This part describes requirements for permitting, design, construction, location, operation, and maintenance of short-term and permanent stockpiling sites. An owner of a stockpiling site must comply with part 7020.2005 and items A to D.
Manure stockpiling sites must be located and constructed such that manure-contaminated runoff from the site does not discharge to waters of the state.
Manure must not be placed on a stockpiling site unless a three-to-one horizontal-to-vertical ratio can be maintained and the manure has, at least, a 15 percent solids content.
The use of rock quarries, gravel or sand pits, bedrock, and any mining excavation sites for stockpiling manure is prohibited.
The size of a short-term stockpile must not exceed a volume based on agronomic needs of the crops on 320 acres of fields and must not exceed the agronomic needs of the crops on the tract of land on which the stockpile is to be applied. The agronomic needs of the crops must comply with the application rates in part 7020.2225.
An owner of a short-term stockpile site must operate and maintain the stockpile such that:
the manure is removed from the site and land applied in accordance with part 7020.2225, within one year of the date when the stockpile was initially established;
a vegetative cover is established on the site for at least one full growing season prior to reuse as a short-term stockpiling site except for the following:
sites located within the confines of a hoofed-animal open lot at a facility having the capacity to hold fewer than 100 animal units; and
sites where manure is stockpiled for fewer than ten consecutive days and no more than six times per calendar year;
it is not located within:
300 feet of flow distance and at least 50 feet horizontal distance, to waters of the state, sinkholes, rock outcroppings, open tile intakes, and any uncultivated wetlands which are not seeded to annual farm crops or crop rotations involving perennial grasses or forages;
300 feet of flow distance to any road ditch that flows to the features identified in subitem (1) or 50 feet of any road ditch where subitem (1) does not apply;
100 feet of any private water supply or unused and unsealed well and 200 feet from any private well with less than 50 feet of watertight casing and that is not cased through a confining layer at least ten feet thick; and
100 feet from field drain tile that is three feet or less from the soil surface;
a minimum distance of two feet is maintained between the base of the stockpile and the seasonal high water table or saturated soils, as identified in the most recent published soil survey for the applicable county or based on a site-specific soils investigation; and
the stockpile is not placed on:
land with greater than six percent slope;
land with slopes between two and six percent, except where clean water diversions and erosion control practices are installed; and
soils where the soil texture of the entire soil profile to a depth of five feet is coarser than a sandy loam as identified in the most recent published soil survey or based on a site-specific soils investigation.
The owner of the short-term stockpile site shall maintain records for each stockpile site containing the information in items A to E. Records must be kept on file for at least three years for all short-term stockpiling by the owner of the animal feedlot at which the manure was produced and be made available to the commissioner or county feedlot pollution control officer upon request. The records must include:
the location of the stockpile;
the date on which each stockpile was established;
the volume of manure stockpiled;
the nutrient analysis of the manure; and
when the stockpiled manure was land applied.
An owner of a permanent stockpile site must comply with this part. The owner shall also install a liquid manure storage area according to part 7020.2100 to collect and contain manure-contaminated runoff, if necessary to comply with the requirements of part 7020.2003. An owner shall submit a permit application, as applicable, under part 7020.0405, subpart 1.
The stockpile site liner must:
have a completed thickness of at least two feet and be constructed of soils having a hydraulic conductivity of 1 x 10-7 cm/sec or less upon completion of construction; or
have other liner materials which achieve a hydraulic conductivity less than 1 x 10-7 cm/sec.
The site must be constructed using diversion structures, elevated platform construction, or other devices to prevent surface waters from entering and passing through the stockpile site. Where upgradient slopes are greater than two percent, clean water diversions must be constructed that surround at least the three upgradient sides of the stockpile site. Diversions must be of sufficient height to prevent outside water from passing over them during snowmelt or rainfall events less than the 25-year, 24-hour storm event.
A permanent stockpile site must be operated and maintained in a manner so as to protect the integrity and structural reliability of the manure storage area.
An owner shall notify the commissioner or county feedlot pollution control officer of intent to construct a minimum of three days prior to commencement of construction and within three days following completion of construction. Notification must be completed by letter, telephone, facsimile, or electronic mail and include:
the permit number, if applicable;
the owner's name, and the name of the facility if different than the owner;
the site location by county, township, section, and quarter section; and
the name of the contractor responsible for installing the permanent stockpile liner.
The owner shall ensure that the liner is installed and maintained above the seasonal high water table or saturated soils, as identified in the most recent soil survey for the applicable county or based on a site-specific soils investigation. Soil surveys are incorporated by reference under part 7020.0205.
25 SR 834; 38 SR 1535
June 6, 2014
Official Publication of the State of Minnesota
Revisor of Statutes