St. Louis County Engineering Solid Waste ConsultingGeolocation: 47.5225, -92.5353

In 2000, Liesch was retained by the County to prepare construction bid documents, administer bids and document/certify construction of a 6-acre cover system at the Landfill. The cover system included a 6-inch grading/buffer layer, installation of a 40-mil HDPE geomembrane, 18 inches of general fill and 6-inches of topsoil. In addition to the cover system, construction also included the installation of deep landfill gas wells, a surficial landfill gas venting system and a surface water drainage system consisting of berming, rip-rap swales and ditching.

Liesch has also assisted the County with the construction of two liner expansions. Liesch prepared construction bid documents, administered bids and documented/certified construction for each cell, both of which were approximately 3 acres. Major construction elements included s ub-base construction, a composite liner (2-feet of clay and 60-mil HDPE geomembrane liner), leachate collection system (leachate collection piping, leachate sump/pump, leak detection system) and perimeter grading to drain. The Landfill is built on an old mine dump, so to maintain stability of the cells, a 4-foot cut underlying the entire liner system needed to be completed and re-compacted.

Liesch was retained in 2009 to assess the effectiveness of the Landfill's leachate land application operations. It was determined that the County was overloading the leachate spray irrigation site with nitrogen. As a result, Liesch prepared a Nitrogen Management Plan to control nitrogen loadings over the land application area. In addition, Liesch developed a design, prepared construction bid documents, administered bids and assisted with the documentation/certification of an expansion of the Landfill's existing leachate spray irrigation system.

Liesch has also assisted the County with the re-permitting of the Landfill twice during the last 10 years. Liesch collaborated with the County and the County's other partners to prepare the required engineering design report, design plans, hydrogeologic report, leachate management report, financial assurance report and industrial waste management plan. In an effort to save costs, Liesch has provided oversight on much of the work while the County and its partners took on the preparation of the majority of the documents.

Virginia, MN 55792