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  Bureau of Environmental Analysis, Restoration and Standards

Ground Water Quality Standards

New Jersey’s Ground Water Quality Standards are established in the Ground Water Quality Standards (GWQS) rules at N.J.A.C 7:9C. The GWQS rules establish classes of ground water according to the hydrogeologic characteristics of the ground water resource and the designated use(s) which are to be maintained, restored and enhanced within the classification area. Designated uses include maintenance of special ecological resources, provision of and conversion to potable water (drinking water), agricultural and industrial water supply, and other reasonable uses. Maps are available that identify the geographic boundaries of Class I-PL, Class III-A and Class III-B ground water (see Ground Water Classification Maps). The GWQS rules also establish the water quality criteria and antidegradation policies applicable to each classification and designed to ensure that the designated uses can be adequately protected. The actual ground water classification, criteria and constituent standards that apply to a proposed activity (e.g., new/expanded discharge to ground water or remediation of a contaminated sit) are determined on a case-by-case, site-specific basis pursuant to the applicable regulatory program (Site Remediation and NJPDES). The Department has developed Frequently Asked Questions (FAQ) on the GWQS to answer general questions about implementation of the GWQS. Questions concerning the application of the GWQS to a specific NJPDES permit or contaminated site should be directed to the permit writer or case manager assigned to the site.

Ground Water Classifications and Criteria

The GWQS rules establish three major classes of ground water: Class I Ground Water of Special Ecological Significance, Class II Ground Water for Potable Water Supply, and Class III Ground Water with Uses Other Than Potable Water Supply. The GWQS rules establish the ground water quality criteria that are applicable to the different classes of ground water.

  • Class I Ground Water of Special Ecological Significance: Class I includes ground water within watersheds of FW1 surface waters, State-owned Natural Areas, and the major aquifers of the Pinelands Area. The primary designated use for Class I ground water is the maintenance of special ecological resources. Secondary uses include potable, agricultural and industrial water. All Class I ground waters are "nondegradation" waters. The Class I ground water quality criterion is "natural quality" in Class I-A and Class I-PL (Pinelands Preservation Area) ground waters, and "background water quality" for Class I-PL (Pinelands Protection Area) ground water. These terms are defined at N.J.A.C. 7:15-1.4.

  • Class II Ground Water for Potable Water Supply: Class II ground water includes all areas not designated as Class I or Class III. The primary designated use for Class II ground water is provision of potable ground waters with conventional treatment at current water quality (Class II-A) or after enhancement or restoration of regional water quality (Class II-B). The ground water quality criteria for all Class II ground waters are health-based concentrations of constituents above which would pose an unacceptable risk for human consumption as drinking water. The ground water quality standard (constituent standard) for Class II waters is the is the higher of the health-based ground water quality criterion and the corresponding PQL listed in Appendix Table 1 of the GWQS rules. The PQL represents the lowest concentration of a constituent that can be reliably achieved among laboratories within specified limits of precision and accuracy during routine laboratory operating conditions (i.e., the lowest quantifiable concentration). The standard for a constituent not found on this table is the interim generic criterion listed in Appendix Table II (based on carcinogenicity), or the higher of the interim specific criterion and interim PQL shown in the Table of Interim Ground Water Quality Criteria.

  • Class III Ground Water With Uses Other Than Water Supply: Class III ground waters are not suitable for potable supplies due to natural hydrogeologic characteristics or natural water quality. The primary use of Class III-A ground water is release or transmittal of adjacent ground or surface waters, Class III-B ground water are designated for any reasonable use at existing water quality, other than potable water. The GWQS rules establish narrative descriptions of these classifications and their corresponding criteria, which are determined by the Department on site-specific, case-by-case basis.

The Department has developed an electronic compendium of standards for water and soil promulgated by the New Jersey Department of Environmental Protection. Included are Surface Water Quality Standards, N.J.A.C. 7:9B; Ground Water Quality Standards, N.J.A.C. 7:9C; Drinking Water Quality Standards, N.J.A.C. 7:10; and soil remediation standards from the Remediation Standards, N.J.A.C. 7:26D. The compendium includes the standards and information about the basis for the standards contained in the above referenced rules. The standards in these rules are used by the Department's regulatory programs to establish site-specific requirements in accordance with the appropriate regulations. Please refer to the official versions of these rules for the most accurate information about the standards currently in effect and how they are administered by the Department. Information on obtaining the official versions of Department rules is available on the Department's Web site at


For more information, please contact Kimberly Cenno, Bureau Chief,
Bureau of Environmental Analysis, Restoration and Standards at (609) 633-1441.

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Last Updated: September 15, 2017