Highest Rated Comments

Few-Ganache141656 karma

It is important to distinguish the fate and transport of vinyl chloride (VC) in different media in order to understand the long term effects of the release. VC will naturally degrade in the environment, but at different rates depending on the substrate. VC readily degrades aerobically, so shallow surface soils and shallow groundwater contamination may last only a few days to a few years depending on the amount released and the immediate actions taken by cleanup crews. If the source materials (e.g. contaminated soil) are removed quickly, then the degradation time can be cut significantly. However, if the VC is allowed to seep deeper into groundwater it may persist for several decades under anaerobic conditions. The concentrations of the recalcitrant VC in deeper groundwater would need to be monitored to determine if it may cause adverse health effects (from drinking water).

Few-Ganache141638 karma

All of the tasks presented in the Norfolk Southern consultant's workplan are consistent with the tasks I would recommend in this scenario (soil removal, area air monitoring, vacuuming up the liquid product at the site, aerated the nearby waterways to promote degradation, etc.). Arcadis is the consultant of record for the cleanup efforts and they are generally a good firm to rely on.


The only thing which I am unsure about is the emergency release of the vinyl chloride to the air. Without additional information, which isn't public yet, I can't really say whether or not it was the best course of action as it sounds like there was a danger of explosion, which goes beyond environmental cleanup and bleeds into mechanical engineering.

Few-Ganache141624 karma

Typically, if you were a company or collective in the vicinity of the spill, you would hire someone like me, an environmental consultant. There are tons of consulting firms. If you would like to independently test media surrounding your home, I would focus on air monitoring rather than drinking water or soil. This is because vinyl chloride is typically a gas at room temperature and it is unlikely that if you are enough distance away from the release that you would detect VC in soil or groundwater on your property. Each state and EPA region has rules and regulations prescribing how soil, groundwater, and air media must be sampled so I would refer to your states specific rules in that regard. VC is in a group of chemicals known as volatile organic compounds (VOCs) and the proper analysis code for a laboratory to analyze a soil or water sample would be EPA Method 8260D. This would provide you with the concentrations of the full suite of the VOC chemicals in the media you submit. You would then need to compare those results to OSHA permissible exposure levels PELs for the various chemicals, or VC specifically if that is all you are looking for. These tests typically cost between $80-120 per sample, depending on the lab. For air monitoring, if you visit the EPA page on the release site, you will notice that they are producing air concentrations for total VOCs. As I mentioned before, VC is a VOC, but there are tons of VOCs, so it isn't giving you an exact measurement of VC in the air. It's like if you saw a flock of birds in the air and you wanted to know how many ducks were in the air, but all the observer could tell you was the total number of birds in the air, which may include ducks, pigeons, hawks, etc. Measuring VOCs is, however, a legitimate strategy to determining if the air is harmful. For instance, if it takes 10 ducks to adversely affect someone, but the observer only counts 5 birds total in the air, then their cant possibly be 10 ducks. That is their current strategy. If there were 100 birds, they may employ a more chemical specific air monitoring method to speciate out what types of birds are in the air.

All that being said, consultants are expensive and after reviewing the EPA numbers, it appears that they didn't skip out on any procedures so far. I would not recommend hiring a consultant by yourself, but if you have an HOA, you might be able to do something as a group.

Few-Ganache141624 karma

Favorite: Creosote, its sticky and tar like, very difficult to remediate, but with careful engineering and adequate data you can manage it. I had a site in London, UK where they had a former manufactured gas plant (MGP), which is similar to creosote (it was coal tar instead) and because it it denser than water it will slowly seep into the subsurface and stop on the nearest impermeable layer. Which in this case was a unit called the London Clay layer. We conducted soil borings throughout the site and determined the topographic surface of the clay layer beneath the site and identified a low point where the coal tar would naturally settle. We then installed a well at that low point and began recovering the coal tar through the well with specialized remediation equipment.

Least Favorite: tetrachloroethylene, its everywhere, sticks around in the environment forever, and it degrades into even worse chemicals, including vinyl chloride over time.

Few-Ganache141619 karma

It is highly unlikely that any contamination would reach that far, vinyl chloride levels measured by the EPA already show that the remaining surface water contamination near the site is limited to the immediate area near the spill and the remaining surrounding surface water contamination is minimal.