5 Colo. Code Regs. § 1002-61.52
The provisions of 25-8-202(1)(d) and (2), 25-8-401, 25-8-501.1, and 25-8-504, C.R.S., provide the specific statutory authority for the amendments to this regulation adopted by the Commission. The Commission has also adopted, in compliance with 24-4-103(4) C.R.S., the following statement of basis and purpose.
BASIS AND PURPOSE
The provisions in section 61.13 apply to permits for housed commercial swine feeding operations (HCSFOs). Now that the regulations have been in place for three years, the Commission has determined that it is appropriate to modify the regulations to provide clarification of certain provisions that implement statutory requirements in section 25-8-501.1 of the Colorado Water Quality Control Act.
Root zone and soil monitoring zone: Section 25-8-501.1(6) of the Colorado Water Quality Control Act ("the Act") states that certain parameters are required to be sampled and monitored within the root zone and soils beneath the root zone. In addition, section 25-8-501.1(2)(a) of the Act states that nutrients must be strictly minimized from passing below the root zone.
Previous regulatory language [subsection 61.13] defined the root zone as being six or ten feet below the land surface, depending on the crop and soil texture. Previous language [subsection 61.13] also stated that applications of residual solids or swine feeding process wastewater shall not be made if soil nitrogen in the root zone (as specified by Colorado State University Cooperative Extension) exceeds the agronomic rate of application.
Attempts to implement this language revealed that the defined root zone depths were too deep for the purpose of calculating agronomic rates of application. The maximum rooting depth of most crops is four feet; a select few crops are known to root deeper. Accounting for nitrogen within six or ten feet of soil when calculating agronomic rates results in an underestimation of the supplemental nitrogen need for the crops since crop roots cannot access all of the nitrogen at deep soil depths. Upon this realization, the Division implemented the use of agronomic root zones for crops that were based on Colorado State University Cooperative Extension published information. Nitrogen found in these zones was then used to calculate agronomic rates of application.
In order to bring consistency between the regulation and fertilizer calculation protocols, the Commission clarified the meaning of root zone by establishing the term "agronomic root zone." This term is defined in subsection 61.2 and replaces the previous root zone language in subsection 61.13 . This root zone is as specified in Colorado State University Cooperative Extension's most current published fertilizer suggestions for the crops to be grown. The depth of these zones is the area within which crops are reasonably expected to access the majority of nitrogen.
As stated earlier, section 25-8-501.1(6) of the Act requires that certain parameters be monitored in the soils beneath the root zone. Previous regulatory language [61.13(4)(j)(i), and elsewhere] required that two feet of soils below the root zone must be sampled and monitored for nitrate-nitrogen. Since the root zone was six or ten feet below the land surface, the two-foot monitoring areas below the root zone were at six-to eight- foot and ten- to twelve-foot depths, depending on the crop and soil texture. These soil depths were assigned nitrate-nitrogen concentration triggers [61.13(4)(e)(ii)(C) and (D)] for use in verifying that nutrients were being strictly minimized from passing below the root zone.
Implementation of the regulation in this manner resulted in soil zones above the six- or ten-foot depths being monitored for nitrogen, but having no nitrate-nitrogen concentration triggers associated with them. Therefore, if excessive nitrate-nitrogen passed below the agronomic root zone, regulatory language did not exist to require HCSFOs to revise their agronomic practices until the nitrogen was moved into the six-to eight foot or ten- to twelve-foot depths. These depths are below the depth where excess nitrogen can be effectively mined out (phytoremediated) by deep-rooted crops, and ground water quality can be at risk from deeper movement of the nitrogen.
As a result, the Commission established the term "monitoring zone." This term is defined in subsection 61.2 and is the soil zone that is monitored to ensure that land application sites are being managed to strictly minimize nitrogen passing below the root zone. The Commission set the shallowest depth of this zone at four feet, since this is the maximum rooting depth that is used for calculating agronomic rates of application, according to Colorado State University Cooperative Extension's published fertilizer suggestions.
The Commission set the maximum depth of the monitoring zone at six or eight feet, depending on the soil texture and rooting depth of the crop that is currently being grown on the land application site. In addition, the Commission clarified the regulatory language to require sampling to the eight foot depth where soils of land application sites are predominantly sandy. The Commission's goal in establishing a deeper monitoring depth for sandy soils is to recognize that water and nitrate-nitrogen may leach through these soils more readily than through tighter soils. Other factors in addition to soil type (e.g. other chemical or soil conditions) can be important factors in leaching rates or concentrations. The Commission believes that it is important for the Division and others to examine more definitive options for identifying situations where more rapid leaching rates are expected, including the potential use of Natural Resource Conservation Service surveys of the relevant area, in considering possible further refinements of this regulation during its next review.
The revised soil monitoring depths were set two to four feet less than those in the previous language because the soil nitrate-nitrogen trigger (see the section below with the header by this name) has been moved to be applicable to this soil zone that is located immediately below the root zone, where it will be used to more readily detect excess nitrogen passing below the root zone. In addition, where excessive nitrogen is found within this newly defined zone, an intervention protocol can be implemented more rapidly to strictly minimize future nitrogen loading, and the excessive nitrogen more likely can be effectively remediated in a timely manner by deep-rooted crops relative to nitrogen that has been observed to migrate to the deeper depths that were stated in the previous regulation.
