Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-81 - REGULATION NO. 81 - ANIMAL FEEDING OPERATIONS CONTROL REGULATION
Section 5 CCR 1002-81.22 - STATEMENT OF BASIS, SPECIFIC AUTHORITY AND PURPOSE: FEBRUARY AND APRIL, 2004 RULEMAKING

1) it is constructed at a site at which no other source is located; or

2) it totally replaces the process or production equipment that causes the discharge of pollutants at an existing source; or

3) its processes are substantially independent of an existing source at the same site. In determining whether these processes are substantially independent, the [Division] shall consider such factors as the extent to which the new facility is integrated with the existing plant, and the extent to which the new facility is engaged in the same general type of activity as the existing source. A source meeting the requirements of the [1), 2), or 3) above] is a new source only if a new source performance standard is independently applicable to it. If there is no such independently applicable standard, the source is a new discharger."

Regarding the definition of "closed facility", the Commission clarifies that it is not the intent of this regulation to define a CAFO as closed where it has ceased operation but intends to sell the facility within a reasonable amount of time, or where the facility will restock animals within two years, or within some other reasonable period of time.

The Commission finds it appropriate to exclude harvested dry forage from being defined as a "raw material." Such forage is commonly found and stored in rural areas, runoff from such forage is not common, and contaminant concentrations in runoff are insignificant. In addition, water quality regulations do not contain provisions regarding runoff from dry harvested forage stored on farm fields or farmsteads.

A best management practice for AFOs is to apply manure and wastewater at agronomic rates. Since the existing regulation does not define "agronomic rate", the Commission added a definition of this term in order to clarify the performance standard for land applications of manure and wastewater. The expectation for meeting the requirements of the definition is use of the most current fertilizer suggestions of Cooperative Extension in Colorado or neighboring states, use of a qualified consultant's fertilizer calculation, or use of the fertilizer calculation in the most current United States Department of Agriculture- Natural Resources Conservation Service Comprehensive Nutrient Management Plan that has been prepared for the AFO.

The Commission also adopted the Federal definition of "land application site" since it is applicable to AFOs. The definition of "land application site" makes reference to land under the control of an AFO or CAFO. The Commission finds it appropriate to clarify that such land is under the control of an AFO where it is owned or leased by the AFO, where cropping and/or nutrient budget decisions for the site are made by the AFO, or where the AFO land applies wastewater or manure to such land. Such land is not under the control of an AFO where the AFO simply agrees to release wastewater or manure to the owner/operator of land that does not otherwise meet the criteria of being under the control of the AFO.

The Commission added a definition of "surface water" since it is this specific subset of waters of the state that is of concern in the process that the Division must use to designate an AFO as a CAFO. In keeping with the Federal interpretation, surface water includes subsurface water that may be hydrologically connected to surface water. The Commission intends that the hydrological connection aspect is pertinent only where it results in a contribution of pollutants being conveyed from ground water to surface water.

The Commission revised the definitions section to delete the following definitions that are obsolete as a result of the new federal CAFO regulations, that are no longer applicable to today's adopted rule, or have been superceded by definitions of other terms: animal unit, average working capacity, expanded facility, housed animal feeding operation, hydrologically sensitive area, new facility, no-discharge, open animal feeding operation, process wastewater, reactivated facility, reconstructed facility, significant groundwater recharge, "ten year twenty-four hour storm and twenty five year twenty-four hour storm", and vadose zone.

To provide clarification of language in the rule and to be consistent with other regulations, the Commission revised the existing definitions of operator, man-made drainage system, and manure, deleted the definition of director, and added definitions for "Division" and "person".

Designation of an AFO as a CAFO: The Federal regulatory language for the process of determining if an AFO will be designated a CAFO was separated from the CAFO definition and placed into its own section (new Section 81.4) for the purpose of more readily finding and identifying the process. As presented in Part A, above, of today's statement of basis, the Federal regulations focus on protection of surface water and a permit can address only protection surface water. This means that an AFO can be designated as a CAFO only where it could reasonably be expected to adversely affect surface water. The existing regulation has language that provides for an AFO to be designated as a CAFO where it is located in a hydrologically sensitive area, which includes areas where contamination of ground water could occur. Therefore, the "hydrologically sensitive area" language was removed in favor of the Federal criteria. However, the ground water protection aspects of the language were added to the "Practices to Protect Groundwater" subsection of the Animal Feeding Operations - Best Management Practices" section [section 81.6(6)].

The Commission understands that as part of the process of determining whether an AFO should be designated as a CAFO, the Division will consider the five criteria listed in today's adopted regulation in order to conclude whether an AFO could cause significant degradation of surface water subject to antidegradation review, or could cause an exceedance of any adopted surface water quality standard. The latter standards are specified in Regulation No. 31, "The Basic Standards and Methodologies for Surface Water."

