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<br />10-'" <br />O':l <br />(,0 <br />C..rl <br /> <br />4.5 Domestic iiastes From Plant <br /> <br />The wastewater from potable and domestic usage after pri~ary screening is <br /> <br />a low TDS, low SOD water ~hich can be treated to acceptable quality for <br /> <br />revegetation, disposal and mine uses by star-card activated sludge treatment~ <br /> <br />The quantity of water to be handled is relatively small, amounti~g to about 45 <br /> <br />gpmor65.000 gal/day. Standard. packaged extended aeration plants can be <br /> <br />purchased for handling this was~e and we have obtained q~otations for such a <br /> <br />pl~~t. The installed cost would run about S150.000 or, when amortized out at <br /> <br />15\ annual1y,about SO. 35/1000 gal. To this cost must be added labor costs of <br /> <br />about 0.5 man years per year. At a burdened labor rate of $20/hr, th~s amOunts <br /> <br />to an additional SO.55/1000 gal. Electricity, che~icals and mainten~,ce add <br /> <br />about another $0.15";1000 gal. ~he resulting total COSt for the secondary <br /> <br />treatment is Sl.95/1000 gal (= S636/acre-ft). The reason for this relatively <br /> <br />high value for ~~eati~g water wi~~ a EOD in che 200 to 250 cg/~ range is ~he <br /> <br />relativ~:y small q~antit7. After seconcarJ ~rea~ent the waeer cculd te ~5ed <br /> <br />for revegetation and o~'er low q~ality needs. <br /> <br />4.6 rteto:-t :va~e.:" fo!' Internal Reuse <br /> <br />In t~e modified i~ situ retorting of oil shale wi~, ste~ injec~~on, :t <br />is estL~ated that ~~ equal vol~e of water is coproduced wit~ t~e shale oi114. <br />For a 57,QOO ~ar~el/cay shale oil plant, this correspones to a prcauc~ion of <br />about 1660 gp~ of ~etQr~ water. The quali~l of ~~is :oul in 5i~~ retor~ ~ater <br /> <br />is quite va=ia=l= a~d ~as a strong ~ependence ~ot only on si~e ar.c ~~thcc of <br />14 <br />processlnq, ~~t also en t~me Apart f~om ~~e difficulty of defining a <br />"representati..,e" i:1 situ retort water, it has been sho\lffi that even t:"le c::-:'emical <br />characte:ization of a given waeer is quite difficult1S. For the most part, <br />all of the waters ~ave high concent=aticns of ammonia and ~igh concentrati~ns <br />of SCD, often in the presence of toxic materials. However, these waters also <br />have veri high ratios of alkalinity to ammonia, resulting from infiltrated <br />ground water or from the leaching of sodium carbonate and bicarbonate. In <br />addition, they may have high COD-to-BOD ratios. <br /> <br />Pespit.e the. fact that there really is n.o "representative" ',.,rater :or <br />modified in si tu ::etorting r for a. "properly" operated in 5i tu retort., whe=e <br />large qua~tities of water relative to oil are not procuced, ~he simulated <br /> <br />90 <br />