Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-61 - REGULATION NO. 61 - COLORADO DISCHARGE PERMIT SYSTEM REGULATIONS
Section 5 CCR 1002-61.17 - CONCENTRATED ANIMAL FEEDING OPERATIONS

Universal Citation: 5 CO Code Regs 1002-61 ยง 17

Current through Register Vol. 47, No. 5, March 10, 2024

61.17(1) SCOPE AND PURPOSE

(a) The provisions in this section 61.17 provide permit regulations for concentrated animal feeding operations as the result of the revised federal concentrated animal feeding operation (CAFO) regulations that became effective on April 14, 2003, and as revised effective July 24, 2007 and December 22, 2008.

(b) The purpose of these regulatory provisions is to ensure that CAFOs take appropriate actions to manage manure and process wastewater effectively in order to protect surface waters.

61.17(2) SPECIFIC APPLICABILITY

(a) The provisions in this section 61.17 are applicable to all new and existing CAFOs and to animal feeding operations that are designated as CAFOs by the Division, except any CAFO defined as a housed commercial swine feeding operation under section 61.2 of these regulations.

(b) Any discharge from a CAFO requires a permit except those that are agricultural storm water discharges as defined in section 61.17 . The owner or operator of a CAFO must seek coverage under a permit if the CAFO discharges to surface water. Specifically, the CAFO owner or operator must either apply for an individual permit or submit a notice of intent for coverage under a general permit.

(c) Land Application Discharges from a CAFO - The discharge of manure or process wastewater to surface water from a CAFO as a result of the application of that manure or process wastewater by the CAFO to land areas under its control is a discharge from that CAFO subject to permit requirements, except where it is an agricultural storm water discharge. For purposes of this section 61.17 , where the manure or process wastewater has been applied in accordance with site specific nutrient management practices that ensure appropriate agricultural utilization of the nutrients in the manure or process wastewater, as specified in those parts of the nutrient management plan that address section 61.17 , a precipitation-related discharge of manure or process wastewater from land areas under the control of a CAFO is an agricultural stormwater discharge.

(d) CAFOs shall comply with the relevant sections of Regulation #61, not superseded by this section 61.17 , which shall be incorporated in the permit, where appropriate.

61.17(3) DEFINITIONS

As used in this subsection, the following definitions of terms apply.

(a) "25-YEAR, 24-HOUR STORM" means a storm of a 24-hour duration which yields a total rainfall of a magnitude which has a probability of recurring once every 25 years.

(b) "CHRONIC STORM" means a series of storms that occur during a 10-day period which yield a total precipitation of a magnitude that has a probability of recurring once every ten (10) years.

(c) "CLOSED FACILITY" means a concentrated animal feeding operation that has ceased operation and for which a permit is not in effect.

(d) "FREEBOARD" means the vertical distance measured from the liquid surface level (elevation) in an impoundment or tank to the top elevation of the impoundment or tank (for example, berm or wall).

(e) "LAND APPLICATION SITE" means land under the control of a CAFO operator, whether it is owned, rented, or leased by the CAFO, to which manure or process wastewater from the production area is or may be applied, or where cropping or nutrient budget decisions for the site are made by the CAFO.

(f) "MAN-MADE DRAINAGE SYSTEM" means a drainage ditch, flushing system, or other drainage device that was constructed by man and is used for the purpose of transporting manure or process wastewater.

(g) "MANURE" means feces, litter, and/or urine and materials, such as bedding, sludge, compost, feed waste, dry harvested forage, and any raw material used in or resulting from the operation of an animal feeding operation, that have been commingled with feces, litter, and/or urine.

(h) "MULTI-YEAR PHOSPHORUS APPLICATION" means phosphorus applied to a field in excess of the crop needs for that year. In multi-year phosphorus applications, no additional manure, residual solids, process wastewater, or swine feeding process wastewater is applied to the same land in subsequent years until the applied phosphorus has been removed from the field via harvest and crop removal.

(i) "OPERATOR" means any person who owns, leases, operates, controls, or supervises an animal feeding operation or concentrated animal feeding operation.

(j) "OVERFLOW" means the discharge of manure or process wastewater resulting from the filling of an impoundment or tank beyond the point at which no more manure or process wastewater can be contained by the structure.

(k) "PROCESS WASTEWATER" means water directly or indirectly used in the operation of a CAFO for any or all of the following: spillage or overflow from animal or poultry watering systems; washing, cleaning, or flushing pens, barns, manure pits, or other CAFO facilities; direct contact swimming, washing, or spray cooling of animals; or dust control. Process wastewater also includes any water which comes into contact with any raw materials, products, or byproducts including manure, litter, feed, milk, eggs, or bedding.

(l) "PRODUCTION AREA" means that part of a CAFO that includes the animal confinement area, the manure and residual solids storage area, the raw materials storage area, and waste containment areas. The animal confinement area includes but is not limited to open lots, housed lots, feedlots, confinement houses, stall barns, free stall barns, milkrooms, milking centers, cowyards, barnyards, medication pens, walkers, animal walkways, and stables. The manure and residual solids storage area includes but is not limited to lagoons, runoff ponds, storage sheds, stockpiles, under house or pit storages, liquid impoundments and tanks, static piles, and composting piles. The raw materials storage area includes but is not limited to feed silos, silage bunkers, and bedding materials. The waste containment area includes but is not limited to settling basins, and areas within berms and diversions which separate uncontaminated storm water. Also included in the definition of production area is any egg washing or egg processing facility, and any area used in the storage, handling, treatment, or disposal of mortalities.

(m) "SETBACK" means a specified distance from surface waters, or potential conduits to surface waters, where manure, residual solids, swine feeding process wastewater, and process wastewater may not be land applied. Examples of conduits to surface waters include but are not limited to: open tile line intake structures, sinkholes, and agricultural well heads.

(n) "TANK OVERFLOW" means livestock drinking water in constant-flow cattle watering troughs that overflows into in-trough drain pipes and is retained separately from process wastewater storage.

(o) "VEGETATED BUFFER" means a narrow, permanent strip of dense perennial vegetation established parallel to the contours of and perpendicular to the dominant slope of the field for the purposes of slowing water runoff, enhancing water infiltration, and minimizing the risk of any potential nutrients or pollutants from leaving the field and reaching surface waters.

61.17(4) DESIGNATION OF AN ANIMAL FEEDING OPERATION AS A CONCENTRATED ANIMAL FEEDING OPERATION

The Division may designate any AFO as a CAFO upon performing an on-site inspection and determining that it reasonably could be a significant contributor of pollutants to surface water.

