Agenda Item #1. Welcome, Introductions, Groundrules

Mr. Karson, from the Air Force Center for Environmental Excellence (AFCEE), convened the meeting at 6:31 PM. He explained that tonight there will be an informational public meeting and a formal public hearing for the Fuel Spill 1 (FS-1) groundwater plume. All oral comments made during the public hearing will be transcribed verbatim, and written comments can also be submitted tonight. Mr. Karson reviewed the agenda and then noted that the public comment period for the FS-1 groundwater plume runs through July 3, 1999.

Agenda Item #2. Presentation of FS-1 Preferred Alternative

Mr. Hoda stated that the purpose of tonight’s meeting is to receive input from the community regarding AFCEE’s recommended remedial alternative to address the FS-1 groundwater plume. He noted that the FS-1 Proposed Plan was issued and is currently in the local libraries, as are the Remedial Investigation (RI) and Feasibility Study (FS) reports. The RI and FS reports include all of the data collected and detailed information about the evaluation of the proposed alternatives.

Mr. Hoda reported that AFCEE’s preferred alternative is Alternative 3b. He noted that the current proposed well scheme will be optimized during the remedial design phase. He also mentioned that the alternative includes long-term groundwater monitoring at the source area. Mr. Hoda stated that contamination has not been found in the soil at the source area, and therefore, the soil will not be addressed. He noted that although methylene chloride was found, its detection was attributed to a laboratory error.

Mr. Hoda reported that the source area of the FS-1 groundwater plume is an aircraft turnaround site where fuel dump valves were tested from 1955 to 1970. He reiterated that there is no unacceptable risk related to the soil at the source area, and reported that toluene, lead, and thallium were detected in the groundwater at the source area. Mr. Hoda stated that if the Air Force’s recommended monitoring of the groundwater at the source area should indicate that the contaminants of concern are migrating from the source area, the Air Force would change its recommendation. He noted that, according to the data, the contaminants are not migrating and will likely degrade over time. Mr. Hoda reported that most of the plume downgradient is made up of ethylene dibromide (EDB), and the majority of the recommended active system will address the EDB plume.

Mr. Hoda displayed a detailed map of the FS-1 groundwater plume and pointed out the plume’s its source area. He noted that the EDB plume is detached from the source area and is upwelling in the Quashnet bog. He also reported that the FS-1 groundwater plume is 7500 feet long, 1200 feet wide, and 100 feet thick. Mr. Hoda displayed a cross section of the plume and noted that approximately 50 feet of clean groundwater is overlaying the EDB contamination. The highest concentration of EDB detected in the groundwater is 10 parts per billion (ppb), and in the surface water, 1.43 ppb.

Mr. Hoda explained that Alternative 3b includes continuation of the bog separation pilot test for a year, at which point its performance will be evaluated. If the bog separation plan is working in an ecologically benign way, operation of the system will continue until the cleanup is accomplished. Mr. Hoda noted that the bog separation system, which was started up in April, prevents the upwelling of the contamination in the groundwater; there is still a need, however, to expedite the cleanup of the aquifer, and the Air Force recommends that this be accomplished by the installation of 18 to 20 extraction wells. The total surface discharge of these wells will be 800 gallons per minute (gpm). Mr. Hoda reported that the capital cost for Alternative 3b is $6.4 million, seven-year operation and maintenance (O&M) cost will be $4.15 million, and the present worth is $10.56 million. He noted that it is predicted that this alternative will clean up the aquifer in seven years.

Mr. Hoda displayed a map titled "Quashnet River EDB Surface Water Sampling Concentrations," and noted that the contamination in the surface water is decreasing. He also said that monitoring will continue in order to ensure that the extraction system is not impacting the ecological resources. Mr. Hoda then reported that, to date, there have not been any impacts to the brook trout in this area. He displayed another map and pointed out a well where non-detect is being achieved.

Agenda Item #3. Questions and Answers

Mr. Karson asked if there were any questions from members of the audience. There were none.

Agenda Item #4. Adjourn

Mr. Karson adjourned the public meeting at 6:43 PM, and a formal public hearing for the FS-1 groundwater plume followed.