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Health Topics > Sierra-Crete Task Force

Sierra-Crete Task Force

Draft Minutes
November 8, 2002

Task Force Members

Present: Brian Balbas, Contra Costa Public Works; Ron Bernal, City of Antioch; Lora Barrett, Department of Toxic Substances Control (DTSC); David Berry, DTSC; Tim Bingman, DuPont; Angela Blanchett, DTSC; Dr. Wendel Brunner, Contra Costa Public Health Director; Brenda DeLaOssa, staff to Donna Gerber, Contra Costa Supervisor District III; Tim Farley, staff to Federal Glover, Contra Costa Supervisor District V; Annette Guiseppi-Elie, DuPont; Martha Harnly, California Department of Health Services; Sara Hoffman, Contra Costa Office of the County Administrator; Bill Kilgore, DTSC; Frank Lopez, DTSC;

Staff: Michael Kent, Contra Costa Health Services

Members of the Public: Sanjay Ahuja, McNamara Law Offices; Stefan Edelbacher, City of Antioch Resident; Bill Faisst, Brown and Caldwell; David Garcia, Mindon and Mjiro; Brian Haydon; Mike Heckathorn, Trident Environmental; Jennifer Jones, Antioch Resident; Alyssa Keith, Pacific States Environmental; Kay LaCour, Cooper, White & Cooper; Vicke Nuetzel; John Pekala, Environ Corp; Brian Poyezdala, Antioch Press; Deborah Proctor, Exponent; Jane Ramsey, Ledger Dispatch; Dani Renan, Trident Environmental; Ron Rinehart, Pacific States Environmental; Ben Strumwasser, Public Affairs Management; Richard Wenning, Environ;

Others Present: Greg Harvey, Contra Costa County Counsel's Office; Linda Wilcox, Contra Costa County Counsel's Office

1. Introductions

Dr. Brunner, Contra Costa Public Health Director, opened the meeting at 9 a.m.. Introductions were made and the agenda was approved after adding two items -- a discussion of the risk assessment process and surface water impacts.

2. Approval of the Minutes

The minutes of the September 27, 2002 meeting were approved.

3. Update on Action Items from Previous Meeting

a) Location of Roads where Sierra-Crete was Used

Brian Balbus, Contra Costa County Public Works Department, reported that they have completed the mapping effort for the unincorporated portion of the County and Oakley and have sent this information to Contra Costa Public Health to be put on the web site. They should be ready to put Antioch and Pittsburg data on the County's web site next week.

Action Item: Contra Costa County Public Works Department will continue to coordinate the collection of this information and placement of it on the County's web site.

4. Review of the Sampling Data

Rick Wenning of Environ reviewed the sampling data and provided a handout containing the data. All samples were tested for 17 dioxins-like compounds. Forty surface wipe samples were taken in Bay Point and the cities of Antioch, Pittsburg, Oakley and Brentwood from stained and unstained roads where Sierra-Crete was used and from background roads. Surface wipes samples were also taken at two schools and a sports complex. The results for all samples ranged from 0.011 to .026 picogram per centimeter squared total dioxin TEQ. Michael Kent, Contra Costa Health Services, asked if DuPont had ever tested Sierra-Crete or surface wipe samples for dioxin-like PCEs. Annette Guiseppi-Elie from DuPont said she would check into this.

Two surface dirt/particulate samples were taken with results of 13.3 and 17.9 picogram per gram of total dioxin TEQ.

Nineteen Sierra-Crete samples were taken from roads in the four cities and Bay Point, and at the two schools and the sports complex. These results averaged 233 picograms per gram of total dioxin TEQ. One sample was unusually high at 1004 and two samples were unusually low at 2.1 and 0.14. These sample results will have to be examined to determined if they are valid.

Sixteen soil samples were taken from beneath Sierra-Crete and four background soil samples were taken. The average dioxin concentration from soil beneath Sierra-Crete was 1.1 and the average concentration beneath background soil was 0.343 picograms per gram of total dioxin TEQ. The reason for the difference was not known, but Mr. Wenning did not think it was caused by leaching from the Sierra-Crete because of the similar dioxin profile from both types of soil.

The results were comparable to results of testing conducted by DuPont last spring.

All data still needed to go through final quality control evaluation before the values could be considered valid.

5. Risk Assessment

David Berry, DTSC, and Rick Wenning review the process for conducting the risk assessment using the new data along with that previously collected by DuPont. The new risk assessment model would take into account comments made by DTSC. The risk assessment would provide explicit exposure and risk analyses for each receptor group. A summary of the results of the final risk assessment is expected to be available in December. The final report is expected to be published in January.

6. Storm Water Analysis

A group of the regulatory agencies had met with DuPont since the last task force meeting. They reported that they had determined that the previously completed risk assessment for storm water was adequate.

7. Public Outreach Strategy

The taskforce discussed the timing of when to inform residents living on streets where Sierra Crete was used of the results of additional testing. The taskforce decided that a letter should be sent as soon as possible to residents living on streets where Sierra-Crete was used explaining the situation. The Department of Toxic Substances Control would lead a separate effort to do outreach to the schools and the sports complex. Contra Costa Health Services would also lead a series of public meetings in January and February to discuss the results of the testing and the risk assessment.

Action Item: Contra Costa Health Services would draft a letter for all Taskforce members to review. They would work with Public Affairs Management, a consultant to DuPont, to identify the appropriate homes to receive the letter.

8. Set next meeting time and Agenda

The next meeting will be Wednesday, December 11 from 9:00 to 11:00 at a location to be determined.

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