PURPOSE: This rule specifies the minimum standards for the design of animal waste management systems. It does not address all aspects of design, and the design engineer may refer to other appropriate reference materials so long as these minimum standards set forth in this rule are met.

PUBLISHER’S NOTE: The secretary of state has determined that the publication of the entire text of the material which is incorporated by reference as a portion of this rule would be unduly cumbersome or expensive. This material as incorporated by reference in this rule shall be maintained by the agency at its headquarters and shall be made available to the public for inspection and copying at no more than the actual cost of reproduction. This note applies only to the reference material. The entire text of the rule is printed here.

1. (1) Applicability. This rule applies to all new or expanding Concentrated Animal Feeding Operations (CAFOs), however, only those applicants that are constructing earthen basins are required to obtain construction permits. The Missouri Department of Natural Resources (department) will not examine the adequacy or efficiency of the structural, mechanical, or electrical components of the concentrated animal feeding operation systems, only adherence to rules and regulations.

2. (2) Definitions.

   1. (A) Definitions as set forth in the Missouri Clean Water Law, Chapter 644, Concentrated Animal Feeding Operation (Hog Bill) section 640.703, RSMo, 10 CSR 20-2.010, and 10 CSR 20-6.300 shall apply to the terms in this rule unless otherwise defined by subsection (2)(B) below.

   2. (B) Other applicable definitions are as follows:

      1. 1. Design storage period—The calculated number of days

that will fill the manure storage structure from the lower to the upper operating level for a covered storage structure or from the lower to the upper operating level for an uncovered, liquid storage structure during a period of average rainfall minus evaporation (R-E).

1. A. For a design storage period of fewer than three

hundred sixty-five (365) days, the largest consecutive average monthly R-E, corresponding with the number of months of the storage period, shall be used.

1. B. For multiple storage stages, the storage period is the

sum of available storage days in each stage.

1. C. For covered liquid manure storage structures, the

upper operating level is one foot (1') below the top of the structure;

1. 2. Freeboard—The elevation difference between the bot-

tom of the spillway to the top of the berm for an earthen basin;

1. 3. Groundwater table—The seasonal high water level

occurring beneath the surface of the ground, including underground watercourses, artesian basins, underground reservoirs and lakes, aquifers, other bodies of water located below the surface of the ground, and water in the saturated zone. For the purposes of this rule, groundwater table does not include the perched water table;

1. 4. Manure—The fecal and urinary excretion of animals;
2. 5. Manure storage structure—A fabricated structure or

earthen basin used to store manure, litter, and/or process wastewater;

1. 6. Rainfall minus evaporation (R-E)— The average depth of

monthly liquid precipitation minus evaporation as published in the most recent National Weather Service Climate Atlas for the geographical region of the proposed structure;

1. 7. Safety depth—One foot (1') of liquid depth or the depth

needed to hold the volume of the ten- (10-) year, ten- (10-) day storm, whichever is greater;

1. 8. Solid manure—Manure that can be stacked without free

flowing liquids;

1. 9. Safety volume—The volume of wastewater stored be-

tween the upper pumpdown and emergency spillway crest;

1. 10. Storage lagoon—A lagoon that does not have adequate

volume to accomplish treatment;

1. 11. Storage volume—The volume of manure, runoff, wash-

water, rainfall, and additional water sources between the lower and upper operating levels;

1. 12. Ten- (10-) year, ten- (10-) day storm—The depth of rain-

fall occurring in a ten- (10-) day duration over a ten- (10-) year return frequency as defined by the most recent publication of the National Weather Service Climate Atlas for the geographical region of the proposed manure storage structure;

1. 13. Total storage capacity—The combined volume of stor-

age and safety volumes stored between the lower pumpdown level and emergency spillway crest;

1. 14. Treatment volume—The permanent volume main-

tained below the lower pumpdown designed for anaerobic treatment of manure based on latitude;

1. 15. Waste treatment lagoon—A lagoon that is sized to have

three hundred sixty-five (365) days of storage volume and adequate treatment volume;

1. 16. Wastewater—A combination of manure, washwater,

runoff, rainfall, and process wastewater; and

1. 17. Wastewater flow—The annual rate of wastewater con-

tributed to an animal waste management system.

1. (3) Permit Application Documents. All engineering documents shall be prepared by, or under the direct supervision of, a registered professional engineer licensed to practice in Missouri.

2. (4) Location.

   1. (A) Protection from Flooding—Manure storage structures, confinement buildings, open lots, composting pads, and other manure storage areas in the production area shall be protected from inundation or damage due to the one hundred- (100-) year flood.

