B1. Management Measure for Facility Wastewater and Runoff from Confined
Animal Facility Management (Large Units)
Limit the discharge from the confined animal facility to surface waters
by:
- Storing both the facility wastewater and the runoff from confined animal
facilities that is caused by storms up to and including a 25-year, 24-hour
frequency storm. Storage structures should:
- Have an earthen lining or plastic membrane
lining, or
- Be constructed with concrete, or
- Be a storage tank;
and
- Managing stored runoff and accumulated solids
from the facility through an appropriate waste utilization system.
This management measure is intended for application by States to all new
facilities regardless of size and to all new or existing confined animal
facilities that contain the following number of head or more:
Head Animal Units (2)
Beef Feedlots 300 300
Stables (horses) 200 400
Dairies 70 98
Layers 15,000 150 (3)
495 (4)
Broilers 15,000 150 (3)
495 (4)
Turkeys 13,750 2,475
Swine 200 80
(2) See Animal Unit in Glossary
(3) If facility has a liquid manure system
(4) If facility has continuous overflow watering
except those facilities that are required by Federal regulation 40 CFR 122.23
to apply for and receive discharge permits. That section applies to
"concentrated animal feeding operations," which are defined in 40 CFR Part 122,
Appendix B. In addition, 40 CFR 122.23(c) provides that the Director of an
NPDES discharge permit program may designate any animal feeding operation as a
concentrated animal feeding operation (which has the effect of subjecting the
operation to the NPDES permit program requirements) upon determining that it is
a significant contributor of water pollution. In such cases, upon issuance of a
permit, the terms of the permit apply and this management measure ceases to
apply.
Under the Coastal Zone Act Reauthorization Amendments, States are subject to
a number of requirements as they develop coastal nonpoint programs in
conformity with this measure and will have some flexibility in doing so. The
application of management measures by States is described more fully in
Coastal Nonpoint Pollution Control Program: Program Development and Approval
Guidance, published jointly by the U.S. Environmental Protection Agency
(EPA) and the National Oceanic and Atmospheric Administration (NOAA) of the
U.S. Department of Commerce.
A confined animal facility is a lot or facility (other than an
aquatic animal production facility) where the following conditions are met:
- Animals (other than aquatic animals) have been, are, or will be stabled or
confined and fed or maintained for a total of 45 days or more in any 12-month
period, and
- Crops, vegetation forage growth, or post-harvest residues are not sustained
in the normal growing season over any portion of the lot or facility.
Two or more animal facilities under common ownership are considered, for the
purposes of these guidelines, to be a single animal facility if they adjoin
each other or if they use a common area or system for the disposal of wastes.
Confined animal facilities, as defined above, include areas used to grow or
house the animals, areas used for processing and storage of product, manure and
runoff storage areas, and silage storage areas.
Facility wastewater and runoff from confined animal facilities are to be
controlled under this management measure (Figure 2-7). Runoff includes any
precipitation (rain or snow) that comes into contact with any manure, litter,
or bedding. Facility wastewater is water discharged in the operation of an
animal facility as a result of any or all of the following: animal or poultry
watering; washing, cleaning, or flushing pens, barns, manure pits, or other
animal facilities; washing or spray cooling of animals; and dust control.
The problems associated with animal facilities result from runoff, facility
wastewater, and manure. For additional information regarding problems, see
Section I.F.3 of this chapter.
Application of this management measure will greatly reduce the volume of
runoff, manure, and facility wastewater reaching a waterbody, thereby improving
water quality and the use of the water resource. The measure can be implemented
by using practices that divert runoff water from upslope sites and roofs away
from the facility, thereby minimizing the amount of water to be stored and
managed. Runoff water and facility wastewater should be routed through a
settling structure or debris basin to remove solids, and then stored in a pit,
pond, or lagoon for application on agricultural land (Figure 2-8). If manure is
managed as a liquid, all manure, runoff, and facility wastewater can be stored
in the same structure and there is no need for a debris basin.
For new facilities and expansions to existing facilities, consideration
should be given to siting the facility:
- Away from surface waters;
- Away from areas with high leaching potential; and
- In areas where adequate land is available to apply animal wastes in
accordance with the nutrient management measure.
