Lemberger Landfill sits on 21 acres in Manitowoc County, Wisconsin, near Whitelaw. It operated as an open dump for roughly 30 years before receiving a sanitary landfill license in 1969. The site accepted municipal waste and power plant ash but had no leachate collection system. After its operating license expired in 1976, regulators required proper closure. The site was added to the federal National Priorities List in June 1986 and remains listed today.
Forty-nine contaminants have been identified at the site. Groundwater contains chlorinated solvents such as trichloroethene, tetrachloroethene, carbon tetrachloride, and 1,1,1-trichloroethane. Metals found in groundwater include arsenic, lead, mercury, chromium, cadmium, and others. Polychlorinated biphenyls (PCBs), pesticides, ketones, phthalates, and aromatic compounds like toluene and xylene are also present. Solid waste and residuals contain several of the same contaminants, including arsenic, lead, trichloroethene, and PCBs.
The Lemberger Site Remediation Group carried out cleanup work under EPA and state oversight. The original 1991 cleanup plan called for extraction wells, a groundwater treatment system, a capped landfill cover, an underground slurry wall, leachate withdrawal wells, and an outfall pipe to the Branch River. A pump-and-treat system operated for about 11 years. When that system was no longer cost-effective, EPA shifted the approach. A 2006 explanation of significant differences moved the strategy toward monitored natural attenuation, which lets contaminants break down naturally while being tracked. A 2021 record of decision amendment further refined the remedy to focus on groundwater monitoring and natural attenuation, updated cleanup standards, and removed some earlier remedy components. Site owners and responsible parties also filed restrictive covenants with Manitowoc County in 2009 and 2010 to limit groundwater use and soil disturbance.
Physical construction of the cleanup is complete across the entire site. Human exposure is currently under control, with no unacceptable exposure pathways identified. Contaminated groundwater is stabilized within the original area and shows no unacceptable discharge to surface water. The site achieved sitewide ready for anticipated reuse status in June 2015. A five-year review completed in 2021 confirmed the cleanup continues to protect people and the environment, and the most recent review was completed in July 2025.
Community members can review site documents and the administrative record at the Manitowoc Public Library.