   2. (B) The minimum setback distances from manure storage structures, manure storage areas, confinement buildings, open lots, or mortality composters shall be as follows:

      1. 1. Ten feet (10') to public water supply pipelines;
      2. 2. Fifty feet (50') to property lines;
      3. 3. Fifty feet (50') to public roads;
      4. 4. One hundred feet (100') to wetlands, ponds, or lakes not

used for human water supply;

1. 5. One hundred feet (100') to gaining streams (classified or

unclassified; perennial or intermittent);

1. 6. Three hundred feet (300') to human water supply lakes

or impoundments; and

1. 7. Three hundred feet (300') to losing streams (classified or

unclassified; perennial or intermittent) and sinkholes.

1. (C) Distances from earthen basins shall be measured from the outside edge of the top of the berm.

1. (5) Manure Storage Structure Sizing.

   1. (A) No Discharge Requirement. All manure storage structures shall comply with the design standards and effluent limitations of 10 CSR 20-6.300(4).

   2. (B) Design Storage Period. The minimum design storage period for manure storage structures shall be as follows:

      1. 1. The minimum design storage period for liquid manure,

solid manure, and dry process waste to be land applied is one hundred eighty (180) days;

1. 2. The minimum design storage period for solid manure

and dry process waste to be sold or used as bedding is ninety (90) days; and

1. 3. The minimum design storage period for waste treat-

ment lagoons without an impermeable cover is three hundred sixty-five (365) days.

1. (C) New Class I swine, veal, or poultry operations shall evaluate proposed uncovered manure storage structures in accordance with applicable federal regulation as set forth in 40 CFR 412.46(a)(1), November 20, 2008, and shall hereby be incorporated by reference, without any later amendments or additions, as published by the Office of the Federal Register, National Archives and Records Administration, Superintendent of Documents, Pittsburgh, PA 15250-7954.

2. (D) Sizing Manure Storage Structures.

   1. 1. The structure shall be designed to hold all inputs,

between the upper and lower operating levels, anticipated during the design storage period.

1. 2. Uncovered liquid storage structures shall also include:

   1. A. One-in-ten (1-in-10) year rainfall minus evaporation

from the surface of the structure, held between the operating levels; and

1. B. Safety volume based on the twenty-five (25) year,

twenty-four (24) hour storm event above the upper operating level.

1. 3. Tanks and pits shall also include six inches (6") of depth

below the lower operating level for incomplete removal allowance.

1. 4. Earthen basins shall also include:

   1. A. At least one foot (1') of freeboard or two feet (2') for

structures that receive storm water from open lots larger than the surface area of the storage structure;

1. B. Two feet (2') of permanent liquid depth below the

lower operating level. Anaerobic treatment volume greater than two feet (2') will satisfy this requirement;

1. C. Sludge accumulation volume; and
2. D. Treatment volume below the lower operating level

for anaerobic treatment lagoons.

1. (6) Construction of Earthen basins.

   1. (A) Geohydrologic Evaluation. A geohydrologic evaluation of the proposed earthen basin prepared by the Missouri Geological Survey shall be submitted to the department. If the geohydrologic evaluation gives a severe rating for collapse potential, an earthen basin shall not be used.

   2. (B) Detailed Soils Investigation. A detailed soils investigation is required to substantiate feasibility and to determine the quantity and quality of soil materials on-site and from a borrow area for use in the basin and/or liner. The following information, in whole or in part, is required:

      1. 1. Atterburg limits;
      2. 2. Standard proctor density (moisture/density relation-

ships);

1. 3. Coefficient of permeability (undisturbed and remolded);
2. 4. Depth to bedrock;
3. 5. Particle size analysis; and
4. 6. Depth to groundwater table.

5. (C) Shape and Location.

   1. 1. The shape of all cells shall be such that there are no

narrow or elongated portions or islands, peninsulas, or coves.

1. 2. The floor of the structure shall be a consistent elevation

with finished elevations not be more than three inches (3") above or below the average elevation of the floor.

1. 3. The floor of the basin shall be at least four feet (4') above

the groundwater table or the water table as modified by subsurface drainage and at least two feet (2') above bedrock.

1. (D) Outer berm slopes shall not be steeper than three to one (3:1), horizontal to vertical, and inner slopes not be flatter than four to one (4:1) or steeper than three to one (3:1) for uncovered lagoons or two and one-half to one (2.5:1) for covered lagoons.

