Chapter 18.116
CRITICAL AQUIFER RECHARGE AREAS (CARAs) AND WELLHEAD PROTECTION ZONES
Sections:
18.116.010 Purpose.
18.116.020 Applicability.
18.116.030 CARA/wellhead protection zones identification methodology.
18.116.040 CARA/wellhead protection zones.
18.116.050 CARA/wellhead protection zone review procedures.
18.116.060 Aquifer recharge/wellhead protection zones standards.
18.116.010 Purpose.
A. The Growth Management Act requires the city of Rainier to designate areas and adopt development regulations for the purpose of protecting areas within the city critical to maintaining groundwater recharge and quality. The Growth Management Act, Water Pollution Control Act, Water Resources Act of 1971, and the Ground Water Quality Standards require these actions be taken to protect groundwater quality and quantity such that its use as potable water can be preserved for current and future uses.
B. This chapter defines a scientifically valid methodology by which the city of Rainier will designate areas determined to be critical in maintaining both groundwater quantity and quality.
C. This chapter specifies regulatory requirements when development within these areas is proposed by avoiding or, where that is not possible, minimizing the risks of contamination from new, expanded, and altered land uses and activities.
D. To identify and protect aquifer recharge areas based on their vulnerability (i.e., physical susceptibility to contamination and the potential for contamination from existing and allowed uses).
E. To recognize and maintain the delicate balance between surface water and groundwater in order to preserve essential natural functions and processes, including maintenance of stream flows and temperatures necessary to sustain anadromous fish.
F. To be consistent with:
1. RCW 36.70A.170 and 36.70A.172;
2. Public Water Systems—Penalties and Compliance, Chapter 70.119A RCW;
3. Washington State Wellhead Protection Program and the Public Water Supplies, Chapter 246-290 WAC; Dangerous Waste Regulations, Chapter 173-303 WAC;
4. The Water Quality Standards for Groundwater of Washington State, Chapter 173-200 WAC.
G. To ensure that there is sufficient infiltration of naturally available water at the land’s surface to sustain aquifers used as a potable water source and to maintain base flows in streams supporting anadromous fish. (Ord. 548 § 2 (Exh. E) (part), 2007)
18.116.020 Applicability.
A. This chapter shall apply to proposals for new development and alteration and expansion of existing uses if any portion of the parcel proposed for development is located in a critical aquifer recharge area (CARA)/wellhead protection zone map, or as hereafter amended.
B. These regulations apply to the one, five and ten (10) year time-of-travel zones of wellhead protection area zones.
C. Activities within a critical aquifer recharge area (CARA)/wellhead protection zone shall comply with the requirements specified in Table 18.116-1, Requirements within Protection Zones.
D. Business License Requirement. The city may revoke a business license or take other corrective measures to gain compliance in submittal of a hazardous substances inventory form, even if the activity may be exempt.
|
Activity |
Requirements Within Protection Zones |
Improvements |
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|
Hazardous Substances Inventory Form |
Hydrogeological Critical Area Assessment Report |
Spill Containment Plan |
Stormwater Infiltration |
|
|
1) Existing or new businesses |
Hazardous materials inventory form |
Required for any activity that handles or stores hazardous materials in quantities greater than 20 gallons or 200 pounds |
A spill containment plan to identify preventive and corrective actions necessary in the event of hazardous materials spill |
Not required |
|
3) Proposed buildings or structures (other than SF residential or associated accessory uses) requiring a land use or building permit |
A hazardous materials inventory form shall be with the application for a land use permit |
Required for any activity that handles or stores hazardous materials in quantities greater than 20 gallons or 200 pounds |
A spill containment plan and/or monitoring plan to identify preventative and corrective actions necessary in spill event of hazardous materials |
Required to ensure sufficient groundwater recharge; an applicant shall infiltrate SW in all mapped CARAs using adopted SW manual |
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4) Residential and associated accessory uses. Accessory uses defined in Division 3 of this title, Development Standards—Zoning |
Existing residential activities are not affected by the provisions of this chapter. Residents are encouraged to become familiar with the educational material provided by the city or county for use and handling of household chemicals, pesticides, herbicides and fertilizers and disposal of paints, solvents, gas, oil and other hazardous substances with potential to degrade groundwater. |
Stormwater infiltration is required for all development per adopted SWMM |
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(Ord. 548 § 2 (Exh. E) (part), 2007)
