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Show 2 Hilltop Times July 1 6, 1 992 Process pulls contamination out of soil IT:'.! ! LM.I Sou rce- - Reco ve rv System m?d Operable Unit 2 Recovery wells Treatment building The Source Recovery System, or SRS, is an array of wells, pipes, tanks and pumps designed to pull solvents and contaminated ground water from the soil beneath Operable Unit 2 (see diagram). Removal is the first step of the process. Following removal, the ground water is treated to remove the high concentrations of contaminants. The treated water is then discharged into the sewer system. While the concept may seem straightforward, the process of removing contamination from the ground is neither easy nor simple. Pulling if out The first step of the process is to remove the solvent from the soiL Five wells have been installed to draw the solvent to the surface. This may sound as easy as slurping soda through a straw, but because the solvents and ground water are mixed with the soil it's more like trying to use a straw to suck syrup out of a sponge. Getting the solvent out of the ground is only part of the recovery problem. In addition to the solvent, the recovery wells also remove a great deal of ground water. Engineers estimate that approximately 5 million gallons of ground water will have to be removed in order to get all of the 100,000 gallons of solvent : in the soil. is pumped out of the tanks to the next treatment phase. To maximize efficiency, three separator tanks are used. The system is designed to operate the three tanks simultaneously but in different stages. For example, while one tank is in the settling stage, another tank is being filled and the remaining tank is being emptied. Through the bottom of the stripper comes steam. The steam is forced up through the water and carries away the contaminants. Contaminants captured in the steam are returned to the separator tanks and repeat the process. The remaining water, now more than 99 percent contaminant free, is sent to the base Industrial Waste Treatment Plant for further treatment before it is discharged into the North Davis County Sewer . 4 , Settling down Once the contaminated water is brought to the surface it is pumped into one of three separator tanks. It is allowed to settle there for several hours as gravity goes to work separating the heavier solvents from the lighter water, much like the cream separates itself from heavier milk. The heavy solvents are pumped from the tanks and disposed of as hazardous waste and the water r way-lighte- Continued from Page 1 community. This recovery system is being built as an interim action to remove the source of the contamination while engineers continue to study ways to clean up the remainder of the contamination at the site in South Weber. "By removing the solvents now, we will eliminate the source and reduce the amount of contamination Page In the final treatment stage, the water taken from the separator tanks is run through a device known as a steam stripper. As its name implies, a steam stripper uses steam to remove contaminants from the water. Contaminated water is pumped into the top of the stripper where it filters down through a maze of screens and steps designed to make the water change directions as many times as possible. system. Although steam stripping is not a suitable treatment method in all instances, it is tailor-mad-e for use at OU-2- . The primary contaminant in the water is trichloroethene, or TCE. TCE evaporates very easily once exposed to air, more easily in hot air. In the past, air strippers were used for the same purpose. But steam strippers are even more efficient because the water vapor in the steam helps carry away more contaminants than does dry air. leaving the base," said Capt. Danielle DeVoney, project manager. "Not only will this reduce the risk to the citizens of South Weber, but it will make it easier to clean up the remaining contamination." Plans for the recovery operation were proposed to South Weber residents in March of 1991 and were finalized with the approval of the Environmental Protection Agency and the Utah Department of Environmental Quality last September. DeVoney said the initial stage of the operation should take about two years. But she added that even after the source is gone, the work has only begun. "We still have contamination in South Weber that needs to be cleaned up," DeVoney said. "That's our next step. Now we're trying to determine the best way to do that." The base is working closely with the UDEQ and EPA to develop overall cleanup strategies for Operable Unit 2. These strategies are scheduled to be proposed to the citizens of South Weber in April 1993i Residents will be given an opportunity to comment on the proposal before a final remedy is chosen. The contamination is confined to the shallow aquifers and does not affect the (Irinking water supply. However, affected residents have been urged not to use water from springs or shallow wells for household purposes. OU-2'- s vent has been carried by shallow ground water into nearby South Weber resulting in contamination of shallow ground water in some parts of the H Continued from The stripper 1 "We need the most accurate information the member can provide," Reese said. "YouH just be cutting your throat by not answering accurately. Don't guess. Take the survey home, get out your records and calculate the most accurate data you can develop." Once the surveys are completed, Reese will box them up for shipment to the Defense Department's VHA survey representative. There all the data is compiled and will be used to determine if a change is needed in current VHA rates at Hill and other bases. Congress is the final authority. CMSgt. John A. Brewer, senior enlisted adviser for the Ogden Air Logistics Center, says there's no guarantee that filling out the surveys will bring a raise in VHA, but he says it's a case of "garbage in, garbage out." Hilltop Times Published by MorMedia. Inc., a private firm in no way connected with the U.S. Air Force, under exclusive written contract with Hill AFB. This commercial enterprise Air Force newspaper is an authorized publication for members of the U.S. military services. Contents of the Hilltop Times are not necessarily the official views of, or endorsed by, the U.S. government, the Department of Defense or the Department of the Air Force. , vide current information from the local community so a correct decision for change can be made by our leaders." 66 Last year, Hill's VHA rates went down for the lower six grades, except for s who saw an inWe need the accurate infor- crease, according to an accounting and finance spokesman. s and above saw an increase and the mation member can provide. rate for officers remained the same. Reese said the return rate for last year's survey You'll be your was a disappointing 40 to 50 percent and some of by not answering accurately. those weren't completly filled out. He hopes to get an 80 to 100 percent return rate this time of fully completed forms. "Without it, it'U all be for naught," he said. "If Mark J. Reese people don't bother to fill out the forms or only do Capt. Hill AFB P.rconnel Office it half way, the whole thing could be a waste of time for everyone else. And, when all is said and done, "If we don't take the time to fill out the surveys money could be taken out of your pocket." accurately and completely, VHA rates won't For more information about the survey, contact change," Brewer said. "It's important that we pro Reese at Ext. E-5- most the just E-7- cutting throat 99 The appearance of advertisements in this publication, including inserts or supplements, does not constitute endorsement by the Department of the Air Force or MorMedia, Inc. of the products or services advertised. Everything advertised in this publication shall be made available for purchase, use or patronage without regard to race, color, religion, sex, national origin, age, marital status, physical handicap, political affiliation or any other nonmerit factor of the purchaser, user or patron. Editorial content is edited, prepared and provided by the Ogden Air Logistics Center Public Affairs Office staff, Bldg. 1102, Room 118, Ext. 77321-- . Unless otherwise indicated, all photos are U.S. Air Force photos. Hill AFB Editorial Staff: Maj. Gen. Dale W. Thompson Ma. Wad. J. Habshty Jr.. Gary Hatch SSgt. Barbara Fisher Francos Kosalcowsky, Jay Jotrsi Commoner, OO-AL- C Director, Public Affair , Cjilor Assistant tditor Staff writor Deadlines: Editorial and "Around the Hill" Hems, 3 p.m. Tuesday, nine days before publication; sports orticles, 9 a.m. Monday, week of publication; classified ads, noon Tuesday, JLa,io"-Fo- r formation, call the editors, Exfs. 7732174598. |