40 CFR § 412.21
Special definitions
June 9, 2020
For the purposes of this subpart:
(a) Dry lot means a facility for growing ducks in confinement with a dry litter floor cover and no access to swimming areas.
(b) Wet lot means a confinement facility for raising ducks which is open to the environment, has a small number of sheltered areas, and with open water runs and swimming areas to which ducks have free access.