(a) The following criteria shall be considered to determine if an AFO will be designated as a CAFO:
(i) The size of the AFO and the amount of wastes reaching surface water;

(ii) The location of the AFO relative to surface water;

(iii) The means of conveyance of animal wastes and process wastewater into surface water;

(iv) The slope, vegetation, rainfall, and other factors affecting the likelihood or frequency of discharge of manure and process wastewater into surface water; and

(v) Other relevant factors.

(b) No AFO with animal numbers below those established for a Medium CAFO shall be designated as a CAFO unless:
(i) Pollutants from the animal feeding operation are discharged into surface water through a manmade ditch, flushing system, or other similar manmade device; or

(ii) Pollutants from the animal feeding operation are discharged directly into surface water that originate outside of the facility and pass over, across, or through the facility or otherwise come into direct contact with the animals confined in the operation.

(c) Where an AFO is at risk of being designated a CAFO, the AFO operator shall submit to the Division, within 60 days of receiving written notice by the Division of such a risk, one of the following:
(i) In consultation with the Division, an approvable work plan and associated timeline for reducing actual or potential environmental impacts such that the Division would not designate the AFO as a CAFO. The operator shall implement the plan within 30 days of it being approved by the Division; or

(ii) A written statement indicating the operator's intention to operate as a CAFO and submit a complete application to be covered under a CAFO discharge permit within 180 days of the date of such statement.

(d) Where an operator does not complete and implement a work plan pursuant to section 61.17 , or does not submit a written statement pursuant to section 61.17 , the AFO may be designated a CAFO by the Division and be required to submit a complete application to be covered under a CAFO discharge permit within 90 days of receiving written notice by the Division of such a designation and permit application requirement.

61.17(5) PERMIT APPLICATIONS

(a) Application Deadlines
(i) The operator of an operation that was defined as a CAFO under regulations that were in effect prior to June 30, 2004, and continues to be defined as a CAFO under subsection 61.2 , must submit a complete application for a permit immediately where the operation discharges.

(ii) The operator of an operation that became defined as a CAFO after June 30, 2004, but which is not a new source, must submit a complete application for a permit as follows where the operation discharges:
(A) For newly constructed operations not subject to effluent limitations guidelines, 180 days prior to the time the CAFO places animals on the operation; or

(B) For other operations (e.g., resulting from an increase in the number of animals), as soon as possible, but no later than 90 days after becoming defined as a CAFO.

(iii) The operator of a new source CAFO must apply for a permit at least 180 days prior to the time that the operator places animals on the operation.

(iv) The operator of an animal feeding operation that is designated a CAFO pursuant to subsection 61.17 , must submit a complete application for a permit no later than 90 days after receiving notice of the designation.

(b) Permit Renewal

The operator of a CAFO that seeks to continue with permit coverage shall submit a new permit application consistent with section 61.17 at least 180 days before the existing permit expires.

(c) Permit Application Requirements (Individual and General Permits)

All new and existing CAFOs shall provide the following to the Division, at minimum, using the application form provided by the Division:

(i) The name of the owner(s) and operator(s) of the operation;

(ii) The contact information of the operator, including mailing address, electronic mail address, facsimile phone number, and office and cell phone numbers;

(iii) The facility location (including section, township, and range) and mailing addresses;

(iv) Latitude and longitude at the entrance to the production area;

(v) A location map (USGS topographic map with 1:24,000 or 1:50,000 scale, or other topographic map of similar accuracy) that illustrates the following:
(A) Location and outline of production areas and land application sites;

(B) Drainage patterns from the production areas;

(C) Location and depths of functional wells, including monitoring wells, within a one-half mile radius of the center of the production areas;

(D) Name and location of public roads located within 1.0 mile of the production areas; and

(E) Name and location of surface waters that will receive discharges from impoundments or terminal storage tanks.

(vi) Specific information about the type and number of animals, whether in open confinement or housed under roof;

(vii) The type of containment and storage for manure and process wastewater (for example, anaerobic lagoon, roofed storage shed, storage ponds, underfloor pits, above ground storage tanks, below ground storage tanks, concrete pad, impervious soil pad, stockpiles, composting), and total capacities for manure and process wastewater storage;

(viii) A site plan of production areas that includes locations of and, where appropriate, names of buildings, manure storage areas, composting areas, impoundments and tanks, piping to impoundments and tanks, transfer piping between impoundments, tanks, manure separation systems, pens, lift stations, berms, process wastewater conveyances, 100-year flood plains (in whole or in part within production areas), and location after each impoundment or terminal tank where permitted discharges to surface waters will occur.

(ix) Design calculations, drawings, specifications, tables, and other documents prepared by or reviewed by a professional engineer registered in Colorado, that document and certify the following. Such documents prepared by a professional engineer shall contain the professional engineer's seal. Such documents reviewed by a professional engineer shall have an accompanying letter indicating what was reviewed and what is being certified by the professional engineer.
(A) The volume of process wastewater runoff generated by portions of the production area that are tributary to each impoundment during applicable storm events;

(B) Drawings for each impoundment that consist of a plan view and cross-sectional views (one each way). The cross sectional views shall include the location of piping, splash pads, chutes, bracing, and spillways. Label in a cross-sectional view, elevations of:
1) the basin floor;

2) manure and process wastewater storage volume (at maximum operating level);

3) precipitation volume from the storm event that is applicable to the permit for which coverage is being requested;

4) process wastewater volume from the storm event that is applicable to the permit for which coverage is being requested;

5) two feet of freeboard, or other freeboard level approved by the Division pursuant to section 61.17 ; and

6) the top of berms;

(C) That a properly designed and constructed spillway is, or will be, in place at each discharging impoundment, unless the Division has approved that a spillway is not required;

(D) That accurate, permanent depth markers are, or will be, in place that indicate the depth of process wastewater in each open surface liquid impoundment and tank, that are clearly marked in one (1) foot increments, and that clearly indicate the two-foot freeboard elevation (or other freeboard level approved by the Division) and the minimum capacity necessary to contain the required rainfall event, plus two feet of freeboard (or other freeboard level approved by the Division);

(E) That two feet of freeboard, or other freeboard level approved by the Division pursuant to section 61.17 (iii)(A), exists in each open surface impoundment and terminal tank, above the precipitation amount of the storm event that will be specified in the permit, plus associated process wastewater runoff volume, plus manure and other process wastewater storage volume.

