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Module 8: Open Feedlot Construction and Management for Water and Air Quality Protection. By Jeff Lorimor. Introduction. Open feedlots are defined as confined areas that are devoid of vegetation or crop residue where animals are held for 45 days per year. CAFO Definition.
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Module 8: Open Feedlot Construction and Management for Water and Air Quality Protection By Jeff Lorimor Certified Nutrient Management Planning
Introduction Open feedlots are defined as confined areas that are devoid of vegetation or crop residue where animals are held for 45 days per year. Certified Nutrient Management Planning
CAFO Definition Federal regulations define a Concentrated Animal Feeding Operation (CAFO) as a feedlot with capacity equal or exceeding: • 1,000 beef animals. • 700 dairy cows. • 2,500 swine over 55 pounds. • Other species of EPA-defined sizes. Certified Nutrient Management Planning
NPDES Permit CAFOS must obtain National Pollutant Discharge Elimination System (NPDES) permits. The permits: • Require capturing feedlot runoff. • Require pumping captured liquids onto crops. • Prohibit releasing runoff except in very large storms (25-yr, 24-hr storm). Certified Nutrient Management Planning
Other CAFO Requirements • Weekly inspection of storm water control devices • Must have depth markers in containments • Record-keeping requirements Certified Nutrient Management Planning
Nearby Water • Feedlots should not have streams running through them. • Feedlots should not drain directly into streams, ditches, tile intakes, or other waterways leading directly to waters of the state. Certified Nutrient Management Planning
Runoff Control and Management • Complete containment • Contain all runoff in a basin below the lot. • To prevent overflow, land apply (irrigate) the liquids. • Discharge systems • Useful for lots smaller than CAFOs • Release after settling solids in a manner that prevents water pollution. Certified Nutrient Management Planning
Diversions • Runoff control should start by diverting clean water away from the lot surface. Downspouts Certified Nutrient Management Planning
Settling Solids • All feedlots should have solids settling basins (debris basins) to capture solids from the feedlot runoff. Certified Nutrient Management Planning
Settling Solids (continued) • Solids settling basins do not store liquids permanently. • Liquid velocity is slowed, but the liquid is released. • State regulations may determine basin design. • Porous outlets should be unplugged frequently to enhance liquid release. • Solids should be removed frequently. Certified Nutrient Management Planning
Nutrients are in Solids • Most of the nutrients (> 90%) from open feedlots are found in the solids, not in runoff liquids. Certified Nutrient Management Planning
Containment Structures • Must have capacity to store runoff from the 25-yr, 24-hr storm • If inadequate capacity exists, pump out the containment. • Maintain the structure in good condition. • Control erosion. • Eliminate rodents. • Keep mowed. • Maintain depth indicator gauge. • Keep accurate records. Certified Nutrient Management Planning
Air Quality • In Western states, dust and odor are bigger concerns than water quality. They are affected by the moisture content of the feedlot surface. • Too dry…dust results • Too wet…odor results • In more humid regions, surface runoff is the primary concern. Certified Nutrient Management Planning
Between 25%–40% Moisture is Optimum in a Feedlot Certified Nutrient Management Planning
Corral Construction • If possible, build on 3%-5% slopes. • Avoid pen-to-pen drainage. • Build mounds up and down the slope, not across the slope. • Build mounds so cattle have access to them without going through a pothole. • Provide convenient access for manure removal. Certified Nutrient Management Planning
Properly Constructed Mounds Stay Dry Certified Nutrient Management Planning
Open Lot Maintenance • Proper maintenance is the most important factor in avoiding air and water quality problems with open lots. • Pull blades are better than push blades for maintenance. Certified Nutrient Management Planning
Make Mounds of Good Soil–Not Manure Mounds should run up and down, rather than across, the slope. Certified Nutrient Management Planning
Open Lot Dust is a Function of • Loose manure depth on the corral surface. • The moisture content of the loose manure. • Hoof action arising from cattle activity. Certified Nutrient Management Planning
Corral Maintenance Keep the surface as hard, smooth, and dry as possible. • Minimize hoof prints that can hold water. • Scrape manure to maintain a 1"-2” base of manure above the soil surface. • Frequently inspect and fill holes and depressions. Certified Nutrient Management Planning
Dust Emissions Loose manure depth is a function of… • Stocking density (animals per unit area). • Animal bodyweight. • Number of days on feed. • Corral surface condition (e.g., wallows, “dust pots”). • Manure harvesting frequency. Certified Nutrient Management Planning
Loose Manure Depth Deep and soft Thin and well compacted Certified Nutrient Management Planning
Manure not yet harvested > 2” deep Manure harvested within previous 3 days < 1” deep Certified Nutrient Management Planning
Manure Moisture Content Certified Nutrient Management Planning
Moisture from Heat Control • Sprinkling lots during hot weather can create wet conditions in humid areas. • Sprinkle only intermittently. • Locate sprinklers in areas that will not create potholes. • Sprinklers should provide 0.25”/day or more. • Patterns should overlap 50% of the diameter. • Do not sprinkle the feed apron. Certified Nutrient Management Planning
Stocking Density • Increased stocking density adds more moisture to the lot surface from cattle urination. • Texas research showed reduced Pm-10 emission at 75 sq ft/head vs. 150 sq ft/head. • Other factors such as cattle performance are important in determining maximum density. Certified Nutrient Management Planning
1 2 3 4 Feed apron Manure Moisture Content Water Trough Low activity; Low moisture High activity; High moisture Certified Nutrient Management Planning
Dust Control • Applying water to the feedyard surface, passively or actively, helps but is not a cure-all. • Frequent manure harvesting (> 1 per turn) decreases water requirements and increases water effectiveness. • Use the off-season to get ready. • Prioritize within the yard and the corral. Certified Nutrient Management Planning
Mortality Management for Odor Control • Limit exposure to the elements; use rapid rendering service pickup. • Compost. • Perforate or cleave thoracic cavity and cover carcass with 1'-2' of dry, organic material. • Burial is no longer acceptable in many states. Certified Nutrient Management Planning
Summary • Preventing water and air pollution from open feedlots starts with good lot design. • Management and maintenance are the keys to ongoing pollution prevention. • Maintain smooth dry lots. • Adjust moisture and scrape carefully to minimize particulate and gas emissions. Certified Nutrient Management Planning