WSR 04-01-174


[ Filed December 23, 2003, 11:25 a.m. ]

Department of Ecology to Develop an NPDES General Permit for

Concentrated Animal Feeding Operations

The Washington State Department of Ecology has made a preliminary determination to develop and issue one or more National Pollutant Discharge Elimination System (NPDES) and state waste discharge general permits for discharges associated with concentrated animal feeding operations (CAFOs). Please see the section "Is my operation a CAFO?" at the end of this notice for more information about CAFOs. A final permit is expected in February 2005. The Department of Ecology issued a general permit for dairies in 2000 that will expire in March 2005.

A recent revision to the NPDES permit regulations and effluent limitation guidelines and standards for CAFOs (40 C.F.R. Parts 9, 122, 123, and 412) by the Environmental Protection Agency changed the regulatory requirements for CAFOs under the Clean Water Act. The revised rule established a mandatory duty for all CAFOs to apply for an NPDES permit and to develop and implement a nutrient management plan. Also, the new effluent guidelines established performance expectations for existing and new sources to ensure appropriate storage of manure, as well as expectations for proper land application practices at the CAFO.

A CAFO general permit will provide coverage for discharges of wastewater from CAFOs to waters of the state of Washington. The CAFOs that will be considered during development of one or more general permits include:

Horses and sheep.


Dairy cows and cattle.

Swine, poultry, and veal calves.

We expect to complete the draft version of the general permit(s) and release it for public comment by October 2004. Notification will be provided if there are significant changes to this schedule.

October 2004 Public notice of draft general permit.
November 2004 Public hearings and public comment period.
January 2005 Issue final general permit. Request application from new permittees.
February 2005 Permit is effective.

We intend to form an advisory group to assist in the development of the general permit(s) and ask those interested in participating to contact Diane Dent at (360) 407-6616. Members of the Permit Subcommittee of the Livestock Program Oversight Committee (recently created by the Washington State Department of Agriculture) are already part of the advisory committee. Others are encouraged to join.

A mailing list will be maintained to inform the public of significant stages in the development of the general permit(s) including notices of draft permit, public hearings, and issuance of the permit. Information will also be posted on the Department of Ecology's web page for the CAFO NPDES general permit at

To join the mailing list, to comment on the appropriateness of general permits instead of individual permits, or to provide information on potential dischargers, please contact Diane Dent, Washington Department of Ecology, P.O. Box 47600, Olympia, WA 98504-7600, e-mail

If you have any questions please call Andrew Kolosseus at (360) 407-7543, e-mail, or Diane Dent at (360) 407-6616, e-mail, or send by postal mail to Department of Ecology, Attention: Andrew Kolosseus, P.O. Box 47600, Olympia, WA 98504-7600.


Your operation is a concentrated animal feeding operation (CAFO) if:

You confine animals for at least 45 days in a 12-month period and

There's no grass or other vegetation in the confinement area during the normal growing season and

The operation meets one of the following CAFO definitions:


Your operation is a large CAFO if it has at least:

700 mature dairy cows

1,000 beef cattle or heifers

1,000 veal calves

500 horses

10,000 sheep or lambs

2,500 swine (each 55 lbs or more)

10,000 swine (each under 55 lbs)

55,000 turkeys

5,000 ducks (liquid manure handling systems - like operations with "wet" lots, lots with storage ponds, lots with swimming areas, and operations that flush manure from confinement buildings to lagoons)

30,000 ducks (other than liquid manure handling systems)

30,000 chickens (liquid manure handling systems - like caged housing where manure is flushed to a lagoon)

125,000 chickens except laying hens (other than liquid manure handling systems)

82,000 laying hens (other than liquid manure handling systems)


Your operation is a medium CAFO if:

A human-made ditch or pipe carries manure or wastewater from your operation to surface water, or

Your animals come into contact with surface water running through the area where they're confined

And your operation has at least:

200 mature dairy cows

300 beef cattle or heifers

300 veal calves

150 horses

3,000 sheep or lambs

750 swine (each 55 lbs or more)

3,000 swine (each under 55 lbs)

16,500 turkeys

1,500 ducks (liquid manure handling systems)

10,000 ducks (other than liquid manure handling systems)

9,000 chickens (liquid manure handling systems)

37,500 chickens except laying hens (other than liquid manure handling systems)

25,000 laying hens (other than liquid manure handling systems)


No matter what size your operation is, if it is an animal feeding operation, it may be designated a CAFO. If your operation is a significant contributor of pollutants, you might need a CAFO permit.

Legislature Code Reviser 


Washington State Code Reviser's Office