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CITY OF SANTA ANA Well No. 32 Nitrate Mitigation and Rehabilitation Study 3.4 Preliminary Cost Estimates Project cost estimates were prepared for the project alternatives which include capital costs, operation and maintenance, and unit costs. The project cost estimating was performed using the Association for the Advancement of Cost Engineering (AACE) International's cost estimating classification system, which defines five separate classes of cost estimates. For a study or feasibility level report, this is considered a Class 4 estimate, and allows for an accuracy range of -15% to -30% on the low side, and +20% to +50% on the high side. 3.4.1 Capital Costs Construction costs consist of site work, mechanical equipment, filters, pumps, chemical metering equipment, piping, valves, structural, electrical and instrumentation. Bonds and insurance have been included at 2% and contractor's overhead and profit is assumed to be 10 %. A 30% construction cost contingency is included for this planning level stage. The total capital cost includes a 20% cost allotment for preparing engineering plans, specifications, bid and construction management and inspection, technical, incidental permits, survey, geotechnical, legal, and administrative costs. The capital cost for the blending option at Garthe Reservoir (Blending Only) is estimated at $4,650,000. The capital cost for the blending option at Garthe Reservoir (Fill Reservoir) is estimated at $4,580,000. The capital cost for the blending option at Memory Lane Pressure Reducing Facility is estimated at $4,700,000. The capital cost for the nitrate treatment facilities is estimated at $11,700,000. It should be noted that the costs for the well rehabilitation as described in Section 4 have been included in the capital cost estimate for each alternative. Estimates of probable construction costs are contained in Appendix C 3.4.2 Operation and Maintenance Costs Annual Operation and Maintenance Costs (O &M) were prepared and include power, chemicals, labor, and maintenance materials for the treatment facilities. The annual O &M costs for the blending options were not developed because the City currently incurs these costs already and would not be new. A cost for off -site IX resin regeneration by a contracting service is also included in the annual costs. The annual estimated O &M cost is $8.02 million and is contained in Appendix C. P:T0059700g6\Engineering \05 \_ Wel1-32- N4ate- Miti,nti�raft RVoiIW2textdocx 14 TETRA TECH 251 -32