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<br />MWSI Project
<br />Phase II Conjunctive Use Summary Report - DRAFT
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<br />August 22, 1995
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<br />The capital well cost, including the engineering for design and management, is assumed
<br />to Occur in the base project year, Well costs are based on current Denver Basin well costs which
<br />are a function of well depth and casing diameter. A well is asswned to have a usable life of 50
<br />years, In addition, we have asswned that a well redevelopment cost amounting to ten percent of
<br />the initial well cost, plus ten percenl of this amount for engineering and contingencies, is
<br />incurred every ten years to maintain efficiency,
<br />
<br />Downhole pwnp and equipment costs are based on an empirical formula reflective of
<br />current costs for submersible pwnping installations in Denver Basin bedrock-aquifer wells
<br />expressed as a function of motor horsepower for a particular installation, The pwnp and
<br />equipment costs includes the following items: downhole pwnp, motor, pipe, electrical cable,
<br />pitless unit, control panel, transformer, vault, piping, miscellaneous fittings and installation. A
<br />nominal pwnp/motor life of seven years is asswned for this cost analysis, though it is not
<br />unusual for one or more components of a submersible pwnping system to have a longer usable
<br />life. Pwnp/motor replacement cost is asswned to be 45 percent of the initial pwnp installation
<br />cost, because such items as control panels, electrical wiring, piping and fittings typically are not
<br />replaced at intervals as frequent as seven years, The cost of bringing power to the well field and
<br />power lines between wells was also included in the analysis. '
<br />
<br />Costs were included for groundwater treatment. The cost of $25 per 1,000,000 gallons
<br />was included in the analysis for chlorination and treatment of iron and manganese at the
<br />wellhead, A cost for pipelines between wells based on a standard wellfield design was provided
<br />by Mulhern MRE,
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<br />Overall pwnping-unit efficiency is asswned to be 60 percent for the life of each
<br />pwnp/motor combination, which is typical of properly-sized equipment in Denver Basin well
<br />installations. Pwnping rate is asswned to be constant throughout the year, Total dynamic head,
<br />which is the head (pressure) against which the submersible pwnp must work to lift water, is
<br />comprised of the pwnping water level, discussed above, a 50-psi system pressure at the wellhead,
<br />plus and additional ten percent to account for estimated friction losses in downhole pipe and
<br />fittings.
<br />
<br />Operation and maintenance fixed costs are computed as ten percent of the capital costs
<br />plus 25 percent of the pwnping costs incurred in any given project year, Operation and
<br />maintenance would include such items as normal facility maintenance, production and water-
<br />level monitoring and reporting, and service calls for minor repair and adjustment.
<br />
<br />Based on the individual components for the wells, pwnps, energy, operation and
<br />maintenance, treatment and pipelines, we have tabulated the total cost expected to be incurred in
<br />any given project year. These are summed in the row entitled, "Estimated Wellfield Cost", The
<br />next row, "Cost Per Acre-Foot", expresses the cost per acre-foot of water yield in any given
<br />project year. In the last row, the "Cost Per 1,000 gal." is calculated. The "Total Cost" column
<br />sums the costs for each line item over the 20-year project period. The last column, "Present
<br />Value", expresses the cost in terms of present value at the base year for the disbursements
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