Generally, any tank over 119 gallons is a bulk tank requires compliance with the federal hazardous materials rules to include placarding, licensing, shipping, etc. However, there are some exceptions:
The Code of Federal Regulations, specifically 49 CFR 173.5(a) and North Dakota Administrative Code, specifically Chapter 38-03, allow exemptions when a farm vehicle is operated on local roads between fields of the same farm and not carrying Class 2 material is exempt from all HAZMAT requirements. Therefore, a farm vehicle traveling on township, county, or state roads between farm fields does not have to meet HAZMAT requirements. However, if traveling on interstate highways, to a town, or to a neighboring farm; the farm vehicle must comply with HAZMAT requirements because the movement does not meet the local roads/fields of the same farm exception.
Nurse Tanks
As Anhydrous Ammonia nurse tank is a class 2 material. The Code of Federal Regulations, 49 CFR 173.5 and North Dakota Administrative Code, Chapter 38-03-02 state that a farmer carrying class 2 materials is only exempt from subpart G and H (training and emergency response information requirements). This means that a farm vehicle carrying anhydrous ammonia on township, county, or state roads between farm fields is exempt from (1) training and emergency response information requirements in accordance with 49 CFR 173.5 (2) shipping paper requirements in accordance with 49 CFR 173.315 (m) and (3) CDL HAZMAT endorsement requirements in accordance with 383.3 (d). The vehicle does have to be placarded/marked in accordance with 49 CFR 173.315 (m).