870.18 General rules for calculating excess moisture.
Excess moisture is the difference between total moisture and inherent moisture.
To calculate excess moisture in HIGH-rank coal, follow section 870.19. To calculate excess moisture in LOW-rank coal, follow section 870.20. Report your calculations on the OSM-1 form, Coal Reclamation Fee Report, for every calendar quarter in which you claim a deduction. But whoever does a test, you are to keep test results and all related records for at least six years after the test date. The following definitions are applicable to 870.19 and 870.20.