Chapter 11.82
AQUIFER RECHARGE AREAS OVERLAY DISTRICT (AROD)
Sections:
11.82.040 Evaluation criteria.
11.82.050 Hydrogeologic evaluation.
11.82.010 Classification.
(1) 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.
(2) Sites identified by this chapter as having a medium or high aquifer vulnerability rating shall be subject to the performance standards of this chapter. (Res. 2021-54 (Att. A), 5/4/21; Res. 2007-97 (part), 7/2/07: Res. 2000-129 (part), 10/17/00).
11.82.020 Designation.
(1) 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).
(2) 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. (Res. 2021-54 (Att. A), 5/4/21; Res. 2007-97 (part), 7/2/07: Res. 2000-129 (part), 10/17/00).
11.82.030 Procedure.
(1) 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.
(2) 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.
(3) 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.
(4) 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. (Res. 2021-54 (Att. A), 5/4/21; Res. 2007-97 (part), 7/2/07: Res. 2000-129 (part), 10/17/00).
11.82.040 Evaluation criteria.
The administrator shall require an aquifer vulnerability evaluation for any development permit, not otherwise exempted from this chapter, if the site or development meets one of criteria (1) through (7) below:
(1) Within a wellhead protection area designated under WAC 246-290-135;
(2) Within a critical aquifer recharge area mapped and identified by a qualified groundwater professional;
(3) Within a sole source aquifer recharge area designated pursuant to the Federal Safe Drinking Water Act;
(4) 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;
(5) 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:
(A) The site will be utilized for hazardous substance (defined in Chapter 70.105 RCW) processing, storage or handling in applications or quantities larger than is typical of household use; or
(B) The site is currently or will be utilized for commercial or industrial activities listed in the U.S. Environmental Protection Agency’s Potential Sources of Drinking Water Contamination Index that can be found in Appendix A to Department of Ecology’s Critical Aquifer Recharge Area Guidance Document; or
(C) The development involves a major subdivision and includes present or future plans to construct dwelling units that will not be connected to a public sewer system and any of the lots are less than one net acre in size; or
(D) The proposed commercial and industrial site is not on a public sewer system and the main structure exceeds four thousand square feet;
(6) The proposed use is as a commercial feedlot, landfill, junkyard, salvage yard, or auto wrecking yard; or
(7) The site will be used for above ground application of sewage or sludge. (Res. 2021-54 (Att. A), 5/4/21; Res. 2007-97 (part), 7/2/07: Res. 2000-129 (part), 10/17/00).
11.82.050 Hydrogeologic evaluation.
(1) 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.
(2) 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:
(A) A summary of readily available existing information for the site vicinity, including hydrogeological and other groundwater reports. Cite all references and information used in the evaluation preparation;
(B) Hydrogeologic characterization of the aquifer based on readily available existing information including permeability and thickness of the vadose zone, depth to groundwater, presence of confining layers and bedrock, estimated hydraulic conductivity of the saturated zone, and groundwater flow direction and gradient;
(C) Review of readily available existing groundwater quality information to characterize existing water quality conditions;
(D) Confirmation of the applicability of evaluation criteria (1) through (5) under Section 11.82.040 to the site proposed for development;
(E) Determination of a rating of low, medium, or high aquifer susceptibility to contamination based on properties of the aquifer as determined by the qualified groundwater professional;
(F) Recommendations for further study, including a specific recommendation for a tier-two evaluation when aquifer susceptibility is rated as high, or whether more information is needed to complete an aquifer susceptibility rating;
(G) If, in the opinion of the groundwater professional, a tier-two evaluation is not necessary, the tier-one evaluation shall provide recommendations for best management practices and other measures to mitigate probable worse-case scenario release of contaminants.
(3) 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:
(A) All elements of a tier-one evaluation or confirmation of findings from a tier-one evaluation if the evaluations are completed by different qualified groundwater professionals or if five years have passed since the tier-one evaluation was completed;
(B) Locations of known land-use activities listed in the U.S. Environmental Protection Agency’s Potential Sources of Drinking Water Contamination Index located within one thousand feet of the proposed development;
(C) Locations of releases of contaminants to the environment reported to Department of Ecology within one thousand feet of the proposed development;
(D) Locations of public water supply wells and wellhead protection areas within one half mile of the development proposal and locations of permit-exempt wells within one thousand feet of the proposed development;
(E) Locations of surface water bodies and springs within one thousand feet of proposed development;
(F) Determination of a rating of low, medium, or high aquifer vulnerability based on aquifer susceptibility and potential for contamination loading resulting from the proposed development as determined by the qualified groundwater professional;
(G) For development proposals having medium or high aquifer vulnerability ratings:
(i) Discussion of potential impacts to groundwater quality resulting from spills or acute releases of contaminants and long-term loading resulting from proposed activities, including evaluation of probable worse case spill scenario;
(ii) Recommendations for further study, including cumulative contaminant loading evaluation and groundwater monitoring;
(iii) Recommendations for mitigating measures, including BMPs and spill response planning.
(H) Recommendations for further study, or whether more information is needed to complete a vulnerability rating. (Res. 2021-54 (Att. A), 5/4/21; Res. 2007-97 (part), 7/2/07: Res. 2000-129 (part), 10/17/00).
11.82.060 Performance standards for uses determined to have a medium or high aquifer vulnerability rating.
(1) 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.
