Skip Navigation

Related Topics

Ozone - Assessment and Treatment Alternatives

CTU = Conservation Treatment Unit
NCPS = National Conservation Practice Standard

Ozone (O3) - A beneficial, invisible gas occurring naturally in the upper atmosphere but at ground levels is a major component of smog. It is not emitted directly but is formed as a secondary pollutant as a result of complex chemical reactions when precursors such as Volatile Organic Compounds (VOCs) and various forms of nitrous oxide (N2O) react in the presence of sunlight. While not listed as a criteria air pollutant, some VOCs have been identified as causes of cancer and other serious human health problems, in addition to smog effects. Major sources of ozone precursors are fuel (gasoline, diesel, wood, oil and coal) burning, solvents, and petroleum processing and storage, pesticides and animal waste. Biogenic (from specific crops) sources of VOCs in Montana are not significant.

Is agricultural or prescribed burning planned on the CTU? Open burning is regulated under the provisions of Montana’s Clean Air Act.

Yes or No.  If yes, consider practices/management techniques that reduce or eliminate both NOx and VOC generation from burning such as:

  • Consider non-burning alternatives (grinding, chipping or shredding residues)
  • Follow smoke and burn management plan (NCPS Number 338)
  • Utilize smoke emission reduction techniques (NCPS Number 338).

Are commercial nitrogen fertilizers used on the CTU?

Yes or No.  If yes, consider practices/management techniques that reduce or eliminate VOC generation from commercial nitrogen fertilizers such as:

  • Reduced volatility - evaluate formulation of nitrogen in fertilizer (NCPS Number 590)
  • Alter method of fertilizer incorporation (NCPS Number 590)
  • Rate and timing of fertilizer application (NCPS Number 590)
  • Precision Agricultural Techniques - Zone Mapping and Variable Rate Application (NCPS Number 590).

Is animal waste generated and/or utilized on the CTU?

Yes or No.  If yes, consider practices/management techniques that reduce or eliminate VOC generation from animal waste such as:

  • Liquid waste injection (Waste Utilization NCPS Number 633)
  • Solid waste incorporation (Waste Utilization NCPS Number 633)
  • Composting (NCPS Number 317)
  • Anaerobic Digester (NCPS Number 366)
  • Agricultural bagging or Waste Facility Cover (NCPS Number 367)
  • Comprehensive Nutrient Management Plan (CNMP)
  • Poultry litter amendments.

Are pesticides used on the farm?

Yes or No. If yes, consider practices/techniques that reduce or eliminate VOC generation such as:

  • Consider different formulations (low volatility, flowables, pellets, powders, oils, etc.) and application techniques to reduce drift - Pest Management (NCPS Number 595)
  • Adopt integrated pest management practices to reduce or eliminate pesticide use (NCPS Number 595)
  • Reduce or eliminate pesticide use - utilize green/organic farming practices
  • Incorporate recapture techniques and equipment
  • Agricultural chemical handling facility (NCPS Number 309).

Are diesel engines utilized in a manner or location within the CTU where undesirable levels of ozone precursors may result?

Yes or No.  Intermountain valleys of western Montana or other locations where inversions or poor air movement regularly develops may be adversely affected by diesel engine emissions. For example, a single, 1986 diesel engine with 350 horsepower running 2,600 hours per year will produce 7.2 tons of NOx per year. A similar 2003 diesel motor produces less than half of this amount.

If yes, consider practices/techniques that reduce or eliminate ozone precursor generation such as:

  • Combustion System Improvement (NCPS Number 372)
  • Switch combustion engines out to electric motors
  • Utilize newer certified engines - diesel, natural gas or propane
  • Retrofit existing engine - add-on technologies to reduce emissions
  • Alternative fuel blends to utilize lower sulfur diesel fuel.
Continue on to Odor - Assessment and Treatment Alternatives