B2. Management Measure for Facility Wastewater and Runoff from Confined
Animal Facility Management (Small Units)
Design and implement systems that collect solids, reduce contaminant
concentrations, and reduce runoff to minimize the discharge of contaminants in
both facility wastewater and in runoff that is caused by storms up to and
including a 25-year, 24-hour frequency storm. Implement these systems to
substantially reduce significant increases in pollutant loadings to ground
water.
Manage 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 existing
confined animal facilities that contain the following number of head:
Head Animal Units (5)
Beef Feedlots 50-299 50-299
Stables (horses) 100-199 200-399
Dairies 20-69 28-97
Layers 5,000-14,999 50-149 (6)
165-494 (7)
Broilers 5,000-14,999 50-149 (6)
165-494 (7)
Turkeys 5,000-13,749 900-2,474
Swine 100-199 40-79
(5) See animal unit in Glossary.
(6) If facility has a liquid manure system.
(7) If facility has continuous overflow watering.
except those facilities that are required by Federal regulation 40 CFR
122.23(c) to apply for and receive discharge permits. 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.
Facilities containing fewer than the number of head listed above are not
subject to the requirements of this management measure. Existing facilities
that meet the requirements of Management Measure B1
for large units are in compliance with the requirements of this management
measure. Existing and new facilities that already minimize the discharge of
contaminants to surface waters, protect against contamination of ground water,
and have an appropriate waste utilization system may already meet the
requirements of this management measure. Such facilities may not need
additional controls for the purposes of this management measure.
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 2-9). 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 goal of this management measure is to minimize the discharge of
contaminants in both facility wastewater and in runoff that is caused by storms
up to and including a 25-year, 24-hour frequency storm by using practices such
as solids separation basins in combination with vegetative practices and other
practices that reduce runoff and are also protective of ground water.
The problems associated with animal facilities are the control of 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 that must be managed
(Figure 2-10). Runoff water and facility wastewater from the facility should be
routed through a settling structure or debris basin to remove solids. 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.
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 discharge is minimized and any stored runoff is
managed in accordance with this management measure. If manure is managed as a
solid, any drainage from the storage area or structure should be routed to the
runoff control practices.
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 against the contamination
of 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. While a nutrient management plan is
not required to be implemented on the vegetative control practices themselves,
ground water should be protected by taking extreme care to not exceed the
capacity of the practices to assimilate nutrients.
When storage structures are used to meet the requirements of this management
measure, 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 each site must be evaluated and the appropriate action
taken 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 that have filled
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 must
be maintained at all times.
Channels must 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 smaller-sized animal production
facilities based on an evaluation of available information that documents the
beneficial effects of improved management of confined livestock facilities.
Specifically, the management measure reduces the amount of pollutants leaving a
facility by using practices that reduce the amount of water that comes into
contact with animal waste materials. It also uses solid removal and filtration
of runoff water to remove a significant amount of the pollutants contained in
the runoff waters. This can be accomplished without the expense of constructing
a runoff storage structure and purchasing the equipment necessary to apply the
stored water to the land.
This management measure also requires that stored runoff and accumulated
solids from the facility are managed through an appropriate waste utilization
system. The size limitations that define a small unit are based on EPA's
analysis of the economic achievability of the management measure.
The effectiveness information presented for large units (Tables 2-9 and 2-10)
also applies to this management measure.
Pollutant loads from runoff caused by storms up to and including the
25-year, 24-hour frequency storm can be reduced by decreasing the potential for
runoff contamination (e.g., by keeping accumulations of manure off the open
lots), and by removing the contaminants to the fullest extent practicable
through vegetative and structural practices (e.g., solids separation devices,
sediment basins, filter strips, and constructed wetlands). Pollutant loads can
also be reduced by storing and applying the runoff to the land with any manure
and facility wastewater in accordance with the nutrient management measure.
