After extensive research and consideration of public concern, and out of an abundance of caution ADEQ requested the owner of the Canyon Mine (EFRI) to apply for an Individual APP and EFRI agreed.

ADEQ has determined that while the existing General APPs meet the requirements set forth in law, and additional groundwater protections are required by the USFS EIS and USFS ROD, and USFS-approved facility Plan of Operations, an abundance of caution suggests that an Individual APP is prudent. An Individual APP will:

• Contain all the environmental protection requirements of the three General APPs issued to the facility and consolidate them into one Individual APP,
• Consolidate into the Individual APP all of the groundwater protection requirements contained in the existing USFS-approved facility Plan of Operations, which will result in the inclusion of additional conditions into the Individual APP, such as increased monitoring and clean closure requirements on final reclamation of the mine,
• Consolidate the extensive data available for this facility from several sources into one hydrogeologic report,
• Provide for the enforceability of the existing voluntary conditions, which were part of the General APPs for the lined impoundment and rock storage piles as well as the groundwater protections required by the USFS EIS and ROD, and USFS-approved facility Plan of Operations during operation and after final closure under one Individual APP, and
• Include additional requirements for EFRI to conduct groundwater monitoring — both existing and planned — as well as any additional groundwater monitoring ADEQ deems necessary after reviewing the application.

To determine specific permit requirements, ADEQ carefully reviews all application elements, which includes a technical review of supporting documents. As part of the permitting process, ADEQ also:

• Seeks and considers stakeholder and public input through offering tribal consultations, public review and comment on a draft permit and a public hearing,
  and
• Prepares a responsiveness summary for public comments received.

If all rule requirements are met, ADEQ is required by law to issue the permit. EFRI may continue to operate under the applicable General APPs until ADEQ makes a final decision for the Individual APP application and EFRI is able to continue operations under the Individual APP.

ADEQ must issue an Individual APP if the application requirements are met. ADEQ can deny an Individual APP application for three reasons [A.A.C. R18-9-A213(B)]:

• An applicant fails or refuses to correct a deficiency in the permit application. Example: ADEQ requests additional information for the impoundment liner design and the applicant does not provide sufficient information for ADEQ to determine whether the liner meets requirements in rule or statute [A.A.C. R18-9-A202(A)(5) and A.R.S. 49-243.B.1].
• An applicant fails to demonstrate that the facility will comply with statutory requirements. Example: In the statutes and rules, the applicant must demonstrate that their discharges will comply with applicable Aquifer Water Quality Standards (AWQSs) at a point of compliance [A.A.C. R18-9-A202.A.6 and A.R.S. 49-243.B.2 and 243.B.3].
  and/or
• The applicant provides false or misleading information.

ADEQ has the authority to revoke an environmental permit if a permittee is not meeting the permit conditions [A.R.S. § 49-242; A.R.S. § 49-245.B; A.A.C. R18-9-A307; A.A.C. R18-9-A213]. ADEQ may then seek a court injunction requiring the facility to cease operations until the violation has been corrected.

In 2009, ADEQ determined the impoundment liner and other engineering requirements of the General APP were protective of  groundwater, in accordance with applicable regulations. At that time, ADEQ augmented the General APP for the impoundment to require:

• Water quality monitoring from the mine shaft,
• An annual report to ADEQ of activities and analytical results, 
• Testing the permeability of the rock at the bottom of the mine shaft to determine the need to install a liner at the bottom of the mine shaft to prevent intrusion of water into the aquifer, and
• A financial assurance mechanism for proper closure of the impoundment.

Under these additional conditions in the General APP, EFRI is required to pump out any water that accumulates in the mine shaft.

Facility annual reports include test results of water samples collected from water pumped from the bottom of the mine shaft. Results show the presence of constituents like arsenic, antimony, nickel and uranium. These results are consistent for a developing mine and contemplated in the USFS EIS and ROD, USFS-approved facility Plan of Operations and existing General APP.

To protect the environment, water from the shaft is contained and managed in two storage tanks and evaporated in a lined impoundment, in accordance with the USFS ROD, USFS-approved facility Plan of Operations and existing General APP | View Current Report >

If the water is above drinking water standards, why is it being allowed to be stored in open impoundments where wildlife can come into contact with or drink it?

Water in the impoundment is not a source of drinking water. Drinking water standards are not used to evaluate wildlife protection, rather, they are allowable levels of certain compounds in water intended for human consumption.

In an effort to prevent larger animals from accessing the property, and to deter smaller animals, the facility is surrounded by a fence. Just as with any other type of impoundment located where wildlife live, such as wastewater treatment ponds and recreational swimming pools, while there is the potential for wildlife to access the impoundment, the probability is low, and even lower that any given animal would access the impoundment on a regular or frequent basis.

