On September 9, the Tacoma City Council adopted amendments to the South Tacoma Groundwater Protection District (STGPD) Code and related sections of Tacoma Municipal Code (TMC) Title 13 to strengthen groundwater protections, improve enforcement, and align regulations with state requirements and best available science.
The South Tacoma Aquifer, part of the Central Pierce County Sole Source Aquifer, supplies up to 50% of Tacoma’s total water demand during peak summer months, making it a vital drinking water source for the city. Historically, the aquifer has faced risks of contamination from spills, leaks, and improper handling of hazardous substances by local industries. To address these threats, the City of Tacoma established the STGPD in 1988 as an overlay zone that regulates hazardous materials and places restrictions on high-impact land uses that could compromise groundwater resources.
The newly adopted amendments are the result of a multi-year process that began in 2021. This process included a work plan, technical studies using best available science, a Health Impact Assessment (HIA) and extensive public engagement through community meetings, two advisory committees, public hearings, Planning Commission review, and finally, City Council approval.
Key updates contained within the package passed by City Council include:
- Prohibiting high-impact land uses, such as underground storage tanks and metal recycling/auto wrecking facilities, to reduce groundwater contamination risk;
- Strengthening enforcement and monitoring tools for faster action on violations;
- Clarifying the timing and frequency of future code reviews, which will occur at least once every 10 years using the best available science;
- Integrating the STGPD within the City’s Critical Areas Preservation Ordinance;
- Updating maps of the STGPD to include the Manitou neighborhood and Wellhead Protection Areas Time of Travel Zones;
- Improving landscaping, tree canopy, stormwater infiltration standards, and lot coverage regulations to improve infiltration, reduce impervious surfaces, and mitigate heat in industrial areas; and
- Expanding outreach to businesses and residents about protecting groundwater.
This update reflects a shared effort between the City’s Planning and Development Services Department, Environmental Services Department, Tacoma Water, and the Tacoma-Pierce County Health Department, highlighting the collaboration needed to safeguard Tacoma’s drinking water supply.
For more information about the STGPD Code amendments, including maps and details on impacted uses, visit tacoma.gov/stgpd.