IEA_AARST_Radon_Reporter_JUNE_2024

THE RADON REPORTER | 15 VAPOR INTRUSION If sampling results indicate that indoor air is affected and mitigation is needed, the DNR designs, installs and commissions the mitigation system; develops a property-specific operation, monitoring and maintenance (OM&M) plan for the homeowner and documents all of the investigation and mitigation activities. Partnerships and public outreach where the investigation is taking place have been critical to the program’s success. The DNR works closely with its state and local health partners to provide the community and occupants with health- based information upfront and address health-related questions as they arise. When possible, the DNR prefers to contact the municipality and property owners before sending printed outreach materials. The DNR’s initial communications package includes an introduction letter to the municipality (typically including the local health, public works and community development departments) and the neighborhood to explain why the investigation is important to public health. DNR’s communication is supported by easily understood fact sheets, including What Is Vapor Intrusion? (DNR Publication RR-892) and the Agency for Toxic Substances and Disease Registry (ATSDR) fact sheets on PCE and TCE . Additionally, the package includes access permission agreements. The DNR follows up with property owners and occupants as needed to provide information and gain permission to access the properties. Follow-up may include neighborhood canvassing with help from other partners such as state or local health agencies and community partners. The state funds the investigation and mitigation work performed by the DNR under this program. To attempt to recover costs from responsible parties, the DNR may file a lien on the source property. Long-term stewardship of the vapor mitigation systems, including OM&M of the mitigation systems, may become the responsibility of the property owner in the absence of a viable responsible party. Long-term responsibility to maintain a vapor mitigation system is assigned in a legally enforceable document that is publicly available through the DNR’s Remediation and Redevelopment Database . As of March 2024, the DNR has investigated 14 residential properties, nine sanitary sewer systems and a small commercial property. The DNR is in the process of conducting mitigation at two single-family and one 16-unit, multi- family residences. The DNR has also inspected and updated vapor mitigation systems previously installed without active alarms at a residence and small commercial property. Going forward, the DNR plans to continue performing vapor investigations and mitigation under this program as funding and workloads allow. For additional information, contact Jennifer Borski, DNR Vapor Intrusion Team Leader, at Jennifer.Borski@wisconsin. gov or Jim Walden, DNR Vapor Intrusion Technical Expert, at Jamese.Walden@wisconsin.gov .