Publication Summary

The Ground Water Quality Standards (Chapter 173-200 WAC) were adopted in December 1990. While the standards provide the first comprehensive approach to protecting ground water quality in Washington State, the regulation does not specifically address how it should be implemented for various types of activities. The Implementation Guidance for the Ground Water Quality Standards explains and interprets the standards providing clear direction to promote consistent statewide implementation for all activities which have a potential to degrade ground water quality. This document was developed with the assistance of an external advisory workgroup. This group was comprised of representatives from various business interests, environmental organizations, cities, counties and other state agencies. This document was also extensively reviewed by Ecology and other interested parties.

The Ground Water Quality Standards (Chapter 173-200 WAC) were adopted in December 1990. While the standards provide the first comprehensive approach to protecting ground water quality in Washington State, the regulation does not specifically address how it should be implemented for various types of activities. The Implementation Guidance for the Ground Water Quality Standards explains and interprets the standards providing clear direction to promote consistent statewide implementation for all activities which have a potential to degrade ground water quality. This document was developed with the assistance of an external advisory workgroup. This group was comprised of representatives from various business interests, environmental organizations, cities, counties and other state agencies. This document was also extensively reviewed by Ecology and other interested parties.

The standards are a regulatory approach to protect and preserve ground water quality. The Ground Water Quality Standards are preventative in nature and protect all waters in the saturated zone. The goal of the standards is to maintain a high quality of ground water and to protect existing and future beneficial uses through the reduction or elimination of contaminants discharged to the subsurface. The goal is achieved through three mechanisms:

1.AKART - all known, available and reasonable methods of prevention, control and treatment. All wastes must be provided with AKART prior to entry into the state's waters, regardless of the quality of water. 2.The antidegradation policy which mandates the protection of background water quality and prevents the degradation of water quality which would harm a beneficial use or violate the Ground Water Quality Standards. 3.The human health and welfare based standards which include numeric and narrative standards.

The standards affect all activities which have a potential to impact ground water quality. This includes both point source and nonpoint source activities. Activities which are regulated by these standards include municipal wastewater treatment facilities, surface impoundments, industrial facilities, ground water recharge projects, land application projects, mines, landfills, injection wells, agricultural activities, and septic systems.

This guidance document implements the Ground Water Quality Standards for all activities regulated by Ecology which have a potential to contaminate ground water. This applies to only those activities which are not covered by another regulation, general permit, guideline or BMPs, which include ground water protection provisions. Ecology will develop memorandums of understanding with other regulatory agencies where Ecology does not have direct regulatory oversight for activities such as agriculture, small on-site sewage systems and solid waste landfills. These activities are not necessarily required to use the guidance to implement the standards. Proponents of all activities that may impact ground water quality have a legal obligation not to violate these standards regardless of whether they are directly regulated by Ecology through permits or through other regulatory mechanisms.