This post will continue a post series that I started toward the beginning of this blog and including:
Those posts described the basic steps associated with the work I do at various types of sites. This post will describe my involvement in the standard dry cleaner site located in a standard shopping center. Let’s say that there is a shopping center that has multiple units and one of them is a dry cleaner. This tenant has been in operation as a dry cleaner since the center was built some 20-30 years ago. The dry cleaning process, as I have discussed in my previous post about green dry cleaning, uses tetrachloroethelene (PCE). From an environmental standpoint, this chemical can be a hassle to purchase, manage, dispose of, and generally use. Due to the difficulties associated with disposal of PCE, many operators of dry cleaning facilities historically disposed of the chemical in the sewer by either dumping it in a floor drain, sink, or the toilet. This practice was generally conducted up until the mid-1970s when environmental regulations became more mainstream. Releases can also occur beneath the dry cleaning machine itself and in the area where the chemical is stored.
Investigating the potential for releases at these types of sites is generally performed in a few phases starting with a soil vapor survey in the area along the sewer line followed by soil samples in impacted areas identified during the soil vapor survey. The final phase of investigation generally consists of groundwater samples in impacted areas identified during the soil sampling.
Remediation of a dry cleaner site generally involves soil vapor extraction (SVE) in the area of impacts. The SVE methods can range from carbon adsorption to chemical oxidation (Generally, carbon is sufficient). Since the impacted areas are commonly inside the building, excavation using small drill rigs and Bobcat-type excavators is necessary. There are a number of challenges associated with the process, but it is rather common and these types of sites can be usually be remediated within a few years.