Air modeling, health assessment demonstrate no adverse risk from proposed Perdue AgriBusiness grain elevator, soybean crushing plant in Pa.
Salisbury, Md. (Wednesday, June 19, 2013) - Perdue AgriBusiness has submitted to the Pennsylvania Department of Environmental Protection (DEP) an Air Dispersion Modeling and Health Risk Assessment demonstrating that the company’s planned grain elevator and soybean crushing plant will pose no adverse health risks to residents - neither in Lancaster County in Pennsylvania where the facility will be located, nor across the river in York County.
Although not required as part of the Air Quality Plan Approval application, Perdue AgriBusiness voluntarily conducted the assessment related to hexane emissions specifically to address community concerns. DEP now will consider the findings as part of its ongoing review of Perdue’s permit application.
According to the assessment, which was performed by ENVIRON International Corp., the highest long-term hexane exposure concentration offsite where such exposure could occur is about five times lower than the U.S. Environmental Protection Agency’s most stringent safe level for chronic exposure to hexane. The highest offsite short-term hexane exposure concentration is about 500 times lower than EPA’s safe level for acute exposure.
Hexane concentrations, and thus potential health risks, decrease rapidly with distance from the facility. So, at locations farther from the facility, predicted exposures are even lower. For example, in Hallam Borough, which is surrounded by Hellam Township, long-term exposure concentrations will be more than 500 times lower than EPA safe exposure levels. These EPA levels already have built in more than an order-of-magnitude (10 times) margin of safety.
“Hexane has been used in soybean oil extraction for more than 70 years because it’s proven, effective and safe --- and this report reinforces that point,” said Project Manager Peter Heller.
Earlier this month, Perdue AgriBusiness submitted a revision to its pending permit application. The project design features the latest hexane recovery technology to achieve the lowest solvent loss ratio relative to facility size in the United States. The facility also will recycle 99.9 percent of all hexane that is used at the facility. By incorporating enhanced environmental controls and advanced hexane recovery technology, projected plant emissions decreased more than 16 percent from 248 tons per year to 208 tons per year.
To conduct the air dispersion modeling and health risk assessment, ENVIRON used state-of-the-art and widely accepted regulatory methods that were reviewed by DEP staff. DEP recommendations about the methodology were incorporated into the risk assessment.
Results are based on evaluation of proposed facility emissions and detailed design information. The air dispersion analysis used the state-of-the-science model recommended by EPA for near-source applications such as this. More than 41,000 hours of meteorological data from each of three different locations were analyzed, one just three miles away along the river.
Effects of temperature inversions on hexane dispersion were calculated and incorporated for every hour.
Separately, Perdue AgriBusiness has worked to answer other issues related to air quality, including ozone. Hexane has a low potential for producing ground-level ozone, or smog. According to EPA, in 2008, Lancaster and York counties combined emitted approximately 47,000 tons per year of ozone-forming volatile organic compounds (VOCs). Perdue’s plant would emit less than 1/200th (0.4 percent) of these emissions. Given the low ozone-forming potential for hexane and the much larger emission contribution from other sources in the region, the incremental impact to regional ozone is expected to be very small.
The complete report, as well as a question-and-answer document that goes into more detail about the science and methodology, can be found at www.perdueagribusinesspa.com.