Ogallala Ground Water Contamination

Overview

The Ogallala Ground Water Contamination site sits in Ogallala, Nebraska, and is listed on the National Priorities List (NPL), the EPA's roster of priority Superfund sites. The site consists of two contaminated groundwater areas. Operable Unit 1 (OU1) covers a plume of trichloroethylene (TCE), perchloroethylene (PCE), carbon tetrachloride, and related volatile organic compounds beneath the Highway 30 business corridor and the former city landfill. Operable Unit 2 (OU2) stems from Tip-Top Cleaners, a former dry cleaning business, and contains PCE in residential and commercial areas. Both units threaten the Ogallala aquifer, which supplies drinking, agricultural, and industrial water across the region.

Site investigations began in 1990 and continued through the mid-1990s. For OU1, EPA selected groundwater extraction and treatment in a 1999 Record of Decision. That system ran until 2003 and was followed by institutional controls and monitored natural attenuation, which continue today. Source plume characterization work took place in 2022 and 2023, with additional investigation planned for 2024 through 2025. For OU2, cleanup included soil vapor extraction, chemical oxidation using sodium permanganate, building demolition, and soil replacement completed in 2011. Between 2016 and 2021, EPA investigated indoor vapor intrusion and installed mitigation systems at affected properties. OU2 remedial actions were completed by late 2016 and transitioned to state-performed operation and maintenance at that time.

EPA's 2021 Five-Year Review found the remedy protective of human health and the environment in the short term. Human exposure to contaminants is under control, and there are no known unacceptable exposures through drinking water. However, groundwater migration is not yet stabilized, and not all cleanup goals have been met. The site is not yet ready for its anticipated future use. Three businesses currently operate at the site, employing 205 people and generating about $29.1 million in annual sales.

A Remedial Investigation and Feasibility Study is underway to evaluate treatment technologies for the remaining groundwater contamination. A Proposed Plan outlining cleanup options is scheduled for completion in 2029. EPA will also begin its fourth Five-Year Review in September 2025, which will assess whether current protections remain adequate and whether additional steps are needed.

Community members can contact the EPA team directly with questions.