Potential impacts to wildlife from the mine area were analyzed by the USFS in its EIS when approving the facility Plan of Operations. Based on the results of its biological evaluation, USFS concluded that “[n]o adverse effects to threatened, endangered or sensitive wildlife species have been identified” (USFS EIS, p. 4.14).

The permitted, lined impoundment at the facility serves as a temporary storage area for water pumped from the lined mine shaft and stormwater runoff. Water in the impoundment slowly evaporates. When necessary, the facility encourages evaporation by employing a permitted evaporative spray system.

ADEQ has determined that the evaporative spray system does not pose a concern for public health or the environment. 

The permitted, lined impoundment at the facility serves as a temporary storage area for water pumped from the lined mine shaft. Water in the impoundment slowly evaporates. When necessary, the facility uses a permitted down-draft evaporative mist system designed to increase the evaporation rate by using water from the impoundment to create a mist over the impoundment.

Using facility-specific data regarding uranium levels water pumped from the shaft and contained in the lined impoundment, ADEQ conducted modeling of the evaporative system to evaluate potential environmental impacts. This analysis indicated that the system complies with health-based state ambient air quality guidelines for uranium.

To ensure these particles in the mist and other windblown sources of dust are not impacting the environment, the state air quality permit for the facility requires soil sampling around the facility and testing for uranium and radium content.

Soil sampling and testing conducted to date for the air quality permit shows activities at the facility are not impacting surrounding soil.

The state air quality permit further requires monitoring for changes in gamma radiation levels around the facility. Results to date indicate that the facility is in compliance with permit conditions.

ADEQ conducts regular inspections of the facility to ensure permit conditions are being followed.

When the lined impoundment is closed, the General APP requires the facility to remove and properly dispose of all liquids and any solid residue [A.A.C. R18-9-D304.G.2.a]. Similar requirements will be included in the Individual APP

Canyon Mine has been studied, scrutinized, and litigated for over 30 years, resulting in an extensive technical record. ADEQ reviewed this record and its findings and agrees with key conclusions that adverse impacts to groundwater from the facility are extremely unlikely.

ADEQ will review any new information and supporting application documents that may be presented during the application review process to inform permit conditions. More details on the available record for Canyon Mine follow:

• The final USFS EIS and ROD for Canyon Mine were issued on September 29, 1986. USFS concluded that no measurable impacts are expected to groundwater. USFS also concluded that, with implementation of planned mitigation measures to seal the mine after operations are completed, the possibility for significant deterioration of water quality at any discharge is very small.
• The Havasupai Tribe and others sued over this decision in the U.S. District Court for the District of Arizona. The District Court ruled for the USFS on all counts, and a subsequent appeal was filed with the U.S. Court of Appeals for the Ninth Circuit, which affirmed the District Court on August 16, 1991.
• On June 25, 2012, the Kaibab National Forest completed a review of the Canyon Mine Plan of Operations and determined that no modification or amendment to the existing Plan of Operations was necessary.
• ADEQ issued a Groundwater Quality Protection Permit (GWQPP) in May of 1988. GWQPPs are predecessor permits to APPs. The permit was appealed by the Havasupai Tribe and went to administrative hearing.  At the end of the hearing, the permit was affirmed in June of 1995. 
• Expert hydrogeologic testimony was provided by the permittee during the administrative hearing. ADEQ re-examined this expert testimony and agrees with key findings, including the expert’s conclusion that it is virtually impossible for the mine to contaminate the Redwall-Muav Aquifer due to the impermeability and thickness of the rock layers between the bottom of the mine shaft and the Redwall-Muav Aquifer.

ADEQ has also reviewed more recent USGS hydrogeological information. ADEQ has determined that this newer information supports a conclusion of virtually no recent recharge occurring to the Redwall-Muav Aquifer or to the Coconino groundwater in the area of the mine. This information further supports the conclusion that intervening rock layers between the Coconino Formation and Redwall-Muav Aquifer are highly impermeable.

Through the General APPs, the facility has in place several engineering controls at the facility including:

• The lined impoundment,
• Drainage design, grading and berming,
• Monitoring of the water in the mine shaft, and
• Pumping water out of the shaft.

These existing engineering controls will carry forward into the Individual APP. These controls protect the two potential aquifers in this area -- Coconino groundwater and the Redwall-Muav Aquifer. Out of an abundance of caution, these controls will be augmented with additional groundwater quality monitoring as part of the Individual APP.

