Aquifer Committee

Stakeholders' Evaluation Group

Sixth meeting Held April 20, 2001

Minutes of the Meeting

Approved Electronically COB 25 April 2001

A regular meeting of the Aquifer Committee was called to order at 12:00 pm, on April 20, 2001, at SEPCO, Bay St., Savannah, GA. The chair, Chris Schuberth, called the meeting to order; Don Ernst was present as secretary to officially record the meeting and prepare the minutes. The meeting Agenda was provided to committee members as posted on the web page and viewed from the overhead projector for those present. Twenty-five members were in attendance.

Chair reminded members present that the important report summarizing the Working Group meeting, dated 13-14 March, is available on the website. Chair recognized the work of Larry Keegan who improved the appearance and ability to access information on the SEG web page including that of the Aquifer Committee. Chair asked for resolution of paragraphs 5.3 and 5.25 of the minutes of the fifth meeting on February 2, 2001. The revised wording of these two paragraphs will be e-mailed to chair.

Chair provided hard copies of Aquifer Committee's John Cox PowerPoint slides that summarize the discussions, conclusions reached, and recommendations proposed by the Working Group. Cox chairs the Working Group. A second hand-out distributed was that of a summary of the 13-14 March Working Group meeting by Harold Gill, as requested by Bill McLemore. Gill joined the Working Group and was in attendance today.

6.1 John Cox, chairman of the Working Group committee, offered an overview of work accomplished by the committee and provided the Aquifer Committee with the following Recommended Technical Concerns the Working Group agreed upon that will lead to a proposed Plan of Study.

1. Increase in rate and quantity of leakage through the upper confining unit that will occur as a result of channel deepening is unknown (previous studies have suggested that increases in leakage resulting will be minimal)
2. Potential temporal changes in chloride concentrations in the Upper Floridan aquifer resulting from channel deepening are unknown.
3. Hydraulic properties, salinity and hydraulic head in the Miocene units are poorly understood, as is the variability of these parameters.
4. Hydraulic properties and geometry of the previously identified paleochannels are poorly understood.
5. The geological framework is not as well refined as needed to fully understand hydrogeolic relationships and interactions.

6.2 Schuberth, at the conclusion of the Working Group presentation, complimented Cox and the members of the Working Group for the outstanding, reflective, and deliberative work carried out by this subcommittee, a comment that received additional public endorsement by Mallory Pearce and Fred Rich. Aquifer Committee, by consensus, agreed that the identification of technical concerns are valid and encouraged the Working Group to continue to meet and to continue to work on forming a final, agreed-upon proposed Plan of Study. AC endorsed the Recommended Technical Concerns. AC tasked the Working Group to continue meeting to devise the potential technical approaches. AC extended appreciation to the Working Group for the cooperative efforts of the individual scientists involved. Mallory Pearce, City of Tybee Island, is pleased that the concerns of the people of Tybee Island are being addressed and agrees with Fred Rich's comment that the Working Group is on the right path.

6.3 Question to the floor asked to define "lateral transport." Lateral movement through the aquifer opposed to vertical intrusion through the Miocene layer..

6.4 Ben Brewton is excited about what the Working Group has accomplished. Questioned if the studies will provide information as to the state of the channel in its natural state prior to any dredging. Will the studies compare the differences between the current depth and proposed depth? Technical discussion followed which included discussion of a "control" study outside the major and dominating 1 million acre cone of depression formed under Savannah. Studies being considered will give the most complete picture and best understanding possible. Stated was that it is possible to predict what conditions existed at natural depth by studying the Savannah River bank to gather historical data.

6.5 It was asked, "What will we not know?" Noted were that gaps in data will exist. The Working Group's proposal will be comprehensive. The Working Group will close as many information gaps as possible with information ranges large enough to capture any parameters. The Working Group will evaluate all available data and information acquired to be able to establish an allowable confidence level. Timeline required to accomplish the study? Not known. Within the private sector, it might require several months but within the structure of governmental checks and balances it could require many more months.

6.6 Bill Farmer asked what do we do with the data once collected and asked if there is an acceptable level of chloride intrusion? Is there a law from any governmental organization or does this have to be established within the group? Noted that there is a law on the books regarding safe drinking water but the absolute value from new information derived by new or proposed studies will require governmental consultation.

6.7 The Working Group endorsed a 2-D model recommended by Rick Kraus to depict vertical movement into the aquifer. With data collected by Camille Ransom of the SCDHEC at the Bull River location will assist with the model and will include information on the poorly understood paleochannel and that can be determined through radio-isotope technology. Question posed is how much of the water in the Miocene is connate (original sea water trapped as the sediments were forming on the seafloor during the Miocene). Studies are necessary to determine how old the water is in the Miocene layer, that is, to see if it was trapped there originally or is subsequently entering it through vertical movement.

6.8 Pearce approves of the Working Group recommendations. Jennings approves of the technical concerns and asks the Working Group to address and refine technical approaches to provide the Aquifer Committee with a recommendation. AC reached consensus on the five Recommended Technical Concerns identified in paragraph 6.1 above.

6.9 Harold Gill provided a brief summary of his professional background and commented that several models are available to address the current problems. Most recent models are accurate for up to a mile from the area studied. Models are sensitive to:

1. Transmissibility of the upper Floridan aquifer

2. Vertical leakage which is understood the least

He noted the best experiment to date was in 1996 when a mill shut down for 9 days reducing pumping on the aquifer by 18 million gallons per day. (see summarization)

6.10 Aquifer Committee agrees that John Cox will repeat the presentation to the full SEG at the 1 May 2001 meeting. Chair will contact Ben Dysart, facilitator of SEG, to place the matter on agenda and specifically requesting 30 minutes for the presentation and q&a.

6.11 Next Aquifer Committee meeting tentatively scheduled for June 22, 2001. Will depend on when Working Group participants can meet again since free time to meet in their tight schedules that matches everyone else is difficult to come by.

6.12 Ben Brewton informed the Aquifer Committee of the proposed dredging and expansion of a turning basin on Elba Island to process delivery of liquid natural gas which overlays the Aquifer Committee's area of concern. Dredging will be to 48" MLT. He suggests the Aquifer Committee to write a letter of concern. A discussion whether it is appropriate for members representing federal or other agencies, and the technical corporations, could "sign off" on such a letter. It was agreed that Ben would draft a letter clearly stating the concern. The letter would be distributed via e-mail to the AC membership to decide whether to respond individually or collectively. To be party to this letter will be decided on an individual basis.

6.13 The Aquifer Committee recognizes and appreciates with thanks the generosity of SEPCO for providing lunch.

6.14 The meeting adjourned at 2:25 pm.

6.15 Attendance Roster: