Pinyon Plain Mine (formerly Canyon Mine) | Permit of Interest | FAQs: Page 6 of 7

Why did ADEQ issue a Notice of Opportunity to Correct resulting from inspections in 2017 and 2018?

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.

Is dust from the rock storage piles affecting air quality?

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.

Is water from the mine shaft being used for dust control?

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.

How does ADEQ ensure compliance with environmental permits and regulations?

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.

Who is responsible for making sure transport of water and ore is done safely?

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.