Coconino Groundwater:

• Groundwater in the Coconino Formation is about 940 feet below the surface. The mine shaft was drilled below the Coconino Formation to a depth of about 1,470 feet, and an impermeable liner was installed at the bottom of the shaft. Groundwater from the Coconino Formation seeps into the shaft and accumulates. Once the water reaches a certain level in the shaft, a sensor turns on a pump to move the water to the surface and direct it into the lined impoundment or storage tanks for evaporation. Because water in the shaft is pumped out, it cannot enter the Coconino Formation. As a result, groundwater cannot be impacted by mining operations.
• In addition, the U.S. Geological Survey (USGS) conducts regular monitoring of Coconino groundwater quality from an observation well located at the facility property boundary. Water quality monitoring results from this well are all below Arizona’s Aquifer Water Quality Standards. These water quality monitoring data are found here | View USGS Data >
• ADEQ is requiring the mine owner (EFRI) through the individual permitting process to establish groundwater monitoring wells in the Coconino groundwater. With these wells, ADEQ will be able to validate what we can already infer from the geologic record: all water on site is being captured by the mine shaft. The groundwater monitoring wells also will be used to determine the groundwater flow direction for the facility and to monitor downgradient groundwater.

Redwall-Muav Aquifer:

• The Redwall-Muav Aquifer is about 2,525 feet below the surface. In addition to the impermeable liner and pumping out water from the shaft previously described, over 500 feet of impermeable rock layers between the bottom of the mine shaft and the Redwall-Muav Aquifer serve as a natural protective barrier that prevents water in the shaft from reaching the Redwall-Muav Aquifer.
• In addition, because of the liner at the bottom of the shaft and the impermeability of the rock layers below the mine, this water cannot enter the Redwall-Muav Aquifer during mining operations.
• The mine has a groundwater monitoring well in the Redwall-Muav Aquifer that was required under the USFS ROD and USFS-approved facility Plan of Operations is being used to confirm lack of adverse impacts to groundwater as well as to ensure proper reclamation after mine closure. Water quality monitoring results from this well are all below Arizona’s Aquifer Water Quality Standards. USGS water quality monitoring data for this well are found here | View USGS Data >

Finally, as part of the Clean Closure Plan required under the USFS-approved facility Plan of Operations, after operations have ceased, the owner will seal off the saturated portion of the Coconino groundwater from the mine shaft, thereby preventing any potential groundwater contamination after final reclamation of the mine. Relevant provisions of the Clean Closure Plan will be reviewed and included in the Individual APP.

Water within the mine shaft is being maintained at the bottom of the lined portion of the shaft, which is about 12 feet high. Per the requirements of the General APP, the permittee must intermittently pump all of this water out of the lined mine shaft and properly manage that water.

Before drilling the mine shaft, EFRI estimated that the mine shaft would generate approximately 10 gallons per minute (gpm). Currently, the mine shaft generates about 19-20 gpm, about twice the original estimate. As a result, EFRI has made the necessary adjustments to their water management practices to accommodate the additional flow in the existing lined impoundment and storage tanks.

The Individual APP application will include a water balance calculation to demonstrate the lined impoundment and storage tanks provide adequate storage capacity for water pumped out of the mine shaft.

ADEQ does not believe tracer studies or spring sampling are warranted:

• Impermeable rock layers between the bottom of the mine shaft and the top of the Redwall-Muav Aquifer serve as a natural protective barrier that prevents water in the shaft from reaching the Redwall-Muav Aquifer.
• Immediately beneath the Canyon Mine, the Redwall-Muav Aquifer flows to the south. Further downgradient it turns to the west and northwest. Therefore, springs in the Grand Canyon located due north of the mine cannot receive groundwater from the area beneath the mine due to the geological and hydrogeological conditions in the region.
• USGS data indicate that the age of Redwall-Muav groundwater beneath the mine and, more generally, within the interior of the Colorado Plateau, is older than 10,000 years. This means that groundwater in the area moves extremely slowly. Therefore, conducting tracer tests between the mine and springs located to the northwest of the mine in the Grand Canyon are not an effective tool to monitor for a connection between the mine and the springs.

Under the USFS ROD and USFS-approved facility Plan of Operations, groundwater monitoring is being conducted for a well in the Redwall-Muav Aquifer. The Individual APP will require EFRI to install additional groundwater monitoring wells in the Coconino Formation prior to beginning active mining. With these wells, ADEQ will be able to establish whether Coconino groundwater in the area is being captured by the mine shaft. The wells also will be used to determine groundwater flow direction beneath the facility and to monitor downgradient groundwater quality.

Mining operations are required to obtain and comply with an air quality permit prior to construction and operation per A.A.C. R18-2-302.B.3 and R18-2-302.01.D. The purpose of the air quality permit is to reduce airborne dust and ensure compliance with federal health-based, ambient air quality standards. As an added level of environmental protection, the facility’s air quality permit also requires EFRI to conduct soil sampling and testing to verify the effectiveness of air quality controls.

Issued in 2009, the air quality permit was reissued in 2016, and must be renewed in 2021.

In addition, radon emissions from the mine are regulated under an approval order issued by the EPA.

