Do you wonder about what Licensed Site Professionals (LSPs) really have to do and the decisions they have to make? Here’s an example.
Omni Environmental Group recently worked at a single family house. They had an underground storage tank which contained fuel oil. They had the tank removed and contamination was found in the soil beneath the tank. The homeowner hired Omni Environmental Group to provide LSP services. Here’s some of the decision that the LSP had to make on this project:
- The LSP had to decide whether the contamination posed a risk and had to be cleaned up. The answer was yes. The petroleum concentrations in soil were high enough to pose a potential risk to human health and be a potential source of contamination to the ground water and indoor air.
- The LSP had to decide the most effective and efficient way to cleanup the contamination. Excavation of the soil was the answer. Excavation was required outside the house, within the basement and beneath the foundation. The excavation beneath the foundation required costly structural support of the foundation.
- The LSP had to decide how much excavation was necessary. For the most part this was straightforward. We excavated until the oily soil was removed based on appearance, odor and screening the soil with a field instrument. After a majority of the contaminated soil was removed, there was a narrow wedge of contaminated soil that continued along and beneath the foundation footing.
- The LSP then had to decide whether it was worth a significant extra cost to continue the structural excavation to remove what appeared to be a fairly small area of contaminated soil. The homeowner did not have insurance coverage for the cleanup. Soil borings and field observations indicated that the contaminated soil was limited in extent. Based on previous experience, the LSP decided that additional excavation was not warranted.
- Finally, the LSP had to decide whether the post-excavation conditions continued to pose a risk to human health and the environment. Post-excavation soil samples indicated the soil did not pose a risk in itself. Omni Environmental Group collected ground water and soil gas samples to see if residual contamination in these media posed a risk. Of primary concern was whether the residual petroleum in soil beneath the foundation would migrate into indoor air and pose a health risk to the residents.
As it turned out, after two rounds of ground water and soil gas sampling, neither the ground water nor migration of petroleum into indoor air posed a risk to human health or the environment. As a result, the LSP submitted a Response Action Outcome Statement to the Massachusetts Department of Environmental Protection (MassDEP) which “closed” the environmental case.
It is important to note that, while the LSP has to make these decision, the LSP isn’t making these decisions alone. It is a collaborative effort as the LSP works with, consults with and gets information and opinions from our client (the homeowner), our risk assessor, the MassDEP and the excavation contractor.