United States Department of Agriculture 318-CPS-1

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NRCS reviews and periodically updates conservation practice standards. To obtain the current 

version of this standard, contact your Natural Resources Conservation Service State office or 

visit the Field Office Technical Guide online by going to the NRCS website at 

https://www.nrcs.usda.gov/ and type FOTG in the search field. 

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Natural Resources Conservation Service 

CONSERVATION PRACTICE STANDARD 

SHORT TERM STORAGE OF ANIMAL WASTE AND BY-PRODUCTS 

CODE 318 

(cf)

DEFINITION 

Temporary, nonstructural measures used to store solid or semisolid organic agricultural waste or manure

(stackable livestock and poultry manure, bedding, litter, spilled feed, or soil mixed with manure) on a shortterm basis between collection and utilization. 

PURPOSE 

This practice is used to accomplish the following purposes: 

• Temporarily stockpile or store manure in an environmentally safe manner for improved nutrient

utilization and conservation. 

• Provide the agricultural operation management greater flexibility in nutrient utilization. 

• Protect surface and groundwater resources. 

CONDITIONS WHERE PRACTICE APPLIES 

This practice applies where a comprehensive nutrient management plan (CNMP) or a nutrient

management plan (NMP) has been developed and where a temporary stockpile or storage is needed

because— 

• Clean out of animal housing facilities or transfer of manure is required at a time when the manure

cannot be readily land applied due to weather, soil conditions, or farm management requirements. 

• Daily spreading operations are not possible when weather or cropping conditions are not

appropriate for field spreading. 

• Land area is limited and split applications of manure nutrients are required for proper nutrient

management and water quality protection. 

• Temporary stockpiling of solid manure is needed until it is applied to the field where it is stockpiled

or transferred offsite. 

• Imported organic material is temporarily stored on farm for the purpose of NRCS Conservation

Practice Standard (CPS) Waste Recycling (Code 633). 

This practice does not apply to the short-term management of human waste or animal mortality. 

Use NRCS CPS Waste Storage Facility (Code 313) for long-term stockpile periods in production areas . 

CRITERIA 

General Criteria Applicable to All Purposes 

Laws and regulations 

Plan, design, and implement the practice to meet all Federal, State, and local laws and regulations. 
Nutrient utilization 

Utilize nutrients in the amounts, at the location, at the identified rates, and at the specified time consistent

with the requirements of NRCS CPS Nutrient Management (Code 590). 

Consistency 

Waste stockpiled will be of a consistency that permits stacking and pile formation. Total solids (manure

solids plus bedding or amendments) will be greater than 25 percent. Waste having a lower percentage of

solids may be acceptable with verification that suitable pile formation is achievable. 

Criteria Applicable To Temporary Field Stockpile Areas 

Locate the storage pad on a site-specific basis to minimize seepage and meet conditions and functional

requirements. 

Provide positive drainage away from the field stockpile area in all directions. Protect water bodies such as

ponds, streams, and springs from runoff. 

Maintain at least 30 feet of vegetative buffer on the downslope side of the stockpile storage area for

filtering solids in the runoff. A manure stockpile may be placed in a fallow field when appropriately sited. 

Provide adequate germination of newly established buffers prior to stockpile formation. Install a sediment

barrier (synthetic silt fence or hay bales) around the pile if vegetation is not well established. 

Maintain the stockpile so that no dust and debris transport to waters or drainageways occurs. 

Seed all disturbed areas beyond the edges of the stored manure to an approved vegetative cover. 

Locate stockpile— 

• Above the 100-year floodplain elevation unless site restrictions require location within the

floodplain. Protect the facility from inundation or damage from a 100-year flood event when in the

floodplain. 

• As far away as practical and at least 100 feet from neighboring residences or public roads or areas. 

• At least 150 feet from wells, springs, streams, and ponds, or 300 feet from wells, springs, streams,

and ponds when water resource is located down gradient from the stockpile area. 

• At least 100 feet from all drainageways. 

• Where the seasonal high water table will be no closer than 2 feet below the bottom of the stored

manure, unless a geosynthetic liner is used. 

• Where there is no groundwater spring, seep, or subsurface drainage tile lines that could be

contaminated by the stored waste. 

• On soils with a maximum saturated hydraulic conductivity class (kSAT) of moderately high (~ 2

in/hr) or on a soil pad, geomembrane lined pad, or similar lining method, and the stockpile is

covered. 

• Where there will be positive drainage from the stack in all directions and clean water runoff is

excluded from the stockpile storage area. 

• Where access is not limited by poor weather conditions such as excessive ice, snow, or muddy

ground. 

Stockpile Storage Period 

Base the maximum stockpile period on the timing required for environmentally safe manure utilization

considering the climate, crops, soil, equipment, and local, State, and Federal regulations, but not greater

than 180 days. 

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Size 

Design field stockpile storage areas to store the manure until it can be utilized as identified in the CNMP or

NMP. Base the size on the required manure utilization schedule. 

The manure stockpile area may be at one or more locations and will have sufficient area to store

accumulated manure. Consider manure consistency and moisture characteristics when locating and

sizing the manure stockpile area. 

To reduce the potential for spontaneous combustion, the maximum height when stacking the manure will

be no greater than 7 feet. Allow a minimum of 4 feet around the edges of the stack to properly anchor the

covering and facilitate the removal of the manure. 

