HomeMy WebLinkAbout2013-03-13 PACKET 05.3.AF,&IL
MEMORANDUM
To: Jennifer Levitt, PE
From: Tom Henning, PE, CHMM
Date: March 12, 2013
RE: Review of Draft Air Permit for 3M Cottage Grove Specialty Additives
At your request Trinity Consultants, Inc. (Trinity) reviewed the Draft /Proposed Air Permit for the 3M Cottage
Grove Specialty Additives facility (Permit Number 16300002 -005). The Minnesota Pollution Control Agency is
accepting comments on the draft permit until March 22, 2013.
Proposed Changes at the Facility
The proposed air permit amendment would authorize 3M Cottage Grove Specialty Additives (3M) to increase
the size of the chamber in their electric heated glass furnace which would increase the hourly production
capacity of the unit. Because the fritting system is downstream of the furnace, the increase to the furnace
capacity also increases the capacity of the fritting system. Allowable throughput would increase from 3,530
pounds per hour (lb /hr) to 4,400 lb /hr. The natural gas glass heater that is used to start up and shut down the
electric glass furnace will not be modified with this permit.
The glass furnace is used to produce molten glass from constituent ingredients. After leaving the furnace the
glass enters the fritting system where the glass is crushed to form "frit," which is essentially large glass granules.
The fritting system is not heated, so the only emissions from this system are dust ( "particulate matter ") emitted
from the crushing process. Emissions are controlled with a fabric filter.
These changes will not increase the particulate matter emission rates for these units. In fact, the emission limits
for particulate matter will not change with this permit amendment. The project will result in small increases of
nitrogen oxide and sulfur dioxide emissions - 0.22 lb /hr and 0.77 lb /hr, respectively.
The permit would allow 3M to make the physical change to the electric furnace when the permit is issued.
However, 3M will not be allowed to increase the production rate above 3,530 lb /hr until 3M has submitted to
MPCA a facility -wide air emission evaluation that shows emissions from the entire Cottage Grove plant meets
federal ambient air quality standards for sulfur dioxide. When 3M has submitted the results of such an
evaluation, the electric furnace is allowed to increase its capacity to 4,400 lb /hr.
Monitoring and Emission Testing
The permit includes new monitoring, recordkeeping and emission testing requirements. 3M will be required to
record and maintain records of the weight of materials processed in the glass furnace and fritting system and the
hours of operation of each process. The permit will require particulate matter and visible emission testing from
the glass furnace and fritting system.
Conclusion
The impact of this project on the air quality in the City of Cottage Grove is negligible. The project will not
increase the particulate matter emission rate from the glass furnace or the fritting system. Emissions increases
of nitrogen oxides and sulfur dioxides are small. 3M must demonstrate that the increased sulfur dioxide
emission rate will not cause an exceedence of ambient air quality standards before they are allowed to increase
the production rate of the glass furnace and fritting system.