The Marengo City Council did the right thing this week when it voted unanimously to temporarily cut residents’ sewer rates almost in half. The reduction comes after expansion work on the city’s wastewater treatment plant was abruptly stopped last month after officials learned that a landfill buried under the site would add significant cost to the $12 million project.

While working on the plant, crews found high metallic content in soil tests as a result of an unregulated landfill that closed in 1975. The city’s engineering firm has said the buried waste is not hazardous but creates new challenges. Much of the material buried in the landfill consists old bottles, refrigerators and other appliances, wood and construction debris.

J.J. Henderson in Gurnee won the expansion contract bid, but says it was not aware of the landfill so did not include it in its estimated costs. City officials, however, say they had conversations about the landfill with the project’s designer, McMahon and Associates.