*£ 3 « c . co ca o F5 o> «- J= O CL fl> U. 0.1110. United States EPA-510-B-92-002 Environmental Protection November 1992 Agency Solid Waste And Emergency Response (OS-420) WF Filter Canisters A New Method For Recovering Free Product <2 . rao1 ffl"~ _ ^o o B o D. §- Printed on Recycled Paper ------- Some Information About Filter Canisters Filter canisters can help to clean up contaminated sites by., removing liquid petroleum, known as free product, floating on groundwater. The diagram shows a filter canister that has been lowered into a monitoring well so that it contacts the layer of free product floating on top of the groundwater. The filter is constructed of a material which allows free product, but no groundwater, to enter. Gravity causes free product to trickle through the filter and then drip into the bottom of the canister. Canisters can store between 0.5 to 2.0 gallons of free product The free product that is collected can be removed from canisters either manually or automatically. Manually operated canisters are pulled up and emptied much like a bailer. Automated canisters are emptied without removal by means of a suction pump. Recov- ered free product can be up to 100-percent pure petro- leum mat is ready to be reused or recycled. Some Applications Of Filter Canisters Use filter canisters to: « Initiate removal of free product immediately. Remove free product at sites with low-permeability soils or low-yield wells, where traditional pumping methods are ineffective. • Remove thin layers of free product and intermit- tently occurring free product • Complement other treatment techniques such as pump-and-treat, vapor extraction, and air sparging. For Additional Information A more detailed discussion of filter canisters is presente in an article entitled "Cutting the High Cost of Free Product Removal," published in LUSTLine (Bulletin 16, March 1992). To order this publication send $2.50 to: NEIWPCC 85 Merrimac Street Boston, Massachusetts 02114 800424-9364 You may contact manufacturers of filter canisters and similiar devices that incorporate filters. As of October 1992, EPA is aware of the following manufacturers: EnviroProducts, Inc. 1431 Renson Street, Suite A Lansing, Michigan 48910 800368-4764 Halliburton NUS Environmental Corporation 16360 Park 10 Place, Suite 300 Houston, Texas 77084 713492-1888 Homer Creative Products, Lie. 212 Morton Street Bay City, Michigan 48706 800443-0711 Keck Instruments, Lie. P.O. Box 345 Williamston, Michigan 48895 800542-5681 ORS Environmental Equipment 32MillStreet Grenville, New Hampshire 03048 800228-2310 PJ Products Company 30 Greenfield Lane Scituate, Massachusetts 02066 617545-1685 ------- Some Advantages Of Filter Canisters Filter canisters have a variety of advantages. • Filter canisters do not disturb or draw down the groundwater level, so they minimize the "smear- ing" of free product below the water table. • Petroleum is separated from water, so discharging and treating contaminated water is unnecessary. • Filter canisters can be installed in monitoring wells in only minutes. • Permits are not required to install or operate filter canisters. • Canisters are relatively inexpensive; prices range from $400 to $1000 per canister. • More free product can be removed with less effort than with traditional manual bailing. • Canisters are reusable. • No power source is required. Some Limitations Of Filter Canisters Filter canisters do not remove fuel bound to soil or : dissolved in groundwater. Filter canisters recover only free product. The rate of free-product recovery depends on the thickness of the free product arid the rate of flow, into the wen. Filter canisters do not control groundwater gradient If free product is spreading quickly, separate groundwater gradient control may be required to prevent further migration of contamination. Several filter canisters may be needed to capture all of the free product Because filter canisters have been in wide use for less than a year only limited performance data are available. ------- |