Documented values for crop uptake. 61.13(3)(f)(vi): The Commission is aware that all crops uptake nitrogen and phosphorus, which are the primary constituents of concern regarding potential effects on water quality. This uptake ability is reflected in fertilizer suggestions for these nutrients that are published by Colorado State University Cooperative Extension (CSUCE). The Commission also notes that if a CSUCE fertilizer suggestion requires the use of historical, on-site nitrogen uptake values for a crop, these values can be required to be submitted by the permittee to the Division under subsection 61.13 of the regulations. These values would be used to verify that applications of residual solids and swine feeding process wastewater are occurring at agronomic rates. As a result, the Commission believes that requiring swine waste management plans to document nutrient uptake is not necessary, and the previous subsection 61.13 was deleted from the regulation. As a result of this action, subsections that followed subsection 61.13 were renumbered for the existing regulation.
Land application site language: The previous regulation used more than one term when referring to land to which swine feeding process wastewater or residual solids was applied. In order to provide consistency, therefore, the Commission adopted the term "land application site" for use where the regulation refers to such lands.
Baseline and background concentrations for state trust lands. 61.13(3)(g)(iii)(A) and 61.13(4)(g)(ii): The previous language for this subsection stated that only background concentrations of elements need to be established for state trust lands under the monitoring plan. The Commission notes, however, that subsection 61.13 indicates that for existing facilities, ground water and soils cannot be degraded beyond baseline (emphasis added) concentrations, which were not specifically required to be established. In addition, the Commission indicated in the Statement of Basis and Purpose accompanying the March 1999 regulations that determination of baseline concentrations is an appropriate requirement for existing operations so as to avoid an application of new requirements that may be extremely difficult to alter. In order to have consistency, therefore, the Commission adopted language for 61.13(3)(g)(iii)(A) that states that baseline concentrations must be established by existing operations on state trust lands.
The situation may occur whereby a permit for an existing operation has expired, lapsed, or otherwise has not been valid for two years or more. Similarly, the situation may occur whereby housed commercial swine feeding operations have not occurred for two years or more at an existing operation. During the interim period of at least two years, soil and ground water constituent concentrations may have changed as the result of various factors, including non-HCSFO agricultural activities that may have occurred. The Commission determined that such factors can result in higher or lower concentration values than those that existed under the previous permit. Since a purpose of the regulation is to prohibit further degradation of soils or ground water quality at HCSFOs, the Commission adopted provisions requiring the re-establishment of baseline values for HCSFO operations on state trust lands that either have not been permitted or have not had HCSFO activities for two or more years.
The situation may occur whereby an existing operation wants to add a new land application site on state trust land that has never received swine feeding process wastewater or residual solids. Such an additional site is comparable to sites that would be used by new housed commercial swine feeding operations, for which background concentrations must be established. Background concentrations establish soil and ground water conditions that have not been impacted by HCSFO operations. Therefore, the Commission adopted provisions requiring that instead of baseline concentrations, background concentrations shall be established for additional land application sites on state trust lands
The adopted provisions described above affected subsections 61.13(3)(g)(iii) and 61.13(4)(g)(ii), where applicable.
Applications to land where ponding is occurring. 61.13(4)(d)(iv): This subsection previously stated that applications of residual solids or swine feeding process wastewater cannot occur on lands that are saturated, on lands where ponding is occurring, or on land with a snow depth of greater than one inch. The Commission recognizes that where ponding is occurring on sites as the result of applications of residual solids or swine feeding process wastewater, the receiving soils are either saturated or have some other barrier to liquid infiltration. Where ponding is occurring, the risk is potentially increased of contaminants being carried via runoff to waters of the state. HCSFOs must manage this risk under subsection 61.13 which requires that land applications be managed to ensure that no solids or wastewater are discharged to waters of the state. Since the regulation prohibits applications of solids or wastewater to saturated lands, and prohibits discharges to waters of the state as the result of such applications, the Commission simplified the regulatory language by removing the reference to ponding.
Soil phosphorus triggers. 61.13(4)(e)(ii)(B): Swine feeding process wastewater and residual solids have significant concentrations of phosphorus. Not all of this phosphorus is necessarily taken up by plants within the growing season that the wastewater or solids is land-applied, thereby resulting in a build up of residual phosphorus in the soil. Soluble phosphorus that exists in runoff water from soils with high phosphorus concentrations can impact the quality of surface waters. In 1999, the Commission recognized this risk to surface waters and included language in the regulation that prohibited applications of wastewater or solids to soils where the phosphorus concentration in the top soil foot exceeded 100 mg/kg, unless a site-specific analysis shows that soil erosion and movement off-site will not occur. Since 1999, the Colorado Phosphorus Index Risk Assessment tool has been published by the USDA-Natural Resources Conservation Service and is currently in the process of being revised. This tool indicates that the risk of off-site soil phosphorus movement is not directly correlated with phosphorus concentrations in the soil; it is also affected by such factors as runoff risk rating for the soil, application method, and application rate. The Commission revised the regulation to change the acceptable threshold phosphorus concentration to 80 mg/kg, based on information in the Colorado Phosphorus Index Risk Assessment. In addition, the Commission has now specified that if this level is exceeded, a site-specific risk analysis must be developed, using a phosphorus risk screening tool approved by the Division. The Colorado Phosphorus Index Risk Assessment provides one such acceptable tool.