This management measure does not require manure storage structures or
areas, nor does it specify required manure management practices. This
management measure does, however, address the management of runoff from
manure storage areas. Manure may be stacked in the confined lot or other
appropriate area as long as the storage and management of runoff from the
confined lot are in accordance with this management measure. If manure is
managed as a solid, any drainage from the storage area or structure area or
structure should be routed to the runoff storage system.
When applied to agricultural lands, manure, stored runoff water, stored
facility wastewater, and accumulated solids from the facility are to be applied
in accordance with the nutrient management measure. An appropriate waste
utilization system to minimize impacts to surface water and protect ground
water may be achieved through implementation of the SCS Waste Utilization
practice (633).
It is recognized that implementation of this measure may increase the
potential for movement of water and soluble pollutants through the soil profile
to the ground water. It is not the intent of this measure to address a surface
water problem at the expense of ground water. Facility wastewater and runoff
control systems can and should be designed to protect ground water.
Ground-water protection will also be provided by minimizing seepage to ground
water, if soil conditions require further protection, and by using the nutrient
and pesticide management measures to reduce and control the application of
nutrients and pesticides.
Seepage to ground water can be minimized by lining the runoff or manure
storage structure with an earthen lining or plastic membrane lining, by
constructing with concrete, or by constructing a storage tank. This is not
difficult to accomplish and should be achieved in the initial design to reduce
costs. For some soils and locations, movement of pollutants to the ground water
is not a concern, but site evaluations are needed to determine the appropriate
action to take to protect the resources at the site.
Operation and Maintenance of This Measure
Operation
Holding ponds and treatment lagoons should be operated such that the design
storm volume is available for storage of runoff. Facilities filled to or near
capacity should be drawn down as soon as all site conditions permit the safe
removal and appropriate use of stored materials. Solids should be removed from
solids separation basins as soon as possible following storm events to ensure
that needed solids storage volume is available for subsequent storms.
Maintenance
Diversions will need periodic reshaping and should be free of trees and
brush growth. Gutters and downspouts should be inspected annually and repaired
when needed. Established grades for lot surfaces and conveyance channels are to
be maintained at all times.
Channels should be free of trees and brush growth. Cleaning of debris
basins, holding ponds, and lagoons will be needed to ensure that design volumes
are maintained. Clean water should be excluded from the storage structure
unless it is needed for further dilution in a liquid system.
This management measure was selected for larger-sized animal production
facilities because it can eliminate the pollutants leaving a facility by
storing runoff from storms up to and including the 25-year, 24-hour frequency
storm. It also uses practices that reduce the amount of water that comes into
contact with animal waste materials. It requires that stored runoff and
accumulated solids from the facility are managed through an appropriate waste
utilization system. Any stored water, accumulated solids, processed dead
animals, or manure are to be applied in accordance with the nutrient management
measure.
The size limitations that define a large unit are based on EPA's analysis of
the economic achievability of the management measure.
The effectiveness of management practices to control contaminant losses from
confined livestock facilities depends on several factors including:
- The contaminant(s) to be controlled and their likely pathways in surface,
subsurface, and ground-water flows;
- The types of practices (section 5) and how these practices control surface,
subsurface, and ground-water contaminant pathways; and
- Site-specific variables such as soil type, topography, precipitation
characteristics, type of animal housing and waste storage facilities, method of
waste collection, handling and disposal, and seasonal variations. The
site-specific conditions must be considered in system design, thus having a
large effect on practice effectiveness levels.
The gross effectiveness estimates reported in Table
2-9 simply indicate summary literature values. For specific cases, a wide
range of effectiveness can be expected depending on the value and interaction
of the site-specific variables cited above.
When runoff from storms up to and including the 24-hour, 25-year frequency
storm is stored, there will be no release of pollutants from a confined animal
facility via the surface runoff route. Rare storms of a greater magnitude or
sequential storms of combined greater magnitude may produce runoff, however. Table 2-10 reflects the occurrence of such storms by
indicating less than 100 percent control for runoff control systems.
As discussed more fully at the beginning of this chapter and in Chapter 1, the
following practices are described for illustrative purposes only. State
programs need not require implementation of these practices. However, as a
practical matter, EPA anticipates that the management measure set forth above
generally will be implemented by applying one or more management practices
appropriate to the source, location, and climate. The practices set forth below
have been found by EPA to be representative of the types of practices that can
be applied successfully to achieve the management measure described above.
