United States
Environmental Protection
Agency
Office of Water
(4606)
EPA916-F-01-026
July 2001
Source Water Protection
Practices Bulletin
Managing Livestock, Poultry, and
Horse Waste to Prevent
Contamination of Drinking Water
Animal waste or feces have long been isolated from people for public health reasons. Yet,
animal waste is deposited daily into rivers, streams, and other water bodies. This waste poses a
continuous threat to human health. Appropriate steps must be taken to lower this risk and
prevent contamination of drinking water sources. This fact sheet addresses some source water
contamination prevention measures related to livestock, poultry, and horses that can improve
water quality and reduce the burden on drinking water treatment facilities. (Refer to the fact
sheet on pet and wildlife waste for information on management measures related to these
animals.)
SOURCES OF ANIMAL WASTE
Livestock and poultry are major
sources of waste. Estimates indicate
that the amount of livestock waste is 13
times greater than the amount of human
sanitary waste generated in the United
States. Livestock and poultry waste
can be introduced to the environment
through direct discharges, through land
application of manure, and from open
feedlots, barns and housing, and
pastures.
Cattle feedlot
Companion animals, such as horses
used for showing and recreation, also produce waste that should be accounted for in pollution
prevention. Horses raised on hobby farms, while similar to livestock, are managed differently,
allowing for alternative prevention measures. The average horse produces about 45 pounds of
waste each day, an amount that can be overwhelming to those operating small, suburban horse
farms. Horses are rarely kept in a single facility of more than 50 animals. Although this lower
density eliminates some of the concerns that pertain to livestock, horse waste can be managed
using many of the same prevention measures used for livestock.
WHY IS IT IMPORTANT TO MANAGE ANIMAL WASTE NEAR THE SOURCES OF
YOUR DRINKING WATER?
Animal waste contains many pollutants that can contaminate surface and ground waters used as
drinking water sources. Probably the greatest health concern associated with livestock,
poultry, and horse wastes is pathogens. Many pathogens found in animal waste can infect
humans if ingested. Organisms like Cryptosporidium, Giardia lamblia, and Salmonella can
induce symptoms ranging from skin sores to chest pain. E. coli, which causes diarrhea and
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abdominal gas, has been the source of disease outbreaks in several States. Particularly virulent
strains of E. coli can cause serious illness and even death. Cryptosporidium is of particular
concern because it is highly resistant to disinfection with chlorine. This protozoan causes
gastrointestinal illness that lasts 2 to 10 days in healthy individuals but can be fatal in people
with weakened immune systems. Cryptosporidium was responsible for more than 50 deaths
and an estimated 403,000 illnesses after contaminating a Milwaukee drinking water supply.
Runoff from cow manure application sites was a suspected source of the Cryptosporidium.
Animal wastes can contribute to nitrates in drinking water. Consumption of nitrates can cause
methemoglobinemia (blue baby syndrome) in infants, which reduces the ability of the blood to
carry oxygen. If left untreated, methemoglobinemia can be fatal. Because of this health risk,
EPA set a drinking water maximum contaminant level (MCL) of 10 milligrams per liter or
parts per million for nitrate measured as nitrogen.
Animal waste contains many other pollutants of concern that affect humans and water quality.
Such pollutants include oxygen-demanding substances that can lead to fish kills and degraded
water quality. Solids from animal waste can increase turbidity and adversely affect the taste
and odor of waters. In addition, metals such as arsenic, copper, selenium, and zinc, which are
often added to animal feed, can be toxic to humans. Antibiotics, pesticides, and hormones, also
used in animal feeding operations, can become harmful pollutants as well.
AVAILABLE PREVENTION MEASURES TO ADDRESS ANIMAL WASTE
Many prevention measures can
significantly reduce the impact of
waste from livestock, poultry, and
horses on water supplies. These
measures vary greatly in complexity
and cost. It should be noted that
individual prevention measures might
not be adequate to prevent
contamination of source waters.
Measures should be combined in an
overall pollution prevention approach
that considers the nature of the animal
waste, the vulnerability of the drinking
water sources, and the cost and
operation and maintenance
requirements of the measures.
Proper management of livestock waste
includes preventing animals and their
waste from coming into contact with
runoff and water sources, properly
applying waste as fertilizer on crop or
pastures, and appropriately managing
pastures.
