Chapter 16C.09


16C.09.01    Purpose and Intent.

16C.09.02    Designation.

16C.09.03    Mapping.

16C.09.04    Submittal Requirements.

16C.09.05    Performance Standards – General Requirements.

16C.09.06    Performance Standards – Specific Uses.

16C.09.07    Uses Prohibited from Critical Aquifer Recharge Areas.

16C.09.01 Purpose and Intent.

(1)    The Growth Management Act (RCW 36.70A) requires local jurisdictions to protect, through designation and protection, areas with a critical recharging effect on aquifers used for potable water, or areas where a drinking aquifer is vulnerable to contamination that would affect the potability of the water. These areas are referred to as Critical Aquifer Recharge Areas (CARAs) in this title.

(2)    Potable water is an essential life sustaining element. Much of Yakima County’s drinking water comes from groundwater supplies. Once groundwater is contaminated it can be difficult, costly, and sometimes impossible to clean up. In some cases, the quality of groundwater in an aquifer is inextricably linked to its recharge area.

(3)    The intent of this chapter is to:

(a)    Preserve, protect, and conserve Yakima County’s CARAs from contamination;

(b)    Establish a protection approach that emphasizes the use of existing laws and regulations, and minimizes the use of new regulations.

(4)    It is not the intent of this title to:

(a)    Regulate everyday activities (including the use of potentially hazardous substances that are used according to State and Federal regulations and according to label specifications);

(b)    Enforce or prevent illegal activities;

(c)    Regulate land uses that use or store small volumes of hazardous substances (including in-field agricultural chemical storage facilities, which do not require permits, or are already covered under existing state, federal, or county review processes and have detailed permit review);

(d)    Establish additional review processes for septic systems, which are regulated by the Washington Department of Health and Yakima County Health District as mandated by WAC 246-270, 246-271, 246-272, 246-272A, 246-272B, 246-272C and 246-273;

(e)    Establish additional review processes for stormwater control, which are covered under existing YCC Chapter 12.10 as required by Washington Department of Ecology’s Eastern Washington Phase II Municipal Stormwater Permit; or

(f)    Require review for uses that do not need building permits and/or zoning review.

The above items are deemed to have small risks of CARA contamination or are beyond the development review system’s ability to control.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011: Ord. 13-2007 §1 (Exh. A)(16C.09.01), 2007).

16C.09.02 Designation.

Critical aquifer recharge areas (CARAs) are those areas with a critical recharging effect on aquifers used for potable water as defined by WAC 365-190-030(2). CARAs are designated as critical areas. CARAs have prevailing geologic conditions associated with infiltration rates that create a high potential for contamination of ground water resources or contribute significantly to the replenishment of ground water. The following areas have been identified based on local conditions.

(1)    Wellhead Protection Areas. Wellhead protection areas shall be defined by the boundaries of the ten-year time of groundwater travel, or boundaries established using alternate criteria approved by the Department of Health in those settings where groundwater time of travel is not a reasonable delineation criterion, in accordance with WAC 246-290-135.

(2)    Sole Source Aquifers. Sole source aquifers are areas that have been designated by the U.S. Environmental Protection Agency pursuant to the Federal Safe Drinking Water Act.

(3)    Susceptible Groundwater Management Areas. Susceptible groundwater management areas are areas that have been designated as moderately or highly vulnerable or susceptible in an adopted groundwater management program developed pursuant to Chapter 173-100 WAC.

(4)    Special Protection Areas. Special protection areas are those areas defined by WAC 173-200-090.

(5)    Moderately or Highly Vulnerable Aquifer Recharge Areas. Aquifer recharge areas that are moderately or highly vulnerable to degradation or depletion because of hydrogeologic characteristics are those areas delineated by a hydrogeologic study prepared in accordance with the State Department of Ecology guidelines.

(6)    Moderately or Highly Susceptible Aquifer Recharge Areas. Aquifer recharge areas moderately or highly susceptible to degradation or depletion because of hydrogeologic characteristics are those areas meeting the criteria established by the State Department of Ecology.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011).

16C.09.03 Mapping.

(1)    Mapping Methodology – The CARAs are depicted in the map titled “Critical Aquifer Recharge Areas of Yakima County.” The CARA map was developed through a geographic information system (GIS) analysis using the methodology outlined in the Washington Department of Ecology - “Guidance Document” ( Publication 05-10-028). This map depicts the general location of the critical aquifer recharge areas designated in YCC 16C.09.02. Yakima County has developed a GIS database of the CARA map that shows the location and extent of critical aquifer recharge areas. This database will be used by the County to determine whether proposed developments could potentially impact CARA. All applications for development within the County that are located within a mapped CARA will be required to follow the performance standards of this chapter. The CARA map estimates areas of moderate, high and extreme susceptibility to contamination, in addition to wellhead protection areas. To characterize hydrogeologic susceptibility of the recharge area to contamination, the GIS analysis used the following physical characteristics:

(a)    Depth to ground water;

(b)    Soil (texture, permeability, and contaminant attenuation properties);

(c)    Geologic material permeability;

(d)    Recharge (amount of water applied to the land surface, including precipitation and irrigation).

(2)    Wellhead Protection Areas. The CARA map includes those Wellhead Protection Areas for which the County has maps. Wellhead Protection Areas are required for all Class A public water systems in the State of Washington. The determination of a wellhead protection area is based upon the time of travel of a water particle from its source to the well. Water purveyors collect site specific information to determine the susceptibility of the water source to surface sources of contamination. Water sources are ranked by the Washington State Department of Health with a high, moderate or low susceptibility to surface contamination. Wellhead protection areas are defined by the boundaries of the ten (10) year time of groundwater travel, in accordance with WAC 246-290-135. For purposes of this chapter, all wellhead protection areas shall be considered highly susceptible.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 6-2011 § 2 (Exh. A) (part), 2011; Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011: Ord. 13-2007 §1 (Exh. A)(16C.09.02), 2007. Formerly 16C.09.02).