(F) That clean water is diverted, as appropriate, from the production areas, manure stockpiles, and composting areas;

(G) That structures used to divert process wastewater from the production areas are sized to carry the flow expected from the storm event that will be specified in the permit for which coverage is being requested; and

(H) That all impoundments, tanks, manure stockpiles, or composting areas located within a 100-year floodplain are protected from inundation and damage from 100-year or smaller flood events.

(x) The total number of acres under control of the applicant available for application of manure or process wastewater;

(xi) A standard operating procedure for measuring and recording precipitation;

(xii) Estimated amounts of manure and process wastewater generated per year (tons/gallons);

(xiii) Estimated amounts of manure and process wastewater transferred to other persons per year (tons/gallons);

(xiv) A nutrient management plan that, at a minimum, satisfies the requirements specified in section 61.17(8)(b);

(xv) Where alternative performance standards are being requested, the information required in subsection 61.17 , and any additional information requested by the Division pursuant to subsection 61.4(1)(k);

(xvi) Other information required by the Division; and

(xvii) Signature of the application form in accordance with the requirements of subsection 61.4(1).

(d) Permit Review and Processing

CAFO owners or operators must submit a notice of intent (i.e., permit application) when seeking authorization to discharge under a general permit in accordance with 61.17(5)(a). The Division will review these submittals to ensure that the notice of intent includes the information required by 61.17(5)(c), including a nutrient management plan that meets the requirements of 61.17(8)(b) and applicable effluent limitations and standards, including those specified in 61.17(6). When additional information is necessary to complete the notice of intent or clarify, modify, or supplement previously submitted material, the Division may request such information from the owner or operator. If the Division makes a preliminary determination that the notice of intent meets the requirements of 61.17(5)(c) and 61.17(8)(b), the Division will notify the public of the Division's proposal to grant coverage under the permit to the CAFO and make available for public review and comment the notice of intent submitted by the CAFO, including the CAFO's nutrient management plan, and the draft terms of the nutrient management plan to be incorporated into the permit.

For permits, the process for submitting public comments and hearing requests, and the hearing process if a request for a hearing is granted, will follow the procedures applicable to draft permits set forth in section 61.5 . For nutrient management plans, the Division may establish an appropriate period of time and process for the public to comment and request a hearing that differs from those specified in section 61.5 . The Division will respond to significant comments received during the comment period and, if necessary, require the CAFO to revise the nutrient management plan in order to be granted permit coverage.

When the Division authorizes coverage for the CAFO owner or operator under the general permit, the terms of the nutrient management plan as specified in 61.17(8)(b)(xii) become incorporated as terms and conditions of the permit for the CAFO. The Division will notify the CAFO owner or operator and inform the public that coverage has been authorized and of the terms of the nutrient management plan incorporated as terms and conditions of the permit applicable to the CAFO.

(i) The incorporation of the terms of a CAFO's nutrient management plan into the terms and conditions of a general permit when a CAFO obtains coverage under a general permit in accordance with 61.17(5), is not cause for modification to the general permit pursuant to the requirements of section 61.17(8)(b)(xv).

1.17(6) EFFLUENT LIMITATION REQUIREMENTS FOR CONCENTRATED ANIMAL FEEDING OPERATIONS

Except where a variance has been granted pursuant to section 61.12 , CAFOs must achieve the following effluent limitations:

(a) All Existing CAFOs
(i) Effluent Limitations for existing Large Horse and Sheep CAFOs - There shall be no discharge of process wastewater into surface water except as follows: whenever precipitation causes an overflow of process wastewater from a production area designed, constructed, operated, and maintained to contain all manure and process wastewater, including the runoff and direct precipitation from a 25-year, 24-hour storm, at minimum, any process wastewater pollutants in the overflow may be discharged into surface water.

(ii) Effluent Limitations for existing duck CAFOs - Discharges resulting from production areas at dry lot and wet lot duck CAFOs with 5,000 or more ducks shall achieve the following effluent limitations:

Regulated Parameter

Maximum

Daily1

Maximum

Monthly Average1

Maximum

Daily2

Maximum

Monthly Average2

BOD5

3.66

2.0

1.66

0.91

Fecal coliform

( 3)

( 3)

( 3)

( 3)

1 Pounds per 1000 ducks.

2 Kilograms per 1000 ducks.

3 Not to exceed MPN of 400 per 100 ml at any time.

(iii) Effluent Limitations for existing Large Dairy Cow, Cattle, Swine, Poultry, and Veal Calf CAFOs
(A) Production areas - Except as provided in paragraphs (iii)(A)(I) and (iii)(A)(II) of this section, there shall be no discharge of manure or process wastewater into surface water from the production area. These Large CAFOs shall attain the limitations and requirements of this section 61.17 as of the date of permit coverage.
(I) Whenever precipitation causes an overflow of manure or process wastewater, pollutants in the overflow may be discharged into surface water provided:
1) The production area is designed, constructed, operated, and maintained to contain all manure and process wastewater, including the runoff and direct precipitation from a 25-year, 24hour storm, at minimum; and,

2) The production area is operated in accordance with the production area best management practices specified in section 61.17 , and the records specified in section 61.17(8)(c), below.

(II) Where a CAFO has requested and the Division has approved effluent limitation based upon site-specific alternative technologies, pursuant to section 61.17(7)(a), below.

(B) Land application areas - Discharges from land application areas are subject to the following requirements. Existing Large Dairy Cow, Cattle, Swine, Poultry, and Veal Calf CAFOs shall attain the limitations and requirements of this section 61.17 or upon the date of permit coverage.
(I) Develop and implement the nutrient management plan specified in section 61.17 , and the best management practices specified in section 61.17.

(II) Maintain a complete copy of the information for the best management practices required by section 61.17(8)(b)(x), and the records specified at sections 61.17(8)(c), (c)(i), and (c)(iv).

(iv) Small and Medium CAFOs - Effluent limitations for these CAFOs shall be determined by the Division using Best Professional Judgment.

(b) New Source CAFOs

The following CAFOs that commenced construction after April 14, 2003 are considered new sources and are subject to the following effluent limitations, as applicable.

(i) Effluent Limitations for new source Large Horse and Sheep CAFOs - There shall be no discharge of process wastewater into surface water except as follows: whenever precipitation causes an overflow of process wastewater from a production area designed, constructed, operated, and maintained to contain all manure and process wastewater, including the runoff and direct precipitation from a 25-year, 24-hour storm, at minimum, any process wastewater pollutants in the overflow may be discharged to surface water.