18.116.030 CARA/wellhead protection zones identification methodology.
The CARA/wellhead protection zones were delineated using application of the calculated fixed radius approach, per Washington Department of Health guidance (DOH Publication No. 331-018, April 1995). (Ord. 548 § 2 (Exh. E) (part), 2007)
18.116.040 CARA/wellhead protection zones.
A. General. CARA/wellhead protection zones are areas that have a critical recharging effect on groundwater used for potable water supplies and/or that demonstrate a high level of susceptibility or vulnerability to groundwater contamination from land use activities.
B. CARA Protection Zones. Land areas categorized as extremely or highly susceptible on the CARA map or a use listed in Table 18.116-2; or
C. Wellhead Protection Zones. Areas within the one, five or ten (10) year time-of-travel zone boundary of a group “A” public water system well as delineated by the water system purveyor or designee, pursuant to WAC 246-290-135. (Ord. 548 § 2 (Exh. E) (part), 2007)
18.116.050 CARA/wellhead protection zone review procedures.
A. General Requirements.
1. The city’s CARA/wellhead protection zone maps provide an indication of where aquifer recharge and wellhead protection areas are located within the city.
2. The department will complete a CARA/wellhead protection zone map review for regulated development proposals to determine if the project area for a regulated activity is within a CARA/wellhead protection zone.
3. When department maps or sources indicate a proposed project area for a regulated activity is located within a CARA zone categorized as extreme or high, or in a wellhead protection zone, the department shall require review as set forth in this chapter.
4. Any proposed regulated development located in a CARA zone categorized as extreme or high, or in a wellhead protection zone, shall comply with the standards set forth in Section 18.116.060.
5. Any hazardous uses, as defined in Section 18.116.060, shall require the submittal of a hydrogeologic assessment, either Class “A” or Class “B,” as set forth in subsection (B) of this section.
6. The department may waive some of the critical area protective measure provisions contained in Section 18.100.080, provided the applicant can present an acceptable alternative to adopted standards.
B. Hydrogeologic Assessments.
1. Regulated development in a CARA/wellhead protection zone requires a hydrogeologic assessment prepared by a state-licensed geologist/hydrogeologist.
2. The assessment shall be submitted in the form of a report detailing the subsurface conditions, the design of a proposed land use action, and the facilities operation indicating the susceptibility and potential for contamination of groundwater supplies.
3. The following types of assessments shall be prepared:
a. A Class “A” site assessment shall be prepared in order to evaluate areas within the boundaries of the CARA categorized as extreme or high. Areas categorized as moderate or low susceptibility generally will not require further site evaluation. Contents should include:
i. Permeability of the unsaturated zone.
ii. Location of nearby sensitive areas (wellhead protection zones).
iii. Groundwater depth and flow direction.
iv. Location, construction, and use of existing wells (one-quarter mile).
v. Site map at 1:2,400 (one inch to two thousand (2,000) feet) scale.
vi. Activity characterization.
vii. Best management practices.
viii. Contingency plan.
b. A Class “B” site assessment to provide detailed information about the hydrogeologic characteristics of the site and to predict the behavior of a contaminant should it reach the underlying aquifer(s). The information required in a Class “B” site evaluation should be newly acquired information regarding the risks of allowing conditional activities to go forth. The evaluation report should contain all the information included as part of a Class “A” site assessment with the following:
i. Background water quality compiled over at least a one-year period.
ii. Contaminant transport modeling based on potential releases to groundwater.
iii. Modeling of groundwater withdrawal effects.
iv. Geologic and hydrogeologic characteristics.
v. Groundwater monitoring plan provisions.
vi. Other information required by the Department of Ecology or the city, including information required under any Washington Department of Ecology site register update.
