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From:Juan a Bacigalupi To: Robert Whritenour Date:219196 Time:09:38:09 Page 3 of 9 <br /> r <br /> such a critical design element! The containment of the groundwater pollution plumes from the <br /> Massachusetts Military Reservation should not result in severe negative impacts to surface water <br /> bodies and the areas natural and recreational resources nor on the perception of a threat to area <br /> communities. <br /> II. Piping <br /> The first concern with the piping design deals with the 65%design showing single wall PVC <br /> pipe from the extraction wells to the treatment units. The design shows flow meters and automatic <br /> flow controls being found at each extraction well. They show a flow meter-integrator and manual <br /> shut-off valve at the start of the pipe run between the well fence and the treatment unit. They show no <br /> flow-meter integrator at the treatment unit end of the extraction pipe run. Consequently, as currently <br /> designed,we would not immediately detect a pipe leak. <br /> One member of the team sees two apparent options to reduce the probability of a new <br /> contamination site due to leakage in the pipe run between the extraction fence and the treatment unit: <br /> 1. Install double wall pipe with leak detection and an alarm system if that would sound <br /> an alarm if it detects a leak between the inner and outer pipes. <br /> 2. If cost considerations drive the design to single wall pipe,high quality,they should <br /> install and frequently calibrate flow meters at each end of the extraction water pipe runs. The <br /> designers of the system should interlock and alarm the output of these meters so any imbalance <br /> comes to the immediate attention of the personnel who operate the system. <br /> Mr. Ray Taylor talked with Alex Chafari(assigned by OPTECH to complete the piping <br /> design for the project) about the concerns raised. Mr. Chafari said that he would address those <br /> concerns, including the monitoring and alerting;systems, in the 9 5%design. <br /> All interested parties should look carefully at the 95%design to insure that the potential for a <br /> significant leak is rr rumal. <br /> A second concern raised by members of the team is the relationship between the volatile <br /> organic compounds and the PVC pipe used in the design. The team raised concerns on the use of this <br /> type of pipe being used to transfer the polluted groundwater to the on-base and off-base ground water <br /> Plume treatment facilities. We believe,that after some time,transfer of the volatile organic <br /> compounds through the pipe into the environment(specially if the pipe is in contact with water)will <br /> occur. <br /> A third concern is the lack of information on an alerting system for leaks that responds. <br /> quickly. If a catastrophic leak occurs,the system must be shut down immediately to avert the <br /> development of a new plume of contamination. ` <br /> The final concern raised by team members deals with the accuracy of the flow meters <br /> Proposed. Dr. Alexander stated that the flow meters,which are the backbone of the leak detection <br /> 2 <br />