Chapter 23.30


23.30.010    Designation and susceptibility rating.

23.30.020    Exemptions.

23.30.030    Hydrogeologic assessments – Level 1.

23.30.040    Hydrogeologic assessments – Level 2.

23.30.050    Substantive requirements.

23.30.060    Uses prohibited from critical aquifer recharge areas.

23.30.010 Designation and susceptibility rating.

A. The city of Pacific hereby designates one critical aquifer recharge area: the 10-year time-of-travel wellhead protection zone which forms a 6,653-foot-radius circle around the city’s wells Nos. 2 and 3 (from which Pacific draws nearly all its drinking water, located near the northeast corner of Ellingson Road and Pacific Avenue), as established in Chapter 6 of the city’s August 1998 water system plan. (See Figure 1.) The city may update this map as new scientific data become available without revising this code.

B. The Washington State Department of Health has identified wells Nos. 2 and 3 as being highly susceptible to contaminants. The city confers this high susceptibility rating to the 10-year time-of-travel wellhead protection zone identified above. No moderate or low susceptibility zones are identified. (Ord. 1592 § 1, 2004).

23.30.020 Exemptions.

In addition to the developments listed in PMC 23.10.070, the following developments shall be exempt from this chapter:

A. Construction of structures, improvements, and additions of less than 2,500 square feet total site impervious surface area that do not increase risk from hazardous substances.

B. Development of parks, recreation facilities, or conservation areas that do not increase risk from hazardous substances. (Ord. 1592 § 1, 2004).

23.30.030 Hydrogeologic assessments – Level 1.

In addition to the requirements of PMC 23.10.090, critical areas reports for critical aquifer recharge areas shall include a hydrogeologic assessment. Level 1 (simpler) hydrogeologic assessment shall contain at a minimum:

A. Available information regarding geology and hydrogeology of the site, including permeability of the unsaturated zone;

B. Ground water depth, flow direction, and gradient based on available information;

C. Available data on wells and springs within 1,300 feet;

D. Location of other critical areas, including surface waters, within 1,300 feet; and

E. Best management practices proposed to be utilized. (Ord. 1592 § 1, 2004).

23.30.040 Hydrogeologic assessments – Level 2.

A. In addition to Level 1, a Level 2 hydrogeologic assessment shall be prepared for:

1. Activities that divert, alter, or reduce the flow of surface or ground waters, or otherwise reduce the recharging of the aquifer;

2. The use of hazardous substances other than household chemicals used according to the directions specified on the packaging;

3. Injection wells; and

4. Any other activity determined by the director likely to have an adverse impact on ground water quality or quantity.

B. Level 2 hydrogeologic assessments shall contain at a minimum:

1. Historic water quality data for the area to be affected by the proposed development;

2. Ground water monitoring plan;

3. Potential effects on water quality and quantity of nearby wells and water bodies; and

4. Analysis of equipment or structures that could fail and regular inspection, repair, and replacement necessary to prevent failure. (Ord. 1592 § 1, 2004).

23.30.050 Substantive requirements.

In addition to the substantive requirements of PMC 23.10.130, the following requirements shall apply to critical aquifer recharge areas:

A. Proposed developments shall not cause contaminants to enter the aquifer or significantly reduce the recharging of the aquifer, and shall comply with the water source protection requirements and recommendations of the U.S. Environmental Protection Agency, Washington State Department of Health, and county health department.

B. Underground facilities for storing hazardous substances shall be designed to prevent releases due to corrosion or structural failure for the operational life of the tank.

C. Above-ground facilities for storing hazardous substances shall be designed to prevent accidental release, shall have a primary containment enclosing or underlying the tank, and shall have a secondary containment built into the tank structure or consisting of an external dike.

D. Vehicle repair and servicing shall be conducted over impermeable pads, within a covered structure capable of normal weather conditions. Chemicals shall be stored in a manner that protects them from weather and provides containment should leaks occur. Infiltration well design must be approved by the director and installed in accordance with BMP.

E. Application of household pesticides, herbicides, and fertilizers shall not exceed times and rates specified on the packaging.

F. Surface percolation or injection of reclaimed water shall conform to adopted water or sewer comprehensive plans, RCW 90.46.010(10), 90.46.042, and 90.46.080(1).

G. The uses listed below shall be conditioned as necessary to protect critical aquifer recharge areas in accordance with the applicable state and federal regulations.


Statutes, Regulations, and Guidance Regarding Ground Water-Impacting Activities 


Statute Regulation Guidance

Above-ground storage tanks

WAC 173-303-640

Animal feedlots

Chapter 173-216 WAC, Chapter 173-220 WAC

Automobile washers

Chapter 173-216 WAC, Best Management Practices for Vehicle and Equipment Discharges (Washington Department of Ecology WQ-R-95-56)

Below-ground storage tanks

Chapter 173-360 WAC

Chemical treatment storage and disposal facilities

WAC 173-303-182

Hazardous waste generator

Chapter 173-303 WAC (boat repair shops, biological research facility, dry cleaners, furniture stripping, motor vehicle service garages, photographic processing, printing and publishing shops, etc.)

Injection wells

Federal 40 CFR, Parts 144 and 146, Chapter 173-218 WAC

Junk yards and salvage yards

Chapter 173-304 WAC, Best Management Practices to Prevent Storm Water Pollution at Vehicles Recycler Facilities (Washington Department of Ecology 94-146)

Oil and gas drilling

WAC 332-12-450, Chapter 173-218 WAC

On-site sewage systems (large scale)

Chapter 173-240 WAC

On-site sewage systems (< 14,500 gallons/day)

Chapter 246-272 WAC, local health ordinances

Pesticide storage and use

Chapter 15.54 RCW, Chapter 17.21 RCW


Chapter 173-303 WAC, Chapter 173-304 WAC, Best Management Practices to Prevent Storm Water Pollution at Log Yards (Washington Department of Ecology, 95-53)

Solid waste handling and recycling facilities

Chapter 173-304 WAC

Surface mining

WAC 332-18-015

Waste water application to land surface

Chapter 173-216 WAC, Chapter 173-200 WAC, Washington Department of Ecology Land Application Guidelines, Best Management Practices for Irrigated Agriculture

(Ord. 1592 § 1, 2004).

23.30.060 Uses prohibited from critical aquifer recharge areas.

The following activities and uses are prohibited in critical aquifer recharge areas (based on Guidance Document for the Establishment of Critical Aquifer Recharge Area Ordinances, by WDOE, Publication No. 97-030):

A. Landfills and solid waste transfer stations, including landfills for hazardous waste, municipal solid waste, special waste, wood waste, and inert and demolition waste;

B. 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;

C. Mining of metals, hard rock, sand, and gravel;

D. Wood treatment facilities that allow any portion of the treatment process to occur over permeable surfaces;

E. Creosote or asphalt manufacturing;

F. Storage, processing, or disposal of hazardous, chemical, or radioactive substances;

G. Electroplating;

H. Class 1A or 1B flammable liquids manufacturing as defined by the Uniform Fire Code;

I. Conversion of heating systems to fuel oil;

J. New petroleum product pipelines;

K. Activities that would significantly reduce the recharge to aquifers currently or potentially used for potable water; and

L. Activities that would significantly reduce base flow to a regulated stream. (Ord. 1592 § 1, 2004).