Conn. Agencies Regs. § 22a-426-7

Current through December 4, 2024

Section 22a-426-7 - Ground waters

(a)General Ground Water Standards and Policies

(1) The policy of the department for areas classified as GAA, GAAs, or GA shall be to maintain or restore all ground water in such areas to its natural quality.

(2) Notwithstanding subdivision (1) of this subsection, if the Commissioner determines that, with respect to a particular pollutant, restoring or maintaining natural quality at a GAA, GAAs, or GA level is not technically practicable, the department's policy shall be to:

(A) maintain or restore water quality such that the ground water is suitable for drinking and other domestic uses without treatment;

(B) maintain or restore water quality such that the ground water will not adversely affect surface water quality or prevent the maintenance or attainment of any designated uses of surface waters to which that ground water discharges;

(C) eliminate sources of pollution to such ground water to the extent that the Commissioner determines to be technically practicable; and

(D) regulate discharges to such ground water so as to prevent pollution.

(3) Ground water is deemed suitable for drinking and other domestic uses without treatment when no pollutant in such ground water:

(A) exceeds a level which the Commissioner of Public Health has determined, pursuant to section 22a-471 of the Connecticut General Statutes, creates or reasonably can be expected to create an unacceptable risk of injury to the health or safety of persons using such ground water for drinking or other personal or domestic use;

(B) is a carcinogen present at a concentration associated with a 1 × 10 ^-6 excess cancer risk;

(C) is a non-carcinogen present at a level exceeding that to which the human population, including sensitive subgroups, can be exposed on a daily basis without appreciable risk of adverse health effects during a lifetime; or

(D) exceeds a level which the Commissioner determines, in consultation with the Commissioner of Public Health, renders the ground water so aesthetically impaired that a person cannot reasonably be expected to consume or otherwise use it.

(4) The policy of the department in areas classified as GB shall be:

(A) to eliminate or reduce in ground water any pollutant which presents a hazard of fire, explosion, or toxic or hazardous emission to the environment or is determined by the Commissioner to otherwise pose a threat to public safety or an unacceptable risk to public health;

(B) to maintain water quality such that ground water will not adversely affect the quality of surface waters to which such ground water discharges or prevent the maintenance or attainment of any designated or existing uses of such surface waters;

(C) to maintain water quality consistent with all designated and existing uses of the ground water, including its use for drinking without treatment provided such ground water has been utilized, and continues to be utilized, for drinking water; and

(D) to regulate discharges to the ground water in order to prevent further degradation of ground water quality.

(5) The policy of the department in areas classified as GC shall be:

(A) to eliminate or reduce in the ground water any pollutant which presents a hazard of fire, explosion, or toxic or hazardous emission to the air or is determined by the Commissioner to otherwise pose a threat to public safety or an unacceptable threat to public health;

(B) to maintain the ground water at a quality that will not adversely affect the quality of surface waters to which such ground water discharges or prevent the maintenance or attainment of any designated or existing uses of such surface waters; and

(C) to limit the impacts of waste discharges on ground water quality to those which, despite the use of treatment technology, cannot be avoided and which result from a discharge which is authorized by a permit under section 22a-430 of the Connecticut General Statutes.

(6) Antidegradation Standards

(A) With respect to ground water whose quality is actually higher than that reflected by the assigned classification, such ground water should be maintained at its existing high quality. To maintain such quality, the Commissioner may require that:

(i) a new, increased, or otherwise modified discharge to such ground water shall be given treatment such that, notwithstanding such classification, the actual higher quality is maintained; and

(ii) if there is an unpermitted release of pollutants to ground water which is classified GB but whose quality is actually GA or GAA, such ground water shall be remediated to the standards for Class GA or GAA.

(B) The department's classification of ground water, whether as GB, GC, or otherwise, conveys no right to degrade that ground water or to utilize less effective treatment measures than those utilized for discharges to ground water designated for use as potable water. Domestic sewage shall be given the same treatment regardless of the classification of the ground water to which such sewage is discharged.