Since the preamble of the Federal regulation allows States to provide an opportunity for an AFO that may be designated a CAFO to take actions that eliminate conditions that pose a risk to surface water quality, the Commission included provisions in the regulations that provides for such an opportunity in the form of an approvable work plan that is developed in consultation with the Division. The Commission is aware that some AFOs may have no easy solutions for eliminating or significantly abating risks to surface water. Such AFOs may indicate to the Division that it intends to remain in its location and operate as a CAFO and apply for a permit. Where an AFO does not complete and implement a work plan as required, the Commission added language that the Division may designate the AFO as a CAFO and be required to submit a complete CAFO discharge permit application.

AFOs can be designated as CAFOs where they directly discharge wastewater or manure into surface water through man-made drainage systems. The Commission clarifies that an overflow from an AFO impoundment or conveyance structure into surface water, or sheet flow runoff from and AFO into surface waters, are not direct discharges through man-made drainage systems.

Clarification of AFO definition: The Commission finds it appropriate to provide clarification of what confined animal feeding operations are AFOs, and what are not AFOs. To be an animal feeding operation (AFO), a lot or facility must have animals stabled or confined for at least 45 days out of 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. Using this criteria, it is not the intent of this regulation to include true pasture and rangeland operations as AFOs. Nor is it the intent of this regulation to include properly grazed crop residues or winter-feeding sites on pastures or rangeland as AFOs. A winter feeding site is not an AFO where it shows no vegetation during the winter but shows regrowth of desirable forage in the spring. However, pasture and grazing operations may have confinement areas (e.g., feedyards, barns, pens) that may meet the definition of an AFO.

Regarding the "no vegetation" cover part of the criteria, page 7189 of the revised Federal regulations states that incidental vegetation existing in a part, or parts, of a confined area, does not exclude the feeding operation from meeting the definition of an AFO. The Commission encourages the Division to use common sense and sound judgment in evaluating confined areas with incidental vegetation for meeting the definition of an AFO.

Part of the AFO definition refers to no vegetative cover being present during the normal growing season. However, Page 7189 of the revised Federal regulations states that the "no vegetation" criteria in the definition is meant to be evaluated during the winter, if animals are confined during that time. The Commission is aware that backgrounding operations are common in the State, where cattle weaned in the fall are fed in pens through the winter until they are turned out to pasture or rangeland in the spring. In keeping with the Federal preamble language, the Commission finds that backgrounding feedlots are AFOs where no vegetation is present for 45 days or more (whether during the winter or normal growing season), and animals are confined for 45 days out of any 12-month period. The Commission encourages the Division to use common sense and sound judgment in evaluating backgrounding feedlots for meeting the definition of an AFO.

Ground water protection requirements: As discussed above, the revised Federal CAFO regulations focus on protection of the nation's surface waters and do not, therefore, require provisions for protection of ground water from pollutants in manure or process wastewater. As a result, ground water protection provisions cannot be included as a condition in a CAFO permit, pursuant to section 25-8-504(2) of the Colorado Water Quality Control Act. The Commission recognized in 1992 the need to protect ground water under CAFOs by including in this Regulation #81 the previously existing section 81.4 , "Ground Water Protection Requirements - Concentrated Animal Feeding Operations." Therefore, the Commission finds that such provisions should be retained in this control regulation, with the following revisions.

The previous provisions were revised to retain a maximum seepage rate of 1 x 10 -6 cm/sec as the baseline liner requirement for impoundments. This seepage rate standard is consistent with the allowable seepage standard provided in subsection 61.14 of Regulation No. 61 (the ground water permit regulations) which states that where the seepage from an impoundment, "does not exceed 1 x 10 -6 cm/sec" such an impoundment "will be considered not to have a discharge to waters of the state, by virtue of the insignificant nature of the seepage...." This standard also is consistent with the statement of basis and purpose language (in Regulation #61) for the July 10, 1989 ground water permitting regulation hearing which states that, "the Division's design criteria requires that domestic wastewater and storage impoundments be sealed such that the seepage from the impoundment does not exceed 1 x 10 -6 cm/sec. This criteria has been used in the design of numerous domestic facilities, and it generally is considered to require an "impervious" liner to meet it."