Table 2-12 shows reductions in pollutant
concentrations that are achievable with solids separation basins that receive
runoff from barnyards and feedlots. Concentration reductions may differ from
the load reductions presented in Tables 2-9 and 2-10 since loads are determined
by both concentration and discharge volume. Solids separation basins combined
with drained infiltration beds and vegetated filter strips (VFS) provide
additional reductions in contaminant concentrations. The effectiveness of
solids separation basins is highly dependent on site variables. Solids
separation; basin sizing and management (clean-out); characteristics of VFS
areas such as soil type, land slope, length, vegetation type, vegetation
quality; and storm amounts and intensities all play important roles in the
performance of the system. Appropriate operation and maintenance are critical
to success.
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. Waste storage pond (425): An impoundment made
by excavation or earth fill for temporary storage of animal or other
agricultural waste.
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.
- b. Waste storage structure (313): A fabricated
structure for temporary storage of animal waste or other organic agricultural
waste.
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.
- c. Waste treatment lagoon (359): An impoundment
made by excavation or earth fill for biological treatment of animal or other
agricultural waste.
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.
- d. Sediment basin (350): A basin constructed to
collect and store debris or sediment.
Sediment basins will remove sediment, sediment
associated materials and other debris from the water which is passed on
downstream. Due to the detention of the runoff in the basin, there is an
increased opportunity for soluble materials to be leached toward the ground
water.
- e. Water and sediment control basin (638): An
earth embankment or a combination ridge and channel generally constructed
across the slope and minor water courses to form a sediment trap and a water
detention basin.
The practice traps and removes sediment and
sediment-attached substances from runoff. Trap control efficiencies for
sediment and total phosphorus, that are transported by runoff, may exceed 90
percent in silt loam soils. Dissolved substance, such as nitrates, may be
removed from discharge to downstream areas because of the increased
infiltration. Where geologic condition permit, the practice will lead to
increased loadings of dissolved substances toward ground water. Water
temperatures of surface runoff, released through underground outlets, may
increase slightly because of longer exposure to warming during its
impoundment.
- f. Filter strip (393): A strip or area of
vegetation for removing sediment, organic matter, and other contaminants from
runoff and wastewater.
Filter strips for sediment and related
pollutants meeting minimum requirements may trap the coarser grained sediment.
They may not filter out soluble or suspended fine-grained materials. When a
storm caused runoff in excess of the design runoff, the filter may be flooded
and may cause large loads of pollutants to be released to the surface water.
This type of filter requires high maintenance and has a relatively short
service life and is effective only as long as the flow through the filter is
shallow sheet flow.
Filter strips for runoff from concentrated
livestock areas may trap organic material, solids, materials which become
adsorbed to the vegetation or the soil within the filter. Often they will not
filter out soluble materials. This type of filter is often wet and is difficult
to maintain.
Filter strips for controlled overland flow
treatment of liquid wastes may effectively filter out pollutants. The filter
must be properly managed and maintained, including the proper resting time.
Filter strips on forest land may trap coarse sediment, timbering debris, and
other deleterious material being transported by runoff. This may improve the
quality of surface water and has little effect on soluble material in runoff or
on the quality of ground water.
All types of filters may reduce erosion on the
area on which they are constructed.
Filter strips trap solids from the runoff flowing
in sheet flow through the filter. Coarse-grained and fibrous materials are
filtered more efficiently than fine-grained and soluble substances. Filter
strips work for design conditions, but when flooded or overloaded they may
release a slug load of pollutants into the surface water.
- g. Grassed waterway (412): A natural or
constructed channel that is shaped or graded to required dimensions and
established in a 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.
- h. Constructed wetland (ASCS-999): A constructed
aquatic ecosystem with rooted emergent hydrophytes designed and managed to
treat agricultural wastewater.
This is a conservation practice for which SCS has developed technical
requirements under a trial program leading to the development of a conservation
practice standard.
- i. 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 effects 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.
- j. Diversion (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.
- k. 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.
- l. 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.
- m. 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. Pollution and erosion
will be reduced. Flooding may be prevented and drainage may improve.
- n. 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 enhance 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.
- o. 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.
- p. 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 used in compliance with all laws, rules, and
regulations.
- q. Commercial rendering or disposal
services
The construction costs for large units (Table
2-11) also apply to this measure. 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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