Comment from Newtrient LLC

Newtrient LLC respectfully submits these comments on the proposed regulations under Section 45Z of the Internal Revenue Code, as published in the Federal Register on February 4, 2026. Newtrient LLC is a leading dairy industry organization dedicated to advancing manure management technologies, nutrient recovery, and the production of renewable natural gas from dairy manure across the United States. We strongly support the overall framework of the proposed regulations, including the designation of the 45ZCF-GREET model as the successor to the GREET model under Section 45Z(b)(1)(B)(ii), the provisions allowing negative emissions rates exclusively for fuels derived from animal manure feedstocks after December 31, 2025, and the emphasis on distinct emissions rates tailored to specific animal manure types such as dairy manure. These elements align directly with the statutory intent to incentivize genuine emissions reductions from dairy operations. We highlight the need for more accurate dairy manure baseline assumptions in the 45ZCF-GREET model using system-specific and housing-type-specific data, and we recommend expedited model updates, support for co-digestion where dairy manure constitutes 50 percent or greater by volume, expanded qualifying sales provisions, authorization of book-and-claim systems for RNG used as process energy (with negative CI scores carrying over), and the use of major pipeline injection standards in lieu of ASTM D8080. These refinements will enhance the credit’s environmental integrity, reduce administrative burdens, and accelerate the adoption of dairy manure-to-energy technologies while supporting rural economies. (Full Comments Attached)