(7) The Commissioner may issue a permit authorizing a discharge of material to ground water, even if such discharge would be inconsistent with subsections (c)(1), (c)(2), (e), or (g) of this section, provided such discharge otherwise conforms with all applicable legal requirements and standards, is necessary to remediate ground water pollution, and is treated or managed such that, to the maximum extent practicable, the discharge does not impair public health or the environment.

(b)Class GAA and GAAs Ground Waters and Designated Uses

(1) Class GAA and GAAs ground waters are those ground waters designated as such on the map titled Water Quality Classifications on file with the department and that may be amended from time to time in accordance with subsections (d) through (g) of section 22a-426 of the Connecticut General Statutes. The designated uses for GAA and GAAs classified ground waters are:

(A) existing or potential public supply of water suitable for drinking without treatment; and

(B) baseflow for hydraulically-connected surface water bodies.

(2) Ground water classified as GAA is ground water used or which may be used for:

(A) public supplies of water suitable for drinking without treatment;

(B) ground water in the area that contributes to a public drinking water supply well; and

(C) ground water in areas that have been designated as a future water supply in an individual water utility supply plan pursuant to Connecticut General Statutes Section 25-32d or in the Area wide Supplement prepared by a water utility coordinating committee pursuant to Connecticut General Statutes Sections 25-32d and 25-33h.

(3) Ground water classified as GAAs is ground water that is tributary to a public water supply reservoir.

(c)Class GAA and GAAs Allowable Discharges

(1) GAA: The Commissioner shall not issue permits authorizing a discharge to class GAA ground water unless such discharge is of treated domestic sewage as defined in section 22a-430-1 of the Regulations of Connecticut State Agencies, waste generated by certain agricultural practices, certain water treatment waste waters from public water supply treatment systems, or certain minor cooling waters or clean waters. If a GAA area is within an Aquifer Protection Area designated in accordance with section 22a-354d of the Connecticut General Statutes, the Commissioner shall not issue permits authorizing a ground water discharge that conflicts with any regulation adopted pursuant to section 22a-354i of the Connecticut General Statutes.

(2) GAAs: The Commissioner shall not issue permits authorizing a discharge to class GAAs ground water unless such discharge is of treated domestic sewage as defined in section 22a-430-1 of the Regulations of Connecticut State Agencies, waste generated by certain agricultural practices, certain water treatment waste waters from public water supply treatment systems, or certain minor cooling waters or clean waters. If a GAAs area is within an Aquifer Protection Area designated in accordance with section 22a-354d of the Connecticut General Statutes, the Commissioner shall not issue permits authorizing a ground water discharge that conflicts with any regulation adopted pursuant to section 22a-354i of the Connecticut General Statutes.

(d)Class GA Ground Waters and Designated Uses

(1) Class GA ground waters are those ground waters designated as such on the map titled Water Quality Classifications on file with the department and that may be amended from time to time in accordance with subsections (d) through (g) of section 22a-426 of the Connecticut General Statutes. The designated uses for class GA ground waters are:

(A) existing private and potential public or private supplies of water suitable for drinking without treatment; and

(B) baseflow for hydraulically-connected surface water bodies.

(2) Ground water classified as GA is ground water within the area of existing private water supply wells or an area with the potential to provide water to public or private water supply wells. The department presumes that ground water in such an area is, at a minimum, suitable for drinking or other domestic uses without treatment.

(e)Class GA Allowable Discharges

The Commissioner shall not issue permits authorizing a discharge to class GA ground water unless such discharge is allowed under subsection (c)(1) of this section or is a discharge from a septage treatment system or of other wastes that are predominantly human, plant, or animal in origin so long as any such wastes are of natural origin, easily biodegradable and, if properly managed, pose no threat of pollution to the ground water. The ground water plume generated by a discharge from a septage treatment system shall terminate in a stream with classification of B or SB unless the permittee treats the discharge in a manner which the Commissioner determines is adequate to maintain class A water in the receiving stream.

(f)Class GB Ground Waters and Designated Uses

(1) Class GB ground waters are those ground waters designated as such on the map titled Water Quality Classifications on file with the department and that may be amended from time to time in accordance with subsections (d) through (g) of section 22a-426 of the Connecticut General Statutes. The designated uses for class GB ground waters are:

(A) Industrial process water and cooling waters;

(B) baseflow for hydraulically-connected surface water bodies; and

(C) presumed not suitable for human consumption without treatment.

