requirements for power generation for in-situ heating processes, retorting, refining, reclamation, dust control and on-site worker demands. Municipal and other water requirements related to population growth associated with industry development will require an additional per day. Hence, a oil shale industry would require of water per year, depending on location and processes used. The largest deposit of oil shale in the United States is in the Green River basin. Though scarce, water in the western United States is treated as a commodity which can be bought and sold in a competitive market. Royal Dutch Shell has been reported to be buying groundwater rights in Colorado as it prepares to drill for oil in the shale deposits there. In the Colorado Big-Thompson project, average prices per share (/share) increased from some $2,000 in 1990 to more than $12,000 in mid-2003 (constant 2001 dollars). CBT Prices from 2001 to 2006 has had a range of $10,000 to $14,000 per share, or $14,000 to $20,000 per acre foot. At $10,000 per acre foot, capital costs for water rights to produce would range between $1.8-4.2 billion. Co-pyrolysis Several co-pyrolysis processes to increase efficiency of oil shale retorting have been proposed or tested. In Estonia, the co-pyrolysis of kukersite with renewable fuel (wood waste), as well as with plastic and rubber wastes (tyres), has been tested. Co-pyrolysis of oil shale with high-density polyethylene (HDPE) has been tested also in Morocco and Turkey. Israel's AFSK Hom Tov co-pyrolyses oil shale with oil refinery residue (bitumen). Some tests involve co-pyrolysis of oil shale with lignite and cellulose wastes. Depending on reaction conditions, the co-pyrolysis may lead to higher conversion ratios and thus lower production costs, and in some cases solves the problem of utilization of certain wastes. See also Price of petroleum Environmental impact of the oil shale industry References External links Economics Energy economics