8/19/1997 BOARD OF SELECTMEN Minutes

Home Browse Search

treating, an disposing dis osin of residuals would be low. and to a wetlands complex are expected The alternative satisfies a statutory preference for impacts would require extensive mitiga treatmentas a principal rinci ai element. planning to minimize construction damage tats and impacts to rare species. Implementability: Full system startup would begin PA-enforceable milestone of June 28, 1999. Construction and operation Id have s wou by the E will not be achievable in less socioeconomic impacts on the residential i Partial system startup than 12 months from the decision date. It is esti- hood near Ashumet Pond because of the that the system will operate for at least 54ir nature of the system and the need.for mated y P , P is an acceptedproven technology that maintenance of wells, pumps, and pipet* years. ETR p can be expected to perform reliably with proper community. maintenance. Because it is a proven technology, Total ca ital cast is estimated to Cost. p regulatory agency involvement to obtain approval million. Annual operating and maintenan P g will be minimal. estimated to be $3.6 million. Life--c} Access to property to install wells between Sand- including capital cost, based on 20 years wich Road and Ashumet Pond could be difficult to tion (for cost-estimating purposes only) is obtain, due to the intrusive nature of the construe- to be $113 million. tion work required. Public Acceptance: The public acceptai 3 health are anticipated the response alternatives will be d Manageable risks to human p duringconstruction and o eration of the system. throughout the public comment period. T� P . Treatment Tants would be located on base, thus tive organizations, agencies, and commun: T P . minimizingpotential risks to the off-base neighbor- (acceptance groups)will review the inform hood. indicate a preferred choice, acceptable sF Significant adverse impacts to rare species, to rare third choices, and any unacceptable alterna species habitat, to a coastal plain pond community, F . CS=10 PLUME RESPONSE ALTERNATIVE B Alternative B would use ETR technology. This nants. Institutional controls include alternative is designed with consideration of ro - drilling of new wells within, or in the dire g P P erty access issues and potential adverse impacts to the CS-1 groundwater plume. Most of sensitive ecological areas along the shoreline of that might otherwise migrate under or int( Ashumet Pond. Instead of an extraction fence along and Johns Ponds would be captured. Cc theP and, this alternative would use an extraction concentrations downgradient of the syster. fence along Sandwich Road. Because the fence is Sandwich Road would decline over time. upgradient of the leading edge of the plume near ical thresholds,, such as minimi2 Ashumet Pond, a portion of the plume would not be down in surface water bodies and minis captured. amount of treated water that flushes th The system would operate at a total flaw rate of ponds, would be met. Construction wa approximately 6.9 mgd, and would include sensitive habitats and rare upland animal approximately 32,000 linear feet of piping, and a impacts can be mitigated by planning a total of approximately 94 extraction and reinjection uling. Impacts to Ashumet Pond habitats wells. avoided by placing the extraction fel Sandwich Road. Matrix Criteria- Compliance with Applicable or Rele t overall Protection of Human Health and the Appropriate Requirements (ARARs ) Environment: Under this alternative,human health native complies with all ARARs. P g percentage would be protected because a high ercenta e of the P groundwater fume is captured, further migration of Effectiveness and Permanence of Respo gr P P g contaminants is greatly reduced, and institutional natives: The table on page 3 summary controls will minimize future exposure to contami- capture by n7ass for all alternatives. A sij 5 4