(ii) Effluent Limitations for new source duck CAFOs
(A) There shall be no discharge of process wastewater into surface water from dry lot and wet lot duck CAFOs with 5,000 or more ducks except as follows: whenever precipitation causes an overflow of process wastewater from a production area designed, constructed, operated, and maintained to contain all manure and process wastewater, including the runoff and direct precipitation from a 25-year, 24-hour storm, at minimum, any process wastewater pollutants in the overflow may be discharged into surface water.

(B) Pretreatment standards - There shall be no introduction of process wastewater to a publicly owned treatment works (POTW) by a new source Duck CAFO with 5,000 or more ducks, except as follows:
(I) As provided in 40 CFR 403.7; or

(II) Whenever rainfall events cause an overflow of process wastewater from a facility designed, constructed, operated, and maintained to contain all manure and process wastewater, including the runoff and direct precipitation from a 25-year, 24-hour storm, at minimum, any process wastewater pollutants in the overflow may be introduced to a POTW.

(iii) Effluent Limitations for new source Large Dairy Cows and Cattle other than Veal Calves
(A) Such a CAFO that commenced construction after April 14, 2003 shall attain the same limitations and requirements as specified in section 61.17 above, except that the limitations and requirements for land application areas shall be attained as of the date of permit coverage.

(B) Such a CAFO that commenced discharging as a new source after April 14, 1993, and prior to April 14, 2003, shall be subject to the effluent limitation provisions specified in section 61.17(6)(a)(iii), above.

(iv) Effluent Limitations for new source Large Swine, Poultry, and Veal Calf CAFOs that commenced construction after April 14, 2003
(A) Production areas - Except as provided in paragraphs (iv)(A)(I) and (iv)(A)(II) of this section, there shall be no discharge of manure or process wastewater into surface water from the production area. These CAFOs shall attain the limitations and requirements of this section 61.17 as of the date of permit coverage.
(I) Any CAFO subject to this subpart may request that the Division establish best management practice effluent limitations designed to ensure no discharge of manure, litter, or process wastewater based upon a site-specific evaluation of the CAFO's open surface manure storage structure. Best management practice effluent limitations included in the permit must address the CAFO's entire production area. In the case of any CAFO using an open surface manure storage structure for which the Division establishes such effluent limitations, "no discharge of manure, litter, or process wastewater pollutants," as used in this section, means that the storage structure is designed, operated, and maintained in accordance with best management practices established by the Division on a site-specific basis after a technical evaluation of the storage structure. The technical evaluation must address the following elements:
(1) Information to be used in the design of the open manure storage structure including, but not limited to, the following: minimum storage periods for rainy seasons, additional minimum capacity for chronic rainfalls, applicable technical standards that prohibit or otherwise limit land application to frozen, saturated, or snow-covered ground, planned emptying and dewatering schedules consistent with the CAFO's Nutrient Management Plan, additional storage capacity for manure intended to be transferred to another recipient at a later time, and any other factors that would affect the sizing of the open manure storage structure.

(2) Open manure storage structures must be designed using procedures and/or software approved by the Division.

(3) All inputs used in the open manure storage structure design including actual climate data for the previous 30 years consisting of historical average monthly precipitation and evaporation values, the number and types of animals, anticipated animal sizes or weights, any added water and bedding, any other process wastewater, and the size and condition of outside areas exposed to rainfall and contributing runoff to the open manure storage structure. If actual climate data is not available, the best available data from the most proximate weather station(s), such as those utilized by the Colorado State University Colorado Climate Center or the National Oceanic and Atmospheric Administration should be used.

(4) The planned minimum period of storage in months including, but not limited to, the factors for designing an open manure storage structure listed in paragraph (A)(I)(1) of this section. Alternatively the CAFO may determine the minimum period of storage by specifying times the storage pond will be emptied consistent with the CAFO's Nutrient Management Plan.

(5) Site-specific predicted design specifications including dimensions of the storage facility, daily manure and wastewater additions, the size and characteristics of the land application areas, and the total calculated storage period in months.

(6) Evaluation of the adequacy of the designed manure storage structure must use evaluations and simulations approved by the Division. The evaluation must include all simulation inputs including, but not limited to, daily precipitation, temperature, and evaporation data for the previous 100 years, user-specified soil profiles representative of the CAFO's land application areas, planned crop rotations consistent with the CAFO's Nutrient Management Plan, and the final modeled result of no overflows from the designed open manure storage structure. For those CAFOs where 100 years of local weather data for the CAFO's location is not available, CAFOs may use a simulation with a confidence interval analysis conducted over a period of 100 years. The Division may approve equivalent evaluation and simulation procedures.

(7) The Division has the discretion to request additional information to support a request for effluent limitations based on a site-specific open surface manure storage structure.

(8) The Division may waive the requirement of (A)(I)(6) for a site-specific evaluation of the designed manure storage structure and instead authorize a CAFO to use a technical evaluation developed for a class of specific facilities within a specified geographical area.

(9) Waste management and storage facilities designed, constructed, operated, and maintained consistent with the analysis conducted in paragraphs (A)(I)(1) through (A)(I)(7) of this section and operated in accordance with the additional measures and records required in section 61.17 and 61.17 below, will fulfill the requirements of this section.

(II) The production area must be operated in accordance with the additional measures and recordkeeping required in section 61.17(8)(c) and 61.17(8)(f) below.

(III) Provisions for upset/bypass, as provided in 61.8(3)(i) & (j), apply to a new source subject to this provision.

(B) Land application areas - New source Large Swine, Poultry, and Veal Calf CAFOs shall attain the limitations and requirements of this paragraph (B) as of the date of permit coverage.
(I) Develop and implement the nutrient management plan specified in section 61.17 , and the best management practices specified in section 61.17.

(II) Maintain a complete copy of the information for the best management practices required by section 61.17(8)(b)(x), and the records specified at sections 61.17(8)(c).

(v) Effluent Limitations for Large Swine, Poultry, and Veal Calf CAFOs that commenced discharging as a new source after April 14, 1993, and prior to April 14, 2003 - Such CAFOs shall be subject to the effluent limitation provisions specified in section 61.17(6)(a)(iii), above.

(c) General pretreatment standards - CAFO permittees that introduce process wastewater pollutants into a publicly owned treatment works (POTW) must comply with 40 CFR 403.