Feedlot Management Measures
Several options are available to reduce
contact between manure and
precipitation or runoff through proper
storage and treatment of the manure
from animal operations. Among them are waste storage lagoons, litter storage structures, clean
water diversions, composting, and runoff treatment.
CAFO Permits
Under the National Pollutant Discharge Elimination
System (NPDES) regulations, concentrated animal
feeding operations (CAFOs) are defined as point
sources and are subject to permitting where they
discharge or have the potential to discharge pollutants
(40 CFR 122.23). EPA regulations define a CAFO
based on the size of the animal feeding operation or its
size in combination with the manner of discharge. An
animal feeding operation can also be designated a
CAFO when the permit authority determines it is a
significant source of pollution. A NPDES permit
authorizes, and imposes conditions on, the discharge
of pollutants. The permit must include technology-
based limitations and, if necessary, more stringent
water quality-based limitations. EPA has published
technology-based limitations (e.g., effluent guidelines)
for feedlots at 40 CFR Part 412. The guidelines
include numeric limits, non-numeric effluent
limitations, and requirements for facilities to use
specific BMPs. EPA published a proposed rule in the
Federal Register on January 12, 2001 (66 FR 2960),
that would revise and update both the definition of a
CAFO and the effluent guidelines for feedlots. These
revisions seek to address water quality issues posed by
changes in the animal production industry as well as to
more effectively address the land application of
CAFO-generated manure and process wastewater.
Additional information on this proposed rule can be
obtained at http://www.epa.gov/npdes/afo.
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A lagoon, or waste storage pond, is made by excavating earth fill to provide temporary storage
of animal waste. This practice can reduce the amount of organics, pathogens, and nutrients
entering surface waters; however, lagoons can contaminate ground water if they are not
constructed and maintained
properly. Lagoons have three
distinct zones containing liquids,
sludge, and solids. These wastes
can later be pumped out and
applied to cropland as fertilizer.
Because of the risk to ground
water, good planning, design, and
maintenance are critical when
using a lagoon for animal waste
Lagoon storage. Two important
components are the location and
the liner of the lagoon. A lagoon should be placed in accordance with State and local
requirements for separation distances from nearby drinking water wells. Lagoons should be
located downslope from wells and never sited on floodplains. Lagoons should be designed to
contain at least a 25-year, 24-hour storm plus process wastewater. (A 25-year storm is one that
has a one-in-25 chance of
occurrence in a given year).
A lagoon should be constructed
with a low-permeability liner
made of synthetic material or
geotextiles or formed by
compacted clay or other soil
material. Once the liner is
established, it is imperative to
maintain its integrity during the
waste removal process. Any
erosion can lead to seepage and
subsequent contamination of
ground water. Two practices to
protect the liner are building a
concrete access ramp for waste
removal equipment, and operating equipment under dry conditions by first removing all the
liquids and letting the solids dry.
Poultry litter storage facilities are designed to keep rainwater and runoff away from poultry
house waste being stored for later application to crops. Litter storage can ensure that poultry
waste is applied under the proper conditions to protect the environment and to coincide with
soil and crop needs. Types of litter storage buildings (ranging from the least to the most
protective of water sources) include open stockpiles, covered stockpiles, bunker-type storage,
and roofed storage structures. The appropriate size of the storage structure depends on the
amount of litter removed and how often the poultry houses are cleaned out.
Clean water diversion is an effective measure that prevents contamination of precipitation or
surface flow as it makes its way to drinking water sources. Proper storm water management in
and around feedlots and livestock yards, including proper protection (or isolation) of
agricultural drainage well inlets, is essential to guarding against ground water contamination.
Rain gutters and downspouts on animal shelter roofs keep runoff clean by directing
precipitation away from manure. Another tactic to prevent runoff contamination is to construct
superficial diversions, such as earthen ridges or diversion terraces built above the feedlot or
barnyard, to direct surface flow away from waste.
