Chelan County Unincorporated
City Zoning Code

Classification is based on an evaluation of the aquifer vulnerability defined as the combination of potential for contaminant loading of a proposed land use, and the susceptibility of aquifer to contamination at the proposed site.

Sites identified by this chapter as having a medium or high aquifer vulnerability rating shall be subject to the performance standards of this chapter.

There is insufficient scientific data at this time to determine with any specificity the location of areas having a critical recharging effect on aquifers used for potable water within the boundary of Chelan County. However, the best available science suggests that an aquifer susceptibility determination will allow Chelan County to designate critical aquifer recharge areas using a conservative approach, which provides a worst case scenario for contaminant movement into and through the subsurface. Therefore, any area found via this chapter to be an area having a medium or high aquifer vulnerability rating shall be designated a critical aquifer recharge area (CARA).

In addition, sole source aquifer recharge areas designated pursuant to the Federal Safe Drinking Water Act, areas established for special protection pursuant to a groundwater management program, Chapters 90.44, 90.48 and 90.54 RCW, and Chapters 173-100 and 173-200 WAC; areas designated for wellhead protection pursuant to the Federal Safe Drinking Water Act, and aquifer recharge areas mapped and identified by a qualified groundwater professional and available from Chelan County shall also be designated as critical aquifer recharge areas.

An applicant seeking to develop property which requires a development permit, not otherwise exempted from the requirements of this chapter, shall submit with the application a certified statement, on a form provided by the Chelan County community development department, which lists criteria (5)(A) though (5)(D), (6), and (7) as set forth in Section 11.82.040 and indicate whether the criteria apply or do not apply to the site or development. Any development application that fails to contain this statement or fails to indicate whether any one of the criteria apply or do not apply shall be rejected and only accepted upon resubmission of the completed statement. “Unknown” or similar responses will not be accepted.

If the administrator determines the development meets one or more of criteria (1) through (4) of Section 11.82.040, or if the administrator determines the development meets criterion (5) of Section 11.82.040 and the applicant indicates the development meets one or more of criteria (5)(A) through (5)(D) of Section 11.82.040, or if the applicant indicates the development meets one or more of criteria (6) or (7) of Section 11.82.040, the department shall require a hydrogeologic evaluation as described in Section 11.82.050. If the development has a medium or high vulnerability rating, the development shall be subject to the performance standards of Section 11.82.060.

If the administrator determines that criteria (1) through (5) of Section 11.82.040 do not apply to the development and an applicant’s statement asserts that criteria (6) and (7) of Section 11.82.040 do not apply to the development, the administrator will accept the statement and proceed with the permitting or approval process, except if the administrator has or obtains information prior to the permit or approval being finalized, which clearly establishes the applicant’s statement is incorrect. In which case, the applicant will be advised in writing of the inconsistent information and advised to either (A) provide an amended statement adding the evaluation criteria as being applicable and complete a hydrogeologic evaluation of the development pursuant to Section 11.82.050, or (B) present sufficient countering information clearly establishing that the basis for the department’s concern is incorrect. If the applicant selects to proceed under (B), upon receipt of the applicant’s information, the administrator shall review the information and obtain whatever additional assistance may be required to resolve the issue. The final determination as to whether a determination of vulnerability is required shall be made by the administrator.

Development proposals for a single-family residential dwelling, accessory dwelling unit, or accessory building that is connected to a public sewer system or has a septic permit approved by the Chelan-Douglas health district shall be exempt from hydrogeologic evaluation under Section 11.82.050.

Within a wellhead protection area designated under WAC 246-290-135;

Within a critical aquifer recharge area mapped and identified by a qualified groundwater professional;

Within a sole source aquifer recharge area designated pursuant to the Federal Safe Drinking Water Act;

Within an area established for special protection pursuant to a groundwater management program, Chapters 90.44, 90.48 and 90.54 RCW, and Chapters 173-100 and 173-200 WAC;

The site contains highly permeable soils, which include soil types 1, 2 and 3 under WAC 246-272A-0220, Table V or soils mapped by U.S. Department of Agriculture Natural Resources Conservation Service as having saturated hydraulic conductivity (Ksat) classification of Moderately High or identified as Hydrologic Soil Group “A” and:

The proposed use is as a commercial feedlot, landfill, junkyard, salvage yard, or auto wrecking yard; or

The site will be used for above ground application of sewage or sludge.

Development proposals meeting any one of the evaluation criteria under Section 11.82.040 will require hydrogeologic evaluation completed by a qualified groundwater professional in accordance with this section, unless the administrator determines an evaluation is not necessary. A minimum of a tier-one evaluation shall be completed. When required, tier-one and tier-two evaluations may be combined in a single report completed by the same qualified groundwater professional.

Tier-One Hydrogeologic Evaluation. A tier-one evaluation comprises the first step to determine aquifer vulnerability by providing an assessment of aquifer susceptibility to contamination. A tier-one evaluation report shall include the following:

Tier-Two Hydrogeologic Evaluation. A tier-two evaluation addresses aquifer vulnerability for subject development proposals. A tier-two evaluation shall be completed for developments meeting criteria (6) or (7) under Section 11.82.040, for sites determined as having an aquifer susceptibility rating of high, as otherwise recommended by a qualified groundwater professional in a tier-one evaluation report, or as directed by the administrator to resolve uncertainty following completion of a tier-one evaluation. A tier-two evaluation report shall include the following:

General. All development regulated by this chapter which has a medium or high aquifer vulnerability rating, as determined by this chapter, shall be required to meet the requirements of this section. These are considered minimum requirements and additional requirements may be required by the administrator based on review of the tier-one or tier-two hydrogeologic report or other available information.

Application of Aquifer Recharge Area Performance Standards.

Agricultural Activities. Agricultural activities shall incorporate best management practices concerning waste disposal, fertilizer use, pesticide use, and stream corridor management.

Prohibited Uses. Landfills, junkyards, salvage yards, auto wrecking yards, and feedlots that cannot be mitigated to a low vulnerability are prohibited within designated critical aquifer recharge areas. Landfills are subject to Chapter 173-351 WAC.

Parks, Schools and Recreation Facilities. Fertilizer, herbicide and pesticide management practices of schools, parks, golf courses and other nonresidential facilities that maintain large landscaped areas shall be evaluated in relation to best management practices as recommended by the cooperative extension service.

Commercial, Industrial and Mining Uses.

Utilities. Utility facilities shall be reviewed and approved consistent with the requirements of subsection (6) of this section.

Aboveground Application of Sewage or Sludge. Projects which involve application of sewage or sludge in areas determined to have a medium or high susceptibility to groundwater contamination shall provide hydrologic information and a management plan that identifies measures that effectively mitigate the threat to contamination; and shall conform to all other applicable state regulations.

Residential Land Subdivisions. Residential land subdivisions regulated by this section shall be evaluated for their impact on groundwater quality. One or more of the following measures shall be required upon recommendation of the Chelan-Douglas health district:

Wood Treatment Facilities. Wood treatment facilities shall conform to the provisions of subsection (6) of this section. Wood treatment facilities that allow any portion of the treatment process to occur over permeable surfaces, both natural and manmade, are prohibited.

Underground Injection Wells. Class I, III and IV injection wells are prohibited. Class II injection wells are permitted under Chapter 173-218 WAC by the Washington State Department of Ecology in conjunction with the Washington State Department of Natural Resources. Class V injection wells, involving the injection of critical materials, may be prohibited by the Washington State Department of Ecology or a permit may be required by said agency. In addition, commercial or industrial uses proposing the injection of critical materials are subject to the provisions of subsection (6) of this section.