2. (E) Berm Construction and Width. Construction specifications shall include the following:

   1. 1. Compact soil used in constructing the basin floor (not in-

cluding clay liner) and berm cores to between two percent (2%) below and four percent (4%) above the optimum water content and to at least ninety percent (90%) standard proctor density;

1. 2. Use lifts for berm construction not exceeding twelve

inches (12") with a maximum rock size not exceeding one-half (1/2) the thickness of the compacted lift; and

1. 3. Construct the top width of the berm a minimum of eight

feet (8') for fill heights from fifteen to twenty feet (15'–20'), use minimum top widths of ten feet (10') and for fill heights from twenty to twenty-five feet (20'–25'), use minimum top widths of twelve feet (12').

1. (F) Emergency Spillway. To prevent overtopping and cutting of berms, an emergency overflow shall be provided that—

   1. 1. Has a minimum bottom width of ten feet (10') and a

minimum depth of one foot (1'); and

1. 2. Is compacted and vegetated or otherwise constructed to

prevent erosion due to possible flow.

1. (G) Compacted Clay Liner.

   1. 1. Liner construction. Compacted clay liners shall be con-

structed to—

1. A. Be scarified and compacted to between two percent

(2%) below and four percent (4%) above the optimum water content and to at least ninety percent (90%) standard proctor density;

1. B. Be raised in lifts not exceeding six inches (6") with a

maximum rock size not exceeding one-half (1/2) the thickness of the compacted lift;

1. C. Be maintained at or above the optimum water con-

tent until the basin is prefilled with water; and

1. D. Have a minimum thickness of twelve inches (12").
2. 2. Permeability. All earthen basins shall be sealed so that

seepage loss through the seal is minimized and to meet the following specifications:

1. A. Cover the floor and extend up the inner slope to

where the side slope intersects with the top of the berm;

1. B. Have a design permeability of the basin seal not

exceeding 1.0 x 10-7 centimeter per second (cm/sec). For soils which have a coefficient of permeability greater than 1.0 × 10-7 (cm/sec), unusual depth, or potable ground water contamination potential, liner thickness of more than twelve inches (12") may be required. The following equation shall be used to determine minimum seal thickness:

t = (H×K)/ 5.4 × 10-7cm/sec

where K = permeability coefficient of the soil in question; H = head (maximum water level depth) of water in the basin; and t = thickness of the soil seal.

1. (H) Protection of Berms. Rip-rap or some other acceptable method of erosion control is required as a minimum around all piping entrances and exits, for aerated cell(s), on the slopes and floor in the areas where turbulence will occur, and for protection from wave action for basins with a surface area greater than five (5) acres.
2. (I) If alternative liners are used, permeability, durability, and integrity of the proposed materials must be satisfactorily demonstrated for anticipated conditions.
3. (J) Depth Gauges. A permanent depth measurement gauge or marker shall be installed and maintained in the basin that is easily readable at one-foot (1') or smaller increments and clearly displayed lower, upper, and emergency spillway levels.
4. (K) Piping. Fill around pipes installed through embankments shall be compacted to prevent seepage and pressurized piping must be valved. Valves are not required on gravity piping into the lagoon.
5. (L) Safety. Consideration shall be given for safety in using open storage structures including the use of prevention and recovery components.
6. (M) Operation and Maintenance. An operation and maintenance plan is required addressing the major components of the concentrated animal feeding operation system.

1. (7) Construction of Tanks and Pits. Construction of tanks and pits shall meet the following requirements:

   1. (A) Soils and Foundation. A thorough site investigation shall be made to determine the physical characteristics and suitability of the soil and foundation for the fabricated storage structure. Position the floor of the below-ground storage tanks two feet (2') above the groundwater table;
   2. (B) Allow one foot (1') of depth at the top of covered structures for agitation and/or ventilation;
   3. (C) Include a permanent depth measurement gauge or marker that is easily readable at one-foot (1') or smaller increments for uncovered tanks and pits;
   4. (D) Use perimeter tiling and granular backfill for below-ground pits;
   5. (E) Locate tank and pit footings at or below the maximum frost depth;
   6. (F) Design concrete and steel features according to published guidelines; and
   7. (G) Design and construct tanks and pits to be watertight.

2. (8) Construction of Solid Manure Components. The following requirements shall be met when constructing poultry buildings, open lots, stacking pads, stacksheds, and other similar structures:

   1. (A) Divert surface water away from animal confinement areas and buildings;
   2. (B) Floors and Pads. Construct the base of covered and uncovered lots, poultry buildings, and other solid manure storage areas of concrete or other rigid, essentially watertight materials or from a firm, compacted, earthen base of Unified Soil Classification System (USCS) class CH, MH, CL, GC, or SC soils a minimum of two feet (2') above the groundwater table and be at least two feet (2') above bedrock;

   3. (C) Uncovered solids storage areas must also meet the following:

      1. 1. Have an overall slope between two percent (2%) and four

percent (4%) for unpaved lots;

1. 2. Be maintained in a way that prevents ponding; and
2. 3. Have a runoff collection structure that meets the re-

quirements of this rule.