Combinations of the following practices can be used to satisfy the
requirements of this management measure. The U.S. Soil Conservation Service
(SCS) practice number and definition are provided for each management practice,
where available. Also included in italics are SCS statements describing the
effect each practice has on water quality (USDA-SCS, 1988).
- a. Dikes (356): An embankment constructed of
earth or other suitable materials to protect land against overflow or to
regulate water.
Where dikes are used to prevent water from flowing onto the floodplain,
the pollution dispersion effect of the temporary wetlands and backwater are
decreased. The sediment, sediment-attached, and soluble materials being
transported by the water are carried farther downstream. The final fate of
these materials must be investigated on site. Where dikes are used to retain
runoff on the floodplain or in wetlands the pollution dispersion effects of
these areas may be enhanced. Sediment and related materials may be deposited,
and the quality of the water flowing into the stream from this area will be
improved.
Dikes are used to prevent wetlands and to form
wetlands. The formed areas may be fresh, brackish, or saltwater wetlands. In
tidal areas dikes are used to stop saltwater intrusion, and to increase the
hydraulic head of fresh water which will force intruded salt water out the
aquifer. During construction there is a potential of heavy sediment loadings to
the surface waters. When pesticides are used to control the brush on the dikes
and fertilizers are used for the establishment and maintenance of vegetation
there is the possibility for these materials to be washed into the surface
waters.
- b. Diversions (362): A channel constructed
across the slope with a supporting ridge on the lower side.
This practice will assist in the stabilization
of a watershed, resulting in the reduction of sheet and rill erosion by
reducing the length of slope. Sediment may be reduced by the elimination of
ephemeral and large gullies. This may reduce the amount of sediment and related
pollutants delivered to the surface waters.
- c. Grassed waterway (412): A natural or
constructed channel that is shaped or graded to required dimensions and
established in suitable vegetation for the stable conveyance of runoff.
This practice may reduce the erosion in a
concentrated flow area, such as in a gully or in ephemeral gullies. This may
result in the reduction of sediment and substances delivered to receiving
waters. Vegetation may act as a filter in removing some of the sediment
delivered to the waterway, although this is not the primary function of a
grassed waterway.
Any chemicals applied to the waterway in the
course of treatment of the adjacent cropland may wash directly into the surface
waters in the case where there is a runoff event shortly after spraying.
When used as a stable outlet for another
practice, waterways may increase the likelihood of dissolved and suspended
pollutants being transported to surface waters when these pollutants are
delivered to the waterway.
- d. Heavy use area protection (561): Protecting
heavily used areas by establishing vegetative cover, by surfacing with suitable
materials, or by installing needed structures.
Protection may result in a general improvement
of surface water quality through the reduction of erosion and the resulting
sedimentation. Some increase in erosion may occur during and immediately after
construction until the disturbed areas are fully stabilized.
Some increase in chemicals in surface water may
occur due to the introduction of fertilizers for vegetated areas and oils and
chemicals associated with paved areas. Fertilizers and pesticides used during
operation and maintenance may be a source of water pollution.
Paved areas installed for livestock use will
increase organic, bacteria, and nutrient loading to surface waters. Changes in
ground water quality will be minor. Nitrate nitrogen applied as fertilizer in
excess of vegetation needs may move with infiltrating waters. The extent of the
problem, if any, may depend on the actual amount of water percolating below the
root zone.
- e. Lined waterway or outlet (468): A waterway or
outlet having an erosion-resistant lining of concrete, stone, or other
permanent material.
The lined section extends up the side slopes to a designed depth. The earth
above the permanent lining may be vegetated or otherwise protected.
This practice may reduce the erosion in
concentrated flow areas resulting in the reduction of sediment and substances
delivered to the receiving waters.
When used as a stable outlet for another
practice, lined waterways may increase the likelihood of dissolved and
suspended substances being transported to surface waters due to high flow
velocities.
- f. Roof runoff management (558): A facility for
controlling and disposing of runoff water from roofs.
This practice may reduce erosion and the delivery
of sediment and related substances to surface waters. It will reduce the volume
of water polluted by animal wastes. Loadings of organic waste, nutrients,
bacteria, and salts to surface water are prevented from flowing across
concentrated waste areas, barnyards, roads and alleys will be reduced.