Soil nitrate-nitrogen trigger. 61.13(4)(e)(ii)(C) and (D): The definition of agronomic rate of application requires that nutrients be applied to plants at a rate that strictly minimizes the amount of nutrients that pass below the root zone. Previous regulatory language [in 61.13(4)(e)(ii)(C) and (D)] included two nitrate-nitrogen concentration values (nitrate-nitrogen triggers) for soils beneath the root zone that, if observed, triggered a presumptive finding that nitrogen passage below the root zone had not been strictly minimized. The observation also triggered the requirement that land applications cease until the swine waste management plan is evaluated and revised. The soil depth within which the two nitrate-nitrogen triggers pertained were ten to twelve feet and six to eight feet, depending on the soil texture and the type of crop grown. No nitrate-nitrogen trigger existed for shallower soil depths.
The Commission finds that a nitrate-nitrogen trigger is appropriate in shallower soil zones for the purpose of detecting in a more timely manner excessive movement of nitrogen below the agronomic root zone. Therefore, subsection 61.13 was revised to indicate that a soil nitrate-nitrogen trigger is applicable in the monitoring zone. Application of the trigger in this zone will allow required changes in agronomic practices to be implemented in a more timely manner for the purpose of strictly minimizing the amount of future nitrate-nitrogen loading.
For the nitrate-nitrogen trigger, the Commission retained the standard that was in the previous 61.13(4)(e)(ii)(D); that is, the agronomic rate of application is presumed to have been exceeded if the comparative concentration has been exceeded by ten milligrams per kilogram. The Commission indicated in the Statement of Basis and Purpose accompanying the March 1999 regulations that, "it was not appropriate to establish a regulatory restriction at a difference of five milligrams per kilogram in view of the large number of samples that would be required from each field to achieve a reliable result." Previous language indicated that the ten milligrams per kilogram nitrate-nitrogen trigger was applicable to one-foot soil increments. Since soil samples in the monitoring zone are typically taken in two-foot increments, the Commission revised the regulation to have the trigger be applicable to two-foot soil increments. The Commission believes that it is appropriate to have the trigger be applicable to the six- to eight-foot depth, in addition to the four- to six-foot depth, for sandy soils and soils with deep-rooted crops. The additional depth of soils are sampled as required in 61.2(49), are available for capturing nitrogen that flows into this soil zone as the result of sandy soils being highly leachable, and are available for capturing nitrogen that may gravitate below the deeper roots of deep-rooted crops.
The Commission also amended previous language that indicated that if soil nitrate-nitrogen concentrations exceed the trigger, applications must cease until a revised swine waste management plan is approved by the Division. The amended language states that when the trigger is hit, an approvable intervention protocol must be developed for the applicable land application site in consultation with the Division, and be implemented within 30 days of the protocol being approved by the Division. The protocol must present adjustments that will be made to agronomic practices, such as reducing nitrogen fertilization rate or changing irrigation practices, that will strictly minimize future nitrogen loading within the monitoring zone. It also may require actions such as phytoremediation of excess nitrogen and cessation of land applications, as required by the Division. The determination of appropriate remediation measures will be a case-specific determination. The examples provided here are not intended to be exhaustive. The protocol also must indicate a timeframe under which the adjusted practices will occur, and criteria that will be used to signal the end of the need for remediation protocol activities.
The Commission believes that the development and implementation of such a protocol is more appropriate than requiring that applications of solids or wastewater immediately cease. However, the Commission has provided that if at any time remediation measures in an approved intervention protocol are not being implemented, land application must immediately cease. Where intervention protocols are required for land application sites not owned by the permittee, the Commission recognizes that the Division does not have the authority to order a non-HCSFO landowner to implement actions specified in the protocols. Where such a landowner declines to perform required actions, the Commission finds that the only practical alternative is to require that applications of swine feeding process wastewater or residual solids to the application site shall immediately cease.
The Commission finds that severe climatic events, rather than agronomic practices, can be the cause of excessive soil nitrogen moving below the agronomic root zone, resulting in the comparative concentration being exceeded by ten milligrams per kilogram. Therefore, the Commission added language that allows permittees to not implement a remediation protocol if the Division approves documentation from the permittee that a force majeure (e.g. a severe climatic event) was the cause of the nitrogen trigger having been exceeded.
The Commission finds that the previous soil nitrate-nitrogen trigger of 160 pounds per acre is not as meaningful as using the ten milligrams per kilogram trigger together with the comparative concentration value. The 160-pound concentration is very difficult to achieve in sandy soils and if observed, represents a significant diversion from the requirement that nitrate-nitrogen be strictly minimized from passing below the agronomic root zone. In other soils the concentration may be observed above a soil compaction layer and may not represent the result of improper agronomic practices. Therefore, the Commission deleted the previous subsection 61.13(4)(e)(ii)(C).
Applications to land not supporting active plant growth, 61.13(4)(e)(iv): Previous parts (A), (B), and (C) of this subsection contained language that is included elsewhere in the regulation: 61.13(4)(j)(vi) which requires quarterly soil monitoring, and 61.13(4)(e)(ii) which requires that applications be made at an agronomic rate. Therefore, the Commission simplified the language in part (A) and deleted part (C). The previous language in Part (B) was replaced by language requiring that applications made to land not supporting active plant growth be done according to appropriate best management practices (BMPs). The Commission believes that the proper selection and use of BMPs that are appropriate for specific on-site conditions (such as sandy soils, steep slopes, bare soil, and close proximity to surface water) will provide for strict minimization of nutrients that run off to surface waters or which pass below the root zone, and provide for applications of swine feeding process wastewater and/or residual solids being made in agreement with the amount and duration requirements of the governing statute.
