PumpandTreat

Pump and treat, formally known as pump-and-treat (PAT), is a groundwater remediation strategy in which contaminated groundwater is pumped from the subsurface, treated to remove pollutants, and either returned to the aquifer and/or discharged. The approach is commonly used at sites with dissolved contaminants that can be captured by pumping and removed through surface treatment.

The system uses extraction wells or trenches to collect groundwater. The extracted water passes through treatment processes such as air stripping, activated carbon adsorption, ion exchange, membrane filtration, or advanced oxidation, removing pollutants like volatile organic compounds, solvents, petroleum hydrocarbons, and, in some cases, metals. Treated water may be reinjected into the aquifer or discharged to a surface-water outlet under regulatory controls.

PAT is among the most widely implemented groundwater remedies, especially for volatile organic compound plumes such as trichloroethylene and tetrachloroethylene in various aquifer types. It can function as a containment measure, a source-control strategy, or an interim remedy while other technologies are planned or developed.

Advantages of pump and treat include straightforward design, controllable operation, and the ability to provide immediate reductions in contaminant mass. Limitations include long timeframes for complete cleanup, dependence on favorable hydrogeology, high energy and maintenance costs, potential rebound of concentrations after pumping ceases, and challenges reaching source zones or low-permeability areas.

Design considerations encompass plume delineation, aquifer properties, extraction-rate optimization, treatment-train selection, and regulatory compliance. In many jurisdictions, PAT is used as part of a broader cleanup strategy under environmental regulations and site-specific remedial objectives.