Health Topics > Sierra-Crete Task Force
Sierra-Crete Task Force
July 26, 2002
Task Force Members
Present: Brian Balbas, Contra Costa Public Works; David Berry, California Department of Toxic Substances Control; Brian Bornstein, City of Brentwood; Joe Brandt, City of Antioch; Dr. Wendel Brunner, Contra Costa Public Health Director; Kathy Chiverton, staff to Donna Gerber, Contra Costa Supervisor District III; Tim Farley, staff to Federal Glover, Contra Costa Supervisor District V; John Fuller, City of Pittsburg; Annette Guiseppi-Elie, DuPont; Martha Harnly, California Department of Health Services; Sara Hoffman, Contra Costa Office of the County Administrator; Devra Lewis, Central Valley Regional Water Quality Control Board;
Absent: Steven Carmichael, City of Oakley; Mike Yeraka, Diablo Water District;
Staff: Paul Andrews, Michael Kent, Contra Costa Health Services
Members of the Public: Roger Brothers, Wm. G. McCullough Co.; Bill Faisst, Brown and Caldwell; Patrick Finley, Glynn and Finley; Will Harper, East Bay Express; Gloria James, Bay Point resident; Terrillynn Kopitar, Bay Point Partnership for the Public's Health; Kay LaCour, Cooper, White & Cooper; Korina Lowe, Bay Point resident; Brian Poyezdala, Antioch Press; Deborah Proctor, Exponent; Richard Wenning, Environ;
Others Present: Greg Harvey, Contra Costa County Counsel's Office; Linda Wilcox, Contra Costa County Counsel's Office
Dr, Brunner, Contra Costa Public Health Director, opened the meeting at 9:00 AM. Introductions were made and the agenda was approved as proposed.
2. Approval of the Minutes
The minutes of the June 26 meeting were approved without corrections.
3. Update on Action Items
a) Location of Roads where Sierra-Crete was Used
Brian Balbas, Contra Costa County Public Works Department, reported that they are continuing to research where Sierra-Crete was used in cooperation with DuPont. They think they have located all the streets in the unincorporated areas of the County and should have all the areas in the City of Oakley located in about a week.
Bill Faisst from Brown and Caldwell report for the City of Antioch that they are pretty close to completing their inventory except for one or two streets. They may have to take some samples to know for sure. They will also track down private locations where it was used. Antioch's sites have been put on a GIS map.
John Fuller from the City of Pittsburg reported that they have only found three streets where Sierra-Crete has been used and they don't have evidence to indicate they will find any more.
Dr. Brunner reiterated that ultimately the goal is to put all the sites in the County on one GIS map that can be posted on the internet.
Action Item: Contra Costa County Public Works Department will continue to coordinate the collection of this information and placement of it on a GIS map.
b) Dioxin Variation in Sierra-Crete Batches
Annette Guiseppi-Elie of DuPont reported that the creation of dioxins resulted from the continuous process of manufacturing titanium dioxide pigments. Therefore, the concentration of dioxins in the waste from that process that was mixed with cement to make Sierra-Crete was probably consistent over time. Sierra-Crete was made in batches, and since the concentration of dioxin in the waste was probably consistent, the concentration of dioxin in the various batches was also probably consistent.
The sampling DuPont did of Sierra-Crete in their initial study should have come from different batches. In the next round of testing the samples that will be taken from different locations, which are know to have been laid at different times, should therefore also represent samples from different batches.
Joe Brandt, City of Antioch, noted that Antioch will be taking samples from Sierra-Crete under Antioch roads they know were laid at different times and therefore should also represent different batches.
c) External Agency Review of the Risk Assessment Submitted by DuPont
Dr. Brunner explained that typically for hazardous waste site clean-ups the Responsible Party contracts with a consultant to conduct the necessary testing and analysis under the supervision of the lead regulatory agency. Split samples are taken and tested by the regulatory agency to verify results. This seems like a good approach to take in this case and this is the approach he plans on taking to conduct further testing and analysis.
He reported that the California Department of Toxic Substances Control has been reviewing the Risk Assessment prepared by DuPont and plans to bill DuPont for this through the clean-up effort being conducted at the Oakley site where the Sierra-Crete was made. He feels this is the best and quickest way to proceed with the review. He acknowledged that Antioch had offered to help pay for sampling with funding they set aside, but doesn't think costs should have to come from the taxpayers.
Annette Guiseppi-Elie agreed with this approach, and agreed it was appropriate for the state agencies to review the risk assessment submitted by DuPont.
