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Groundwater Treatment System Peer Review and Design

East Greenwich, Rhode Island

Services: Remedial Design, Feasibility Study
Clients Served: Industrial

Loureiro was retained by the Stanley Works to provide a detailed technical and economic peer review of a proposed 350-gallon per minute carbon adsorption groundwater treatment system. The treatment system was designed as part of a large-scale effort to contain groundwater and prevent further migration of the dissolved plume of chlorinated solvents in saturated overburden and shallow bedrock using both an interceptor subdrain and bedrock extraction wells. Groundwater treatment techniques evaluated included advanced oxidation, wet carbon adsorption, and air stripping. Loureiro identified air stripping as the more economical alternative, and evaluated several stripping techniques, including shallow tray aeration and packed column aeration. Air stripping using a packed column was determined to be the most effective technique.

Based on the findings and subsequent recommendations developed from the peer review, Loureiro replaced the prior consultant as the engineer responsible for the complete redesign of the treatment facility. Our services involved the preparation of detailed plans and specifications, construction administration services, technical liaison and oversight during the commissioning process, and preparation of the Operation and Maintenance Manual for the treatment facility.

The redesigned treatment system consists of a 20,000-gallon air sparging tank designed to oxidize excessive iron followed by a triplex bag filter station for removal of the iron precipitates prior to entering the air stripping process. The air stripping equipment consists of two five-foot diameter by 25-foot high packed columns in series. The system includes various monitoring and operating instrumentation, a data gathering/monitoring station and a state-of-the-art electrical control system.

The system is constructed, is in full operation, and is meeting or exceeding the performance criteria. Effluent limits for the system were based on protection of a sensitive freshwater ecosystem, and as such, are in some instances lower than corresponding primary drinking water standards.

Highlights

  • Technical and economic peer review
  • Feasibility assessment
  • Elimination of iron fouling
  • High efficiency VOC removal
  • Design plans and specifications
  • New System Commissioning