(2) Application of Aquifer Recharge Area Performance Standards.
(A) Certain residential dwelling units and their accessory uses are exempt under Section 11.82.030(4). New residential subdivisions are subject to the provisions of subsection (9) of this section.
(B) The standards for approval of development regulated by this chapter shall be defined in subsequent subsections.
(C) The assurance that these standards are applied to development regulated by this chapter is the responsibility of the administrator.
(i) Appropriate standards for approval as applied to development regulated by this chapter shall be the responsibility of the Chelan County community development department and hearing examiner as otherwise described in agency rules.
(ii) Appropriate safeguards, to be included in the design of buildings newly constructed or remodeled, shall be the responsibility of the Chelan County community development department.
(iii) Site planning and other considerations for areas outside of buildings shall be the responsibility of the appropriate office or agency as may be elsewhere described in agency rules.
(iv) Appropriate sanitary, industrial and solid waste disposal practices employed shall be the responsibility of the Chelan-Douglas health district or other appropriate agency (e.g., Washington State Department of Health or Ecology).
(v) When the occupancy of a building changes, any new commercial or industrial occupant shall not operate without a certificate of occupancy as issued by the Chelan County community development department; such certificate of occupancy is subject to review pursuant to subsection (2)(C) of this section.
(D) If the applicant does not have a specific proposal, the department shall recommend that the action be conditioned, or shall so condition a license/permit, with the performance criteria of subsections (3) through (11) of this section.
(E) Even though an activity is permitted in the underlying zone classification, any activity which, following review in accordance with this chapter, is determined to have a medium or high vulnerability rating shall be required to conform to the conditions set forth in subsections (3) through (11) of this section.
(3) Agricultural Activities. Agricultural activities shall incorporate best management practices concerning waste disposal, fertilizer use, pesticide use, and stream corridor management.
(4) 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.
(5) 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.
(6) Commercial, Industrial and Mining Uses.
(A) For the purposes of this section, all forms of mining activities shall be considered an industrial use.
(B) Contingency Plans.
(i) All commercial and industrial uses that are rated as having a medium or high vulnerability shall submit a contingency plan that identifies:
(a) Types of hazardous substances (defined in Chapter 70.105 RCW) and contaminants listed in U.S. Environmental Protection Agency’s Potential Sources of Drinking Water Contamination Index that would be stored or used for the proposed land use;
(b) On-site containment facilities designed to handle accidental releases of materials identified in subsection (6)(B)(i)(a) of this section;
(c) Spill response and notification procedures.
(C) Changes in occupancy of an existing site and/or expansions of existing activities are subject to complete evaluation by the county under the provisions of this chapter.
(D) All activities listed in U.S. Environmental Protection Agency’s Potential Sources of Drinking Water Contamination Index shall only be approved as conditioned so that:
(i) Facilities will be designed and built so that any spilled or leaked materials are contained on-site; and
(ii) Facilities will be designed and built so that any spilled or leaked materials cannot infiltrate into the ground; and
(iii) No permanent disposal of any waste containing critical materials shall be allowed on-site.
(E) Commercial or industrial activities listed in U.S. Environmental Protection Agency’s Potential Sources of Drinking Water Contamination Index shall have specially designed and installed storm runoff drainage facilities in areas where spills might occur. Such facilities shall be designed and installed to:
(i) Prevent the commingling of storm runoff and critical materials spills; and
(ii) Enhance spill cleanup procedures.
(F) All mining activities shall comply with current Washington Department of Natural Resources requirements for surface mining and Washington Department of Ecology’s Sand and Gravel General Permit. Mining activities in areas determined to have a medium or high vulnerability shall submit a study completed by a qualified groundwater professional demonstrating that the proposed activity will not cause contaminants to enter the aquifer and that the proposed activity will not adversely affect the recharging of the aquifer. The administrator shall determine whether these conditions are adequately addressed in the tier-two hydrogeologic evaluation and require additional reporting as needed.
(7) Utilities. Utility facilities shall be reviewed and approved consistent with the requirements of subsection (6) of this section.
(8) 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.
(9) 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:
(A) An analysis of the potential nitrate loading to the groundwater may be required to assess the impact on groundwater quality;
(B) Alternative site designs, phased development and/or groundwater quality monitoring will be required to reduce contaminant loading where site conditions indicate that the proposed action will measurably degrade groundwater quality;
(C) Open spaces may be required on development proposals overlying areas highly susceptible for contamination of groundwater resources;
(D) Community/public water systems, community drainfields, and hookup to public sewer systems (in conformance with the Washington State Department of Health and Chelan-Douglas health district requirements, the provisions of the sewer purveyor, and Chapter 36.70A RCW) are encouraged and may be required where site conditions indicate a high degree of potential contamination to individual wells from on-site or off-site sources. Where required, community systems shall be placed in the most favorable location for the prevention of groundwater contamination;
(E) Where wells are required to be abandoned, the applicant shall ensure that they are abandoned according to state guidelines;
(F) Known contaminants shall be removed from stormwater runoff prior to their point of entry into surface or groundwater resources using available and reasonable best management practices consistent with the Stormwater Management Manual for Eastern Washington, as revised, pursuant to Chapter 13.16.
(10) 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.
(11) 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. (Res. 2021-54 (Att. A), 5/4/21; Res. 2007-97 (part), 7/2/07: Res. 2000-129 (part), 10/17/00).