Lemna Environmental Technologies

Lemna Environmental Technologies, established in 1983 and headquartered in Vadnais Heights, Minnesota, specializes in lagoon-based wastewater treatment solutions under the LemTec brand. The company designs and manufactures a complete range of in-tank treatment technologies including biological treatment processes, moving bed bioreactors (MBBR), partial-mix facultative lagoon systems, and recirculating sand filters. Their aeration technology delivers year-round effluent limits as low as 10 mg/L BOD, 10 mg/L TSS, and 2 mg/L NH3-N. Lemna also provides dedicated phosphorus removal systems and polishing reactors for tertiary treatment. Their cover product line includes modular insulated covers for heat retention, segmented covers for flexible access, and gas collection covers for biogas recovery and odor control. A hydraulic baffle system optimizes flow patterns within lagoons and basins. The company serves municipal clients ranging from small communities to mid-sized cities, as well as industrial sectors including agriculture, chemical processing, energy, food and beverage, and general manufacturing. Lemna positions its turnkey approach—spanning engineering, project management, and commissioning—as achieving comparable treatment performance at a fraction of the cost of conventional mechanical plants. Both new construction and retrofit applications are supported across all product lines.