61.17(7) VOLUNTARY ALTERNATIVE PERFORMANCE STANDARDS

Pursuant to sections 61.17 and 61.17 above, a Large Dairy Cow, Cattle, Swine, Poultry, or Veal Calf CAFO, may voluntarily request the Division to establish alternative Colorado Discharge Permit System effluent limitations based upon the operation's proposed use of site-specific alternative technologies. The request shall include the information specified below. The owner or operator shall attain the limitations and requirements of subsection 61.17 , as applicable, as of the date of permit coverage.

(a) Large Dairy Cow, Cattle, and Existing Source Swine, Poultry, and Veal Calf CAFOs - A supporting technical analysis and any other relevant information and data that would support such site-specific effluent limitations within the time frame provided by the Division. The supporting technical analysis and other relevant information and data shall consist of, but not be limited to, the following.
(i) Information about the proposed innovative technology that includes, but is not limited to:
(A) A description of the technology, manufacturer's name and contact information;

(B) How process wastewater and manure will be treated using the proposed innovative technology;

(C) The reason for and goal of using the technology;

(D) A summary and supporting documents of any research and non-research results that document the performance of the technology;

(E) Information about any deviation from research and non-research conditions, and the anticipated impacts of such deviations on the performance of the proposed innovative technology;

(ii) Results from use of an appropriate technical analysis that calculates the following for discharges from the existing facility, unless an alternative evaluation method is approved by the Division. The calculations shall be based on a site-specific analysis of a storage system designed, constructed, operated, and maintained to contain all manure and process wastewater, including runoff from a 25-year, 24-hour storm. The calculations shall also be based on all daily inputs to the storage system, including manure, all process wastewater, direct precipitation, and runoff, and all daily outputs from the storage system, including losses due to evaporation, sludge removal, and the removal of process wastewater for use on cropland at the CAFO or transported off site.
(A) A calculation determining the predicted median annual overflow volume from the production area based on a 25-year period of actual rainfall data applicable to the site.

(B) Site-specific pollutant data for the CAFO, including colonies of fecal coliform and Escherichia coli, and of the mass of ammonia, phosphorus, biological oxygen demand (BOD5), total suspended solids (TSS), chemical oxygen demand (COD), total organic carbon (TOC), temperature, pH, total dissolved solids (for discharges to the Colorado River System only), and other constituents required by the Division. The pollutant data shall be the result of representative sampling and analysis of all sources of input to the storage system, or other appropriate pollutant data.

(C) A predicted annual average discharge of the pollutants identified in subsection 61.17 above, expressed where appropriate as a mass discharge on a daily basis (lbs/day), and calculated considering subsections 61.17(7)(a)(ii) and 61.17(7)(a)(ii)(A) and (B), above.

(iii) Results from an appropriate analysis that provides the following for the proposed innovative technology:
(A) A prediction of the median annual volume of process wastewater that will occur over the same 25-year period identified in section 61.17(7)(a)(ii), above.

(B) A prediction of the annual average discharge of pollutants identified in subsection 61.17 , above, that will be associated with the discharges specified in subsection 61.17(7)(a)(iii)(A), above.

(C) A demonstration that the proposed innovative technology will achieve a quantity of pollutants discharged from the production area equal to or less than the quantity of pollutants calculated pursuant to subsection 61.17(7)(a)(ii)(C), above.

(iv) Documentation that provides the rationale and justification for the models and analysis that were used to address subsections 61.17 above, and for conclusions made. The Division may, with accompanying justification, request additional information from the operation for the proposed innovative technology, which may include an on-site inspection.

(v) A plan for implementing the innovative technology, including quality assurance practices that the permittee will use to ensure the proper functioning of the innovative technology, and an approach for monitoring performance.

(b) Where the frequency of discharges to surface waters under alternative performance standards is greater than that from a 25-year, 24-hour storm, as applicable, water quality standards-based effluent limits for pollutants in such discharges shall be set pursuant to the requirements of subsection 61.8(2)(b).

(c) Where the frequency of discharges to surface waters under alternative performance standards is greater than that from a 25-year, 24-hour storm, as applicable, discharges shall be monitored, recorded, and reported pursuant to the requirements of subsection 61.8(4).

61.17(8) ADDITIONAL REQUIREMENTS FOR CONCENTRATED ANIMAL FEEDING OPERATIONS

(a) Production Area Design and Construction Requirements.
(i) Process wastewater Storage Capacity Requirements - Concentrated animal feeding operations, except existing dry lot and wet lot duck CAFOs with 5,000 or more ducks, shall meet one of the following design and construction standards regarding process wastewater storage capacity. Precipitation data used to comply with design and construction requirements for storage capacity shall be from a document approved by the Division.
(A) Small and Medium CAFOs - Process wastewater storage capacity requirements shall be determined by the Division using Best Professional Judgment.

(B) Baseline Impoundment and Tank Storage Capacity Requirement for Large CAFOs - Impoundments and tanks for production areas of Large CAFOs (except existing duck CAFOs with 5,000 or more ducks) shall be designed and constructed so that they are capable of storing, at minimum, the volume of all liquid manure and process wastewater, including the runoff resulting from a 25-year, 24-hour Storm, or the runoff volume resulting from a Chronic Storm whichever is larger. Prior to rebuilding or constructing a new impoundment or tank, the operator or owner is strongly advised to contact the Division for the purpose of determining the required storage capacity standard for permitting purposes.
(I) New Source Swine, Poultry, or Veal Calf Operations - Impoundments and tanks for production areas of these new source CAFOs shall be designed and constructed so that these structures meet the requirements set forth in 61.17(6)(b)(iv).

(II) Other New Sources, including Duck CAFOs with 5,000 or More Ducks - New source CAFOs that are not swine, poultry, or veal calf operations shall meet the same baseline storage capacity requirement as specified in subsection 61.17(8)(a)(i)(B) above.

(C) Evaporation Storage System Standard - Evaporation impoundment systems shall be designed and constructed to withstand a consecutive 10-year period of maximum recorded rainfall, as determined by a water budget analysis process which includes manure and process wastewater loading during that period and provides sufficient capacity to retain all rainfall and process wastewater from the applicable design storm event without overflow. For purposes of determining the consecutive 10-year period of maximum recorded rainfall, the entire period of record shall be utilized. Such impoundments shall also be capable of containing any planned volume of liquid manure and process wastewater, including the runoff resulting from a 25-year, 24-hour storm. If a new source Swine, Poultry or Veal Calf Operation, such impoundments shall be capable of meeting the requirements set forth in 61.17(6)(b)(iv).