Soils and Foundation 

Perform the stacking operations on a firm, uniform surface. When compaction of onsite soils alone are

not adequate to resist rutting from normal equipment operation, select a more suitable site or use NRCS

CPS Waste Storage Facility (Code 313). 

Covering 

When specific site and local conditions or regulations require covers, cover field-stacked manure or store

in geotextile bags. 

Acceptable materials include geotextiles (tarps) that shed rainfall and allow transpiration, opaque plastic

or polyethylene sheeting having a minimum thickness of 6 mils, or other water-resistant material. 

Place the cover over the pile with care to prevent tearing. Provide a minimum of 24 inches of overlap.

Use weights, anchors or other tie-down mechanisms to anchor the cover and prevent tearing during high

winds. Place screw type anchors on 2-foot centers around the pad. 

CONSIDERATIONS 

General Considerations 

Divert nonpolluted runoff around the storage facility site to the fullest extent possible. 

Consider runoff from the covering in water management planning around the stockpile site. 

To reduce migration of nutrients into the soil, consider spreading a bedding layer of compost, sawdust, or

similar material prior to stockpile formation. 

Monitor the temperature of the manure stack to ensure temperature does not reach unsafe levels. 

Where material is spread on land not owned or controlled by the producer, a nutrient management plan

establishing environmentally acceptable utilization of the material is recommended. 

Due consideration should be given to environmental concerns, economics, the overall waste management

system plan, and safety and health factors. 

Considerations for site selection 

Consider the following factors in selecting a site for manure stockpile areas: 

• Unless there is evidence on the farm that the manure is more stackable, assume that it will not

stack higher than 4 feet with a 4:1 angle of repose. 

• Proximity of the manure stockpile storage facility to its source and land application area. 

• Access to other facilities. 

• Ease of loading and unloading manure. 

• Adequate maneuvering space for operating loading and unloading equipment. 

• Appropriate health regulations. 

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• Compatibility with respect to prevailing winds and landscape elements such as building

arrangement, landforms, and vegetation, in order to minimize odors and protect aesthetic values. 

Considerations for improving air quality 

Maintain appropriate manure moisture content for solid manure stockpile facilities. Excessive moisture

will increase the potential for air emissions of volatile organic compounds, ammonia, and nitrous oxide,

and may lead to anaerobic conditions, which will increase the potential for emissions of methane and

hydrogen sulfide. Too little moisture will increase the potential for particulate matter emissions, although

covering the stockpile will reduce that potential. 

Some fabric covers are effective in reducing odors. 

PLANS AND SPECIFICATIONS 

Plans and specifications will describe the requirements for applying this practice. As a minimum, include

in the engineering plans, specification, and reports of the following: 

• Plan view of stockpile locations and layout. A plan map showing the location of all stockpile areas,

access roads to these areas, slopes, surfaces to be graded, necessary cuts and fills, and location

of sensitive areas such as wells, springs, streams, and floodplains, with setback distances from

water bodies, streams, sinkholes, etc. 

• Stockpile period. Link the stockpile to the nutrient management plan, and crop rotation, or both for

the field in which the manure is stockpiled. 

• Dimensions of field stockpile storage areas including length, width, and additional width for edge

area for working and cover anchor, as appropriate. 

• Maximum design height for stacking manure. 

• Type of covering and details for anchoring the cover, as needed. 

• Specifications for cover or bagging material, as needed. 

• Vegetative , or other, buffer requirements. 

• Quantities of stockpiled material to be managed. 

• Soil and foundation findings, interpretations, and reports, as required for site suitability. 

• Pad and liner specifications, as required. 

• Temporary erosion control measures during construction, as required. 

• Odor management or minimization requirement and pest management (fly control). 

• Location of utilities and notification requirements. 

OPERATION AND MAINTENANCE 

Develop an operation and maintenance plan that is consistent with the purposes of the practice and safety

requirements. 

Provide for the proper utilization of the stockpiled material in the plan. Include the requirement that

manure will be removed from the stockpile and utilized at locations, times, rates, and quantities in

accordance with the overall waste management system plan. 

Include a strategy for removal and disposition of manure with the least environmental damage during the

normal stockpile period. Provide for establishment of vegetation on areas disturbed by removal of the

stockpiled material. 

Develop an emergency action plan where there is a potential for an accidental manure spill event. Include

site-specific provisions for emergency actions that will minimize these impacts. 

Include instruction for replacement of plastic or polyethylene covering that will deteriorate over time.

Provide for disposal of damaged liners and covers in conformance with local laws and regulations. 

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When soil material is inadvertently removed during the manure removal process, provide maintenance

and reconstruction of the soil pads. 

Take care during removal of the stored material not to damage the geomembrane, when geomembranes

are used to line the pad. Promptly complete any needed repairs of the geomembrane. 

Inspect and repair as needed, the pad, cover, and adjacent area after each major storm event. 

Prevent ponding of water in the area surrounding the field stockpile and divert runoff from the stockpile

area. 

Provide instructions for record keeping for the hauling of stockpiled material from one geographical area to

another including— 

• Type and amount of material transferred. 

• Solids percentage of the material. 

• Date of the transfer. 

• Name and address of the source and destination of the material. 

• Condition of the material as left at the destination (spread, stockpiled, and covered, etc.). 

REFERENCES 

USDA NRCS. National Engineering Handbook, Part 651, Agricultural Waste Management Field

Handbook. Washington, DC. 

USDA NRCS. Soil Survey Technical Note 6, Saturated Hydraulic Conductivity: Water Movement

Concepts and Class History. Washington, DC.

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