Feedlot/Wastewater Filter Strip
A vegetated wastewater treatment strip on a feedlot. Photo courtesy of Sauk County (WI).
Looking upslope at a wastewater treatment strip with two gravel spreaders. Photo courtesy Stearns County (MN) SWCD.
A feedlot filter strip immediately down-slope from a runoff spreader and manure settling basin, where manure solids settle out before the liquids are released to the filter strip. Photo courtesy USDA NRCS.
A fenced, newly constructed feedlot/ wastewater filter strip prior to grass planting. Photo courtesy Stearns (MN) SWCD.
Feedlot/wastewater filter strips are generally areas of grassy vegetation engineered to receive and treat feedlot wastewater before it has a chance to enter nearby waters. Feedlot/wastewater filter strips are a key feature and usually the final component of runoff control systems required on open feedlots in Minnesota.
Minnesota feedlot regulations (Minnesota Rules Chapter 7020) identify five levels of runoff control. Level 1 controls are the strictest and generally apply to the largest feedlots (those with more than 1,000 animal units, where one animal unit equals 1,000 lbs. live weight), while Level 5 controls generally apply to the smallest. Level 1 controls require full containment (no discharges) but Levels 2 through 5 can be achieved with runoff treatment systems, all of which involve vegetated feedlot/wastewater filter strips.
The Minnesota feedlot rule refers to feedlot/wastewater filter strips as infiltration areas, treatment strips or buffer strips depending on the exact way in which runoff is treated at each level. (Each level from Level 2 to Level 5 has distinct requirements and the engineering specifications can be complex.) In any case, a process to separate or settle out manure solids from liquids generally comes first; then the liquids are released to the wastewater filter strip. Filter strips may include gravel beds, woodchip beds or other devices to spread runoff uniformly.
Treatment system requirements for the smallest feedlots are generally simpler. Other factors in addition to feedlot size may determine the required treatment level, such as site characteristics and proximity to and condition of local surface waters.
Guidance from USDA's Natural Resources Conservation Service
Minnesota feedlot regulations
See contacts for specific programs that fund this practice in the side-by-side payment comparison or contact your local Soil and Water Conservation District