1. 30,000 laying hens or broilers (if the facility has a liquid manure system),

  2. 5,000 ducks, or

  3. 1,000 animal units; or

  1. More than the following number and types of animals are confined:

    1. 300 slaughter or feeder cattle,

    2. 200 mature dairy cattle (whether milked or dry cows),

    3. 750 swine each weighing over 25 kilograms (approximately 55 pounds),

    4. 150 horses,

    5. 3,000 sheep or lambs,

    6. 16,500 turkeys,

    7. 30,000 laying hens or broilers (if the facility has continuous overflow watering),

    8. 9,000 laying hens or broilers (if the facility has a liquid manure handling system),

    9. 1,500 ducks, or

    10. 300 animal units;

and either one of the following conditions is met:

pollutants are discharged into navigable waters through a man-made ditch, flushing system or other similar man-made device;

or pollutants are discharged directly into waters of the United States that originate outside of and pass over, across, or through the facility or otherwise come into direct contact with the animals confined in the operation.

Provided, however, that no animal feeding operation is a concentrated animal feeding operation as defined above if such animal feeding operation discharges only in the event of a 25 year, 24-hour storm event.

The term animal unit means a unit of measurement for any animal feeding operation calculated by adding the following numbers:

the number of slaughter and feeder cattle multiplied by 1.0, plus the number of mature dairy cattle multiplied by 1.4, plus the number of swine weighing over 25 kilograms (approximately 55 pounds) multiplied by 0.4, plus the number of sheep multiplied by 0.1, plus the number of horses multiplied by 2.0.

The term man-made means constructed by man and used for the purpose of transporting wastes.

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