Collaboration Delivers Sustainable Groundwater Remediation
10th Street Superfund Site remediation approach reduces municipal water supply burden
At the 10th Street Superfund site near Columbus, Nebraska, volatile organic compounds from three dry-cleaning businesses have contaminated soil and groundwater with tetrachloroethene and trichloroethene, affecting the city’s southern municipal well field. For cleanup success, hazardous waste and water supply disciplines collaborated in an innovative and sustainable resource recovery practice: using treated water from a Superfund Site in a potable water supply.
CDM Smith completed a remedial investigation/feasibility study, interim remedial design and interim remedial action for the site, and subsequently designed a supplemental in situ chemical oxidation program to accelerate the overall groundwater remediation. The U.S. Environmental Protection Agency’s (EPA) interim Record of Decision specified groundwater extraction and treatment and the operation of an air sparging/soil vapor extraction system. Designed and built by CDM Smith, the system is integrated with the city’s water supply treatment and distribution, meets State of Nebraska drinking water standards and conserves this valuable resource.
Since startup, the integrated systems have increased Columbus’ drinking water supply by providing more than 5 billion gallons of treated groundwater without developing land for additional supply wells. Computer models are updated annually to optimize the system, improving remedy effectiveness while reducing use of energy and resources. A community outreach program bolstered public acceptance of treated groundwater as supplementary water supply. Unifying operations of the remedial system and the city water supply has realized operational efficiencies while reducing costs, conserving non-renewables and saving time. CDM Smith, EPA and Columbus are exploring additional opportunities for re-use of the treated water.