What should I consider after a spill?
No

Anhydrous ammonia is used as a fertilizer by field corn and wheat growers. Anhydrous ammonia (or just called ammonia) provides nitrogen, an essential plant nutrient to maximize yields. Ammonia is also found naturally in the environment, the result of vegetation and animal waste decay.

Fertilizer ammonia is transported from the site of production via barge, pipeline, rail, and truck to fertilizer terminals or directly to dealers. To conserve space and make it easy to handle, ammonia is kept as a liquid under pressure in specially designed bulk tanks. The fertilizer dealer pumps liquid ammonia from their bulk tank into smaller mobile nurse tanks (illustration of common transfer setup). These nurse tanks are towed to a field and hitched up behind a tractor with a tool bar equipped with knives that inject the liquid ammonia into the soil. Once in the soil, ammonia will quickly react with soil moisture and change to a form the crop can use.

Ammonia was initially used to produce explosives. After World War I ammonia was used as a fertilizer and in the manufacture of numerous other chemicals. It is also very commonly used as a refrigerant, often for food processing and cold storage facilities. Anhydrous ammonia has also been used of late as a precursor in the illegal production of the highly addictive drug, methamphetamine. Although it has many uses and the MDA is only responsible for it when used as an agricultural chemical, much of the response information here does carry over to those other uses.

Ammonia is commercially produced by the reaction of nitrogen from the air and hydrogen gas (from the methane found in natural gas) under high temperature and pressure. This process excludes water thus the term "anhydrous."  Fritz Haber of Germany was the first to successfully produce ammonia for which he received the Nobel Prize in Chemistry. Later Carl Bosch refined the process which lead to the first commercial production plant in 1913.

Minnesota Educational & Regulatory Ammonia Program
  • For each construction area up to 500 square feet - collect 2 composite samples.
     
  • For each additional 5,000 square feet of construction area or fraction thereof - collect 1 additional composite sample, up to a maximum of 6 samples for the construction area. [Exception: When soil is excavated before it is sampled, additional samples are necessary from the excavated soil pile (see “How do I collect the samples?”).]
How many samples do I need to collect?
  • For each construction area up to 500 square feet - collect 2 composite samples.
     
  • For each additional 5,000 square feet of construction area or fraction thereof - collect 1 additional composite sample, up to a maximum of 6 samples for the construction area. [Exception: When soil is excavated before it is sampled, additional samples are necessary from the excavated soil pile (see “How do I collect the samples?”).]
No
  • Choose sample areas where there is the highest potential for contamination within the proposed construction area.
     
  • Contamination should be suspected in any area where pesticides or fertilizers have been handled. This would include previous mixing, loading, equipment parking, fertilizer impregnation tower areas, earthen dike interiors, bulk storage areas, equipment repair areas, areas with pesticide staining, dead or barren vegetation areas, scale pits, pesticide container burning areas, runoff ponding areas, water fill sites, along with any areas associated with previous spills.
Where should I collect the samples?
  • Choose sample areas where there is the highest potential for contamination within the proposed construction area.
     
  • Contamination should be suspected in any area where pesticides or fertilizers have been handled. This would include previous mixing, loading, equipment parking, fertilizer impregnation tower areas, earthen dike interiors, bulk storage areas, equipment repair areas, areas with pesticide staining, dead or barren vegetation areas, scale pits, pesticide container burning areas, runoff ponding areas, water fill sites, along with any areas associated with previous spills.
No
  • Each sample should be a composite sample, taken from an area no larger than 15 feet in diameter. Each composite sample should consist of no more than 6 subsamples from the same depth.
     
  • If the planned construction will include significant excavation, collect the samples from below the excavated area. The samples should be collected from the 6-inch interval below the excavation. This could be completed through soil borings to the depth of the planned excavation and then sampling or by excavating the soil that needs to be removed and then sampling the bottom of the excavation. If you choose to excavate the area of construction first and then sample, please be aware that you will need to secure the excavated area and the soil pile while you are awaiting laboratory results and MDA review and approval.

* Note, Minnesota statutes require written approval from the MDA for application of pesticide or fertilizer contaminated media. This means that you MUST have prior written approval from the MDA to spread or otherwise use any excavated soil which you know or suspect might be contaminated with pesticides or fertilizer. 

  • If significant excavation is not required for the structure(s), sample from the 0 - 6-inch interval, except in graveled areas where samples should be collected from the base of the gravel to 6 inches below the base of the gravel (gravel is loose gravel and/or stones).
     
  • Additional composite soil samples are needed from the soil removed during excavation in order to determine the proper treatment for excavated soil. The soil pile should be mixed before collecting the samples. The following table illustrates the additional number of samples required to evaluate the excavated soil. Refer to MDA guidance document GD11 Soil Sampling Guidance for more information on stockpiling samples.
Volume of Soil (cubic yards) Number of Samples
<200 1
200-500 2
500-1000 3
1000-2000 4