Written by Steve Henshaw, P.G., President & CEO, EnviroForensics
As seen in the February 2013 issue of Cleaner & Launderer
I’ve been involved with a number of environmental site cleanups where the chemicals in the soil and groundwater were not believed to be a significant threat to human health or the environment. There are a number of situations where this scenario applies, such as an old light-industrial manufacturing site in the middle of a blighted industrial urban area. In such a case, the surrounding sites were identified as being the cause for the majority of the groundwater impacts in the near vicinity and if we were to remediate the groundwater beneath our site, the contamination from neighboring sites would continue to migrate beneath our property essentially re-contaminating it. Another example would be when a site exhibits soil impacts, but the groundwater does not indicate significant impacts, even though the contamination has persisted for 20 plus years. The site is capped with an asphalt or concrete parking lot and building.
There are many, many scenarios where it would appear that a risk-based closure with no physical remediation is warranted. The assumptions are that the site has been adequately characterized so the extent of the contamination is known in the soil and groundwater. The contamination is not reaching the groundwater and that an inventory has been conducted to determine that no wells are located nearby and that no person is drinking from nearby wells. Finally a risk evaluation is conducted to determine what pathways might exist where by contaminants from the site could have an adverse impact on people or the environment. That is to say that no person or animal (including wildlife and marine organisms) would come into physical contact with the contamination, breathe vapors emanating from the contaminants, or drink contaminated water. Continue reading “Risk Based Closures Require Long Term Monitoring; What is the True Cost of Implementing Institutional Controls?”