Joe Brandt wanted to know if, for the additional sampling that will be done, the County staff overseeing the process will take split samples of all samples taken and then randomly select certain ones for analysis, or if they will only take split samples at certain sites for analysis. Paul Andrews responded that it is his intention to take split samples of all samples taken and to randomly select a certain percentage of them for analysis by a different laboratory.
Annette Guiseppi-Elie noted that they want to develop the sampling plan quickly so they will be ready to start sampling during the hottest times of the year.
Dr. Brunner noted that they may also want to hire an independent consultant to review the risk assessment that is done with the new sampling data, but that that decision would be made later.
David Berry, California Department of Toxic Substances Control, reported that his agency has begun to review the risk assessment submitted by DuPont and that they should be done by the first part of AuguStreet He will submit their findings to the project manager overseeing the clean-up of the Oakley DuPont site for review, and the final copy should be sent to Contra Costa Health Services by around August 10th. Their concerns so far relate to sampling locations. They would like to be part developing the sampling plan.
Martha Harnly, California Department of Health Services noted that she would not be able to review the risk assessment until September.
Annette Guiseppi-Elie reminded the group that DuPont has prepared addendums to the risk assessment concerning school sites and surface runoff.
Action Item: Michael Kent, Contra Costa Health Services, will put these addendums on the web site.
(At this point, the discussion shifted to Item 4 on the Agenda)
4. Review of the Sampling Plan
Paul Andrews, Contra Costa Hazardous Materials Programs, reported that his goal for the sampling plan was to get discrete samples of the Sierra Crete and underlying soil samples from the different jurisdictions. They will take more surface wipe samples in the hot season, and more background samples. They also want to take more samples at sensitive receptors such as schools. He will be accompanying the consultant taking the samples and will be taking split samples for random analysis. In all, they will take about 50 samples. They will coordinate with the City of Antioch to take samples of the Sierra-Crete below road surfaces.
Bill Faisst said Brown and Caldwell has developed protocols for their sampling of the Sierra-Crete that they can share.
Annette Guiseppi-Elie said she wants to make sure they sample sensitive receptors, and her vision of the sampling plan is to do some compositing of samples.
Deborah Proctor, Exponent, said that in the past they had been able to get solid samples of oozing material on the road surfaces that could be sampled. Martha Harnly noted that taking wipe samples can be problematic and that solid samples would be preferable because there is no background literature on how to collect wipe samples. Annette Guiseppi-Elie said that in the earlier sampling they did have problems with the limited amount of sample. They took samples from areas where Sierra-Crete wasn't used to serve as a background reference.
Richard Wenning, Environ, said that wipes were the best they could do when they did their sampling, but in the hotter weather they may be able to take solid samples, and would do so if it is possible. He added that he would welcome any data that has been collected to add to the risk assessment. He also added that they took a compositing approach in the first study so that they could take lots of samples. In the upcoming sampling plan they may also want to continue with a compositing approach, remembering that there is variation in residues in different areas.
Deborah Proctor asked if Environ analyzed individual samples that had been composited. Richard Wenning responded that they had not.
Dr. Brunner wanted to know more about the problem with taking wipe samples. Richard Wenning explained that when they took samples in April and May they just couldn't find and solid pieces of sample to collect. So they went with a wipe approach and tried to mimic NIOSH methodology of consistency. Martha Harnly noted that there is lots of subjectivity when collecting wipe samples.
Joe Brandt returned to the topic of compositing samples and raised a concern about doing this because one of their goals is to know what the highest levels workers and others might be exposed to. Dr. Brunner agreed and Deborah Proctor Pointed out that compositing can mask finding the locations where dioxin concentrations are the highest.
Devra Lewis, Central Valley Regional Water Quality Control Board, reported that she has not received the risk assessment or addendums concerning surface water runoff yet. She is fairly certain that this isn't a groundwater problem, but isn't sure yet if it is a surface water problem. She thinks they should develop a methodology to determine surface water impacts, perhaps in the rainy season. She will follow up on this. (Annette Guiseppi-Elie provided Devra Lewis with the addendum to the risk assessment during the meeting.)
Bill Faisst asked whether they could take samples from catch basin sediments to determine impact. Dave Berry noted this might be a quick way to collect preliminary data. Annette Guiseppi-Elie expressed concern that because of background levels of dioxin in the catch basin sediments there must be a control. Bill Faisst suggested sampling catch basins where Sierra-Crete wasn't used. Bill Wenning said they had done some of this in their work that was reported in the addendum to the risk assessment.