Hog parlor with lagoon
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Composting can help eliminate pathogens and reduce the volume of manure. Composting is
the controlled biological decomposition of organic materials; it can be aerobic (occurring with
oxygen) or anaerobic (occurring with little or no oxygen). It is perhaps the most common and
least costly method of handling livestock waste. Compost sites should be located away from
drinking water wells and water sources to avoid leaching during heavy rain. Also, piles should
be situated on fairly flat sites where water does not collect or run off. Once manure has fully
broken down into usable compost, it can be spread as fertilizer, using proper application
methods. Composting should take place at the correct temperature and for an appropriate
length of time to kill the pathogens in the manure.
Once runoff becomes contaminated, vegetative filter strips and other means can be used to
control overland flow. Such measures treat the runoff from feedlots or grazing areas by
absorbing nutrients, bacteria, and chemicals. More detailed descriptions of these types of
prevention measures can be found in the fact sheet on managing storm water runoff.
Proper Land Application of Manure
Effective nutrient management minimizes the quantity of nutrients available for loss. This is
achieved by developing a comprehensive nutrient management plan and using only the types
and amounts of nutrients necessary
to produce the crop, applying
nutrients at the proper times and
with appropriate methods,
implementing additional farming
practices to reduce nutrient losses,
and following proper procedures
for fertilizer storage and handling.
Correct placement of manure in
the root zone can greatly enhance
plant nutrient uptake and minimize
losses. Manure should be . . . , „ ....
Animal waste used as fertilizer
incorporated into the subsurface,
rather than simply applied to the surface to reduce runoff and production of vapors. Waste
should never be applied to frozen, snow-covered, or saturated ground. Good management of
irrigation water can help maximize efficiency and minimize runoff or leaching.
Proper manure application rates are also important. Applying waste at the time of maximum
crop uptake can minimize loss to surface runoff and decrease the amount of manure needed to
fertilize crops. Calculating the optimal rate of application also includes crediting other
sources that contribute nitrogen and phosphorus to the soil. Furthermore, appropriate manure
application is based on yield goals established by the crop producers. Yield expectations are
established for each crop and field based on soil properties, available moisture, yield history,
and management level. Soil sampling is necessary to determine plant nutrient needs and to
make accurate fertilizer recommendations.
Conservation tillage and buffers can reduce runoff over feeding and grazing lands and transport
of livestock wastes to water sources. In conservation tillage, crops are grown with minimal
cultivation of the soil. Plant residues are not completely incorporated into the soil; instead they
remain to provide cover and reduce runoff. Buffer strips and filter strips are created by
planting dense vegetation near surface water bodies. The vegetation reduces runoff and filters
sediments and chemicals. For more information on buffer strips and filter strips, see the fact
sheet on storm water runoff.
In some areas of the country, the amount of animal waste produced is more than can be used by
all the crops in the area. In these cases, programs to move the excess manure out of the
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watershed or source water protection area or to develop an alternative use for the manure
(other than land application) might be necessary.
Crop rotation can often yield crop improvement and economic benefits by minimizing
fertilizer and pesticide needs. Planting legumes as part of a crop rotation plan provides
nitrogen for subsequent crops. Deep-rooted crops can be used to scavenge nitrogen left in the
soil by shallow-rooted crops. See the fact sheet on agricultural application of fertilizer for
additional information on measures such as laser-controlled land leveling, conservation tillage,
and buffer strips.
Pasture Management
Several methods are available to keep livestock away from
water bodies. In addition to preventing damage to stream
banks, fencing can be used to keep livestock from defecating
in or near streams or wells. Fencing designs include
standard or
conventional
(barbed or smooth wire), suspension, woven wire,
and electric fences. The height, size, spacing, and
number of wires and posts are a function of the
landscape topography as well as the animals of
concern. Optimum design criteria depend on the
specific situation and should be developed through
consultation with biologists. Providing alternative
water sources and hardened stream crossings for
use by livestock lessens their impact on water
quality.
FOR ADDITIONAL INFORMATION
These sources contain information on animal waste pollution prevention measures. All of the
documents listed are available free of charge on the Internet.
Contact the Natural Resources Conservation Service (NRCS), Conservation District, and
Agricultural Extension Service representatives in your area. They can provide more
information on nutrient management and cost-share programs, such as the Environmental
Quality Incentives Program (EQIP), the Conservation Reserve Program (CRP), and the
Conservation Reserve Enhancement Program (CREP), to assist in financing source water
protection measures.
