A. 
Areas with a critical recharging effect on aquifers used for potable water as defined by WAC 365-190-030(2) are hereby designated critical areas and shall be subject to the provisions of this chapter.
B. 
The approximate location and extent of known or suspected critical aquifer recharge areas are shown on the city’s adopted critical area maps within the comprehensive plan environmental element. Critical aquifer recharge areas are shown on the maps as moderate and high sensitivity and also include the Cross Valley Aquifer, which is a sole source aquifer. These maps shall be used as a guide for the city, applicants and/or property owners, and may be continuously updated as new critical areas are identified.
C. 
For purposes of this chapter, critical aquifer recharge areas include the following:
1. 
Areas designated by United States Geological Survey (USGS) as aquifers with moderate and high sensitivity.
2. 
Wellhead protection areas as defined by the boundaries of the one-, five- and 10-year time of ground water travel, or boundaries established using alternate criteria approved by the Snohomish County health department in those settings where ground water time of travel is not a reasonable delineation criterion, in accordance with WAC 246-290-135.
3. 
Sole source aquifers (Cross Valley).
(Ord. 2004-603 § 2)
A. 
Activities that do not cause degradation of ground water quality and will not adversely affect the recharging of the aquifer may be permitted in a critical aquifer recharge area, and do not require preparation of a critical area report; provided, that they comply with the Mill Creek stormwater management regulations and applicable state and federal regulations, including the water source protection requirements of the Federal Environmental Protection Agency, the state Department of Health, and the Snohomish County health department. These activities typically include residential, commercial and industrial development that does not include storage, processing, or handling of any dangerous waste or hazardous substance, or other development that does not substantially divert, alter, or reduce the flow of surface or ground waters.
B. 
Activities that have the potential to cause degradation of ground water quality or adversely effect the recharging of the aquifer may be permitted in critical aquifer recharge areas only in accordance with an approved critical area report and mitigation plan. The applicant shall have the burden of proof. These activities include but are not limited to:
1. 
Activities that substantially divert, alter, or reduce the flow of surface or ground waters, or otherwise adversely affect aquifer recharge;
2. 
The use, processing, storage or handling of hazardous substances, or dangerous wastes, other than household chemicals used according to the directions specified on the packaging for domestic applications;
3. 
The use of injection wells, including on-site septic systems, except domestic septic systems releasing less than 14,500 gallons of effluent per day and that are limited to a maximum density of one system per one acre; or
4. 
Any other activity determined by the director likely to have an adverse impact on ground water quality, or on the recharge of an aquifer.
(Ord. 2004-603 § 2)
The following standards shall apply to uses within critical aquifer recharge areas:
A. 
Underground Storage Tanks. All new underground storage facilities proposed for use in the storage of hazardous substances or dangerous wastes shall be designed and constructed in accordance with Chapter 173-360 WAC, Underground Storage Tank Regulations and the Uniform Fire Code, so as to:
1. 
Prevent releases due to corrosion or structural failure for the operational life of the tank;
2. 
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
3. 
Use material in the construction or lining of the tank that is compatible with the substance to be stored.
B. 
Aboveground Storage Tanks. All new aboveground storage facilities proposed for storage of hazardous substances or dangerous wastes shall be designed and constructed in accordance with Chapter 173-303 WAC, Dangerous Waste Regulations, and the Uniform Fire Code, so as to:
1. 
Prevent releases to the ground, ground waters, or surface waters;
2. 
Have a primary impermeable containment area enclosing or underlying the tank; and
3. 
Include a secondary containment system either built into the tank structure or a dike system built outside the tank for all tanks.
C. 
Vehicle Repair and Servicing. Vehicle repair and servicing shall 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 shall be stored in a manner that protects them from weather and provides containment should leaks occur.
D. 
Residential Use of Pesticides and Nutrients. Application of household pesticides, herbicides, and fertilizers shall not exceed times and rates specified on the packaging.
E. 
Spreading of reclaimed water must meet the ground water recharge criteria given in RCW 90.46.010(10) and 90.46.080.
(Ord. 2004-603 § 2)
A. 
The following activities and uses are prohibited in critical aquifer recharge areas:
1. 
Dry Wells. Dry wells on sites used for vehicle repair and servicing shall not be allowed in critical aquifer recharge areas. Dry wells existing on any site prior to facility establishment shall be abandoned using techniques approved by the state Department of Ecology prior to commencement of the proposed activity;
2. 
Landfills, including hazardous substances or dangerous waste, municipal solid waste, special waste, and inert and demolition waste landfills;
3. 
Injection of reclaimed water;
4. 
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;
5. 
Storage, processing, or disposal of radioactive substances, including facilities that store, process, or dispose of radioactive substances; and
6. 
Other uses as determined by the director that:
a. 
Would significantly reduce the recharge to aquifers currently or potentially used as a potable water source; or
b. 
Would significantly reduce the recharge to aquifers that are a source of significant baseflow to a regulated stream or water body; or
c. 
Would significantly affect ground water quality.
B. 
Sand and gravel mining is prohibited in critical aquifer recharge areas designated as highly vulnerable.
(Ord. 2004-603 § 2)
In addition to the general critical area report requirements of MCMC § 18.06.530, a hydrogeo-logic report for aquifer recharge areas shall include the following additional site- and proposal-related information at a minimum:
A. 
Available information regarding geologic and hydrogeologic characteristics of the site, including the surface location of all critical aquifer recharge areas located on site or immediately adjacent to the site, and permeability of the unsaturated zone;
B. 
Ground water depth, flow direction and gradient based on available information;
C. 
Currently available data from wells and springs within 1,300 feet of the project area;
D. 
Location of other critical areas, including surface waters, within 1,300 feet of the project area;
E. 
Historic ground water and surface water quality data for the area to be affected by the proposed activity compiled for at least the previous five-year period;
F. 
Best management practices proposed to be used;
G. 
Ground water monitoring plan provisions;
H. 
Discussion of the effects of the proposed project on the ground water quality and quantity, including predictive evaluation of ground water withdrawal effects on nearby wells and surface water features and predictive evaluation of contaminant transport based on potential releases to ground water; and
I. 
A spill plan that identifies equipment and/or structures that could fail, resulting in an impact. Spill plans shall include provisions for regular inspection, repair, replacement of structures and equipment that could fail, cleanup and disposal of all materials spilled.
(Ord. 2004-603 § 2)