Disagreement among parties existed as to whether appropriate BMPs should be provided in a guidance document that is developed in a public process. The Commission believes that the public process is the best way to develop appropriate BMPs and that a guidance document of the BMPs will provide the Division and permittees with a known set of practices from which to select on a site-by-site basis. The Commission recognizes that use of a guidance document could unnecessarily restrict the use of BMPs that are not specifically listed in the document. Therefore, the guidance document should include language that allows the Division to approve the use of BMPs that are not specified in the document In addition, the document should be opened for review as necessary for possible revision of existing BMPs, or to include newly developed practices.
Water Quality Setbacks. 61.13(4)(f): The Commission finds that the previous language for this subsection was unclear about the meaning of a land application system, and whether the ten-foot vertical setback from ground water was applicable to just these systems or to other HCSFO structures, sites, or systems. It therefore deleted the term land application system", and replaced it with "site." The Commission also notes that swine housing units, wastewater conveyance, treatment, storage, and evaporative structures, land application sites, and residual solids stockpiles and impoundments all pose a risk to the quality of shallow ground water. In addition, shallow ground water may pose structural design and construction problems for housing units and wastewater storage systems. Therefore, the Commission revised this subsection to indicate that all of the above-listed structures and sites must not be located within 10 feet vertically of the seasonally high ground water level.
In addition, the Commission revised language in part (iii) of this subsection to clarify that the 200-foot setback from any body of surface water is applicable to land application sites, as opposed to land application systems.
Finally, the Commission assigned part (vii) to the last paragraph of the existing language of this subsection so that it is an identifiable paragraph.
Financial assurance. 61.13(4)(h): The statute requires that HCSFOs, "provide financial assurance for the final closure of [such facilities], the conduct of any necessary post closure activities, the undertaking of any corrective action made necessary by migration of contaminants from the operation into the soil and ground water, or cleanup of any spill or breach." The previous regulation states that permittees must submit financial assurance to the Division within 90 days following the Division's approval of a new or revised financial assurance plan (FAP). The Commission is aware that situations may occur whereby a permittee is not making adequate progress towards producing an approvable financial assurance plan. In order to ensure that financial assurance is in place to fund closure, post-closure, or corrective action activities absent an approvable FAP, the Commission revised 61.13(4)(h)(v) to indicate that the Division can require interim financial assurance to be submitted when a permittee has not made specified progress towards providing an approvable FAP.
Regarding financial assurance mechanisms, the Commission stated in the Statement of Basis and Purpose accompanying the March 1999 regulation that such instruments shall include wording approved by the Division to ensure that financial assurance remains adequate. The Commission also stated that, in determining appropriate wording, the Division should draw on language from existing financial assurance requirements for other environmental programs. Upon investigating the financial assurance requirements of the Departments Solid Waste and Hazardous Waste programs, the Division became aware of the potentially tenuous ability of financial test and guarantee instruments to indicate that adequate money is readily available for funding a third party to perform corrective actions, and closure and post-closure activities.
Of the allowable financial assurance instruments listed in subsection 61.13 , the financial test and guarantee (FT&G) instruments are the only ones that do not allow the Division to readily access cash funds. As a result, where a permittee has been approved to use one of the FT&G instruments, the expectation exists that the permittee will use its own funds to properly close/post-close the HCSFO operation before abandoning the operation or going out of business. Where this expectation is not met, the only recourse available to the Division for hiring a third party to close/post-close the operation is to sue for the required funds in court, which may be a bankruptcy court. The Division may not have the financial ability or time to pursue such a lawsuit, thereby leaving waters of the state and other environmental attributes at risk from the abandoned operation, which is contrary to the requirements of the governing statute.
The Commission finds that ensuring that adequate funds are readily available at all times for hiring a third party to properly close/post-close a HCSFO operation is essential to meeting the requirements of the statutory provisions. Therefore, the Commission revised subsection 61.13 to require that approval by the Division of financial test and guarantee instruments submitted by permittees be based on criteria specified in a guidance document that is developed cooperatively by the Division and stakeholders, and presented at a public hearing before the Water Quality Control Commission. The criteria should indicate financial standards (e.g., ratios) that a permittee must meet on at least an annual basis, such that only permittees that have solid financial status are qualified to use a financial test or guarantee for the purpose of satisfying the financial assurance requirements of the regulation.
The Commission recognizes that it is highly probable that not all permittees will be able to use the financial test or guarantee, and that for those that cannot, providing a cash-funded form of financial assurance could be a hardship. The Commission encourages the Division to consider alternative mechanisms, such as trusts that are funded by the permittee over time, for use by permittees to satisfy financial assurance requirements.
