Leachate Solution Provides Cost Saving and Environmental Benefits

Background

The Landfill of North Iowa (LNI) has worked with Foth for many years to provide annual engineering services, strategic planning services, and design and construction management. In 2018, LNI and Foth worked to solve a challenging and expensive leachate management concern. The Landfill was generating an average of 3.4 million gallons of leachate annually and incurring costs of $300,000-500,000 to manage the material. Together, we knew there was a better way to manage leachate.

Approach

LNI managed their leachate by pumping it into tankers and hauling it to the Mason City Wastewater Treatment Plant, or occasionally to the Clear Lake Sanitary District. Unfortunately, hauling could not keep up with maintaining the required 12″ or less level on the liner. Knowing they needed a more cost-effective and efficient option, the client asked us to find a better long-term leachate management plan.

Foth developed a detailed assessment of historical and current leachate generation and evaluated current and future anticipated leachate disposal costs. It was quickly decided that recirculation would not be an option due to the high leachate levels in determining a long-term solution. Foth prepared three alternatives for LNI’s Board to consider.

At its core, this project’s goal was to develop a long-term strategy to manage leachate, ensuring the Landfill can continue operations and reduce any manageable risks to groundwater. The LNI Board analyzed the advantages and disadvantages, the costs, and the long-term effects of each option before deciding to construct a force main to Mason City sanitary sewers. Construction began as quickly as possible, and the new system began operation in October 2018.

Results

The new leachate management plan has achieved its intended purpose by providing LNI with a long-term solution to its leachate management that provides cost savings and environmental benefits. LNI saves an average of ~$1,000 per day using the force main versus the cost of hauling the leachate.

Hauling was causing significant issues due to the the number of truckloads a day that could be managed. With the force main, they can continuously and consistently pump leachate to reduce head levels, reducing groundwater contamination potential. Another significant benefit is related to environmental and human health. By not hauling leachate, Foth estimates greenhouse gas emissions are reduced by 37 tons annually.