The purpose of this chapter is to protect ground water resources in the aquifer system from hazardous substances and hazardous waste pollution by controlling or abating future pollution from new land uses or activities. Additionally, it is the purpose of this chapter to increase public awareness regarding potential impacts to aquifer recharge areas arising from land use and site design.
(Ord. 343 § 1, 2002)
A. 
Identification. Critical aquifer recharge areas are areas where the prevailing geologic conditions allow infiltration rates, which create a high potential for contamination of ground water resources or contribute to the replenishment of ground water.
B. 
Classification. The entire City is located within a critical aquifer recharge area as defined by Clover/Chambers Creek Aquifer Basin Boundary, the 10-year wellhead protection areas as identified by TPCHD and the DRASTIC zones that are rated 180 and above.
(Ord. 343 § 1, 2002; Ord. 797, 12/1/2025)
A. 
Permeable Surfaces. Uses that are not identified as a threat to the aquifer shall provide as much open permeable space as possible and impervious surfaces shall be minimized. Carefully planned site layout and design may significantly reduce the need for impervious surfaces, which in turn can help promote the health of the City’s water resources and reduce costs associated with development of surface water control and treatment systems. Property owners shall practice appropriate disposal of hazardous substances and other pollutants to protect aquifer health.
B. 
Prohibited Uses. The following uses shall be prohibited within the critical aquifer recharge area:
1. 
Landfills.
C. 
Conditionally Permitted Uses.
1. 
Uses identified in Table 1 shall only be permitted after review and approval of a hydrogeologic assessment. All mitigation measures required pursuant to the references in Table 1 shall be implemented.
Table 1. Statutes, Regulations and Guidance Pertaining to Groundwater Impacting Activities
Activity
Statute – Regulation – Guidance
Automobile Washers
Chapter 173-216 WAC, Best Management Practices for Vehicle and Equipment Discharges (WDOE WQ-R-95-56)
Treatment Storage and Disposal Facilities
WAC 173-303-141
Hazardous Waste Generators (Boat Repair Shops, Biological Research Facilities, Dry Cleaners, Furniture Stripping, Motor Vehicle Service Garages, Photographic Processing, Printing and Publishing Shops, etc.)
Chapter 173-303 WAC
Above Ground Storage Tanks
WAC 173-303-640
Below Ground Storage Tanks
Chapter 173-360A WAC
Injection Wells
Federal 40 C.F.R. Parts 144 and 146, Chapter 173-218 WAC
Junk Yards and Salvage Yards
Chapter 173-304 WAC, BMPs to Prevent Stormwater Pollution at Vehicle Recycler Facilities (WDOE 94-146)
On-Site Sewage Systems (Large Scale)
Chapter 173-240 WAC
On-Site Sewage Systems > 14,500 gal/day
Chapter 246-272A WAC
Pesticide Storage and Use
Chapter 15.54 RCW, Chapter 17.21 RCW
Sawmills
Chapter 173-303 WAC, Chapter 173-304 WAC BMPs to Prevent Stormwater Pollution at Log Yards (WDOE 95-53)
Solid Waste Handling and Recycling Facilities
Chapter 173-304 WAC
Surface Mining
Chapter 332-18 WAC
2. 
In addition to the uses noted in Table 1, the following uses of land shall require a hydrogeologic assessment of the proposed site:
a. 
Hazardous substance processing or handling;
b. 
Sludge land application sites categorized as S-3, S-4 and S-5;
c. 
Animal containment areas;
d. 
Wood treatment facilities.
3. 
The hydrogeologic assessment shall include information as required by TPCHD. Uses requiring a hydrogeologic assessment may be approved, conditioned or denied by the city based upon the TPCHD’s evaluation of the hydrogeologic assessment.
4. 
The Director may grant relief from some or all of the provisions of this chapter if those pro-visions would be ineffective at a particular site. Alternative measures may be required.
D. 
Use of Existing Laws and Regulations. Other uses, including but not limited to septic systems and surface water management facilities, shall be regulated pursuant to existing laws, regulations and programs including, but not limited to, UPMC Title 13, City Public Works Standards, the King County Surface Water Design Manual, and the TPCHD Source Protection Program.
(Ord. 343 § 1, 2002; Ord. 797, 12/1/2025)