(ii) Spillways - An impoundment shall have a spillway that is designed and maintained to prevent erosion of the structural integrity of the impoundment, except where the operator requests and the Division approves that a spillway is not required.
(A) An impoundment that holds a depth of process wastewater that is five feet or less, retains process wastewater for 48 hours or less and, from which any overflow will be captured by a down gradient impoundment or tank, shall be exempt from this requirement.

(B) An operator may request approval from the Division that no spillway is required for an impoundment where the operator demonstrates that structural integrity of the impoundment will be maintained without a spillway in the event of an overflow.

(iii) For new source Large CAFOs and newly constructed CAFOs - designs of diversion structures and impoundments for process wastewater, and of structures that divert clean water from running onto production areas, manure stockpiles, and composting areas shall be prepared and certified by a professional engineer registered in the State of Colorado.

(iv) Clean water shall be diverted, as appropriate, from running onto feedlots, holding pens, manure and process wastewater storage systems, manure stockpiles, composting areas, and the like. Structures used to divert clean water from running onto new source Large Swine, Poultry, and Veal Calf CAFOs, shall be capable of meeting the requirements set forth in 61.17(6)(b)(iv).

(v) Structures used to divert process wastewater from production areas to impoundments or tanks shall be sized such that they can carry the flow expected from a 25-year, 24-hour storm. For new source Large Swine, Poultry, and Veal Calf operations, such structures shall be capable of meeting the requirements set forth in 61.17(6)(b)(iv).

(b) Nutrient Management Plan Requirements
(i) Any permit issued to a CAFO must include a requirement to implement a nutrient management plan that, at a minimum, contains best management practices and procedures necessary to meet the requirements of this section and applicable effluent limitations and standards.

(ii) The permittee shall develop and implement a nutrient management plan upon the date of permit coverage for existing and new source CAFOs.

(iii) Ensure adequate storage of manure and process wastewater, including procedures to ensure proper operation and maintenance of the impoundments and tanks. The procedures shall include, but not be limited to:
(A) Except during the designed storm event, manure and process wastewater stored in impoundments and terminal tanks shall be removed as necessary to maintain a minimum of two (2) feet of freeboard, except where the operator requests and the Division approves an alternative freeboard level. The request shall include documentation that the alternative level will protect structural integrity of impoundments and terminal tanks and be functionally equivalent to two feet of freeboard in preventing overflows caused by factors such as wind and receiving direct precipitation.

(B) For operations that land apply process wastewater, whenever the design capacity of impoundments and tanks is less than the volume required to store runoff from the designed storm event, the structures shall be dewatered to a level that restores the required capacity once soils on a land application site has the water holding capacity to receive process wastewater.

(iv) Ensure proper management of animal mortalities (that is, dead animals) to prevent discharge of pollutants to surface waters. Mortalities shall remain on the production area until disposal and shall be managed to ensure that they are not disposed of in a liquid manure, storm water, or process wastewater storage system that is not specifically designed to treat animal mortalities;

(v) Ensure that clean water is diverted, as appropriate, from the production area;

(vi) Prevent direct contact of confined animals with surface waters;

(vii) Ensure that chemicals and other contaminants handled on-site are not disposed of in any manure, storm water, or process wastewater storage system unless specifically designed to treat such chemicals and other contaminants;

(viii) Site-specific conservation practices that have been identified and will be implemented, including as appropriate, buffers or equivalent practices, to control runoff of pollutants to surface water. Such practices shall include, but are not limited to:
(A) Solid manure shall be incorporated as soon as possible after application, unless the application site has perennial vegetation or is no-till cropped, or except where the nutrient management plan adequately demonstrates that surface water quality will be protected where manure is not so incorporated.

(B) Process wastewater to furrow- or flood-irrigated land application sites shall be applied in a manner that prevents any process wastewater runoff into surface waters.

(C) When process wastewater is sprinkler-applied, the soil water holding capacity of the soil shall not be exceeded.

(D) Process wastewater shall not be applied to either frozen or flooded land application sites.

(E) Manure or process wastewater shall not be land-applied within 150 feet of domestic water supply wells, and within 300 feet of community domestic water supply wells.

(ix) Identify protocols for appropriate sampling and testing of manure, process wastewater, and soil;

(x) Establish protocols to land apply manure or process wastewater in accordance with site specific nutrient management practices that ensure appropriate agricultural utilization of the nutrients in the manure or process wastewater. Such protocols shall include, but are not limited to:
(A) No application of manure or process wastewater shall be made to a land application site at a rate that will exceed the capacity of the soil and the planned crops to assimilate nitrate-nitrogen within twelve (12) months of the manure or process wastewater being applied.

(B) Manure and process wastewater shall be applied as uniformly as possible with properly calibrated equipment.

(xi) Identify specific records that will be maintained to document the implementation and management of the minimum nutrient management plan elements described in subsections 61.17(8)(b)(i) through (x), above.

(xii) Terms of the Nutrient Management Plan
(A) Any permit issued to a CAFO must require compliance with the terms of the CAFO's site-specific nutrient management plan. The terms of the nutrient management plan are the information, protocols, best management practices, and other conditions in the nutrient management plan requested by the Division for clarification or justification in order to meet the requirements of paragraph 61.17(8)(b) of this section.

(B) The terms of the nutrient management plan, with respect to protocols for land application of manure, litter, or process wastewater required by paragraph 61.17(8)(b)(x) of this section and, as applicable, 61.17(8), must include:
(I) The fields available for land application;

(II) Field-specific rates of application properly developed, as specified in paragraph 61.17(8)(b)(xii)(B)(IV) below, to ensure appropriate agricultural utilization of the nutrients in the manure, litter, or process wastewater; and

(III) Any timing limitations identified in the nutrient management plan concerning land application on the fields available for land application;

(IV) Description of the rates of application of manure, litter, and process wastewater to be land applied, according to the following specifications:
(1) Maximum amounts of nitrogen and phosphorus derived from all sources of nutrients, for each crop identified in the nutrient management plan, in chemical forms determined to be acceptable to the Division, in pounds per acre, for each field;

(2) The outcome of field-specific assessment of potential for nitrogen and phosphorus transport to surface water for each field, using the USDA, NRCS Colorado Phosphorus Index Risk Assessment tool or other Division-approved method;

(3) The crops to be planted in each field or any other uses such as pasture of fallow fields (including alternative crops identified in accordance with paragraph 61.17(8)(b)(xii)(B)(IV)(7) of the section);

(4) The realistic yield goal for each crop or use identified for each field;

(5) The nitrogen and phosphorus recommendation for each crop or use identified for each field from a method approved by the Division. Such methods may include, but are not limited to, the most current published fertilizer suggestions of the Cooperative Extension in Colorado or adjacent states, or the most current nutrient management planning guidelines for Colorado as published by the USDA, NRCS.

