Minnesota Administrative Rules
Agency 167 - Pollution Control Agency
Chapter 7060 - UNDERGROUND WATERS
Part 7060.0600 - STANDARDS

Subpart 1. Prohibition against discharge into saturated zone.

No sewage, industrial waste, or other wastes shall be discharged directly into the zone of saturation by such means as injection wells or other devices used for the purpose of injecting materials into the zone of saturation, except that the discharge of cooling water under existing permits of the agency may be continued, subject to review of the permit by the agency for conformance with subpart 3.

Subp. 2. Prohibition against discharge into unsaturated zone.

No sewage, industrial waste, other waste, or other pollutants shall be allowed to be discharged to the unsaturated zone or deposited in such place, manner, or quantity that the effluent or residue therefrom, upon reaching the water table, may actually or potentially preclude or limit the use of the underground waters as a potable water supply, nor shall any such discharge or deposit be allowed which may pollute the underground waters. All such possible sources of pollutants shall be monitored at the discharger's expense as directed by the agency.

Subp. 3. Control measures.

Treatment, safeguards, or other control measures shall be provided by the person responsible for any sewage, industrial waste, other waste, or other pollutants which are to be or have been discharged to the unsaturated zone or deposited there, or which have been discharged to the zone of saturation, to the extent necessary to ensure that the same will not constitute or continue to be a source of pollution of the underground waters or impair the natural quality thereof.

Subp. 4. Toxic pollutants.

Toxic pollutants including, but not limited to, radioactive substances, chemicals, metals, solvents, petroleum products, plating wastes, and acids and bases, shall not be discharged or deposited in any manner such as to endanger the quality or uses of the underground waters.

Subp. 5. Construction of rule.

This rule shall not be construed as prohibiting the use of septic tank systems or holding tanks for disposal or storage of sewage or other acceptable organic wastes where public or other sewage or other waste disposal systems with surface discharge of effluent are not available or cannot reasonably be made available (except as agency rules may in the future apply to the construction, location, maintenance, or use of such disposal systems), nor shall it be construed as prohibiting land disposal of acceptable organic wastes or the use of chemicals and fertilizers for the production or protection of agricultural crops or products, nor the recharge of ground waters under controlled conditions, provided that such practices do not pose a significant pollution hazard.

Subp. 6. Monthly reports.

All persons operating or responsible for sewage, industrial waste, or other waste disposal systems, except septic tanks and related soil adsorption systems, which discharge effluent to the unsaturated zone, or deposits of pollutants or other operations from which residues may reach the underground waters, shall submit regularly every month a report to the agency on the operation of the disposal system, the waste flow, and the characteristics of the influent, effluent, and underground waters of the vicinity. Sufficient data on measurements, observations, sampling and analyses, and other pertinent information shall be furnished as may be required by the agency to, in its judgment, adequately reflect the condition of the disposal system, raw wastes, deposited material, effluent, residues, and the receiving or affected soils and underground waters. These data shall be collected under the supervision and direction of the agency.

Subp. 7. Long-term underground storage.

The long-term storage underground for later treatment of sewage, industrial waste, or other wastes, except solid wastes under permit of the agency, is prohibited. Liquids or other substances not sewage or industrial waste which may pollute or tend to pollute the underground waters of the state shall not be stored underground without safeguards adequate to reasonably assure proper retention against entry into the underground waters. The use of sewer systems for purposes of conveyance or control of the flow to outlets or treatment works, including temporary storage for such purposes, shall not be construed to be long term storage within the meaning of this rule.

Subp. 8. Natural state of groundwater.

The groundwater may in its natural state have some characteristics or properties exceeding the standards for potable water supplies. Where the background level of natural origin is reasonably definable and is higher than the accepted standard for potable water and the hydrology and extent of the aquifer are known, the natural level may be used as the standard.