5 Colo. Code Regs. § 1002-81.8

Current through Register Vol. 47, No. 11, June 10, 2024

Section 5 CCR 1002-81.8 - BEST MANAGEMENT PRACTICES

The following Best Management Practices (BMPs) shall be utilized by AFOs and CAFOs, as appropriate, based upon existing physical conditions and site constraints. Best management practices means, for purposes of this regulation, activities, procedures, or practices necessary for the reduction of impacts on surface or ground water, as described in this section. Additional surface water and ground water protection elements required of CAFOs are detailed in sections 81.6 and 81.7 of this regulation.

The following practices, designed to decrease runoff volume, are BMPs within the meaning of this regulation:

(1) Divert runoff from uncontaminated areas away from animal confinement areas, and manure and wastewater control facilities to the extent practicable through:

(a) Construction of ditches, terraces or other waterways

(b) Installation of gutters, downspouts and buried conduits to divert roof drainage;

(c) Construction of roofed areas over animal confinement areas everywhere it is practicable.

(2) Decrease open lot surface area, where practicable by:

(a) Reducing lot size;

(b) Improving lot surfacing to support increased animal density;

(c) Providing roofed area to the maximum extent practicable; and

(d) Eliminating animal confinement areas, and manure and wastewater control facilities in areas that slope in directions such that wastewater/rainfall cannot be collected.

(3) Decrease water volume by:

(a) Repairing or adjusting waterers and water systems to minimize water wastage.

(b) Using lowest practical amounts of water for manure and wastewater flushing.

(c) Recycling water used to flush manure from paved surfaces or housed confinement areas, if practical.

(4) Decrease wastewater discharges to surface water by:

(a) Collecting and allowing process-generated wastewater to evaporate.

(i) Additionally, for Medium AFOs that do not apply wastewater to land application sites (i.e. evaporative impoundments only), the impoundment(s) must be capable of storing the volume of all process-generated wastewater for 180 days, at a minimum.

(b) Collecting and evenly applying wastewater to land application sites at agronomic rates.

(i) Additionally, for Medium AFOs that apply wastewater to land application sites, the impoundment(s) must be capable of storing the volume of all open-lot runoff and process-generated wastewater for 120 days, at a minimum.

(ii) For Medium AFOs that land apply wastewater, the operator shall keep records demonstrating that wastewater has been applied to each land application site at an agronomic rate.

(A) Such records shall be maintained on-site for five years from the date they are created.

(B) Such records shall be made available to the Division or its designee, upon request.

(c) Treating open-lot wastewater through use of one of the following:

(i) A wastewater treatment strip; or,

(A) Inflow to a wastewater treatment strip shall be pretreated by a solid/liquid waste separation facility, as appropriate based upon site constraints and to have the wastewater treatment strip adequately assimilate pollutants.

(ii) A method approved by the Division.

(d) Preventing animals from having direct contact with surface water. A stock watering point may be used where animals have access to no other source of drinking water. A stock watering point shall be cleaned frequently of manure and have wastewater diverted at the watering point entry.

(e) Locating wastewater retention structures or collection sites away from areas where stormwater run-off or seasonally high stream flow may carry the waste into waters of the state.

(f) Not locating wastewater retention structures located within a mapped 100 year flood plain as designated by the Colorado Water Conservation Board (CWCB) unless proper flood proofing measures (structures) are designed and constructed.

(g) Managing animal mortalities in a manner that prevents a discharge of pollutants to surface water.

(5) Minimize manure transport to surface water by:

(a) Locating manure stockpiles away from surface water, and above the 100 year flood plain as designated and approved by CWCB, unless adequate flood proofing structures are provided, and bermed to minimize runoff.

(b) Locating manure stockpiles away from areas where stormwater run-off or normally high stream flow will carry the waste manure into the waters of the state, unless the area is bermed to minimize runoff.

(c) Providing adequate manure storage capacity based upon manure and wastewater production.

(d) Removing settleable solids by using solids-settling basins, terraces, diversions, or other solid removal methods approved by the Division. Construction of solids-settling facilities shall not be required where the Division determines existing site conditions provide adequate settleable solids removal. Sufficient capacity shall be provided in the solids-settling facilities to store settled solids between periods of manure and wastewater disposal.

(e) Applying manure to land application sites at an agronomic rate.

(i) For Medium AFOs that land apply manure, the operator shall keep records demonstrating that manure has been applied to each land application site at an agronomic rate.

(A) Such records shall be maintained on-site for five years from the date they are created.

(B) Such records shall be made available to the Division or its designee, upon request.

(f) Avoiding applications on saturated soils and lands subject to excessive erosion.

(g) Using edge-of-field, grassed strips, filter fences or straw bales to separate eroded soil and manure particles from the field runoff.

(h) Collecting manure frequently.

(6) Practices to Protect Groundwater.

(a) Operators shall locate manure and wastewater management facilities hydrologically downgradient and a minimum horizontal distance of 150 feet from all water supply wells.

(b) When applying manure and wastewater to land, operators shall utilize a buffer area around water wells sufficient to prevent the possibility of waste transport to groundwater via the well or well casing.

(c) An impoundment at a Medium AFO shall have a liner that is constructed and maintained such that the seepage rate from the impoundment does not exceed 1 x 10^-6 cm/sec.

(i) The operator of such a facility shall have documentation prepared by a professional engineer registered in Colorado certifying that each impoundment has a liner that does not allow a seepage rate in excess of 1 x 10^-6 cm/sec. Such documentation shall be available prior to wastewater entering the impoundment.

(ii) The operator shall make a copy of such documentation available to the Division or its designee, upon request.

(d) Where the Division determines that an AFO with animal number below those established for a Medium AFO, could adversely affect ground water quality, the operator of such an AFO shall install a liner in all impoundments such that the seepage rate from each impoundment does not exceed 1 x 10^-6 cm/sec.

(i) The Division shall determine that such an AFO could adversely affect ground water quality by demonstrating that it is in a location where:

(A) Significant ground water recharge occurs as determined using the United States Department of Agriculture, Natural Resources Conservation Service's current "Agricultural Waste Management Field Handbook, Part 651, Chapter 7, Geologic and Ground Water Considerations"; or,

(B) Contamination from the AFO could cause ground water to exceed the standards adopted by the Colorado Water Quality Control Commission; or,

(C) A water source susceptibility analysis results in the AFO having a "medium-high" or "high" potential for contaminating existing or reasonably likely future public drinking water system withdrawals. Such an analysis shall examine the physical setting of ground water and the contaminant threat that the AFO poses to the ground water source. Factors that shall be considered in examining the physical setting include aquifer sensitivity at the water source intake location, depth to the water source, structural integrity of the water system at the withdrawal point, flow of the water source and first draw of the water source. Factors that shall be considered in examining the contaminant threat are migration potential, contaminant hazard, potential volume and likelihood of contaminant release.

(ii) A liner, where required, shall be installed according to a work plan approved by the Division.

(A) The operator shall, in consultation with the Division, develop and submit an approvable work plan that includes a timeline for installing each liner within 60 days of receiving the written request from the Division.

(B) The operator shall implement the plan within 30 days of it being approved by the Division.

(C) The operator shall submit to the Division, within 30 days of each liner having been properly constructed, documentation prepared by a professional engineer registered in the State of Colorado certifying that the seepage rate from each impoundment does not exceed 1 x 10^-6 cm/sec.

5 CCR 1002-81.8

40 CR 13, July 10, 2017, effective 7/31/2017