TMDLs also may be established for a portion of a watershed. In actuality, a TMDL is a planning document.
TMDL allocations are the amounts of pollutants that can be discharged from each category.
The TMDL does not specify how dischargers must attain their particular load allocation. Trading is allowed between or within the load allocation and the wasteload allocation categories. Nonpoint sources are not regulated through a permit program. The New Mexico Environment Department has advocated and implemented a voluntary approach to non-point source pollution prevention. According to the New Mexico Water Quality Act, any person can propose changes to the standards.