(2) Ground water classified as GB is ground water within a historically highly urbanized area or an area of intense industrial activity and where public water supply service is available. Such ground water may not be suitable for human consumption without treatment due to waste discharges, spills or leaks of chemicals or land use impacts.

(g)Class GB Allowable Discharges

The Commissioner may issue permits authorizing a waste discharge to class GB ground water if such discharge would be allowable in a GA area under subsection (e) of this section or if such discharge meets all of the following criteria:

(A) the Commissioner has determined that such waste is generated by a source which is unlikely to produce persistent pollutants or pollutants that do not biodegrade in soil;

(B) the waste will be treated as necessary to render it amenable to attenuation by the receiving soil so that the ground water will not be impaired; and

(C) such discharge otherwise conforms with all applicable legal requirements and standards.

(h)Class GC Ground Waters and Designated Uses

(1) Class GC ground waters are those ground waters designated as such on the map titled Water Quality Classifications on file with the department and that may be amended from time to time in accordance with subsections (d) through (g) of section 22a-426 of the Connecticut General Statutes. The designated use for class GC ground water is assimilation of discharges authorized by the Commissioner pursuant to section 22a-430 of the Connecticut General Statutes.

(2) Ground water classified as GC is ground water to which the Commissioner has authorized a discharge under section 22a-430 of the Connecticut General Statutes.

(3) Ground waters classified as GC are not suitable for development of public supplies of potable water.

(4) The most important consideration in making a determination to classify ground water as GC shall be the impact of any authorized ground water discharges on adjacent surface waters.

(i)Class GC Allowable Discharges

The Commissioner may issue permits authorizing a discharge to class GC ground water of any material, provided such discharge otherwise conforms with all applicable legal requirements and standards.

(j)Zones of Influence

The Commissioner may establish zones of influence when, in the course of permitting discharges to the ground water under section 22a-430 of the Connecticut General Statutes, the Commissioner allocates ground water and soil resources for the treatment of pollutants. Within such zone of influence the permittee under section 22a-430 of the general statutes may degrade the ground water such that it may not meet the standards for the assigned classification or be suitable for uses designated under such classification.

(1) For a subsurface sewage disposal system permitted under authority delegated pursuant to section 22a-430-1 of the Regulations of Connecticut State Agencies to the Commissioner of Public Health, the zone of influence shall be that area required by the minimum separating distances established in section 19-13-B103d of the Regulations of Connecticut State Agencies.

(2) For discharges to ground water of treated domestic sewage other than discharges of domestic sewage identified in subdivision (1) of this subsection, agricultural wastes, and storm water, the zone of influence shall be the area in which such discharge causes the ground water to be:

(A) altered in quality from its natural condition or

(B) lowered in quality from that which is suitable for drinking and other domestic uses without treatment. The Commissioner may require the applicant for a permit under section 22a-430 of the Connecticut General Statutes to submit for the Commissioner's approval an engineering plan showing the areal extent of any such zone of influence.

(3) The applicant for a permit under section 22a-430 of the Connecticut General Statutes authorizing a discharge other than a discharge of treated domestic sewage, agricultural waste, or storm water shall delineate the zone of influence associated with the proposed discharge. Such zone of influence shall include all areas beneath which the ground water which is or may be affected in quality by such discharge. The Commissioner may require that such zone of influence extend to a receiving water body with a classification of B or SB.

(4) The Commissioner may require the applicant for a permit under section 22a-430 of the Connecticut General Statutes to demonstrate that the applicant has acquired rights to the zone of influence of the proposed discharge. Acquisition of such rights means that the applicant owns the land overlying such zone, has obtained an easement with respect to such land and has recorded such easement in the applicable Town Clerk's office, or otherwise controls such zone to the Commissioner's satisfaction. Any such easement or other control mechanism shall:

(A) provide the applicant with the exclusive right to use the ground water in such zone and such right to enter the land overlying such zone as the Commissioner deems necessary to accommodate monitoring or remediation; and

(B) assure that the ground water within such zone will not be used for potable water supply.

