ARS | Publication request: Characterization of cotton gin particulate matter emissions

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings/Symposium
Publication Acceptance Date: February 13, 2009
Publication Date: N/A

Interpretive Summary: The development of PM2.5 emission factors for gins across the cotton belt will benefit local cotton gins and state air pollution regulatory agencies by providing sound science based data needed to amend cotton gin air quality permits for PM2.5 emissions. Since more and more states are moving toward using dispersion modeling to determine a gin eligibility for an operating permit, the development of a high quality data set that can be used to evaluate and modify current dispersion models is critical and urgently needed. This data set could be used to develop new, more accurate models for low-level agricultural point sources, which would greatly benefit cotton gins and other agricultural processing facilities. Under current regulatory agency assumptions, cotton gins will be regulated and permitted based on PM2.5 data that are likely more than 10 to 14 times higher than true PM2.5 levels because of over-sampling issues. Conducting this comprehensive study and including state and federal regulatory agencies in all phases of the study could lead to the over-sampling and model over-prediction problems being addressed in policy and regulatory changes by state and federal agencies. The goal of this research project is based on environmental stewardship and economic viability. From an environmental perspective: Determination of scientifically sound PM2.5 cotton gin emissions data. Will cotton gins meet the upcoming PM2.5 regulations? Will cotton gins have problems obtaining PM2.5 operating permits? From an economic viability perspective: If state regulatory agencies mandate additional cotton gin PM2.5 controls, the decisions need to be based on sound science. If substantial abatement system changes are mandated, fixed and variable costs could substantially increase and would likely be passed on to the producers. With cotton production input costs soaring, all input decisions including ginning issues need to be based on sound science. Sound science is a key to ensuring that the US cotton industry remains strong and competitive on the world market.

Technical Abstract: In 2006, EPA implemented a more stringent standard for particulate matter with an effective diameter less than 2.5 microns (PM2.5). The implementation time line for this standard will vary by state/district regulatory agency. For example, the San Joaquin Valley Air Pollution Control District has proposed to include cotton gins in their PM2.5 State Implementation Plan by the end of 2008 under the assumption that the PM2.5 emissions from cotton gins are significant enough to warrant further study and possibly even additional control measures above and beyond the current mandate to install enhanced "1D-3D" cyclones on all emission points. All cotton gins across the cotton belt will eventually be impacted by this standard. The primary issues surrounding particulate matter regulations for cotton ginning industry are: 1) limited or lack of PM2.5 data; 2) potential over-prediction of current dispersion models; and 3) effects of sampler errors. The cotton ginners¿ associations across the cotton belt, including the National, Texas, Southern, Southeastern, and California associations, have agreed that there is an urgent need to collect gin emission data to address these issues. In response to the gin associations' requests, the project outlined in this paper was developed.