Pollution and erosion will be reduced. Flooding may be prevented and drainage
may improve.
- g. Terrace (600): An earthen embankment, a
channel, or combination ridge and channel constructed across the slope.
This practice reduces the slope length and the
amount of surface runoff which passes over the area downslope from an
individual terrace. This may reduce the erosion rate and production of sediment
within the terrace interval. Terraces trap sediment and reduce the sediment and
associated pollutant content in the runoff water which enhances surface water
quality. Terraces may intercept and conduct surface runoff at a nonerosive
velocity to stable outlets, thus reducing the occurrence of ephemeral and
classic gullies and the resulting sediment. Increases in infiltration can cause
a greater amount of soluble nutrients and pesticides to be leached into the
soil. Underground outlets may collect highly soluble nutrient and pesticide
leachates and convey runoff and conveying it directly to an outlet, terraces
may increase the delivery of pollutants to surface waters. Terraces increase
the opportunity to leach salts below the root zone in the soil. Terraces may
have a detrimental effect on water quality if they concentrate and accelerate
delivery of dissolved or suspended nutrient, salt, and pesticide pollutants to
surface or ground waters.
- h. Waste storage pond (425): An impoundment made
by excavation or earth fill for temporary storage of animal or other
agricultural wastes.
This practice reduces the direct delivery of
polluted water, which is the runoff from manure stacking areas and feedlots and
barnyards, to the surface waters. This practice may reduce the organic,
pathogen, and nutrient loading to surface waters. This practice may increase
the dissolved pollutant loading to ground water by leakage through the
sidewalls and bottom.
- i. Waste storage structure (313): A fabricated
structure for temporary storage of animal wastes or other organic agricultural
wastes.
This practice may reduce the nutrient, pathogen,
and organic loading to the surface waters. This is accomplished by intercepting
and storing the polluted runoff from manure stacking areas, barnyards and
feedlots. This practice will not eliminate the possibility of contaminating
surface and ground water; however, it greatly reduces this possibility.
- j. Waste treatment lagoon (359): An impoundment
made by excavation or earth fill for biological treatment of animal or other
agricultural wastes.
This practice may reduce polluted surficial
runoff and the loading of organics, pathogens, and nutrients into the surface
waters. It decreases the nitrogen content of the surface runoff from feedlots
by denitrification. Runoff is retained long enough that the solids and
insoluble phosphorus settle and form a sludge in the bottom of the lagoon.
There may be some seepage through the sidewalls and the bottom of the lagoon.
Usually the long-term seepage rate is low enough, so that the concentration of
substances transported into the ground water does not reach an unacceptable
level.
- k. Application of manure and/or runoff water to
agricultural land
Manure and runoff water are applied to agricultural lands and incorporated
into the soil in accordance with the management measures for nutrients.
- l. Waste utilization (633): Using agricultural
wastes or other wastes on land in an environmentally acceptable manner while
maintaining or improving soil and plant resources.
Waste utilization helps reduce the transport of
sediment and related pollutants to the surface water. Proper site selection,
timing of application and rate of application may reduce the potential for
degradation of surface and ground water. This practice may increase microbial
action in the surface layers of the soil, causing a reaction which assists in
controlling pesticides and other pollutants by keeping them in place in the
field.
Mortality and other compost, when applied to agricultural land, will be
applied in accordance with the nutrient management measure. The composting
facility may be subject to State regulations and will have a written operation
and management plan if SCS practice 317 (composting facility) is used.
- m. Composting facility (317): A facility for the
biological stabilization of waste organic material.
The purpose is to treat waste organic material biologically by producing a
humus-like material that can be recycled as a soil amendment and fertilizer
substitute or otherwise utilized in compliance with all laws, rules, and
regulations.
- n. Commercial rendering or disposal
services
Construction costs for control of runoff and manure from confined animal
facilities are provided in Table 2-11 10k.
The annual operation and maintenance costs average 4 percent of construction
costs for diversions, 3 percent of construction costs for settlement basins,
and 5 percent of construction costs for retention ponds (DPRA, 1992). Annual
costs for repairs, maintenance, taxes, and insurance are estimated to be 5
percent of investment costs for irrigation systems (DPRA, 1992).
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