The Center for Watershed Protection, Storm Water Manager's Resource Center. Pollution
Prevention Fact Sheet: Animal Waste Collection. Retrieved February 19, 2001, from the
World Wide Web: http://www.stormwatercenter.net
Fulhage, Charles D. (1993, October). Storing Poultry Litter. University of Missouri-Columbia,
Department of Agricultural Engineering. Water Quality Initiative Publication WQ212.
Retrieved May 21, 2001, from the World Wide Web:
http://muextension.missouri.edu/xplor/envqual/wq0212 .htm
Hammond, C. Animal Waste and the Environment. The University of Georgia College of
Agricultural & Environmental Sciences Cooperative Extension Service. Retrieved January 19,
2001 from the World Wide Web: http://www/ces.uga.edu/pubcd/c827-w.html
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Kellogg, R. L., C.H. Lander, D. C. Moffitt, and N. Gollehon. (2000, December). Manure
Nutrients Relative to the Capacity of Cropland and Pastur eland to Assimilate Nutrients:
Spatial and Temporal Trends for the United States. U. S. Department of Agriculture, Natural
Resources Conservation Service Economic Research Service. Retrieved May 21, 2001, from
the World Wide Web: http://www.nhq.nrcs.usda.gov/land/pubs/manntr.html
Koelsch, R. (1999, January) Sludge Management for Anaerobic Lagoons and Runoff Holding
Ponds. Nebraska Cooperative Extension. G98-1371-A. Retrieved February 27, 2001, from
the World Wide Web: http://www.ianr.unl.edu/pubs/wastemgt/gl371.htm
Natural Resource Conservation Service, Water Science Institute. (2000, June). Waterborne
Pathogens in Agricultural Watersheds. Retrieved May 1, 2001, from the World Wide Web:
http://www.wcc.nrcs.usda.gov/watershed/products.html
North Carolina State University Water Quality Group. (2000, August). National Management
Measures to Control Nonpoint Source Pollution from Agriculture [Draft]. U.S. EPA, Office
of Water, Nonpoint Source Control Branch. Retrieved May 1, 2001, from the World Wide
Web: http://www.epa.gov/owow/nps/agmm/index.html
U.S. Department of Agriculture, Natural Resources Conservation Service. (1999, August).
Conservation Practices Training Guide. Retrieved April 30, 2001, from the World Wide Web:
http://www.ftw.nrcs.usda.gov/tech_ref.html
U.S. Department of Agriculture, Natural Resources Conservation Service. (2000, December).
Comprehensive Nutrient Management Planning - Technical Guidance. Retrieved April 30,
2001 from, the World Wide Web:
http://www.nhq.nrcs.usda.gov/PROGRAMS/ahcwpd/ahCNMP.html
U.S. EPA, Office of Ground Water and Drinking Water. (1999, April). Uncovered Finished
Water Reservoirs Guidance Manual. EPA-815-R-99-011. Retrieved February 19, 2001, from
the World Wide Web: http://www.epa.gov/safewater/mdbp/pdf/uncover/ufw8p.pdf
U.S. EPA, Office of Science and Technology. (1999, January). Preliminary Data Summary:
Feedlots Point Source Category Study. EPA-821-R-99-002. Retrieved February 19,2001,
from the World Wide Web: http://www.epa.gov/ostwater
The following sites provide publications and information on livestock management and related
prevention measures:
Idaho One Plan (http://www.oneplan.org) provides a catalog of best management
practices.
Iowa State University Extension. http://www.exnet.iastate.edu/Pages/pubs/fml.htm
Michigan Department of Agriculture. Right to Farm Program.
http: //www .mda. state .mi .us/right2farm/farm .htm
Texas Agricultural Extension Service, http://agextension.tamu.edu
U.S. Department of Agricultural, Natural Resources Conservation Service's
Conservation Practice Standards site provides links to State Conservation Practice
Standards and other documents. http://www.ftw.nrcs.usda.gov/practice_stds.html
U.S. EPA, Office of Wastewater Management, has a site dedicated to animal feeding
operations. http://www.epa.gov/owmitnet/afo .htm
U.S. EPA, Office of Wetlands, Oceans, and Watersheds.
http ://www .epa.gov/owow/nps/agriculture .html
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