C. Storage Tank Permits. In addition to the requirements set forth in this division, the Washington Department of Ecology, or delegated designee, regulates permits for storage tanks and regulates and authorizes permits for underground storage tanks pursuant to Chapter 173-360 WAC. The Department of Ecology regulates the installation, repair, replacement, or removal of underground storage tanks in coordination with the city in consideration of the wellhead protection zones. (Ord. 575 § 28, 2009: Ord. 548 § 2 (Exh. E) (part), 2007)
18.116.060 Aquifer recharge/wellhead protection zones standards.
A. General. All regulated activities not exempt or prohibited under the provisions of this chapter shall ensure sufficient groundwater recharge. In order to achieve sufficient groundwater recharge, the applicant shall comply with the city’s adopted stormwater manual or demonstrate that the infiltration rate for the proposed project area will be the same amount for post-development as the predevelopment rate.
B. Prohibited Uses. Landfills (other than inert and demolition landfills), underground injection wells (Class I, III, and IV), metals mining, wood treatment facilities, pesticide manufacturing, petroleum refining facilities (including distilled petroleum facilities), and the storage of large volumes of petroleum products are prohibited within CARA/wellhead protection zones.
C. Agricultural Activities. New agricultural activities that do not involve hazardous substance handling or application are allowed within an extreme or high CARA or wellhead protection zone subject to the following:
1. An applicant is required to submit a farm management plan prepared by the USDA, NRCS, Thurston Conservation District, or Washington State University Cooperative Extension Office that certifies that water quality and quantity within the aquifer recharge area is maintained. The farm management plan shall at a minimum address the following:
a. The limits of the proposed agricultural activities.
b. The proposed scope of agricultural activities, including the use of any pesticides, fertilizers, or other chemicals.
c. The existing nitrate levels on the site and any proposed increases in nitrate levels.
2. Integrated pest management (IPM) practices for pest control and best management practices (BMPs) for the use of fertilizers, as described by the Washington State University, Pierce County Cooperative Extension Office, shall be utilized.
3. Nitrate levels at down-gradient property lines shall not exceed two and one-half mg/L or, if the background nitrate concentration exceeds two and one-half mg/L, then the concentration will not be increased more than one-tenth mg/L, with the cap being set by Thurston County public health and social services department (TCPH&SSD) standards maximum allowable quantities for nitrate concentrations.
4. Additional protective measures may be required if deemed necessary by the department or to protect public health or safety.
D. Conditionally Permitted Activities. Activities that pose a moderate threat to the groundwater quality can be permitted if sufficient mitigation measures are imposed and implemented and the use does not adversely affect aquifer recharge or infiltration. A determination of degree of threat includes consideration of the susceptibility of the aquifer and potential of the activity to pollute. The applicant shall employ AKART (all known, available, and reasonable treatment) to ensure that the highest degree of protection is afforded to the aquifer. Conditional uses that may be allowed are listed in Table 18.116-2 pursuant to Section 18.16.100, Process III procedures; provided, that the use is also allowed within the designated zone, pursuant to Division 3 of this title, Development Standards—Zoning. Table 18.116-2 also provides guidance on existing federal or state statutes or regulations pertaining to the specific activity mitigative measures within the protection zones.