Baseline concentrations. 61.13(4)(j)(i): Like other businesses, HCSFO operations can be sold to new owners and operators. The previous regulations were unclear as to whether new baseline concentrations were required of new owners of previously permitted HCSFOs. The Commission believes that baseline concentrations should not normally be re-established for on-going operations upon transfer of a permit or upon issuance of a new permit to such operations. It is aware, however, that situations may occur whereby a permit for an existing operation has expired, lapsed, or otherwise has not been valid for two years or more. Similarly, the situation may occur whereby HCSFO activities have not occurred for two years or more at an existing, permitted operation. During the interim period of at least two years, soil and ground water constituent concentrations may change as the result of various factors, including non-HCSFO agricultural activities that may have occurred. The Commission determined that such factors can result in higher or lower concentration values than those that existed under an issued permit. Since a purpose of the regulation is to prohibit further degradation of soils or ground water quality at HCSFOs, the Commission revised subsection 61.13 to require the re-establishment of baseline values for HCSFO operations that either have not had a valid permit or have not had HCSFO activities for two or more years. New baseline values would serve the purpose of re-establishing the relevant "starting point" for permitted sites that would reflect the result of any intervening land surface activities on soil and ground water.
Comparative concentration. 61.13(4)(j)(ii): The Commission became aware that the previous language was unclear regarding to what the baseline nitrate-nitrogen concentration should be compared to derive the comparative concentration. Specifically, the phrase "prior to the most recent planting or growing season, for the crop to be grown that year" was difficult to interpret. Therefore, this regulatory subsection was amended to state that the baseline concentration is to be compared with the nitrate-nitrogen concentration found in the soil sample just prior to the most recent soil sample that was taken from below the land application site.
The Commission finds that the comparative concentration value should continue to reflect improvement in soil nitrate-nitrogen levels that may result from applications of swine feeding process wastewater or residual solids made at agronomic rates of application. Such comparative concentrations allow for effective use of the 10 milligram per kilogram nitrate-nitrogen trigger indicated in 61.13 . The Commission also finds that: no reasonable justification exists for the continued use of a 1.0 milligram per kilogram lower limit for comparative concentrations. It therefore removed language that sets a lower limit for comparative concentration.
The Commission is aware that a soil nitrate-nitrogen concentration value can be significantly greater than the previous comparative concentration value, while still being below the baseline concentration. Where such a significant increase is the result of the permittee having exceeded the agronomic rate of application, the Commission finds that it is not appropriate for the succeeding comparative concentration to reflect the unwarranted increase in soil nitrate-nitrogen concentration. Therefore, the regulation was revised to specify how such a succeeding comparative concentration is to be calculated.
Quarterly monitoring reports. 61.13(4)(j)(v): Language was added to this subsection to state that information pertaining to impoundment seepage monitoring (required by the governing statute) and to intervention protocol activities (required under the existing subsection 61.13(4)(e)(ii)(C)) must be reported to the Division. The Commission is aware that quarterly reporting of intervention protocol activities may not be appropriate because such activities may not occur every quarter. Such activities would thus be reported in reports for quarters within which intervention activities occurred, or as otherwise required by the Division. Similarly, seepage monitoring results may more effectively be reported on a semi-annual or annual frequency, if provided for under the statute. Therefore, the Commission left to the Division's discretion the reporting frequency requirements for impoundment seepage monitoring.
Submittals to the Division of quarterly monitoring reports in a non-standard format presents challenges to the Division in being able to effectively review the reports in a timely manner for compliance of HCSFO activities with the regulations. Therefore, the Commission revised subsection 61.13 to indicate that reports, except of intervention protocol activities, must be prepared on current forms supplied by the Division. The Division indicated its intent to work with interested stakeholders in developing appropriate forms.
The existing language for this subsection requires that surface water monitoring information be included in quarterly monitoring reports. However, such monitoring is not required in the statute. Therefore, the words "surface water" were removed from the subsection.
Sampling and monitoring. 61.13(4)(j)(vi): The Commission notes that the previous language for this subsection was lengthy and addressed more than one topic of sampling and monitoring. Therefore, it segmented the subsection into five parts, (A) through (E), in addition to the introductory paragraph. Each part addresses a specific subtopic of monitoring.
The previous language stated that "nitrogen species" must be monitored in soils within the root zone and beneath the root zone. The Commission notes that the term "nitrogen species" can be interpreted in different ways, and can include the requirement that soil samples be analyzed for such species as nitrite-nitrogen or organic nitrogen, which have no practical relevance for agronomic rate of application or soil monitoring purposes. The nitrogen species of practical relevance are nitrate-nitrogen and ammonium-nitrogen. The former species is of primary concern since it is a soluble, mobile element that can easily be transported to ground water. In addition, a human health risk standard of 10 milligrams per liter of drinking water exists for this species. Finally, a monitoring trigger exists for nitrate-nitrogen within the monitoring zone (see subsection 61.13(4)(e)(ii)(C).
Ammonium-nitrogen, while also is soluble, is positively charged and tends not to be transported through soils, except in coarse-textured soils. In addition, this species is typically mineralized (converted) rapidly by soil bacteria to the nitrate-nitrogen species. This mineralization activity occurs dominantly within the root zone of soils (within the top four feet) where air and moisture tend to be favorable for the biological process. As a result, minimal to negligible amounts of ammonium-nitrogen pass below the root zone and, once below the root zone, will remain in the ammonium-nitrogen form (that is, it will not be mineralized to nitrate-nitrogen). Where ammonium-nitrogen is transported to ground water, no human health risk standard exists for ammonium-nitrogen in drinking water. In addition, no monitoring trigger exists in the regulations for this nitrogen species.
