BRANCH ACTIVITIES

San Francisco Branch Activities
November 1997, and January and March 1998

In November we had a combined afternoon workshop and dinner meeting on geophysics presented by William Black, William Henrich, and Kenneth Blom of NORCAL Geophysics. The workshop reviewed surface geophysical methods and their geotechnical, environmental, and groundwater development applications. An interactive interpretation of processed geophysical data was used to show the importance of “ground truth.” New, as well as traditional, surface geophysical methods can be useful and cost-effective tools in the appropriate circumstances. Borehole geophysics are standard procedures in many common situations. NORCAL’s thorough and informative presentation and handouts were appreciated by all.

Our New Year began with a presentation in January by Stephen Morse, Chief of the Toxics Cleanup Division, and Gregory Bartow, Senior Engineering Geologist, of the San Francisco Bay Regional Water Quality Control Board.

Mr. Bartow presented 1) the East Bay Plain Groundwater Basin Beneficial Use Pilot Project, 2) Regional Board participation in a nationwide chlorinated VOC plume study, and 3) new and innovative groundwater remediation technologies.

Under SWRCB Resolution 88-63 most groundwater is assigned a beneficial use as a potential source of drinking water. This strict interpretation of beneficial use requires groundwater clean ups to reduce contaminant concentrations to below drinking water standards. In reality, however, many aquifers have a low probability of use as drinking water. Suitability as drinking water can be limited by economics, yield, quality, risk of sea water intrusion, and other factors. The East Bay Plain Groundwater Basin Beneficial Use Project will determine the feasibility of defining multiple beneficial uses based on local conditions. An initial assessment was to evaluate the vertical differentiation of beneficial uses, such as drinking water in the deeper aquifers and less-than- drinking-water quality in the shallow aquifers. The feasibility of this differentiation is complicated by the abundance of old undocumented abandoned water supply wells in some areas of the East Bay Plain.

A nationwide study, coordinated by Lawrence Livermore National Laboratory, will evaluate site history data from up to 500 chlorinated VOC plumes in an attempt to improve the chlorinated VOC cleanup process. The Regional Board is seeking data from well characterized plumes in California for inclusion in this study. Contact Mr. Bartow if you have a site that is suitable and available. It is intended that this project will have a more rigorous level of project management and peer review than the LLNL petroleum hydrocarbon study. Results are expected towards the end of this year or in early 1999.

New and innovative groundwater cleanup technologies the Regional Board will be reviewing in 1998 include the following: 1) the use of passive and semi-passive in-situ groundwater treatment systems, 2) reactive walls, 3) injection of molasses to enhance the biotransformation of hexavalent chromium, 4) air lifting to recirculate water within wells and remove volatiles, 5) natural attenuation of a chlorinated VOC plume, 6) risk-based corrective action (RBCA) and risk-based decision making (RBDM), 7) a special emphasis on dioxin and mercury contamination, and 8) the use of geocomposite layers, instead of the traditional one-foot thick clay barrier layer, in landfill cover design.

Stephen Morse presented the following groundwater regulatory issues for 1998: 1) Underground Storage Tank cleanups, 2) Brownfields, 3) Bayside Development and Cleanups, and 4) migration of the Regional Board computer bulletin board to the Internet.

A draft update to the January 1996 Supplemental Instructions on USTs is expected this Spring. This will have updated analytical requirements and coverage of MtBE and MtBE alternates. The University of California will conduct an investigation of the toxicity of MtBE. Santa Monica and Santa Clara Valley groundwater basins will initiate GIS mapping and data management programs this year to define potential petroleum hydrocarbon releases under AB 592 and SB 1189.

The Regional Board is looking for suitable Brownfields sites in the Bay Area, especially in economically impacted communities. This is an area of interest to the Board members and staff. Prospective Purchaser Agreements (e.g., Mutual Release, Covenant Not-to-Sue) have been used successfully. The Containinent Zone policy is alive, but not well. It has been difficult to implement for real cases.

The Regional Board’s Bay Protection and Toxics Cleanup Program (BPTCP), which was started in 1990, will submit a draft report to the State Board this year. This report, based on several years of regional monitoring, will define toxic “hot spots” (about ten) and “sites of concern” (e.g., closed military bases). The report will make recommendations for onshore site cleanup and offshore sediment remediation.

The San Francisco Regional Board is phasing out their existing computer bulletin board (510) 286-0404 and replacing it with an Internet site (www.swrcb.Ca.gov/ - rwqcb2).

The results of a questionnaire passed out during the meeting indicate approval of our every-other-month program of both environmental and water supply technical topics, together with regulatory and legal topics. Our dinner meetings are inexpensive and accessible. We also schedule about two afternoon workshops each year. Results of the questionnaire will be used to guide our choice of future meeting topics, speakers, and activities.

The following GRA SF Branch officers for 1998 were confirmed by a show of hands at our January meeting -- President: Clif Davenport, Vice President: Linda Spencer, Treasurer: David Abbott, and Secretary: Jim Ulrick.

Our March meeting presentation, entitled “Twenty-One Myth-Conceptions About Groundwater,” was presented by Joseph Birman. This was a revealing talk about some of the more important general insights gained by someone who has been in the business of groundwater for quite a long time. For example: 1) Thank goodness we have engineers who deal in black-and-white facts and certainties in order to actually build something. And thank goodness, also, for geologists who deal in multiple hypotheses and uncertainties in order to represent geologic features for what they are more likely to be. 2) Much of the value of the hydrogeologist lies in interpreting the departures of field data from the ideal physical process as represented by mathematical equations, such as the Theis Equation, Darcy’s Law, geothermal gradient, or a digital model.

Check the GRA Internet home page ( http://www.grac.org ) for upcoming San Francisco Bay Branch meetings.