18.08.188 Aquifer recharge areas | Gig Harbor Municipal Code

18.08.188 Aquifer recharge areas.

Aquifer recharge areas are particularly susceptible to contamination and degradation from land use activities. Areas which have a high potential for ground water resource degradation are identified as aquifer recharge areas under this section and shall be subject to the requirements herein.

A. Designation/Classification. For the purposes of this section, the boundaries of any aquifer recharge areas within the city shall consist of the two highest DRASTIC zones which are rated 180 and above on the DRASTIC index range. Any site located within these boundaries is included in the aquifer recharge area.

1. Hydrogeologic Assessment Required. The following land uses shall require a hydrogeologic assessment of the proposed site if the site is located within an aquifer recharge area:

a. Hazardous substance processing and handling;

b. Hazardous waste treatment and storage facility;

c. Wastewater treatment plant sludge disposal categorized as S-3, S-4 and S-5;

d. Solid waste disposal facility.

2. Hydrogeologic Assessment Minimum Requirements. A hydrogeologic assessment shall be submitted by a firm, agent or individual with experience in hydrogeologic assessments and shall contain, at a minimum, and consider the following parameters:

a. Documentable information sources;

b. Geologic data pertinent to well logs or borings used to identify information;

c. Ambient ground water quality;

d. Ground water elevation;

e. Depth to perched water table, including mapped location;

f. Recharge potential of facility site, respective to permeability and transmissivity;

g. Ground water flow vector and gradient;

h. Currently available data on wells and any springs located within 1,000 feet of the facility site;

i. Surface water location and recharge potential;

j. Water supply source for the facility;

k. Analysis and discussion of the effects of the proposed project on the ground water resource;

l. Proposed sampling schedules;

m. Any additional information that may be required or requested by the Pierce County environmental health department.

3. Review of Hydrogeologic Assessment. A hydrogeologic assessment prepared under this section shall be submitted to the Pierce County department of environmental health for review and comment. Comments received by the department of health within 60 days of submittal of the assessment shall be considered by the city in the approval, conditional approval or denial of a project.

4. Findings for Consideration of Approval. A hydrogeologic assessment must clearly demonstrate that the proposed use does not present a threat of contamination to the aquifer system, or provides a conclusive demonstration that application of new or improved technology will result in no greater threat to the ground water resource than the current undeveloped condition of the site. Successful demonstration of these findings warrants approval under this section. (Ord. 1036 § 31, 2006).