The report, compiled by On-Scene-Coordinator Myles Bartos, takes time to explain how measurements are considered by health officials over time.
“Generally, as the concentration of a chemical increases, the acceptable duration of exposure is reduced. The lower the concentration, the acceptable duration to the chemical would increase,” the report reads. “For example, exposure to a chemical for 24 hrs a day 7 days a week for 30 years may have a value of 10 ppbV. Exposure to the same chemical for only 15 minutes may have a limit of 100 ppbV. It is not linear and is dependent on the chemical.”
Benzene: How much and Where?
The “ppbV” noted in the report stands for parts per billion by Volume, so for every billion water molecules found in one sample from Oct. 2021 there were roughly 45 molecules of Benzene. The report explains later that those peak times lasted for 1-2 minutes, in one specific testing location, and that the more important measure is 24hr average concentration.
The highest 24hr concentration found by the EPA was 9.52 ppbV, 0.48 ppbV short of Bartos’s example for constant exposure. The report states that while no Benzene levels found in any sites prompted EPA intervention, samples collected at a “Location #9” outpaced other sites in the area. The next major compound discussed is Acrolein, a chemical that Bartos describes as “pungent and irritating.”
Data collection for the chemical Acrolein is still underway, and the report describes several issues in equipment and collection that have hampered the evaluation. Bartos explains that while Acrolein levels of 2.05 ppbV were found at Location #9, those numbers might be skewed by several known issues with Acrolein detection.
EPA standard operating procedure allows for used, uncleaned sampling canisters, and only requires that 1 in 20 used for collection are certified as clean. According to the report, used and uncleaned canisters have the potential to let Acrolein “grow” on its own while tests are underway. This leads to a higher level detected than what might have been present in the original sample site.
In order to more accurately represent the levels that may be present, Bartos writes that brand-new containers will be used to conduct further Acrolein tests in the area. If new tests are consistent with those collected earlier, the report says local environmental officials can assume they are accurate.
Bartos also mentions the origin of Acrolein, stating that it is present in biocides and can be produced by the burning of fats. While the report mentions the presence of a potato chip factory in the area, which would use deep-frying oils, Bartos says he does not believe the factory is the primary source of the chemical.
So, what happens now?
Moving forward, Bartos outlines the EPA’s plan regarding the facility:
- Continue coordination with the community
- Continue evaluation of lab data
- Redact and release Oct. 2021 Data Summary Report
For further data, EPA testers will also also collect more samples in unannounced visits to prevent altered landfill operation during their time on-site. The report says up to 12 different samples will be collected throughout multiple locations.
For continuing coverage of issues arising out of the Bristol, Virginia landfill, make sure to click here.