As a result of the above discussion, the Commission finds that it is reasonable to require the monitoring of both nitrate-nitrogen and ammonium-nitrogen within the agronomic root zone, and of nitrate-nitrogen within the monitoring zone.
The Commission is aware that residual solids or swine feeding process wastewater is not applied annually to every permitted land application site. For example, applications in a wheat-fallow system commonly are made once every two years. Some HCSFOs apply to rangeland once every three years. It is not reasonable to require that soils be sampled quarterly in these circumstances. In recognition of this fact, the Commission added a third exception to the requirement that soils be monitored quarterly [in 61.13(4)(j)(vi)(A)]: where applications of solids or wastewater will not be made for at least three consecutive quarters, quarterly soil sampling and analysis is not required. For these situations, soil samples should be taken prior to applications, and after a crop is harvested or goes into dormancy. The Commission included language that allows for additional soil samples to be required at the Division's discretion, based on nitrate-nitrogen levels found in the soil samples. The three consecutive quarters standard was selected based on the fact that fertilizer applications would typically occur within this period where crops are planted annually on a field. The Commission also included language that requires permittees to timely notify the Division in their quarterly reports of their intention not to apply solids or wastewater to specific land application sites for at least three consecutive quarters.
The statute requires that nitrogen, phosphorus, heavy metals, and salts be monitored in soils. The Commission understands that nitrogen is the main element of concern in protecting ground water as the result of HCSFO activities. It therefore included language in 1999 that allowed the Division to waive monitoring requirements for heavy metals if it is demonstrated that no reasonable potential exists of contamination from the metals. Since phosphorus and salts are typically immobile in the soil, the Commission has now adopted provisions [in 61.13(4)(j)(vi)(B)] that provide the Division the ability to waive monitoring requirements for these elements below the first soil foot and in ground water if the same demonstration is made as required for heavy metals. Monitoring of phosphorus in the top foot of soil remains as a minimum requirement in order to comply with 61.13(4)(e)(ii)(B). Regarding salts, the Commission is aware that swine feeding process wastewater and residual solids can have high salt concentrations and when land applied, can cause an excess build up of salt concentrations in the soil, which can affect crop germination and growth. Therefore, the Commission finds that monitoring salts in the top soil foot is appropriate.
Monitoring around water beneath each land application site. 61.13(4)(j)(vi)(E): The previous regulation stated that ground water beneath each land application site must be monitored on a quarterly basis, except where not practicable due to specified conditions. The Commission is aware that such monitoring ideally is accomplished by sampling ground water in monitoring wells. Where shallow ground water (within approximately 50 feet of the ground surface) exists beneath a land application site, it is reasonable to expect that monitoring wells be installed. However, literally hundreds of different land application sites are listed in HCSFO permits. Most of these sites are owned and operated by local, independent farmers that have no relationship to a HCSFO except for agreements that allow swine feeding process wastewater or residual solids to be applied to the farmer's land. It is highly unlikely that the farmers would agree to having at least one monitoring well placed on their land. Such a well is an intrusion on their private property, can act as a conduit for pollutants from the surface to ground water, and the monitoring of these wells will result in the ground water quality information below their private lands being available to the public under the state's open records statute.
If monitoring wells at private application sites are uniformly required, therefore, it is likely that most, if not all, of the farmers would no longer give HCSFOs the right to land apply wastewater or solids. As a result, HCSFOs would have to expand their lagoon capacity, buy their own land application sites, or otherwise manage the wastewater and solids.
An additional impact on permittees is the fact that the cost of installing one monitoring well (most sites will need at least two wells) is about $30 per foot. Most HCSFO land application sites have ground water that is at least 150 feet below the ground surface, meaning that each monitoring well will cost at least $4,500. In addition, since most wells would be installed on land not owned by a HCSFO, the HCSFO will not own the wells that it paid to have installed.
A question of the usefulness of installed monitoring wells also exists. As mentioned in the paragraph above, most land application sites have ground water that is at least 150 feet below the surface, meaning that it will take at least ten to twenty years for nitrogen applied with wastewater or solids, and which passes below the agronomic root zone, to reach ground water. By this time, the discovery of an excessive nitrogen plume is already too late to reflect the impact of current HCSFO activities on ground water.
In response to the above information, the Commission finds that allowing measures for proactive protection of ground water to substitute for the uniform use of wells to monitor deep ground water, will better effectuate the statutory intent of ensuring that ground water beneath land application sites is reasonably protected from applications of wastewater and residual solids. The Commission also finds that allowing the use of proactive protection measures will assist HCSFO operators in effectively allocating their resources to better protect the groundwater resources of the state. To ensure that proactive measures are effective in protecting ground water, the Commission adopted regulatory language requiring a higher standard of soil nitrate-nitrogen monitoring than that required for land application sites beneath which there is shallow ground water, where wells act as a back-up system for ensuring that ground water is not being contaminated. In addition, the Commission finds that not all land application sites, because of factors such as soil texture and geology, may be suitable to having ground water monitored using wells. The Commission concluded that a reasonable interpretation of the statute requires the establishment of some limit beyond which the risk of ground water contamination is so attenuated that monitoring serves no purpose related to protection of ground water. Although no well-established limit exists, the Commission considered the legislative definition of nontributary ground water in section 37-90-103 (10.5), C.R.S., in determining what constitutes a reasonable limit for these purposes. Accordingly, the Commission added regulatory language that provides HCSFOs the opportunity to proactively protect ground water, in lieu of installing monitoring wells, if they submit a ground water risk assessment that confirms that water that passes below the root zone will not reach ground water for at least 100 years.
