Draft Rumford Air Toxics Monitoring Report

The Maine DEP has published a draft air toxics monitoring report for public comment. The report is entitled, "Maine DEP’s Ambient Air Toxics Monitoring Program in Rumford/Mexico, Maine1997 – 2003, Revision of October 28, 2004." (Adobe PDF, 1.5 Mb).

Comments should be filed by January 15, 2005 in order to be fully incorporated into the final document. Electronic comments are preferred. Comments should be directed to David Wright at:

E-mail: david.w.wright@Maine.gov

Mail: MEDEP – BAQ
17 SHS
Augusta, ME 04333-0017
Phone: 207-287-6104
Fax: 207-287-7641

Abstract of the Draft Rumford HAPs Report

The Maine Department of Environmental Protection (MEDEP) initiated an Air Toxics (AT) Monitoring program in the Rumford Maine area in 1991. That pilot study found ambient levels of chloroform; tetrachloroethylene; 1,3-butadiene; and benzene above safe levels for long-term exposure. A follow-up study in 1992 found similar exposures across the state, with benzene; 1,3-butadiene; carbon tetrachloride, and chloroform posing unacceptable risks in several Maine towns. MEDEP sampled Rumford for ATs again in 1993, and found that ambient levels of Chloroform had decreased below ambient air guidelines. The decline was attributed to decreased use of chlorine in a local paper mill. Otherwise, the results were consistent with the results of earlier studies. Limited follow-up studies between 1995-1997 revealed the presence of benzene. However, the data could only indicate the potential for problems, as there was insufficient data to determine valid annual averages for comparison with the annual guidelines.

This report contains the results of MEDEP’s detailed Air Toxics monitoring program in the Rumford area from late 1997 until 2003. During this time, MEDEP collected three, 24-hour samples every six days at three sites, until the summer of 1999, when MEDEP scaled back to one long-term trend site. Monitoring locations were established in likely areas of high impacts from a local paper mill. The study site is located in a valley with complex meteorology, making it impossible to establish a “background” monitoring site. Samples were collected and analyzed for select Volatile Organic Compounds (VOCs) using EPA method TO-15. Method TO-15 contains many protocols to ensure that results accurately represent ambient concentrations of the pollutants that were monitored. Samples from collocation sites showed good replicate precision for most parameters.

Sample results were averaged, and compared to ambient air quality guidelines (AAQG). The results show that benzene levels posed a greater than acceptable cancer risk. That is, the incremental lifetime cancer risk (ILCR) was in excess of 10 in a million. Four other compounds likely exceed acceptable health risk levels: 1,3 butadiene; tetrachloroethene; carbon tetrachloride; and 1,2-Dibromethane. Twenty-six (26) compounds were determined to not pose a significant risk to public health. MEDEP was not able to determine the risk posed by air toxics that were not monitored for, the risk posed by 23 compounds that were sampled for but that lack risk-based ambient air guidelines, and for 14 compounds whose detection limits are too high to enable measurement down to their low ambient air guideline levels. Of particular concern are acrolein; 1,4 dichlorobenzene and 1,1,2,2-Tetrachloroethane, which have high detection limits, but were occasionally detected well in excess of their respective AAQGs. Chloroform concentrations have decreases from the levels that were detected in the earliest sampling efforts in the area, to levels that do not pose a risk.

Data Set

A complete summary of analytical results from ambient air samples collected in the Rumford/Mexico area between 1997-2003 is available in Access® format (for download), and includes the valid and invalid sample results, along with the associated data qualifiers. Summary and detailed reports are also available.

File Name or Description	File Fomat and Size
Rumford/Mexico Area - Analytical results from ambient air samples, 1997-2003	Microsoft Access® (27.4 Mb)
Laboratory Analytical Precision Report for Maine DEP HAPs Field Samples, 1997-2003: Summary Report	Adobe PDF (506 Kb)
Laboratory Analytical Precision Report for Maine DEP HAPs Field Samples, 1997-2003: Detailed Report	Adobe PDF (2.9 Mb)