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s Evaluation continued from pages Cost: The present-worth cost would treat contaminants only if of this alternative is estimated at they arrive in concentrations above most effective way to treat them is $103 million. Present-worth costs drinking water standards at drink- at several different surface facilities are a way to compare costs of pro- ing water wells that are in use. The on the LLNL site.The treatment jects that extend over different actual treatment technology would technology for each location is time periods. be decided at the time the treatment designed to treat a slightly different GW Altemative No.2 is needed. In the meantime,moni- combination of compounds. toring and a public awareness pro- The main difference between this gram to limit new well drilling Seven treatment system locations alternative and Alternative No.1 is would be used to prevent human (called A to G—see Figure 2)are the number and placement of the contact with contaminated ground described in the PRAP. They were extraction wells. Ground water water. selected to minimize the length of would be extracted at approximately piping required from the extraction 10 locations,primarily at the west- Estimated Cleanup Time: It is wells to the treatment facilities and ern and southern edges of the con- likely to take over 200 years,if ever, to provide efficient discharge routes taminated water,to stop further for contaminants from LLNL to for treated ground water. migration. The water would be reach currently used water wells in Facilities A,B,C,E,and G are treated at four treatment facilities downtown Livermore in concentra- near areas where only VOCs need on-site. Facilities A,B,and F would tions above drinking water stan- treatment. Facility D is near use UV light/oxidation. Air strip- dards. It is estimated to take about in would be used at Facility C. 30 years to reduce the concentra- ground water that contains both ping tq tions to below drinking water stan- VOCs and chromium. Treatment Following treatment,the water g would be returned to the subsurface dards using air stripping after Facility F is near ground water that If left untreatedg�ins. contains VOCs,FHCs,and lead or used at LLNL. treatment be , above cleanupstandards. studies show that natural processes Estimated Cleanup Time: It will would reduce the VOC concentra- GW Alternative No.l (The Pre- probably take more than 90 years to tions everywhere to below drinking ferred Alternative) reduce all contaminant concentra- water standards in about 300 years This alternative involves tions to levels below drinking water from now. round water at 18 initial standards under this alternative. pumping g Cost: The present-worth cost of locations for treatment at seven Cost: The present-worth cost of this alternative is between$12 millon treatment facilities. Four facilities this alternative is about$99 million. (monitoring only)and$87 million (A,B,E,and F)would use UV/ GW AltNo.3 (monitoring and cleanup,assuming oxidation as the primary treatment the use of air stripping technology). process. Air stripping would be This is a "delayed action'altema- used at Facilities C,D,and G,due live. Under this alternative,LLNL to the presence of compounds such as chloroform,carbon tetrachloride and Freon 113,which are less effec- . '. lively treated by UV/oxidation. At �e ,� r all facilities,exhaust air would be aa°,.,n.m.mr.ex — filtered through activated carbon ®r«..b•� .,,..,. --___ ..,,„„nem awa prior to release to the atmosphere to .�« ccNc remove contaminants. The treated •^••��. _ � o__ o� water would be returned to the sub- c� surface or used at the LLNL site. y°°^A, The extraction systems will be r rg e designed to prevent concentrations l l`� f �] 17 c of tritium above Federal and State drinking water standards from 1 Jf ! •� 'p - '>__ "!�`l entering the treatment facilities. rr`9+�\ '"°j` p ��a• oo'°' °•" .y I – rout This alternative results in the r • ^• o i aw°I complete removal of the contami- �; , r nated water and the most rapid "� ��' ` o` ' ":''•' e practical remediation of contami- nants in the ground water. / y �Bnln(lwa wlM Estimated Cleanup Time:Under this alternative,currently it is estimat- ed to take about 50 years to reduce all contaminant concentrations in the Figure 2. Preliminary ground water extraction and treatment facility locations with shaded areas affected ground water to levels below showing where VOCs are above drinking water standards in ground water. drinking water standards.