Site Cleanup Unit

The North Coast Regional Water Quality Control Board Site Cleanup Unit implements the State Water Board contaminated site cleanup programs. These programs include the Site Cleanup Program, the Underground Storage Tank Cleanup Program, the Department of Defense Cleanup Program, and the Brownfields Program.

Sites enter these programs due to recent or historic discharges or suspected discharges of hazardous materials (for example, fuels or solvents) to the surface or subsurface, resulting in groundwater and soil contamination. Sites include industrial facilities, dry cleaners, lumber mills, underground and above ground petroleum storage tanks, accidental spills and leaks.

Information on these State Water Board programs can be found at the following links:

The Regional Water Board is one of several regulatory agencies that oversee such cleanup work in our region. Others include: the California Department of Toxics Substances Control (DTSC), the U.S. Environmental Protection Agency, and local environmental health agencies.You can find information on sites overseen by DTSC by visiting EnviroStor.

According to the State Water Resources Control Board’s Resolution No. 92‑49 (As Amended on April 21, 1994 and October 2, 1996) “Policies and Procedures for Investigation and Cleanup and Abatement of Discharges Under Water Code Section 13304,” the cleanup goal for groundwater is to restore the groundwater to background conditions. If that is found to not be feasible, Water Quality Objectives, based on the Water Quality Control Plan for the North Coast Region (Basin Plan), are used. A guide for numerically interpreting narrative water quality goals can be found on the State Water Resources Control Board’s Water Quality Goals webpage.

Vapor intrusion, the migration of contaminant vapors from the subsurface up into structures, is a concern at many cleanup sites. Vapor intrusion can produce health risks for the building occupants. North Coast Regional Water Board staff utilize the Cal/EPA vapor intrusion guidance documents in directing the evaluation and mitigation of vapor intrusion. Those guidance documents are available on the Department of Toxic Substances Control’s (DTSC’s) website at

In determining if contamination in soil and indoor air pose potential human health risks at a site, a human health risk assessment may be needed. The simplest human health risk assessment is to compare the contaminant concentrations to preliminary screening levels. North Coast Regional Water Board staff utilize DTSC’s “Human Health Risk Assessment Note 3 ‑ DTSC-Modified Screening Levels (DTSC-SLs)” (available at to determine preliminary screening levels for soil and indoor air. More detailed, site‑specific human health risk assessments may also be needed.

    Electronic Data Reporting

    The State Water Board maintains GeoTracker, a web-based geographic information system (GIS) program that provides the public and regulators with online access to environmental data, including cleanup site data and documents. GeoTracker is available online at The State Water Board adopted regulations that require electronic submittal of information for groundwater cleanup programs (Title 23, CCR, Division 3, Chapter 30).

    Cleanup Site Records Review

    Regional Water Board site records comprise both a paper file and an electronic file. Beginning in 2005, select file material was uploaded to the State Water Resources Control Board’s GeoTracker website and is not necessarily included in the paper file.  All new file material after 2014 is retained only electronically on the GeoTracker website.  The paper file may be reviewed at the North Coast Regional Water Quality Control Board office from 8:00am to 5:00pm Monday through Friday.  Appointments are recommended and can be arranged by calling (707) 576‑2220.

  (Page last updated 8/29/23)