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l\) co -J c.. I For both surface and modified in-situ retorting processes, the pyrolysis oil and tar which are initially produced may be viscous materials ..'"... :', which cannot be pumped at room. temperature. In: addition, they contain '\""i: amounts of nitrogen and sulfur which make' the pyrolysis product unsuit- able as a refinery feedstock... Thus, until rec~ntly, it was thought that a pumpable crude oil suitable as a refinery feedstock would have to be produced at the site of the oil shale facility.' This upgrading process would account for as much as 2,000 acre-feet per year or more of consump- tion. . However, recent engjneering designs call for the use of low, cost pour point depressants to reduce the pyrolysis oil's viscosity enou~h to permit. its introduction directly into a pipeline system. Thw:., this assess-' ment has assumed that on-site upgrading processes w~l not be necessary. From the.above 'discussion, it is apparent that one could use an esti- mate of annual consumption. ranging anYWhere from.2,000 to 9,000 acre-feet per 50,000 bbl/day oil shale facility. Furthermore,. the complexity of the situation is compounded when one takes into account the fact that any number of future process mixes could be assumed. Rather than assuming the development of any particular retorting process or mix of processes, it has simply been assumed for the purposes of this assessment that 5,700 acre- feet of water would be consumed annually for each 50,000 bbl/day of post- ulated oil shale development. Use of this single figure can then be taken to represent a number of potential future situations. For example, if future oil shale developments were to consist of half surface retort plants and half modified in-situ operations, the 5,700 acre-foot figure would represent average consumption per unit-sized ;~~: plant, assuming that the surface retorts consumed 8,000 acre-feet per year, while the modified in-situ plants consumed 3,500 acre-feet per year. Alternatively; the 5,700 acre-foot figure could be taken to represent any number of other possible process mixes and assumed water-consuming character- istics. Furthermore it should be noted that consumption of 5,700 acre-feet per year per 50,000 bbl/day plant probably is reasonably close to represent- ing the upper limit of consumption for a surface retorting operation, given the improved understanding of the most recent engineering and design studies and the probable ability to dispense with on-site upgrading. Thus, even if one assumes a future industry composed almost entirely of surface retorting plants, the 5,700. acre-foot figure should provide a reasonable estimate of maximum consumption. In terms of total consumption by the postulated oil shale developments, table 7.4 shows the estimated consumption that would occur in each subbasin within the Upper Basin given the siting pattern assumed for the purposes of this assessment. ".:.(:"- . xxviii