HomeMy WebLinkAbout2015-04-08 PACKET 05.4.-A
SEH
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TO: Jennifer Levitt, PE, City of Cottage Grove
FROM: Tom Henning, PE, SEH
DATE: March 26, 2015
MEMORANDUM
RE: Review of Draft Air Permit for 3M Cottage Grove Specialty Additives
SEH No. 122701 COTTG
At your request, Short Elliott Hendrickson Inc. (SEH) reviewed the Draft/Proposed Air Emission Permit
for the 3M Cottage Grove Specialty Additives facility (Permit No. 16300002 -006). The Minnesota Pollution
Control Agency (MPCA) is accepting comments on the draft permit through April 17, 2015. There are four
procedures the City of Cottage Grove may take in responding to this draft permit 1) submit written
comments to the MPCA on the draft permit, 2) request that the MPCA hold a public information meeting,
3) request that the MPCA hold a contested case hearing, and /or 4) submit a petition to the Commissioner
requesting that the MPCA Citizen's Board consider the permit matter.
Plant Overview
The 3M Cottage Grove Specialty Additives facility manufactures specialty glass products referred to as
glass "bubbles ". Emissions from the facility result from raw material handling, fuel combustion and from
the production process. The emission units that generate the greatest emissions include three glass
bubble "makers ", two glass furnaces, material handling and storage operation, and backup generators.
Baghouses (i.e. fabric filters) are used to control particulate emissions from several of the processes. 3M
Cottage Grove also operates equipment and processes that are defined as insignificant activities.
OVERVIEW OF DRAFT PERMIT
The draft air permit is a major amendment to the facility's current Title V air operation permit and
incorporates several separate permitting actions: two major and one minor amendment requests by the
facility and an MPCA- initiated change related to periodic monitoring.
No emission increases are associated with the proposed permit amendment. The draft permit will require
the changes described below.
1) New Emission Limits - Emission limits were added to some emission units. For example, two
emission units had emission limits for particulate matter (PM) and particulate matter less than 10
microns in diameter (PM and MPCA added limits for particulate matter less than 2.5 microns in
diameter (PWO. For other units, the emission limit was changed from a concentration limit
(grains per dry standard cubic foot — a "grain" is 1/7 '000th of a pound) to mass emission limits
(pounds per hour). This change was made to increase the enforceability of the emission limits.
2) Facility -Wide Emission Limits - The permit contains emission "caps" designed to ensure that
facility -wide emissions do not exceed regulatory thresholds. In the draft permit, MPCA is
proposing to add calculation methods and emission factor requirements to be used for
Engineers I Architects I Planners I Scientists
Short Elliott Hendrickson Inc., 809 North 8th Street, Suite 205, Sheboygan, WI 53081 -4032
SEH is 100% employee -owned I sehinc.com 1 920.452.6603 1 888.908.8166 fax
Review of Draft Air Permit for 3M Cottage Grove Specialty Additives
March 26, 2015
Page 2
compliance demonstration and reporting purposes. The draft permit will also change the potential
emission rates from some insignificant activities. Emission rates from insignificant activities are
generally relatively small, but they need to be added to the facility total and compared to the cap.
The draft permit will change how emissions from some insignificant activities are accounted for in
the cap emission calculations.
3) Air Dispersion Modeling — An air dispersion modeling evaluation was conducted which
incorporated all emission sources at the 3M Cottage Grove campus. The evaluation was
completed to determine if emissions from the 3M Cottage Grove campus caused or contributed to
an exceedance of state and federal ambient air quality standards for sulfur dioxide. The results
showed that facility impact was very small, 0.005 micrograms per cubic meter, compared to the
standard, 196 micrograms per cubic meter.
4) Emergency Generators - The draft permit will add requirements to the diesel fired emergency
generators operated at the site. The new requirements are from new federal emission standards
applicable to diesel fired emergency engines. In addition, 3M is agreeing to implement Best
Management Practices related to the operation and testing of the engines. These practices are
designed to reduce emissions from the engines and to reduce their impact on air quality. These
practices include using ultra -low sulfur fuel (to minimize sulfur dioxide emissions), vent emissions
upward from a stack (to improve dispersion), minimize test run length (to minimize emissions)
and test multiple engines individually rather than simultaneously (so their emissions are not
additive). 3M has also agreed to defer engine testing if the Air Quality Index or the forecasted Air
Quality Index is greater than 90.
5) Pollutant Calculations — The permit review evaluated new emission calculations of volatile organic
compounds and sulfur dioxide emissions from an additive used at the plant. With this
information, MPCA developed emission factors and compliance calculations for 3M to use. 3M
also submitted and MPCA reviewed facility -wide emission calculations of greenhouse gases. The
calculations demonstrated the facility is not a major source of greenhouse gases.
6) Monitoring and Recordkeeping - The MPCA added monitoring and recordkeeping requirements to
the permit. Emission testing to verify PM, PM and PM 2.5 emission factors will be required for the
glass bubble makers, the glass furnace and the fritting system. The permit also contains
additional recordkeeping for the fuel burned in the emergency generators.
SUMMARY AND CONCLUSIONS
MPCA is proposing to issue a revised permit for the 3M Specialty Additives facility located at the 3M
Cottage Grove campus. The revised permit modifies several emission limits, changes compliance
demonstration methods, and adds new requirements of some to the emission units. No emission
increases are associated with this permit and for some emission units, such as the emergency
generators, emissions will be reduced as a result of new restrictions in the permit.
The MPCA has evaluated the potential air quality impacts as part of the air permitting process and
determined that, with the issuance of this permit, 3M will continue to comply with applicable
environmental regulations and emissions from the facility will not exceed state and federal air quality
standards. Based on these reviews, this permit change will not have a significant impact on the citizens
of Cottage Grove.
TAH /FJM
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