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8.10.3 Other Benefits <br /> In addition to its benefit as a drought supply, this alternative provides the ability to supply <br /> water when beneficial for blending with raw water from Lake Decatur. The supply may be <br /> used to blend to reduce raw water nitrate, minimizing the reliance on ion-exchange (IX) nitrate <br /> removal facilities for regulatory compliance. The supply may also be used to blend to reduce <br /> turbidity, minimizing labor required for additional monitoring and testing during poor water <br /> quality events, chemical costs, and the need to notify sensitive customer groups of increased <br /> alum feed rates. If developed with horizontal wells, the supply may also be used for temperature <br /> regulation. Blending to reduce high water temperatures may reduce the rate of formation of <br /> disinfection by-products (DBP's) in the distribution system, reducing the risk of regulatory <br /> non-compliance. Blending to increase low water temperatures may help to reduce the higher <br /> rate of water main breaks during the coldest winter months. The supply also provides additional <br /> flexibility and resiliency for managing spills in Lake Decatur. <br /> To the extent that anticipated water quality benefits related to nitrate, turbidity, DBP's <br /> and main breaks are realized, there will be a perceived improvement in the level of service <br /> received by customers. Pumping operations may also provide a benefit or cost savings to the <br /> mine operator, with the potential to negotiate cost sharing or reduced cost of the lease. <br /> 8.10.4 Risks <br /> While the gravel mine is still in operation, there is a risk of contamination caused by spills or <br /> leaks from mining equipment. Best management practices (BMP's) may be used to minimize <br /> these risks. <br /> 8.10.5 Costs <br /> The estimated engineering,construction,operation,and life-cycle costs are summarized in Table <br /> 8.12. Additional details of the cost estimates and economic analysis are provided in Appendix <br /> D. <br /> 8.10.6 Implementation <br /> Time to Implement It is estimated that this alternative could be implemented in approxi- <br /> mately 48 to 60 months. <br /> Permitting Requirements IEPA construction and operating permits will be required for <br /> pumping and pipeline facilities. Easements and right-of-way permits will be required for pipeline <br /> construction. The gravel pit is within the floodway, and a Joint Application to USACE, IEPA <br /> and IDNR will be required for permitting of construction activities. <br /> 118 <br />