Nov. 25, 2025
By Tim Hundt
VIROQUA, Wis. — The City of Viroqua is facing mounting pressure from the Wisconsin Department of Natural Resources (DNR) to resolve high levels of methane gas migrating from its old municipal landfill, an issue that has escalated from an initial safety concern into a complex, multi-phased environmental remediation project. The City Council received an update on the progress of that abatement effort on Tuesday, Nov. 11.
History of the ‘Town Dump’
The site, located near Sands Road and adjacent to the city’s south side developments, is what officials refer to as a “town dump”. City Engineer Sarah Grainger noted that the site was originally an informal “hole in the ground” where the city deposited waste for years. The landfill was formally closed in the early 1990s after the state implemented stricter regulations, leading the county to construct a new, state-compliant facility. While the site is capped, current zoning prevents it from being developed, though alternative uses like dog parks are possible if the liner is not penetrated.
Escalation and DNR Mandate
The current crisis began in early 2025 when Grainger alerted the DNR after a utility working near Sands Road detected high gas readings adjacent to the landfill. Subsequent investigation confirmed significant methane migration beyond the landfill’s boundary. A finalized report in May 2025 revealed that a monitoring probe adjacent to a nearby church on Sands Road showed gas readings between 1.2% and 20.5% methane by volume. State regulations mandate that explosive gas concentration in the soil beyond the landfill property boundary cannot exceed the lower explosive limit, which is 5% methane by volume. Following this discovery, the DNR issued a notice of non-compliance and ordered the city to develop a remediation plan by June 6 and begin work by June 30.
Consultant Mike Amstadt with TRC, the firm hired by the city to development the abatement plan, found that passive vents installed when the site was closed were not functioning. The gas, created by “biological activity” as “bugs… are eating waste”, was instead following the path of least resistance through a sand layer, venting horizontally off the property instead of up.
Phase One Shows Inconsistent Results
To address the immediate concern, the City Council approved an urgent waiver of the normal bid process in May 2025, allowing the immediate start of remediation work. Phase one involved installing a new passive venting system—a trench filled with porous rock and piping—on the north and east sides of the site.
Phase one construction began in July 2025. However, city staff soon found the landfill’s behavior “wildly inconsistent”. The site is subject to significant fluctuations due to weather and atmospheric pressure, sometimes showing “positive pressure and gas is coming out” and sometimes having “negative pressure”. Amstadt used the analogy that the landfill is “breathing in and out”. This inconsistency has complicated attempts to understand the gas flow.
Amstadt and Grainger said they have been working with the DNR to meet their requirements and thresholds. Because gas was detected beyond the property line, the DNR requires the city to determine the full “nature and extent” of gas migration around the entire perimeter, including the previously unmonitored “west landfill”. In response, the City Council approved a motion to install additional gas probes at a total cost of approximately $88,000 to surround the remaining areas of the site.
Financial Implications and Future Costs
The city initially estimated the entire multi-phase remediation project would cost between $450,000 and $750,000. The Phase One contract with Badger Environmental was estimated at approximately $187,583. The city realized some cost savings because Vernon County agreed to accept the excavated waste material, reducing disposal costs by about $15,000.
To fund the necessary infrastructure, the city allocated a large portion of its recent debt issuance, borrowing funds with roughly $700,000 earmarked for landfill remediation.
A major concern is the next potential remediation step is switching from a passive system to an active system, which uses a large blower to pull gas out. Staff fear that this expensive equipment could quickly deplete the limited gas supply and begin pulling oxygen into the site. Amstadt said oxygen ingress could alter the decomposition process, creating heat and potentially resulting in dangerous landfill fires. Therefore, the city is focusing on continuous, meticulous monitoring until enough data is gathered to determine the least risky and most effective long-term solution.
The city will face continuous financial obligations for monitoring the newly installed probes. Amstadt confirmed that the DNR will require the city to continue gas monitoring indefinitely, likely quarterly for the first couple of years, requiring Viroqua to budget for this requirement well into the future. The city is currently renting monitoring equipment, which is estimated to cost in the $17,000 to $20,000 range, prompting consideration of whether purchasing the equipment would be more cost-effective over time.
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