For impoundments that collect wastewater runoff only, the previous provisions were retained that required a maximum seepage rate of 7.35 x 10 -6 cm/sec (1/4" per day). The Commission recognizes that this weaker seepage standard, relative to the baseline standard, is appropriate for the more dilute nature of the retained wastewater and the short retention time allowed (see statement of basis and purpose for 1992 revisions to this regulation), but it may not be sufficiently protective of ground water where porous, low nutrient-retaining soil, such as sands, exists below an impoundment. The primary constituent of concern regarding ground water quality that typically seeps below impoundments is ammonium-nitrogen, which has a positive charge. Where ammonium-nitrogen is exposed to air (such as after an impoundment is abandoned), it can rapidly be converted to nitrate-nitrogen, which is negatively-charged and soluble and can move rapidly to ground water in sandy-type soils. Positively-charged ions can be adsorbed by negatively-charged soil particles, thereby being deterred from leaching to any significant depth in the soil. Therefore, the adopted rule specifies that the more lenient seepage rate can be used only where the ten (10) foot soil depth zone immediately beneath the impoundment has a cation exchange capacity (CEC) of at least 15 meq/100 g of soil, which is based on information in the Journal of Environmental Quality (Volume 29, November-December 2000) entitled, "Toward Site-specific Design Standards for Animal-Waste Lagoons: Protecting Ground Water Quality." The intent of these regulations is that the required CEC must exist below the entire surface of the impoundment, which requires that representative soil sampling be made in multiple locations, including perimeter and interior locations, within the "foot print" surface area of the impoundment.

As discussed above, ground water protection measures cannot be included as conditions in CAFO permits. While the existing rule required some, but not all, CAFOs to have evidence of a completed liner having been constructed in impoundments, the amended rule specifies that such evidence is required of all CAFOs, that it be prepared by a professional engineer certified in Colorado, and that it be provided to the Division upon request. The Commission recognizes that most CAFOs do not currently have the newly required evidence. To allow time for the CAFOs to obtain the evidence, the Commission set a deadline of April 13, 2006 by which CAFOs must have the evidence. This date is the latest deadline by which existing CAFOs must have applied for a permit under the revised federal CAFO regulations. After the deadline, the Division will request the evidence when a permit application is received, and during an inspection.

The Commission is aware that ground water located too close to impoundment bottoms can cause functional problems with construction and maintenance of impoundments. It also recognizes that impoundments pose a greater risk to ground water quality where they are located in close proximity to ground water. This risk is heightened where ground water supplies drinking water for the public. The Commission also recognizes that existing impoundments may be difficult to re-locate, but that it is appropriate to subject newly-constructed lagoons at new source CAFOs to location constraints. In order to provide for reasonable locations of impoundments, but not where they pose a potentially high risk to ground water quality or to proper construction and maintenance, the adopted rule specifies setbacks for impoundment locations for new source CAFOs.

The Commission added language requiring that manure and wastewater be removed from impoundments in a manner that does not damage the integrity of the liner. Liner integrity is at risk where manure is removed from impoundments using mechanical equipment and where it is difficult to discern the bottom of settled out manure versus the top of a soil liner, or where liquid remains in the impoundment. Mechanical equipment includes rubber- tired or track machinery, track hoes, and agitator pumps. It does not include other pumps such as floating pumps. Where an impoundment will be dewatered via pumps, agitators, or the like, the potential impacts to the structure should be considered and necessary protective features should be put into place, such as concrete pads, rip rap or additional sacrificial material, or an indicator of the impoundment bottom to signal an equipment operator where to stop pumping.

The Commission believes that a high level of assurance needs to exist that the liner standard continues to be met after manure removal, in order to assure the public that ground water is being protected. Therefore, the regulation was revised to require CAFOs to submit to the Division for approval a Standard Operating Procedure ("SOP") that the CAFO will use and that demonstrates how manure will be removed such that the liner integrity is not damaged. Examples of appropriate methods include, but are not limited to, removing teeth from mechanical cleaning equipment and adding a protective "lip" to mechanical cleaning buckets to prevent digging. The adopted regulation also requires the operator to certify that manure was removed according to the SOP, maintain on-site copies of the SOP and certifications, and submit the SOP or certifications to the Division upon request. Where the SOP was not followed, it is appropriate to require that the liner be made available for inspection and, where just cause exists upon inspection, to require that the liner be re-certified by a professional engineer.

The Commission added an additional provision to the regulations that requires an operator to visually inspect exposed liners weekly to assure that a liner is maintained to minimize seepage. The requirement is applicable to exposed liners since the liner on impoundment bottoms is commonly not visible, being hidden by wastewater or manure sludge. The exposed liners would be inspected to identify physical changes or deficiencies that may affect the liner, such as rodent burrows, deep-rooted plants, rills, and step erosion caused by wave action. The weekly inspection frequency is the same as required for other inspections that must be made of impoundments, in accordance with the CAFO permit provisions in section 61.17 of the Colorado Discharge Permit System Regulations. Where deficiencies are found, the adopted regulation requires that they be corrected within 30 days, unless a longer correction period that was used by the operator is accompanied by an explanation of why the longer time period was necessary. These provisions are also consistent with the CAFO permit provisions in section 61.17 of the Colorado Discharge Permit System Regulations.