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Activity |
Statute—Regulation—Guidance |
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Aboveground Storage Tanks |
WAC 173-303-640 |
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Automobile Washers |
Chapter 173-216 WAC, BMPs for Vehicle and Equipment Discharges (WDOE WQ-R-95-56) |
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Below-Ground Storage Tanks |
Chapter 173-360 WAC |
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Chemical Treatment Storage and Disposal Facilities Hazardous Waste Generator (Boat Repair Shops, Biological Research Facility, Dry Cleaners, Furniture Stripping, Motor Vehicle Service Garages, Photographic Processing, Printing and Publishing Shops, etc.) |
WAC 173-303-182; Chapter 173-303 WAC |
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Injection Wells |
Federal 40 CFR Parts 144 and 146, Chapter 173-218 WAC |
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On-Site Sewage Systems (Large Scale) |
Chapter 173-240 WAC |
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On-Site Sewage Systems > 14,500 Gal/Day |
Chapter 246-272 WAC, Local Health Ordinances |
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Solid Waste Handling and Recycling Facilities |
Chapter 173-304 WAC |
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Wastewater Application to Land Surface |
Chapter 173-200 WAC, Chapter 173-216 WAC, WDOE Land Application Guidelines, BMPs for Irrigated Agriculture |
E. Nonhazardous Uses. Subdivision of land, pursuant to Division 6 of this title, Subdivisions and Platting, residential structures of three or more units, new agricultural activities that do not involve hazardous substance handling or application, and all commercial and industrial sites or activities that do not include or involve hazardous substance processing, handling or processing in CARA/wellhead protection zones are allowed subject to the following standards:
1. Stormwater treatment and control shall be provided in conformance with the adopted city stormwater management manual.
2. Floor drains shall not be allowed to drain to the stormwater system and must be designed and installed to meet the adopted plumbing code standards.
3. If any roof venting carries contaminants, then the portion of the roof draining from this area must go through pretreatment pursuant to adopted plumbing code standards.
4. All nonresidential vehicle washing must be self-contained or be discharged to a sanitary sewer system, if approved by the sewer utility, and subject to adopted plumbing code standards.
5. Integrated pest management (IPM) practices for pest control and best management practices (BMPs) for the use of fertilizers as described by Washington State University.
6. For new or changes in regulated activities served by on-site sewage systems, the applicant must demonstrate to the Thurston County public health and social services department (TCPH&SSD) that nitrate levels at the down-gradient property line will not exceed two and one-half mg/L or that, if the background nitrate concentration exceeds two and one-half mg/L, the concentration will not be increased more than one-tenth mg/L, with the cap being set by TCPH&SSD standard maximum allowable quantities for nitrate concentrations.
7. Additional protective measures may be required if deemed necessary by the city, TCPH&SSD, the Department of Health or the Department of Ecology to protect public health or safety.
F. Hazardous Uses—General. Hazardous substance processing or handling, hazardous waste treatment and storage facilities, animal containment areas, and solid waste facilities within CARA/wellhead protection zones require a solid waste handling approval/permit, which shall be issued pursuant to conditional use permit review as specified in subsection (D) of this section. In addition, approval of these or other uses specified in Table 18.116-2 shall only be allowed in CARA/wellhead protection zones subject to review and approval of a Class “B” hydrogeologic assessment. Mitigation measures of potentially negative impacts associated with the proposed development may be imposed. At a minimum, the TCPH&SSD, Department of Health and Department of Ecology shall be allowed comment opportunity on all CARA/wellhead protection zones conditional use permit applications.
G. Hazardous Uses—Storage Tanks. In addition to the requirement to submit a hydrogeologic assessment, the following standards apply to storage tanks in a CARA/wellhead protection zone:
1. Underground Tanks. All new underground storage facilities used or to be used for the underground storage of hazardous substances or hazardous wastes shall be designed and constructed so as to:
a. Prevent releases due to corrosion or structural failure for the operational life of the tank;
b. 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 substance; and
c. Use material in the construction or lining of the tank which is compatible with the substance to be stored.
d. The installation of underground storage tanks shall also be subject to other state and local permit requirements.
2. Aboveground Tanks.
a. No new aboveground storage facility or part thereof shall be fabricated, constructed, installed, used, or maintained in any manner which may allow the release of a hazardous substance to the ground, groundwater, or surface waters of Rainier within a CARA/wellhead protection zone.
b. A new aboveground tank that will contain a hazardous substance will require both a double-walled tank and a secondary containment system separate from the tank that will hold one hundred ten percent (110%) of the tank’s capacity. The secondary containment system or dike system must be designed and constructed to contain material stored in the tank(s). (Ord. 548 § 2 (Exh. E) (part), 2007)