Deborah Proctor asked whether leaching testing should be done on any solid samples collected to account for bioavailability. Bill Wenning responded that this would be useful if it were possible.
Dr. Burnner summarized the discussion of the sampling plan:
Enough sub-surface samples of Sierra-Crete will be taken to cover the geographic and time distribution of different batches, and to be statistically valid (Martha Harnly noted that there is a person at the State lab that could be helpful in developing the protocol.)
Additional surface samples will be collected to achieve this as well, with background samples being taken also.
Sampling to determine surface water impacts needs to be done.
Split samples will be collected and tested by Contra Costa Health Services.
Solid samples of residue will be taken if possible.
Tim Farley, Supervisor Glover's Office, wanted to know if there were problems with spliting samples of solid residue. Deborah Proctor explained that solid samples are not necessarily homogeneous and therefore the different splits could contain different amounts of dioxin. Pat Finley, Glynn and Finley, expressed concern about how to compare the results from solid samples to residue wipe samples.
Pat Finley was also concerned that when you sample the sediments from a catch basin you are measuring the amount of dioxin left behind, not that in the water that is going into water bodies. Annette Guiseppi-Elie suggested that the regulatory agencies look at the stormwater addendum to the risk assessment before they design additional sampling. Devra Lewis agreed and said she would be providing her comments to Dave Berry. Dave Berry said his agency is looking at this addendum as well.
Dr. Brunner directed a that a smaller group develop the sampling plan with Dave Berry taking the lead. A draft of what they proposed should be sent to the group for them to have 3 - 7 days to comment on it. The plan should be completed before the end of AuguStreet
Action Item: Dave Berry will lead a smaller group to develop a sampling plan to be distributed to the whole group to review for 3 - 7 days.
(At this point the discussion moved back to Item 3. d.)
3.d) Public Involvement and Outreach
Kathy Chiverton, Supervisor Gerber's Office, observed that from the public's perspective, the sampling plan needs to be above reproach.
Dr. Brunner asked the members of the public if they had any questions or comments. Gloria James, Bay Point resident, wanted to know if it was a new product and how it could hurt someone if it is below the asphalt. Dr. Brunner told her the history of the Sierra-Crete issue, and said that based on the health risk assessment conduct for DuPont he doesn't feel the dioxins in Sierra-Crete pose a health risk. She further asked why the dioxin issue wasn't addressed when the product was approved for use. Dr. Brunner said he didn't have an answer for that question. Joe Brandt sad it wasn't studied before because it wasn't an issue then. Annette Guiseppi-Elie explained that now we know that any process using chlorine at high temperatures creates dioxin and we are more sensitive to looking for it now.
Sara Hoffman, Contra Costa Office of the County Administrator, asked if residents have been informed of the issue in a targeted manner. Dr. Brunner responded that there hasn't been targeted outreach yet, but there have been several press releases written, and the media has covered the issue. The level of future outreach will depend in part on the level of interest expressed by the community.
Kathy Chiverton suggested that it is better for the public to be over-informed, and that she is not comfortable that we are doing enough outreach. Tim Farley echoed her concerns. Joe Brandt raised the concern that we really don't have anything to tell the public at this point because the health risk assessment done thus far shows no health risk. But he added that maybe a newspaper article explaining the issue to the public would be a good idea. Kathy Chiverton suggested a targeted mailing be done, and Gloria James said she felt a courtesy letter explaining the issue would be appropriate.
The group agreed that providing residents living near the sites where sampling will occur should be provided with door hangers explaining what is going on, and that a press release be sent out before the sampling begins. Dr. Brunner clarified that we would not be identifying specific sites in the press release. Joe Brandt said the Antioch City Council meetings are televised and an announcement could be made there. He also said water bills could include a statement as well. The group agreed that these avenues of public outreach should be pursued.
Action Item: Michael Kent will facilitate the development of the door hangers, the press release, the City Council meeting announcement and the water bill stuffer.
Michael Kent informed the group that he is currently planning one public meeting to be held when the next round of test results are back and have been factored into the risk assessment, but that can be adjusted depending on the level of intereStreet He is still interested in locating any residents that may be interested in reviewing the sampling plan.
5. Set next meeting time and Agenda
The next meeting will be Wednesday, August 28, 2002 from 9:00 to 11:00 in the Antioch Police Station Community Room at 300 "L" Street in Antioch.