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An introduction to cleaning up contamination

When you encounter contaminated soil or groundwater, the first step is to report the contamination to the DNR in accordance with the Spills Law, ch. 292, Wis. Stats. Property owners or the person who caused the discharge are responsible for reporting contamination, although an environmental consultant may make this report on behalf of the responsible person. The Spills Law applies equally to a recent spill and to old contamination that has been discovered. If the DNR determines that further investigation is needed, the responsible person will receive a letter from the DNR outlining the requirements.

A private consultant is usually hired to do an environmental investigation and to recommend cleanup options. The cleanup must address the full extent of contamination in soil and groundwater, even if it has gone beyond the property boundaries. The DNR is responsible for all environmental cleanups in the state, other than agricultural-related cleanups [exit DNR] which are the jurisdiction of the Department of Agriculture, Trade and Consumer Protection. In addition, the One Cleanup Program Memorandum of Agreement clarifies how the DNR and the U.S. EPA work together on cleanups in Wisconsin.

Basic steps in the cleanup of contaminated soil or groundwater

Basic information about soil and groundwater standards

The NR 700 rule series [exit DNR] governs the process of investigating and cleaning up contamination. Our rules allow development of site-specific soil performance standards [PDF] and the use of natural attenuation for groundwater, which means that the contamination is allowed to naturally break down over time. Chapter NR 140, Wis. Adm. Code [PDF exit DNR] covers Wisconsin's groundwater standards. Most, but not all, of Wisconsin groundwater standards are the same as federal drinking water standards. For more information about drinking and groundwater, please visit Drinking water.

Case closure - After investigation and remedial action

After the responsible person and the consultant have completed an environmental investigation and cleanup, a case closure request [PDF] may be submitted to the DNR's regional office. If the criteria for closure have been met, the responsible party will receive a case closure letter.

Wisconsin, like most states, may allow some residual contamination to remain after an environmental cleanup. The DNR ensures long-term protection of public health and the environment in regard to those residuals by establishing continuing obligations in the state's cleanup approval document (closure letter). The most common obligations are obtaining DNR approval prior to constructing a water supply well and properly treating or disposing of any excavated contaminated soil. Other obligations may include property-specific land use controls, such as maintaining pavement over a specified area of soil contamination. The DNR adds these properties to the Wisconsin Remediation and Redevelopment Database (WRRD) to help inform the public and potential future property owners of these obligations. For more information, about continuing obligations established as part of the cleanup approval, please see our residual contamination page.

Tools to manage environmental liability

A case closure with an optional, fee-based certificate of completion ensures that the DNR will not require the property owner, or future property owners, to conduct any additional investigation or cleanup for that incident after the certificate is issued. Other information about liability clarification tools may be found on Environmental liability.

For information on the basics of brownfields redevelopment, see: Brownfields Redevelopment in Wisconsin: Essential steps and resources for successful redevelopment of brownfields (RR-933) [PDF].