StormwaterUIC

Stormwater Underground Injection Control (UIC) System Requirements

Regulatory Background

The federal Underground Injection Control (UIC) program was enacted in 1974 under the Safe Drinking Water Act (SDWA). The program is administered by the Oregon Department of Environmental Quality (DEQ) and is intended to protect groundwater resources from contamination.

Stormwater UIC systems are any man-made design or structure which allows discharge of stormwater below ground. Common UIC systems include, for example, dry wells, soakage trenches, and infiltration galleries. A UIC must be approved by the DEQ through Authorization by Rule (AR) or under an individual Water Pollution Control Facilities (WPCF) permit. Requirements for obtaining AR, operating a UIC or closing a UIC are set forth in Oregon Administrative Rules (OAR) 340-044-0005 through 340-044-0055.

Closure Requirements

The professional staff of BB&A Environmental can assist clients with tasks required to close or decommission a UIC including, for example:

  • Preparation of a UIC closure plan, if required;
  • Characterizing through sampling and analysis any soil, gravel, sludge, liquids or other materials removed from the UIC;
  • Proper disposal of materials removed from the UIC; and
  • Plugging and sealing the UIC to prevent vertical movement of fluids.

Authorization by Rule (AR)

The professional staff of BB&A Environmental can assist clients with tasks necessary to obtain AR or an individual WPCF permit including, for example, verifying the following:

  • No other waste are mixed with stormwater;
  • Site development, design, and construction practices have minimized stormwater runoff;
  • No other method of stormwater disposal is available;
  • No domestic drinking water wells are present within 500 feet;
  • The UIC will not be located within a two (2) year time-of-travel zone or closer than 500 feet to a public water supply well;
  • No soil or groundwater contamination is present in the area of the UIC;
  • The UIC does not exceed a depth of 100 feet and does not discharge directly into groundwater or below the highest seasonal groundwater level; and
  • Design, construction, and operation of the UIC will protect groundwater from contamination.

Operational Requirements

The professional staff of BB&A Environmental can also assist clients with operational requirements, including the following:

Certification that stormwater discharged to the UIC system is not exposed to industrial activities and/or hazardous substances through:

  • Preparation of site assessment information including location, type of industrial activities, and identification of hazardous substances;
  • Analytical results of representative stormwater samples collected from the UIC before discharge to the subsurface; and
  • Identification of site controls, best management practices, spill prevention and response procedures.

Preparation and implementation of a written stormwater management plan including:

  • Preparation of site assessment information identifying location and construction details of the UIC system;
  • Implementation of site controls and best management practices; and
  • Monitoring stormwater discharge through sampling and analysis to document effectiveness of stormwater management plan.

Regulatory reporting as required.