Winter 2008

Dec. 31 Deadline for Combined Indoor/Outdoor Livestock Operations

PRINT VERSION (pdf) Download the Winter 2008 issue of Iowa Manure Matters - Odor and Nutrient Management Newsletter in pdf format.

By Karen Grimes and Randy Clark, Iowa Department of Natural Resources

Act Now! — What to Do If You Need a PermitAs many producers with combined open feedlot/confinement operations already know, they may be required to apply for a National Pollutant Discharge Elimination System (NPDES) permit by Dec. 31, 2008.

Those who must apply include producers who meet both of the following conditions:

  • House a large number of animals of the same type in both indoor (totally roofed) and outdoor facilities. The key words here are “animals of the same type” as provided in federal regulations
  • Have manure, manure-laden runoff or process wastewater (such as bedding or feedstuffs) run off to reach Iowa waters.

Dairy and cattle producers are the most likely to be affected by this requirement. It’s important to understand that mature dairy cows are one distinct type of animal. It takes 700 or more milked or dry mature dairy cows housed both indoors and out to need an NPDES permit. Another separate type of animal is veal calves, with 1,000 or more in combined housing requiring a permit. Then, all other cattle (1,000 or more) would be a third and different type of animal. This category could include heifers or steers; dairy or beef. See table 1 for a list of animal types and the number of animals needed to determine permit status.

Swine producers with 2,500 finishers who have combined confinement and partially roofed open lots could also need a permit.

More information and the animal numbers for each type can be found in a fact sheet on the DNR web site at 

Producers who think their operation may need a permit should act quickly to apply for the NPDES permit before Dec. 31. Please note that this change is in addition to requirements concerning when an open feedlot, not combined, must obtain an NPDES permit; those requirements have not changed. 


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