Pumping well method containment plume

Reinjection of coproduced groundwater through the use of wells is commonly used to return the water to the same aquifer and to set up hydraulic barriers in an effort to contain the plume. Injection wells are commonly used in conjunction with withdrawal systems to enhance the recovery of hydrocarbons. Injecting water at appropriate locations will create a pressure ridge to increase the hydraulic gradient effectively toward the withdrawal point. Normally, the water pumped from the recovery wells is used as the injection water and is injected, without treatment. This method provides an economical way of handling the produced water, as well as being beneficial to the recovery effort. 

Four typical well patterns for contaminant plume containment are described in Ref. 16. The first is a pair of injection-production wells. The second is a line of downgradient pumping wells. The third is a pattern of injection-production wells around the boundary of a plume. The fourth, the double-cell system, uses an inner cell and outer recirculation cell, with four cells along a line bisecting the plume in the direction of flow. Two other methods of plume containment are bio filters and a funnel-and-gate system, which are described in the in bioremediation section. 

These two methods, which are used as an emergency action, can also be utilized for the cleaning of plumes. Containment methods can often be extended to plume treatment by using the trench or well pumping to recover the free product. 

Plume Containment. Wells can be placed at a contaminated site to prevent the contamination from spreading further or migrating offsite. In the past, containment efforts often reHed on physical methods such as bentonite slurry trenches, grout curtains, sheet piHngs, well points, and fixative injections. Containment by judiciously placed wells generally costs less, takes less time to install, and is more flexible because pumping rates and locations can be varied. 

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