Critical Aquifer Recharge Area
Over half of the drinking water within the City of Issaquah comes from groundwater drinking water wells. These wells are located in the valley floor, close to downtown and near many of Issaquah's business. To help prevent groundwater pollution, aquifer protection is regulated under the city's Critical Aquifer Recharge Area (CARA) Ordinance IMC 13.29.
Hazardous chemicals and materials can threaten Issaquah’s groundwater water supply, if they are not stored and managed properly. This resource outlines Best Management Practices for Issaquah’s businesses to implement and includes a map of the CARA classification boundary.
Businesses located within CARA Class 1 or 2 are subject additional pollution prevention requirements. The city enforces these regulations as part of the permit submittal process and during physical site inspections.
The Hazardous Materials Inventory (HMI) statement shall reflect all current and anticipated types and quantities of hazardous materials that will be stored, handled, treated, used, produced, recycled or disposed of at a facility. The HMI shall be kept on site at all times. New and existing commercial and industrial land uses and activities located in Class 1 and Class 2 CARAs as identified in IMC 18.10.796(C), Classification, shall submit an HMI statement.
The Hazardous Materials Management Plan (HMMP) should list quantities that correspond to the aggregate total of all hazardous materials, not individual chemicals. Facilities that use aggregate quantities of hazardous materials equal to or greater than 20 gallons or the equivalent of 200 pounds, or that use hazardous materials that may be a potential risk to the WHPA, shall be reviewed to determine the potential risk to the aquifer and the need for an HMMP. Commercial and industrial land uses and activities using aggregate quantities of hazardous materials equal to or greater than 50 gallons or the equivalent of 500 pounds, or that use hazardous materials that are considered to be a potential risk to the aquifer in lower quantities, shall submit an HMMP to the City.
To help reduce these threats and ensure continued water quality standards are met, the City requires construction and development activities located within Class 1 and Class 2 CARAs to inventory all hazardous materials and comply with additional environmental requirements. This document is submitted directly to our Community Planning and Development Department, as required during permitting.
For questions, clarification, or to submit HMIs or HMMPs, please email our team.