Independent Consultant's Report on MCSM Indoor Air Quality Tests

Our independent environmental consultant, Peter Strauss, distributed a letter report addressing the latest Con Edison indoor air tests conducted in August at the November PA meeting and summarized its findings for the parents who attended. Below is a copy of his letter report's contents.



From: Peter Strauss
Re: MCSM Testing Results
Date: November 14, 2008


I have reviewed the October sampling results, as preliminary preparation for the meeting next Tuesday. Accompanying this memo, as I did previously, is a spread sheet that I hope makes it easier for you and the community to understand. I have excluded most data on chemicals that do not have any significant result. As I did in my last memo, I’ve added columns that provide the Regional Screening Levels for air (previously preliminary remediation goals or PRGs) for three EPA Regions: III, VI, and IX, the NJ Screening Levels for residential indoor air, and the DOH outdoor air. I did this because there are no standards for most chemicals in the air; this is intended to give the Parents Association something to gauge the results. NY State uses a matrix for only a few chemicals, which considers both concentrations in air and soil gas. I have highlighted in red results that are above the approximate 50th percentile of NY DOH background indoor air samples. This does not mean it is an immediate health concern; only that approximately 50 percent of the buildings have background that is less than that measured at the sampling points.

I’ve also added a few new chemicals to the list; these are highlighted in green. The chemicals that were added are ethylbenzene, naphthalene, styrene, and TCE. I’ve added these because I think that the data is relevant to any remediation at the site. The first three chemicals may be related to MGP residual wastes, and naphthalene is often thought of as a signature for the presence of MGP wastes. I’ve also added TCE. This chemical, unrelated to MGP operations, is a solvent found in many soil and groundwater contamination sites around the country. It has recently undergone a revision in its health risks, which could lead to significant lowering of acceptable levels in the air. It may be related to the dry cleaning industry, but is found in many other types of industrial applications.

One of the problems I have had with this review is that the sample locations are labeled differently then they were previously. Based on the Figures showing the sample locations, I was not able to correspond the locations of the samples to the previous samples. Thus, I was unable to analyze any trends. Also, this is the first time I’ve reviewed the soil vapor samples side by side with the indoor samples.

As I mentioned in my previous memo to about this site, there is not an immediate hazard to health. However, levels of benzene, toluene and xylene, all of which are endemic in the environment should be continually monitored. One basement sample warrants extra attention (ia05) because almost all contaminants listed were measured at fairly high levels. The Evaluation of Results indicates that this sample was taken from an equipment storage room. It also concludes that based on soil vapor sampling in a similar area, a subsurface pathway is not likely. I agree with this conclusion, although I recommend that this room should continue to receive heightened attention. In addition, as I noted in my last memo, the HVAC system around this area should be checked to make sure it is operating properly, and consideration should be given to removing some of the equipment to out-of the room to a different location; preferably not within the school building. Soil vapor samples indicate that there is a large amount of PCE in the underlying soil. This chemical is usually related to dry cleaning establishments. This should also be followed closely, and is likely to require some type of mitigation.