The air quality permit includes controls to reduce airborne dust, and, as an added level of environmental protection, EFRI is required to conduct soil sampling and testing to verify the effectiveness of the controls. Analytical results for soil samples collected to date as part of the required testing plan for soils surrounding the facility show that soils are not impacted | View Current Report >

ADEQ inspected the facility in 2017 after receiving a complaint about water from a lined impoundment being sprayed in the air. The ADEQ air quality inspector observed an evaporative spray system not specified in the air quality permit. ADEQ issued a Notice of Opportunity to Correct Deficiencies (NOC) to the facility to include the system in their air quality permit. The facility applied for and received a minor permit amendment to include the system in the permit in 2017. Since that time, EFRI has replaced the original spray system with a more modern, improved spray system.

ADEQ issued two NOCs related to the General APPs in late 2018 as a result of an on-site inspection of the one rock stockpile in use and permitted, lined impoundment. The NOCs identified deficiencies in on-site berm maintenance, vegetative control, and controlling the water spray within the lined impoundment. The facility achieved compliance by submitting documentation that the berms have been re-built, vegetation removed and water spraying equipment was reconfigured to direct spray downwards over the lined impoundment.

To ensure compliance with federal health-based, ambient air quality standards, the facility has an air quality permit issued by ADEQ. The permit includes air quality controls to reduce airborne dust, and, as an added level of environmental protection, the facility owner is required to verify the effectiveness of the controls through conducting soil sampling around the facility and testing these samples for uranium and radium content.

To date, analytical results for soil samples collected as part of the required testing plan for soils surrounding the facility show activities at the facility are not impacting surrounding soil.

The state air quality permit further requires monitoring for changes in gamma radiation levels around the facility. Results to date indicate that the facility is in compliance with permit conditions.

ADEQ conducts regular inspections of the facility to ensure permit conditions are being followed.

ADEQ confirmed with EFRI that water from the shaft was never used for dust control on roads leading to and from the facility. The source of water for those dust control activities on roads leading to the facility is a well located on the property that draws water from the Redwall-Muav Aquifer, not the mine shaft.

Water from the mine shaft was used for dust control within the facility property.

In December 2019, EFRI agreed to suspend use of impacted mine shaft water on the property, with the exception of the development rock stockpile that is specifically designed to direct any runoff into the lined impoundment.

EFRI provided a demonstration to ADEQ in February 2021 indicating use of groundwater harvested from mine shaft collection rings for on-site dust control does not have a reasonable probability of reaching the underlying aquifer. EFRI subsequently notified ADEQ of its decision to use groundwater harvested from the mine shaft collection rings for on-site dust control and other beneficial uses such as stock watering for local ranchers.

ADEQ has a compliance and enforcement function to ensure permit holders comply with all environmental protection permits and regulation. ADEQ performs regular inspections of all permitted facilities, as well as inspections in response to complaints. Additionally, permits require the permit holder to monitor environmental parameters, keep appropriate records, and make regular reports to ADEQ, which are reviewed to ensure compliance.

State law does not allow ADEQ to consider haul truck travel on state and federal highways in the granting or denial of environmental protection permits. Haul truck travel on State and Federal highways is governed by the Arizona Department of Transportation (ADOT).

In the event of a spill, the Department of Public Safety Hazmat and ADOT Emergency Response are contacted and responsible for implementing plans to assess and respond to the emergency situation. When the emergency situation is over, ADOT ensures cleanup, and notifies the Arizona Radiation Regulatory Agency (ARRA), ADEQ, and the Nuclear Regulatory Commission (NRC), as appropriate.

If active mining operations temporarily cease, the facility is required to continue to fulfill its environmental permitting obligations:

• Continuously pump out any water that accumulates in the mine shaft,
• Maintain all engineering controls as specified in the permits,
• Continue environmental sampling and testing,
• Maintain financial assurance, such as bonds, held in reserve by ADEQ and USFS, to fund proper closure in the event the owner is unable to complete proper closure.

When mining operations at the facility are complete, the owner is required by USFS and ADEQ to properly close the mine, which includes, but is not limited to:

• Plugging the mine shaft and sealing off groundwater in the Coconino Formation,
• Removing all equipment and structures, cleaning the area of operations and re-contouring and vegetating the surface of the property, and
• Conducting post-closure environmental sampling and testing.

Under a state Individual APP, ADEQ will review the USFS-approved mine closure plan and may require additional conditions and additional financial assurance for APP costs not accounted for in the USFS-approved closure plan

• Arizona Revised Statutes | Title 49, The Environment | View > 
• Arizona Administrative Code | Title 18, Environmental Quality | View > 

Pinyon Plain Mine | Permit of Interest >
Aquifer Protection Permit >

USFS - Canyon Uranium Mine >
EPA - Canyon Uranium Mine >