Finally, the Commission is aware that some land application sites will not have ground water beneath them, or will have an impermeable geological layer beneath them that prevents water and nitrate-nitrogen within the vadose zone from moving to ground water. The Commission concludes that no risk of groundwater contamination exists where the permittee demonstrates to the satisfaction of the Division that either no groundwater exists beneath a land application site or that an impermeable geological layer exists above the shallowest aquifer at the site. The Commission added language to subsection 61.13 clarifying that monitoring is not required under these circumstances.
Typographical Errors. Corrections, and Updates: The Commission has corrected typographical errors in numerous sections of the regulation and has corrected inconsistencies in the use of terms where they were found throughout the regulation. These corrections either have no effect on the meaning of the regulation or revise the meaning of the regulation so that it is consistent with the parallel statutory language.
Section 61.1 has been updated to reflect the latest standards and requirements promulgated by the U.S. Environmental Protection Agency that are adopted and incorporated by reference into the regulation.
Definitions (Section 61.2): The Commission adopted definitions for the terms "biosolids," "load allocation," "total maximum daily load," and "wasteload allocation" as those terms were in use in the existing version of the regulation and substantial additional language that uses the latter three terms has been adopted.
Application Requirements (Section 61.4): The Commission reviewed the application requirements in section 61.4 of the regulation to ensure consistency with the requirements in the federal regulations. This section was revised to:
Application Review Requirements (section 61.5(1)(c)): The Commission revised the language in this section to clarify that the one hundred eighty (180) day deadline for the Division to issue the permit is to be extended by the number of days that an applicant takes to submit additional information requested by the Division, plus fifteen (15) days provided to the Division to evaluate additional information.
Issued Permits (section 61.6(e)): The Commission revised this section to clarify, for renewal permits, rather that issuing a temporary permit if a permit is not issued within the statutory time frame, the previous permit is to be extended in accordance with section 61.8(3)(o) of the regulations.
Conditions of Permits - Prohibitions (section 61.8(1)(e)): The Commission revised this section to clarify the conditions under which interim limits and a schedule of compliance can be included in a permit. This includes situations where the Commission has: adopted new standards where standards for a parameter were not previously in place, adopted temporary modifications, adopted revised standards that have become more stringent, or where the Division has developed new interpretations of existing standards (including, but not limited to, implementation requirements through approved TMDLs and wasteload allocations and antidegradation reviews).
Definition of Effluent Limitations (section 61.8(2)): The Commission added subheadings to this section for ease of review and made the following changes to this section:
Recently there has been a proliferation of new industrial sources that have operations and associated discharges at multiple locations. An example is the recent growth in the development of energy fuel and mineral resources that has occurred in the upper Colorado River Basin. This type of industrial development may involve the drilling of relatively closely spaced wells into one or more geological formations for the purpose of extracting oil, gas or minerals in solution. Large-scale ground water remediation efforts involving multiple pump and treat systems operating for longer than one year may share similar characteristics. With such energy and mineral development and ground water remediation efforts there is the possibility of a single major industrial operation being comprised of numerous individual point source discharges under common or affiliated ownership or management that produce significant quantities of water as a byproduct or waste product over a long period. Given the large scope of these types of major industrial sources and the often elevated concentrations of salinity in their produced water, the total amount of salt loading that they could generate may be very large in comparison to efforts to mitigate salinity impacts through the Forum's plan of implementation and associated salt removal projects. Relatively small quantities of this produced water could generate one ton per day in discharges to surface waters. Since salinity is a conservative water quality constituent, such discharges of produced water, if uncontrolled, could have an adverse effect on achieving the adopted numeric salinity standards in the Colorado River.
These kinds of major industrial sources strain the conventional interpretation of the industrial source waiver set forth in section 61.8 of the regulation, which authorizes a discharge of salinity from a single point source of up to one ton per day in certain circumstances. This provision was adopted well before most of the new major industrial sources that have operations and discharges at multiple locations began to appear in the Colorado River Basin. A new category of industrial sources is, therefore, warranted. Permit requirements for "New Industrial Sources with Operations and Discharges at Multiple Locations under Common or Affiliated Ownership or Management" are set forth in section 61.8 of the regulation. These new requirements are intended to apply to new industrial sources with operations that commence discharging after October 30, 2002.
For purposes of interpreting the regulation, "common or affiliated ownership or management" involves the authority to manage, direct, superintend, restrict, regulate, govern, administer, or oversee, or to otherwise exercise a restraining or directing influence over activities at one or more locations that result in a discharge of salinity into the Colorado River system. Common or affiliated ownership or management may be through the ownership of voting securities or may be indicated where individual sources are related through one or more joint ventures, contractual relationships, landlord/tenant or lessor/lessee arrangements. Other factors that indicate two or more discharging facilities are under common or affiliated ownership or management include: sharing corporate executive officers, pollution control equipment and responsibilities, common workforces, administrative functions, and/or payroll activities among operational facilities at different locations.