(6) The methodology by which the nutrient management plan accounts for the following factors when calculating the amounts of manure, litter, and process wastewater to be land applied:
a) Results of soil tests conducted in accordance with protocols identified in the nutrient management plan, as required by paragraph 61.17(8)(b)(ix) of this section;

b) Credits for all nitrogen in the field that will be plant available;

c) The amount of nitrogen and phosphorus in the manure, litter, and process wastewater to be applied;

d) Consideration of multi-year phosphorus application;

e) Accounting for all other additions of plant available nitrogen and phosphorus to the field;

f) The form and source of manure, litter and process wastewater;

g) The timing and method of land application; and

h) Volatilization of nitrogen and mineralization of organic nitrogen.

(7) For alternative crops identified in the CAFO's nutrient management plan that are not in the planned crop rotation:
a) The crops must be listed by field, in addition to the crops identified in the planned crop rotation for that field;

b) The nutrient management plan must include realistic crop yield goals and the nitrogen and phosphorus recommendations from sources specified in 61.17(8)(b)(xii)(B)(IV)(5) above;

c) Maximum amounts of nitrogen and phosphorus from all sources of nutrients and the amounts of manure, litter, and process wastewater to be applied must be determined in accordance with the methodology described in paragraph 61.17(8)(b)(xii)(B)(IV)(6) of this section.

(C) If approved by the Division, nutrient management plan terms that meet the requirements of 40 CFR 122.42(e)(5)(i) may also be used to satisfy the requirements of 61.17(8)(b)(xiii).

(xiii) The following projections must be included in the nutrient management plan submitted to the Division, but are not terms of the nutrient management plan:
(A) The CAFO's planned crop rotations for each field for the period of permit coverage;

(B) The projected amount of manure, litter, or process wastewater to be applied;

(C) Projected credits for all nitrogen in the field that will be plant available;

(D) Consideration of multi-year phosphorus application;

(E) Accounting for all other additions of plant available nitrogen and phosphorus to the field;

(F) The predicted form, source, and method of application of manure, litter, and process wastewater for each crop.

(xiv) CAFOs must calculate maximum amounts of manure, litter, and process wastewater to be land applied at least once each year using the methodology required in paragraph 61.17(8)(b)(xii)(B)(IV)(6) of this section before land applying manure, litter, and process wastewater and must rely on the following data:
(A) A field-specific determination of soil levels of nitrogen and phosphorus, including, for nitrogen, a concurrent determination of nitrogen that will be plant available consistent with the methodology required by paragraph 61.17(8)(b)(xii)(B)(IV)(6) of this section, and for phosphorus, the results of the most recent soil test conducted in accordance with soil testing requirements approved by the Division; and

(B) The results of most recent representative manure, litter, and process wastewater tests for nitrogen and phosphorus taken within 12 months of the date of land application, in order to determine the amount of nitrogen and phosphorus in the manure, litter, and process wastewater to be applied.

(xv) Changes to a Nutrient Management Plan
(A) Any permit issued to a CAFO must require the following procedures when a CAFO owner or operator makes changes to the CAFO's nutrient management plan previously submitted to the Division.
(I) The CAFO owner or operator must provide the Division with the most current version of the CAFO's nutrient management plan and identify changes from the previous version, except that the results of calculations made in accordance with the requirements of paragraph 61.17(8)(b)(xiv) of this section are not subject to the requirements of paragraph 61.17(8)(b)(xv) of this section.

(II) The Division must review the revised nutrient management plan to ensure that it meets the requirements of this section and applicable effluent limitations and standards, including those specified in 61.17(6) above, and must determine whether the changes to the nutrient management plan necessitate revision to the terms of the nutrient management plan incorporated into the permit issued to the CAFO. If revision to the terms of the nutrient management plan is not necessary, the Division must notify the CAFO owner or operator and upon such notification the CAFO may implement the revised nutrient management plan. If revision to the terms of the nutrient management plan is necessary, the Division must determine whether such changes are substantial changes as described in paragraph 61.17(8)(b)(xv)(A)(III) of this section.
(1) If the Division determines that the changes to the terms of the nutrient management plan are not substantial, the Division must make the revised nutrient management plan publicly available and include it in the permit record, revise the terms of the nutrient management plan incorporated into the permit, and notify the owner or operator and inform the public of any changes to the terms of the nutrient management plan that are incorporated into the permit.

(2) If the Division determines that the changes to the terms of the nutrient management plan are substantial, the Division must notify the public and make the proposed changes and the information submitted by the CAFO owner or operator available for public review and comment. The process for public comments, hearing requests, and the hearing process if a hearing is held must follow the procedures applicable to draft permits set forth in 61.5. Once the Division incorporates the changes to the terms of the nutrient management plan into the permit, the Division must notify the owner or operator and inform the public of the final decision concerning changes to the terms and conditions of the permit.

(III) Substantial changes to the terms of a nutrient management plan incorporated as terms and conditions of a permit include:
(1) Addition of new land application areas not previously included in the CAFO's nutrient management plan. Except that if the land application area that is being added to the nutrient management plan is covered by terms of a nutrient management plan incorporated into an existing permit in accordance with the requirements of paragraph 61.17(8)(b)(xii) of this section, and the CAFO owner or operator applies manure, litter, or process wastewater on the newly added land application area in accordance with the existing field-specific permit terms applicable to the newly added land application area, such addition of new land would be a change to the new CAFO owner or operator's nutrient management plan but not a substantial change for purposes of this section;

(2) Any changes to the maximum amounts of nitrogen and phosphorus derived from all sources for each crop, as set forth in paragraph 61.17(8)(b)(xii)(B)(IV) of this section;

(3) Addition of any crop or other uses not included in the terms of the CAFO's nutrient management plan and corresponding field-specific rates of application expressed in accordance with paragraph 61.17(8)(b)(xii) of this section; and

(4) Changes to site-specific components of the CAFO's nutrient management plan, where such changes are likely to increase the risk of nitrogen and phosphorus transport to surface water based on the USDA, NRCS Colorado Phosphorus Index Risk Assessment tool or other Division-approved method.