The existing regulation has language regarding the design, construction, and performance standards of wastewater conveyance structures. The existing language requiring that conveyance structures be constructed to prevent exceedances of water quality standards was deleted since wastewater is conveyed by such structures for only a short period of time (during storms) and the depth of flow is minimal. In addition, the process of determining whether seepage in a structure will prevent an exceedance of ground water quality standards can be complicated and expensive. The existing language requiring seepage of wastewater from conveyances to be limited through the use of very low permeability materials and proper compaction was revised in response to stakeholder input and information provided by the Colorado conservation engineer for the United States Department of Agriculture- Natural Resources Conservation Service. Based on this information, conveyance structures constructed in soils with less than 35 percent gravel do not need to be compacted or lined. Structures placed in soils with greater than 35 percent gravel need to be compacted or lined in order to sufficiently minimize seepage in the structures.

The Commission is aware that conveyance structures that carry process-generated wastewater have a higher risk of seepage from the structures impacting ground water as a result of the higher concentrations of pollutants in the wastewater and the greater frequency of flow of the wastewater. The Commission also is aware that the extent of seepage below a conveyance structure can be greater where the structure is constantly in a wetted condition, such as where process-generated wastewater flows daily from a milking parlor. The Commission considers such a structure to be essentially an impoundment and, therefore, required in the adopted regulations that conveyances that carry process-generated wastewater non-intermittently (48 hours or less between conveyance events) be constructed and maintained to seep at a maximum rate of 1 x 10 -6 cm/sec.

The existing section 81.8 was deleted since it addressed water quality monitoring that may be required of either surface or ground water, or both. Since ground water protection provisions are being retained in today's adopted rule, ground water monitoring language was added to the new section 81.5 . The Commission believes that ground water monitoring beneath impoundments is not justified, except where the liner in an impoundment is not being properly maintained, or where required evidence of ground water protection measures does not exist or is not provided to the Division upon request. In such situations, the Commission found it appropriate to specify the factors the Division shall consider before determining whether ground water monitoring is required. Where the Division determines that ground water monitoring is necessary, it is reasonable to allow the monitoring to be done using, to the extent practicable, existing facility wells, such as irrigation wells and drinking water wells.

Impoundment Closure: Closed impoundments are a risk to ground water quality once they become dry since ammonium-nitrogen that has seeped below a lagoon can be exposed to air. The oxygen in air can convert the ammonium to nitrate-nitrogen, which is negatively-charged and soluble and movable to ground water. Therefore, the Commission revised the regulation to include the requirement that a closed CAFO remove wastewater and manure from impoundments and backfill the impoundments with at least five feet of soil to minimize the access of oxygen to soil ammonium. Because backfilling may be difficult during the winter, the Commission allowed 120 days for the backfilling to be completed. It also included language that provides a CAFO the opportunity to submit to the Division for approval an alternative closure procedure that provides for protection of ground water.

Practices for AFOs to Protect Ground Water: As presented in the "Designation of an AFO as a CAFO" section above, the ground water protection provisions of the existing "hydrologically sensitive area" language can no longer be included as criteria for designating an AFO as a CAFO. As a result, these provisions were added to subsection 81.6 as a best management practice for protecting ground water quality. In this way, the Commission's intent is maintained whereby ground water is protected where it is at risk from an AFO being located above it.

The Commission finds it appropriate to clarify in today's rulemaking the existing "hydrologically sensitive area" language pertaining to ground water. Regarding an AFO being in a location where significant ground water recharge occurs, stakeholders indicated their preference that specific criteria be stated in the regulation for how such recharge will be determined, so that AFOs are aware of the standard to which they may be held. Stakeholders also agreed that the following publication be used for making a determination: 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". The Commission found it appropriate to specify in the regulation use of this document.

Regarding protection of future drinking water system withdrawals, the Commission added language that requires the Division to perform a water source susceptibility analysis. The goal of the analysis is to reveal whether an AFO has a "medium-high" or "high" potential for contaminating existing or reasonably likely future drinking water system withdrawals from ground water. The Commission clarifies that "reasonably likely future drinking water system withdrawals" refers to any new development or public facility, such as a new housing area or school, proposed to be located within a Source Water Assessment area. In addition, the Commission intends that the Division use its current "Source Water Assessment Methodology for Ground Water Sources" document for conducting the water source susceptibility analysis, and that the Division may accept the use of other methodologies that appropriately evaluate the physical setting of the ground water and the contaminant threat from the AFO, using the factors stated in the regulation.

Where an AFO could adversely affect ground water quality, the Commission adopted language requiring that the AFO protect ground water by installing a liner such that the seepage rate from each impoundment does not exceed 1 x 10 -6 cm/sec, which is the same seepage rate standard required of CAFOs. Language also was added that provides for liners to be installed according to an approvable plan that is developed in consultation with the Division.

PARTIES TO THE RULEMAKING HEARING