Sections 61.8 of the regulation have been amended to allow the Division to authorize "fresh water industrial discharges" where the discharged water does not cause or contribute to exceedances of the adopted numeric salinity standards for the Colorado River system. Different end-of-pipe concentrations of salinity as shown in the table in section 61.82)(l)(i) of the regulation, are appropriate for discharges to tributaries depending upon their location within the basin. The concept of "benchmark concentrations" has been developed in order to address this need for different end-of-pipe concentrations. These benchmark concentrations are not to be interpreted as water quality standards. Rather, they are intended to serve solely for the establishment of effluent limits for implementing the waiver for "fresh water discharges." The allowance for freshwater discharges is intended to preserve flows from discharges in the basin, which do not cause significant degradation of existing ambient quality with respect to salinity. Operations or individual discharges that qualify for the freshwater waiver shall not be subject to any further limitation on salt loading under this policy.
The regulation has been amended to allow the Division to authorize industrial sources of salinity to conduct or finance one or more salinity-offset project when the permittee has determined that it is not practicable to prevent the discharge of all salt from proposed new construction or to reduce the salt loading to the Colorado River to less than one ton per day or 366 tons per year and the proposed discharge is not of sufficient TDS concentrations to be considered "fresh water." Presently, the Division can consider the costs and availability of implementing off-site salinity control measures to mitigate the adverse impacts of the permitted salt load. It is not intended that the applicant be required to develop or design an off-site salinity control project or establish a salt bank, but rather to assess the costs of conducting or buying into such projects where they are available. In the future the Forum or another entity may create a trading/banking institution to facilitate the implementation of a salinity-offset program, basin-wide. This would allow industrial sources to conduct or finance the most cost-effective project available at the time an offset project is needed regardless of the project's location in the basin.
Section 61.8 of the regulation has been added to address discharges of water that has been used for once-through non-contact cooling water purposes. The policy for such discharges shall be to permit these uses based upon a finding that the returned water does not contribute to the loading or the concentration of salts in the waters of the receiving stream beyond a de minimis amount. A de minimis amount is considered, for purposes of this policy, as an average annual increase of not more than 25 milligrams per liter (mg/l) in total dissolved solids measured at the discharge point or outfall prior to any mixing with the receiving stream in comparison to the total dissolved solids concentration measured at the intake monitoring point of the cooling process or facility. This regulation is not intended to supersede any other water quality standard that applies to the receiving stream, including but not limited to narrative standards promulgated to prohibit impairment of designated uses of the stream. It is the intent of the forum to permit the return of once-through non-contact cooling water only to the same stream from which the water was diverted. Non-contact cooling water is distinguished from blow-down water, and this policy specifically excludes blow-down or any commingling of once-through non-contact cooling water with another waste stream prior to discharge to the receiving stream. Section 61.8 of the regulation governs discharges of blow-down or commingled water.
PQLs (section 61.8(2)(m)): In July 1994, the Commission added Section 6.9.2 to this regulation to formalize establishment of PQLs for permits. This provision allows a permittee to demonstrate unique conditions relevant to its discharge that may translate into a PQL for its effluent. This provision also allows the Division to develop site-specific or discharge-specific PQLs utilizing appropriate methodologies. In addition, the PQLs for organics which had previously been contained in The Basic Standards and Methodologies for Surface Water," § 3.1.0, (5 CCR 1002-8), and "Basic Standards for Ground Water," § 3.11.0 (5 CCR 1002-8), were deleted from those documents and placed in this regulation.
The Commission intended that the list of PQLs in Section 6.9.2 should be routinely reviewed and that proposed changes should be referred to the Commission for consideration for adoption at a rulemaking hearing. The Commission encouraged the Division to establish a committee with representatives from the appropriate interest groups to assist the Division in reviewing the PQLs listed in Section 6.9.2 . The list of PQLs were listed in Section 61.8(2)(m).
Because in recent years, the Division has been focused primarily on reducing the backlog of administratively extended discharge permits, the Division has not been able to review the PQLs listed in Section 61.8 and propose revisions for Commission consideration.
The Commission now believes that the most appropriate method of managing and updating the PQLs listed in Section 61.8 of the regulation is to remove Table 1 from this regulation and incorporate it into a "PQL Guidance Document." This change will afford the Division more flexibility in reviewing the PQLs and updating them without the necessity of submitting them to the Commission for review and consideration at a Rulemaking Hearing. The Commission has retained the current language pertaining to the Division's development of site-specific or discharge-specific PQLs. The Commission has amended section 61.8 to allow the Division to use PQLs listed in the most current edition of the "PQL Guidance Document." Until the guidance is completed the PQLs in the previous version of the regulation will continue to be appropriate unless the Division, based on standard laboratory practice, determines that an alternate PQL is appropriate.
Permit Modification, Suspension, Revocation and Reissuance and Termination (section 61.8(8): The Commission added two new sections (61.8(8)(a)(v) and (vi)) to clarify that the Division has the authority to reopen a permit to implement new standards and wasteload allocations derived from TMDLs into permits immediately. The Commission finds that it is important for these actions intended to improve water quality be implemented through discharge permits as soon as practicable.
Water Quality Standards Based Permits - Determination of Economic, Environmental, Public Health, and Energy Impact (section 61.11): The Commission deleted section 61.11 as it is duplicative of section 61.9(1)(e).
Variances (section 61.12): The Commission modified section 61.12 of the regulation to clarify that the requirements for variances under the Federal Clean Water Act and the regulations promulgated thereunder must be met.
PARTIES/MAILING LIST TO THE RULEMAKING HEARING January, 2003
5 CCR 1002-61.52