(c) Recordkeeping Requirements

The permittee shall maintain on site a copy of its most current nutrient management plan and make it available to the Division or its designee, upon request. In addition, the permittee must create, maintain on-site for five years from the date they are created, and make available to the Division or its designee, upon request, the following records:

(i) All applicable records identified in the nutrient management plan, pursuant to subsection 61.17(8)(b)(xi) above.

(ii) The completed permit application required pursuant to subsection 61.17(5)(c), above.

(iii) The following complete records:
(A) Records documenting the visual inspections of the production area required under subsection 61.17(8)(f)(ii)(A) and (B);

(B) Weekly records of the depth of the manure and process wastewater in the liquid impoundment and terminal storage tank as indicated by the depth marker required under subsection 61.17(8)(f)(ii)(D);

(C) Records documenting any actions taken to correct deficiencies required under subsection 61.17 . Deficiencies not corrected within 30 days shall be accompanied by an explanation of the factors preventing immediate correction;

(D) Records of mortalities management and practices used by the large CAFO to meet the requirements of subsection 61.17(8)(b)(iv);

(E) Records documenting the current design of any manure storage structures, including volume of solids accumulation, design treatment volume, total design volume, and approximate number of days of storage capacity;

(F) Records of date, time, and estimated volume of any overflow.

(iv) For permitted Large Dairy, Beef, Cattle, Swine, Poultry, and Veal Calf CAFOs, the following complete records for land application sites:
(A) Expected crop yields;

(B) The date(s) manure or process wastewater is applied to each land application site;

(C) Weather conditions at the time of land application and for 24 hours prior to and following application;

(D) Test methods used to sample and analyze manure, process wastewater, and soil;

(E) Results from manure, process wastewater, and soil sampling and analysis;

(F) Explanations of the basis for determining manure and process wastewater application rates, in accordance with the nutrient management plan;

(G) Calculations showing the total nitrogen and phosphorus that will be applied to each land application site, including sources other than manure or process wastewater;

(H) The total amount of nitrogen and phosphorus actually applied to each land application site, including documentation of calculations for the total amount applied;

(I) The method used to apply the manure and process wastewater;

(J) Date(s) of manure application equipment inspection.

(d) Transfer of Manure or Process Wastewater to Third Parties

Prior to transferring manure or process wastewater to other persons, Large CAFOs must provide the recipient of the manure or process wastewater with the most current nutrient analysis. The analysis provided must be consistent with the requirements of the nutrient management plan (subsection 61.17 . Large CAFOs must retain for five years records of the date, recipient name and address, and approximate amount of manure or process wastewater transferred to another person.

(e) Annual Reporting Requirements

The permittee must submit an annual report to the Division that shall include the following:

(i) The number and type of animals, whether in open confinement or housed under roof;

(ii) The estimated amount of total manure and process wastewater generated by the CAFO in the previous 12 months (tons/gallons);

(iii) Estimated amount of total manure and process wastewater transferred to other persons by the CAFO in the previous 12 months (tons/gallons);

(iv) The total number of acres for land application covered by the nutrient management plan developed pursuant to subsection 61.17(8)(b);

(v) The total number of acres of land application sites that were used for application of manure and process wastewater in the previous 12 months;

(vi) A summary of all manure and process wastewater discharges from the production area that have occurred in the previous 12 months, including date, time, and approximate volume;

(vii) A statement indicating whether the current version of the CAFO's nutrient management plan was developed or approved by a certified nutrient management planner;

(viii) The actual crop(s) planted and actual yield(s) for each field, the actual nitrogen and phosphorus content of the manure, litter, and process wastewater, the results of calculations conducted in accordance with paragraph 61.17(8)(b)(xii) of this section, and the amount of manure, litter, and process wastewater applied to each field during the previous 12 months; and

(ix) The results of any soil testing for nitrogen and phosphorus taken during the preceding 12 months, the data used in calculations conducted in accordance with paragraph 61.17(8)(b)(xii) of this section, and the amount of any supplemental fertilizer applied during the previous 12 months.

(f) Operation and Maintenance Requirements.
(i) Accumulations of manure shall be removed from impoundments and tanks as necessary to maintain the capacity of the structures to retain the storage volume from the designed storm event.

(ii) Production Area Best Management Practices - The following best management practices shall be established and properly maintained by permitted Large Dairy, Beef Cattle, Swine, Poultry, and Veal Calf CAFOs:
(A) Perform weekly inspections of all stormwater run-on diversion devices, runoff diversion structures, animal waste storage structures, and devices channeling process wastewater to impoundments or tanks.

(B) Perform daily inspections of water lines, including drinking water or cooling water lines.

(C) Perform weekly inspections of impoundments and tanks and record the process wastewater level in open surface impoundments and terminal storage tanks as indicated by the depth marker required under section 61.17(8)(f)(ii)(D), below.

(D) Install depth markers in all open surface impoundments and terminal storage tanks to indicate the design volume and to clearly indicate the minimum capacity necessary to contain a "25-year, 24-hour", storm event, as applicable, and to clearly indicate the two-foot freeboard elevation, or other approved freeboard elevation. At minimum, depth markers should be clearly marked in one (1) foot increments.

(E) Correct any deficiencies found as a result of daily and weekly inspections as soon as possible, but no later than 30 days of such a deficiency having been identified, unless factors preventing correction within 30 days have been documented.

(iii) Inspect Land Application Equipment - The permittee must periodically inspect for leaks from equipment used for land application of manure or process wastewater. At minimum, such inspection shall be made annually and within the six month period prior to the first application of manure or process wastewater, and at least once daily when process wastewater is being applied.

(iv) Setback Requirements - Unless the permittee exercises one of the alternatives provided for in 61.17(8)(f)(iv)(A) and (B) below, manure and process wastewater shall not be applied closer than 100 feet to any down-gradient surface waters, open tile line intake structures, sinkholes, agricultural well heads, or other conduits to surface waters.
(A) As a setback alternative, the permittee may substitute the 100-foot setback with a 35-foot wide vegetated buffer where applications of manure or process wastewater are prohibited.

(B) As a setback alternative, the permittee may demonstrate that a setback or buffer is not necessary because implementation of alternative conservation practices or field-specific conditions will provide pollutant reductions equivalent or better than the reductions that would be achieved by the 100-foot setback.

(g) Closure Requirements - A permittee shall demonstrate to the satisfaction of the Division that there is no remaining potential for a discharge of manure or process wastewater that was generated while the operation was a CAFO.

Disclaimer: These regulations may not be the most recent version. Colorado may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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