A. The purpose of this chapter is to designate and protect critical aquifer recharge areas (CARAs) pursuant to the Growth Management Act (Chapter 36.70A RCW) in order to safeguard the public health, safety, and welfare and to protect groundwater resources. CARAs include: sole source aquifers, Group A wellhead protection areas as identified and defined by the Washington State Department of Health, and areas sensitive to groundwater contamination. These areas contribute to the recharge of aquifers, springs, and/or wells, and are susceptible to contamination through infiltration of pollutants through the soil.

B. This chapter applies to the following activities:

A. CARAs are those land areas that contain hydrogeologic conditions that facilitate aquifer recharge and/or transmission of contaminants to an underlying aquifer. Some may also have recharging effects on streams, lakes, and wetlands that provide critical fish and wildlife habitat. Factors considered in the identification of critical aquifer recharge areas include depth to water table, presence of highly permeable soils (Group A hydrologic soils), presence of flat terrain, and the presence of more permeable surficial geology.

B. CARAs are classified based on the following criteria:

C. Only CARAs meeting the criteria of subsections (B)(3) and (B)(4) of this section are identified in Snohomish. Future designations may occur.

D. Mapping resources referenced in this chapter are advisory only and are subject to evaluation by a qualified professional. Final designations shall be based on site conditions and other available data. (Ord. 2533, 2025)

A. Site Plan Requirements. All applications subject to this chapter shall be required to submit a site plan of the proposed development. The site plan required pursuant to this chapter may be combined with the land use or building permit application materials, as long as all submittal requirements are met. The site plan shall be drawn to a standard engineering scale and include the following elements:

B. When a Hydrogeologic Assessment Is Required. A hydrogeologic assessment is required for any of the following:

C. Hydrogeologic Assessment Requirements. The hydrogeologic assessment shall be prepared by a qualified professional such as a geologist, hydrogeologist, or engineering geologist, licensed in Washington State, with experience preparing hydrogeologic assessments. The hydrogeologic assessment shall contain the following information:

A. The project proponent shall make all reasonable efforts to avoid and minimize impacts to critical aquifer recharge areas pursuant to the requirements of this section, in the following sequential order of preference:

B. Any activity or use specifically listed in SMC 14.265.050 shall comply with the best management practices and mitigation plan identified in the hydrogeologic assessment, when required.

C. All development activities shall comply with the groundwater quality standards contained in Chapter 173-200 WAC and Chapter 90.48 RCW.

D. Where the Department determines that a use or activity not specifically listed in SMC 14.265.050 has the potential to harm water quality or quantity within CARAs, the applicant shall provide all submittal requirements of SMC 14.265.030 and apply best management practices and all known and available reasonable technology appropriate to protect CARAs.

E. Proposed developments shall not cause contaminants to enter the aquifer or significantly reduce the recharging of the aquifer and shall comply with the water source protection requirements and recommendations of the U.S. Environmental Protection Agency, Washington State Department of Health, Washington State Department of Ecology, and Snohomish County Health Department.

F. Underground facilities for storing hazardous substances shall be designed to prevent releases due to corrosion or structural failure for the operational life of the tank.

G. Above-ground facilities for storing hazardous substances shall be designed to prevent accidental release, shall have a primary containment enclosing or underlying the tank, and shall have a secondary containment built into the tank structure or consisting of an external dike.

H. Abandoned wells shall be decommissioned to comply with Federal and State standards.

I. The uses and activities listed in SMC 14.265.050 shall be conditioned as necessary to protect CARAs in accordance with the applicable State and Federal regulations and to the extent that a City approval is required for said uses. (Ord. 2533, 2025)

A. Level 1 CARAs are those with low sensitivity as described in SMC 14.265.020(B).

B. Level 2 CARAs are those with medium or high sensitivity as described in SMC 14.265.020(B).

C. No sole source aquifers or Group A wellhead protection areas are in Snohomish. If information is obtained that causes the City to designate sole source aquifers or Group A wellhead protection areas, they will be a separate level of CARA with different requirements than those in Table 1.

D. Permitted uses and activities shall be subject to the substantive requirements of SMC 14.265.040.

A. Underground injection control wells shall be conditioned as necessary to protect CARAs in accordance with the applicable State and Federal regulations and recommendations from an approved hydrogeologic report required pursuant to SMC 14.265.030.

B. Water reuse projects for reclaimed water and stormwater are regulated in accordance with the adopted water, sewer, or stormwater comprehensive plans that have been approved by the Departments of Ecology and Health. Where allowed, underground injection control wells shall be subject to City review and approval and shall comply with the requirements of Chapters 173-200 and 173-218 WAC and the Snohomish Municipal Code. For all proposals that include infiltration or injection of stormwater, unless waived by the City and the local water purveyor, a hydrogeologic assessment shall be submitted that includes an analysis to assess the risks to the specific aquifer and viability of the proposed infiltration and/or UIC. The report shall meet the requirements described in SMC 14.265.030 and Chapter 173-218 WAC.

C. Underground injection control wells designed in conjunction with stormwater handling facilities shall conform to the City’s adopted stormwater manual. For all proposals that include infiltration or injection of stormwater, unless waived by the City and the local water purveyor, a hydrogeologic assessment shall be submitted that includes an analysis to assess the risks to the specific aquifer and viability of the proposed infiltration and/or UIC. The report shall meet the requirements described in SMC 14.265.030 and Chapter 173-218 WAC. (Ord. 2533, 2025)

A. Construction of structures, improvements, and additions of less than 2,000 square feet of total site impervious surface area, which do not increase the risk to the critical area from hazardous substances.

B. Development of parks, recreation facilities, or conservation areas that do not increase the risk to the critical area from hazardous substances. (Ord. 2533, 2025)