16C.09.04 Submittal Requirements.

(1)    Applications for any development activity or division of land which requires review by Yakima County and which is located within a mapped Critical Aquifer Recharge Area or Wellhead Protection Area shall be reviewed by the Administrative Official to determine whether hazardous materials (see definitions) will be used, stored, transported, or disposed of in connection with the proposed activity. If there is insufficient information to determine whether hazardous materials will be used, the Administrative Official may request additional information, in addition to the submittal requirements outlined in 16C.03.

(2)    The Administrative Official shall make the following determination:

(a)    No hazardous materials are involved.

(b)    Hazardous materials are involved; however, existing laws or regulations adequately mitigate any potential impact, and documentation is provided to demonstrate compliance.

(c)    Hazardous materials are involved and the proposal has the potential to significantly impact Critical Aquifer Recharge and Wellhead Protection Areas; however, sufficient information is not available to evaluate the potential impact of contamination. The County may require a Hydrogeologic Report to be prepared by a qualified groundwater scientist in order to determine the potential impacts of contamination on the aquifer.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011).

16C.09.05 Performance Standards – General Requirements.

(1)    Activities may only be permitted in a critical aquifer recharge area if the applicant can show 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.

(2)    The proposed activity must comply with the water source protection requirements and recommendations of the U.S. Environmental Protection Agency, Washington State Department of Health, and the Yakima County Health District.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011).

16C.09.06 Performance Standards – Specific Uses.

(1)    Storage Tanks. All storage tanks proposed to be located in a critical aquifer recharge area must comply with local building code requirements and must conform to the following requirements:

(a)    Underground Tanks. All new underground storage facilities proposed for use in the storage of hazardous substances or hazardous wastes shall be designed and constructed so as to:

(i)    Prevent releases due to corrosion or structural failure for the operational life of the tank;

(ii)    Be protected against corrosion, constructed of noncorrosive material, steel clad with a noncorrosive material, or designed to include a secondary containment system to prevent the release or threatened release of any stored substances; and

(iii)    Use material in the construction or lining of the tank that is compatible with the substance to be stored.

(b)    Aboveground Tanks. All new aboveground storage facilities proposed for use in the storage of hazardous substances or hazardous wastes shall be designed and constructed so as to:

(i)    Not allow the release of a hazardous substance to the ground, groundwaters, or surface waters;

(ii)    Have a primary containment area enclosing or underlying the tank or part thereof; and

(iii)    Have a secondary containment system either built into the tank structure or a dike system built outside the tank for all tanks.

(2)    Vehicle Repair and Servicing.

(a)    Vehicle repair and servicing must be conducted over impermeable pads and within a covered structure capable of withstanding normally expected weather conditions. Chemicals used in the process of vehicle repair and servicing must be stored in a manner that protects them from weather and provides containment should leaks occur.

(b)    No dry wells shall be allowed in critical aquifer recharge areas on sites used for vehicle repair and servicing. Dry wells existing on the site prior to facility establishment must be abandoned using techniques approved by the State Department of Ecology prior to commencement of the proposed activity.

(3)    Residential Use of Pesticides and Nutrients. Application of household pesticides, herbicides, and fertilizers shall not exceed times and rates specified on the packaging.

(4)    Use of Reclaimed Water for Surface Percolation or Direct Recharge. Water reuse projects for reclaimed water must be in accordance with the adopted water or sewer comprehensive plans that have been approved by the State Departments of Ecology and Health.

(a)    Use of reclaimed water for surface percolation must meet the groundwater recharge criteria given in RCW 90.46.010(10) and 90.46.080(1). The State Department of Ecology may establish additional discharge limits in accordance with RCW 90.46.080(2).

(b)    Direct injection must be in accordance with the standards developed by authority of RCW 90.46.042.

(5)    Proposed new groundwater uses must provide evidence that the proposed water source is physically and legally available and meets drinking water standards.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011).

16C.09.07 Uses Prohibited from Critical Aquifer Recharge Areas.

The following activities and uses are prohibited in critical aquifer recharge areas:

(1)    Landfills. Landfills, including hazardous or dangerous waste, municipal solid waste, special waste, wood waste and inert and demolition waste landfills;

(2)    Underground Injection Wells. Class I, III and IV wells and subclasses 5F01, 5D03, 5F04, 5W09, 5W10, 5W11, 5W31, 5X13, 5X14, 5X15, 5W20, 5X28, and 5N24 of Class V wells;

(3)    Wood Treatment Facilities. Wood treatment facilities that allow any portion of the treatment process to occur over permeable surfaces (both natural and manmade);

(4)    Storage, Processing, or Disposal of Radioactive Substances. Facilities that store, process, or dispose of radioactive substances;

(5)    Mining. Hard rock; and sand and gravel mining, unless located within the mineral resource designation; and

(6)    Other Prohibited Uses or Activities.

(a)    Activities that would significantly reduce the recharge to aquifers currently or potentially used as a potable water source;

(b)    Activities that would significantly reduce the recharge to aquifers that are a source of significant base flow to a regulated stream.

(Ord. 5-2017 § 2(C) (Exh. 1) (part), 2017: Ord. 1-2011 § 2 (Exh. A (4) (part)), 2011).