N.Y. Comp. Codes R. & Regs. tit. 1, § 21.12 – Types of plants.

(a) Pool plant means a plant, other than a pool plant pursuant to a Federal Milk Marketing Order, where milk is received from producers, is approved by a health authority for the processing of fluid milk for distribution in any part of the marketing area, and which meets the requirement of paragraph (1) or (2) of this subdivision.
1. (1) At least 50 percent of the milk received from producers and as transfers of bulk milk from other plants during the month is processed at the plant and disposed of as route disposition of fluid milk products in the marketing area or as transfers of packaged fluid milk products to pool plants.
2. (2) A plant which meets the requirement of paragraph (1) of this subdivision during any month shall remain a pool plant until the second consecutive month in which it fails to meet such requirement.
(b) Nonpool plant means a plant other than a pool plant pursuant to this Part from which fluid milk products are distributed or otherwise sold as route disposition in the marketing area.
(c) Diversion plant means a plant other than a pool plant designated by the commissioner pursuant to section 21.17 of this Part to which milk may be diverted by direct delivery from farms of producers in bulk farm tank trucks.