University of Illinois Extension

Illini DairyNet Papers

Basic Practices for Reducing Surface and Groundwater Pollution from Illinois Dairy Farms
Ted L. Funk and Randy E. Fonner


  • If your dairy farm wasn’t planned and built to prevent water pollution, the farm may be a target for regulatory action.
  • Some changes that you can make may greatly reduce the amount of pollutants leaving your farm, and possibly keep you out of trouble.
  • Manage to keep storm runoff out of streams and daily wastewater during the times of low stream flow.

Today’s livestock production climate is tough. Regulatory issues add to the challenges, but working effectively with those issues is important to your farm’s survival and the sustainability of the dairy industry in the Midwest. Of those regulatory issues, water pollution control is a vital consideration for Illinois dairy farmers.

It is against federal and state laws for you to release contaminated water that is, water that contains manure, feed, milk, detergents, silage leachate, etc. into streams, lakes, rivers, or water wells. These laws have been in effect for thirty years. You don’t have to look far to find livestock producers who have violated the statutes, have had complaints filed, and are paying the price.

How will you reduce pollution from your farm, be a good neighbor, and stay in business? Here is a list of practices that may help you avoid water pollution complaints involving your dairy farm. The top three priorities are (1) reduce the volume of contaminated water leaving your property, (2) settle out solids from contaminated water to reduce the pollutant load, and (3) contain and/or treat daily discharges of contaminated water. Polluted water that you store must be applied to cropland at appropriate rates.

First, keep clean water clean. Don’t give clean stormwater a chance to run across the feedlot and carry pollutants off the site. Divert all non-contaminated water from the feedlot. Installing and maintaining gutters on barns is one of the first things regulators mention when they investigate feedlot problems. Build berms around feedlots so that “outside” rainwater or snowmelt does not drain across a manure-covered surface and thus become contaminated too. Fix overflowing waterers and tanks. Consider building more roof area over the feedlot, to reduce total contaminated runoff from the site.

Second, settle, collect and land-apply solids in feedlot runoff. Solids that settle out of the contaminated feedlot runoff actually contain a fairly large proportion of the pollutants that you must retain on your property. Scrape feedlots frequently into the manure storage area or storage structure, especially during the rainy seasons. Install a porous dam, weir, or other feedlot drainage to slow down the flow of contaminated water leaving the feedlot, so the solids will have time to settle out as much as possible.

Third, capture daily wastewater for on-the-spot treatment, or for land application later. Catch the first few gallons of milk solids-rich pipeline rinse water after each milking, and feed that rinsate to animals rather than drain it as uncontrolled wastewater.

Here are some other items to consider. These will require more investment, and you may want to inquire about cost sharing through EQIP or other government programs.

Concentrate feedlot runoff.

Remember the “gold standard” to attain is zero point-source discharge from your livestock operation. To achieve zero discharge there are two acceptable options for handling contaminated runoff: (1) put the water in a holding pond or other storage until you can apply the water on cropland, or (2) let the water pass through a “vegetative filter”, a specially designed grass waterway. Sometimes the most creative part is how to get the water from the feedlot to the storage or treatment area. If you don’t have storage or treatment yet, the first step in the plan is to concentrate the runoff. Use the available feedlot slopes and existing channels. By having only one or two runoff points you can more easily move the contaminated runoff water to storage or treatment areas later. Use curbs, slopes and/or berms in and around the feedlot. Plan how you would now or eventually be able to transfer the runoff water by gravity or pumps to the holding or treatment area. If the farm is built on very hilly terrain and at the bottom of a slope (“pollution control by dilution,” a popular method of runoff control many years ago) you will almost certainly have to pump the liquid uphill sometime.

Collect and treat or land-apply feedlot runoff liquid.

Construct a vegetative filter area or holding pond. Install a lift station to transfer the liquid. If you are building a holding pond, you will need to devise a small irrigation system for applying the liquid to cropland. A liquid manure tanker is a much more expensive way to apply “dirty water” to cropland than a small sprinkler irrigation system is.

Treat milking center wastewater.

There are several ways to treat daily wastewater. Alternate-dosed vegetative filters a filter system that lets one filter “rest” while dosing the other with liquid are a good solution. You might consider putting in a storage tank for milking center wastewater, and having that tank pumped out periodically. For that option, water conservation and wastewater re-use should be implemented wherever possible, to reduce the total liquid amount. See the publication, Guideline for Milking Center Wastewater, NRAES-115, for designs and applications.

Isolate and protect water wellheads from contamination.

Test well water to see if there is a significant problem with nitrates or bacteria. Improve wellhead construction to approved levels, and be sure to fence cattle away from the area near the wellhead. Slope the grade within 50 feet to drain away from the wellhead.

Hold or treat silo leachate.

Liquid seeping from silos is a very strong pollutant. A dual flow system to hold concentrated leachate and release dilute liquid to a vegetative filter is an excellent method for reducing discharges of this pollutant to surface water. If you have a liquid manure system you may prefer to drain or pump the silo leachate into the liquid manure storage. See for designs and more information on silage leachate control.

Minimize manure spreading on sloping, frozen ground.

Increase the size of your manure storage facility to give storage capacity that allows for timely land application of manure. Maintain and operate manure spreaders in a manner that minimizes manure spillage on roadways.

Develop a manure management plan.

Include a scaled map of facilities showing runoff areas, water sources, all slopes, etc. Put in animal inventories, manure storage descriptions, and field maps with pertinent crops and soils information. Keep records of manure sample laboratory results and manure applications. See the Illinois Manure Management Plan section of the Department of Agricultural Engineering web page at

Good general sources of information on manure management and pollution control are available through MidWest Plan Service. Ask for MWPS-7, Dairy Freestall Housing and Equipment, and MWPS-18 Section 2, Manure Storages, Manure Management Systems Series.

PLEASE NOTE: By Illinois state law (latest amendments to the LMFA or Livestock Management Facilities Act), any construction involving barns, manure storages, feedlots, vegetative filters, and anything else that involves manure must be approved by the Illinois Department of Agriculture. Plan ahead, and contact IDOA for details before you start any construction. Information on the LMFA is available at

Where to get publications: Order NRAES and MWPS publications by e-mailing the authors or by contacting the Department of Agricultural Engineering, University of Illinois, 332E AESB, 1304 W. Pennsylvania Ave., Urbana, IL 61801, phone 217.333.3572.