1. (9) Design and Construction of Pipelines, Pump Stations, and Land Application Systems.

   1. (A) General. Design of pipelines shall be based on the following requirements:

      1. 1. Ensure the storage/treatment facilities can be emptied

within the time limits stated in the nutrient management plan;

1. 2. Convey the required flow without plugging, based on

the type of material and total solids content;

1. 3. Install at a depth sufficient to protect against freezing;
2. 4. Install with appropriate connection devices to prevent

contamination of private or public water supply distribution systems and groundwater;

1. 5. Size pumps to transfer material at the required system

head and volume;

1. 6. Install a minimum of three feet (3') below the natural

stream floor and as nearly perpendicular to the stream flow as possible;

1. 7. Encase when buried under public roads; and
2. 8. Separation from potable water lines. Pipelines shall

be located at least ten feet (10') horizontally from and at least eighteen inches (18") below the base of any potable water line.

1. 9. Aerial pipeline crossings of streams shall:

   1. A. Provide support for all joints in pipes utilized in the

crossing;

1. B. Protect from the impact of flood waters and debris;

and

1. C. Be constructed so that they will remain watertight

and free from changes in alignment or grade.

1. (B) Gravity Pipelines. Design of pipelines shall be based on the following requirements:

   1. 1. Use a minimum slope of one percent (1%) for four inch

(4") pipe, six-tenths percent (0.6%) for six inch (6") pipe, and four-tenths percent (0.4%) for eight inch (8") pipe;

1. 2. Design with clean-outs at a maximum interval of three

hundred feet (300') and with maximum horizontal curves of ten degrees (10°) at pipe joints; and

1. 3. Design gravity discharge pipes used for emptying a

storage/treatment structure with a minimum of two (2) valves in series.

1. (C) Force Mains and Pressure Pipes. Design velocities shall be between three (3) and six (6) feet per second.
2. (D) Testing. Hydro-pressure tests shall be made only after the completion of backfilling operations and for a minimum of one (1) hour using a minimum test pressure of the maximum system operating pressure.

3. (E) Pump Stations.

   1. 1. Water supply protection. Manure pump stations shall

not be connected to a potable water supply and shall be located at least three hundred feet (300') from any potable water supply well.

1. 2. Alarm systems. Alarm systems are required for pumping

stations that are activated in cases of power failure, pump failure, or any cause of high water in the wet well.

1. (F) Land Application Systems. Land application systems shall be designed with—

   1. 1. Spray application equipment specified that minimizes

the formation of aerosols;

1. 2. The pumping system and distribution system sized for

the flow and operating pressure requirements of the distribution equipment and the application restrictions of the soils and topography;

1. 3. Provisions for draining the pipes to prevent freezing, if

pipes are located above the frost line;

1. 4. A suitable structure provided for either a portable

pumping unit or a permanent pump installation, the intake to the pumping system providing the capability for varying the withdrawal depth, the intake elevation maintained twelve to twenty-four inches (12"–24") below the liquid elevation, the intake screened so as to minimize clogging of the sprinkler nozzle or distribution system orifices, and, for use of a portable pump, a stable platform and flexible intake line with flotation device to control depth of intake;

1. 5. Thrust blocking of pressure pipes; and
2. 6. An automatic pump or engine shut-offs in case of pres-

sure drop.

1. (10) General System Details.

   1. (A) Mechanical Equipment. Mechanical equipment shall be used and installed in accordance with manufacturers’ recommendations and specifications and major mechanical units installed under the supervision of the manufacturer’s representative.
   2. (B) Potable Water Supply Protection. No piping or other connections shall exist in any part of the concentrated animal feeding operation system, which under any conditions, might cause the contamination of a potable water supply.
2. (11) Mortality Management. Class I operations shall not use burial as a permanent mortality management method to dispose of routine mortalities.

AUTHORITY: sections 640.710 and 644.026, RSMo 2016.* Original rule filed July 14, 2011, effective April 30, 2012. Amended: Filed Jan. 26, 2016, effective Oct. 30, 2016. Amended: Filed June 15, 2018, effective Feb. 28, 2019. Emergency amendment filed Dec. 8, 2020, effective Dec. 22, 2020, expired June 19, 2021. Amended: Filed Jan. 8, 2021, effective Sept. 30, 2021. *Original authority: 640.710, RSMo 1996 and 644.026, RSMo 1972, amended 1973, 1987, 1993, 1995, 2000, 2012, 2014.