(5) The delineation by a permit applicant under section 22a-430 of the Connecticut General Statutes of the zone of influence of a proposed waste discharge indicates that the underlying ground water may not be suitable for human consumption or other uses. Installation of a withdrawal well in or near such a zone of influence may result in an induced flow of polluted ground water to such well. When reviewing an application to withdraw ground water pursuant to sections 22a-365 through 22a-378a of the Connecticut General Statutes the Commissioner considers the potential impacts on water quality attributable to induced flow of polluted water from a zone of influence associated with a waste discharge.

(k)Ground Water Reclassification

(1) The commissioner may raise the ground water classification of any area if the commissioner finds that such ground water meets the standards for the higher classification.

(2) The Commissioner may consider an application to lower a ground water Classification to GB.

(A) Such application shall be subject to the public participation requirements of section 22a-426 of the Connecticut General Statutes and shall:

(i) describe the nature and extent and date of commencement of pollution of the ground water proposed to be reclassified;

(ii) identify all sources of drinking water in the area whose ground water is proposed to be reclassified and identify all existing uses of ground water within and down gradient of such area;

(iii) assess the potential of the subject area to produce ground water in an amount suitable for a public water supply;

(iv) describe all past and present land uses in the subject area with dates; and

(v) provide such other information the Commissioner may reasonably require to determine the most appropriate ground water classification.

(B) A ground water classification shall not be lowered to GB unless the applicant has satisfactorily demonstrated that:

(i) any person within or down gradient of the area to be reclassified extending to an area previously classified as GB or to a surface water body to which the ground water discharges will be provided with an adequate public water supply;

(ii) lowering of a ground water classification will not prevent attainment of adjacent surface water quality goals or present unacceptable health risks; and

(iii) any of the following:

(I) that the ground water to be reclassified is polluted as a result of intense urban, commercial, or industrial development which occurred prior to 1981, and the hydrologic conditions of the subject area are not suitable for the development of a significant public water supply;

(II) that the ground water proposed to be reclassified is polluted and remediation of such ground water to a quality suitable for drinking without treatment is not technically practicable; or

(III) that there is an overriding social or economic justification for reclassifying the ground water to GB and the proposed reclassification is supported by the affected municipality or municipalities, as affirmed, in writing, by the chief executive officer(s) of the municipality or municipalities. For the purposes of this subsection an "affected municipality" is one in which ground water classifications are to be altered; "social justification" means a specific social need of the affected municipality or the state and "economic justification" means avoidance of an economic impact that would substantially impair or otherwise detrimentally affect the economy of the community or the state. The applicant shall also demonstrate that the purposes for the reclassification will not result in development that is inconsistent with the State Policies Plan for Conservation and Development, as adopted pursuant to section 16a-30 of the Connecticut General Statutes.

(3) The Commissioner may consider an application to lower a ground water classification to GC. Any such application shall be subject to the public participation requirements of Section 22a-426 of the Connecticut General Statutes and:

(A) Such application shall be accompanied by a completed application under section 22a-430 of the Connecticut General Statutes for a permit to discharge leachate from a solid waste land disposal facility to the subject ground water.

(B) A ground water classification shall not be lowered to GC unless the applicant has satisfactorily demonstrated in its application that:

(i) there is an overriding social or economic justification for reclassifying the ground water to GC and the affected municipality or municipalities have been notified of the proposed reclassification;

(ii) the ground water proposed to be reclassified is not suitable for development of a significant public water supply and is suitable for waste treatment;

(iii) the subject area is adjacent to and hydraulically connected with a surface water body classified B or SB; and

(iv) the applicant has delineated the zone of influence of the ground water proposed to be reclassified as extending from the proposed solid waste land disposal facility to the receiving surface water body, and the applicant owns the land overlying such zone of influence, or has an easement with respect to such land which easement is properly recorded and provides protections, as described in subdivisions (2)(A) and (2)(B) of subsection (j) of this section, or otherwise controls the zone of influence to the satisfaction of the Commissioner.

Conn. Agencies Regs. § 22a-426-7

Effective October 10, 2013