ammonia. These revisions delete certain language that is no longer necessary or applicable, and make minor clarifications in the existing provisions.
A number of additional proposals for revisions to this regulation were raised during this rulemaking proceeding. Although no attempt is made to comprehensively list every such proposal, several of the more significant ones considered and rejected by the Commission are noted below.
Several proposals were advanced to add new definitions to section 3.1.5 . The Commission does not believe that the additional definitions proposed are necessary at this time. The Commission rejected a proposal to add additional provisions to section 3.1.6 regarding "upgrading" because it does not believe these revisions are necessary at this time. A proposal for revised mixing zone provisions was not addressed, since it was not within the scope of the issues noticed for this hearing. A proposal to revise section 3.1.10 regarding Otherwise Dry Streambeds was rejected because the Commission believes that the concerns raised are more appropriately addressed in the pending revisions to the State's biomonitoring regulations. Finally, several proposals to revise the narrative standards in section 3.1.11 were rejected because the Commission believes that the current standards are workable, and it has not been demonstrated that there is a need for revisions at this time.
PARTIES TO THE RULEMAKING HEARING FOR BASIC STANDARDS & METHODOLOGIES FOR
SURFACE WATER AND GROUND WATER
5 CCR 1002-31.26