Plan Review & Prohibitions

New Development and Tenant Improvements

Wellhead Protection Program staff review development proposals, construction and tenant improvement permits to help ensure that they are in compliance with codes related to groundwater protection, critical areas regulations, secondary containment requirements and prohibited land uses.

Development or redevelopment of a property within Wellhead Protection Zones 1, 2 or 3 will require the preparation of a Critical Areas Report (CAR) for wellhead protection, to determine that the proposed development and activities will not adversely impact groundwater resources. The CAR must be completed by a Professional Engineer or Licensed Geologist. They can find resources for completing the CAR such as the depth to groundwater map book or for groundwater quality and quantity data by contacting WHP staff.

For more information contact Aaron Moldver at 425-556-2756.

Prohibited Activities in Wellhead Protection Zones

Land uses or activities for new development or redevelopment that pose a significant hazard to the City’s groundwater resources resulting from storing, handling, treating, using, producing, recycling, or disposing of hazardous materials or other deleterious substances are prohibited in Wellhead Protection Zones 1 and 2. These land uses and activities include, but are not limited to:
  • On-site community sewage disposal systems, as defined in Chapter 248-272 WAC;
  • Hazardous liquid pipelines as defined in Chapter 81.88 RCW and Chapter 21.78 RZC;
  • Solid waste landfills;
  • Solid waste transfer stations;
  • Liquid petroleum refining, reprocessing, and storage;
  • Bulk storage facilities as defined in Chapter 21.78 RZC;
  • The storage or distribution of gasoline treated with the additive MTBE;
  • Hazardous waste treatment, storage, and disposal facilities except those defined under permit by rule for industrial wastewater treatment processes per WAC 173-303-802(5)(c);
  • Chemical manufacturing, including but not limited to organic and inorganic chemicals, plastics and resins, pharmaceuticals, cleaning compounds, paints and lacquers, and agricultural chemicals;
  • Dry cleaning establishments using the solvent perchloroethylene;
  • Primary and secondary metal industries that manufacture, produce, smelt, or refine ferrous and non-ferrous metals from molten materials;
  • Wood preserving and wood products preserving;
  • Mobile fleet fueling operations;
  • Class I, Class III, Class IV and the following types of Class V wells: 5F1, 5D3, 5D4, 5W9, 5W10, 5W11, 5W31, 5X13, 5X14, 5X15, 5W20, 5X28, and 5N24 as regulated under Chapter 90.48 RCW, and Chapters 173-200 and 173-218 WAC as amended; and
  • Other land uses and activities that the City determines would pose a significant groundwater hazard to the City’s groundwater supply.
  • Permanent dewatering of the aquifer for new projects and redevelopment.
  • Irrigation with graywater or reclaimed water.
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Deleterious Substances

Include, but are not limited to, chemical and microbial substances that are not classified as hazardous materials under RZC 21.78.080, whether the substances are in usable or waste condition, that have the potential to pose a significant groundwater hazard, or for which monitoring requirements or treatment-based standards are enforced under Chapter 246-290 WAC


Water in a saturated zone or stratum beneath the surface of the land or below a surface water body.

Hazardous Materials

Any hazardous waste, hazardous substance, dangerous waste, or extremely hazardous waste that is a physical or health hazard as defined and classified in Chapter 70.105 RCW and Chapter 173-303 WAC, whether the materials are in usable or waste condition. Hazardous materials shall also include petroleum or petroleum products that are in a liquid phase at ambient temperatures, including any waste oils or sludges. 


The physical structure, facility, or device at the land surface from or through which ground water flows or is pumped from water-bearing formations.

Wellhead Protection Zone

Land areas delineated by the City for purposes of safeguarding groundwaters that supply, or potentially supply, drinking water to wells operated by the City. (Ord. 2269 § 2 (part), 2005: Ord. 2180 § 1 (part), 2003).

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