Dust, Odor & Noise Control
On November 22, 2004, the Air Pollution Control Division (APCD) of the Department of Environmental Conservation (VTDEC) met with Omya to suggest that the company conduct a study to determine if the Omya facility was the source of odors of which area residents had expressed concern. APCD also recommended that Omya investigate if potential health effects could result from the facility’s emissions. (Omya previously had provided to the DEC information on both of those issues.)
In response, Omya selected TRC Environmental Corporation (TRC), from a list of EPA approved odor consultants, to develop and implement a study to determine the sources of these odors, independent of Omya’s earlier efforts. TRC’s other objectives were to determine if the Omya facility was the source of these odors and, if so, to recommend an odor abatement strategy to reduce these odor impacts.
Phase I Study
TRC developed the Omya Odor Study Work Plan dated December 23, 2004, which was approved by Air Pollution Control Division (APCD) of the Department of Environmental Conservation (VTDEC) on February 7, 2005. The study was conducted in three (3) phases under review and supervision by the APCD. The Phase I Preliminary Study, completed on June 14, 2005, concluded that the originally suspected sources are the origins of the odor episodes in the neighboring community.
Phase II Study
Phase II consisted of “Odor Testing and Dispersion Modeling” to determine the odor emission rates of odor sources and their impacts on downwind locations. TRC completed the Phase II onsite sample collection activities on Wednesday, October 5, 2005. As part of Phase II, an odor threshold value was determined by a certified odor panel. The results of TRC’s odor dispersion modeling and odor causing compound characterization are summarized in the Phase II Report. Outcomes of this phase recommended the investigation of specific odor abatement technologies to reduce odor impacts in the neighboring community.
Based upon the results of Phase II, TRC proceeded with Phase III by conducting further air sampling, quantifying concentrations of responsible air contaminants from its emission source, and evaluating the potential health risks from the detected compounds.
Omya submitted its Phase II, Odor Testing and Dispersion Modeling Report to the VT Air Pollution Control Division on January 18, 2006. This report concluded that during the test period, emissions from Omya’s East Plant resulted in perceptible odor impacts at downwind locations. The report also recommended Omya proceed with Phase III of the study to conduct air testing and health risk assessment and investigate existing odor abatement technologies.
The Air Pollution Control Division Director responded to Omya’s submission on February 2, 2006 acknowledging Omya’s Odor Study efforts and “commitment to take action to abate” odors after the “completion of Phase III of the plan.”
Phase III Study
Preliminary test results from the Phase III Study indicated that the East Plant’s emissions contained formaldehyde levels exceeding state ambient air standards at the plant’s property line. Omya voluntarily shut down its East Plant on Friday, June 9, 2006, after receiving notification of this information from TRC. Omya reopened the plant after the VT Department of Environmental Conservation reviewed and determined that Omya’s modifications, proposed as part of the Phase III Study process, will lower the plant’s emissions of air contaminants and odors.
TRC completed its Odor Study investigation following the State’s approval on Omya’s proposal for a manufacturing process modification. On June 30, 2006, TRC submitted its final Phase IIII Report in the form of Control Recommendations and an Odor Survey Report. On August 2, 2006 Omya received a supplementary letter from TRC providing additional information to complete a Hazardous Most Stringent Emission Rate (HMSER) for organic compounds.
Subsequently, Omya submitted all reports and supplementary materials received from TRC to the State and is currently awaiting a final written response. All relevant Odor Study documents are currently available to you in our Environmental Programs Project Library.
Related Odor Documents
- 02.21.06 Letter from the Director of Air Pollution Control at the Vermont Agency of Natural Resources regarding odor resulting from Omya’s operations