On this page: INL Oversight Program | 1995 Settlement Agreement | Regulatory Information
Beginning in 1949, the US Department of Energy (DOE) designed, built, and tested experimental nuclear reactors at an 890 square-mile area located in southeastern Idaho now known as the Idaho National Laboratory (INL). The INL is also home to the Naval Reactor Facility where the US Navy transports spent nuclear fuel from submarines and aircraft carriers for examination and temporary storage. The site has also been used to store nuclear waste from out-of-state operations.
INL Oversight Program
The Idaho Legislature established a comprehensive state oversight program in 1989 to independently assess environmental and public health impacts from the INL. In 1990, Idaho became the first state in the nation to negotiate an agreement with DOE to provide funding for the independent monitoring and oversight of a DOE facility. This work is now carried out by DEQ’s INL Oversight Program.
The Idaho National Laboratory Oversight Program (INL OP) evaluates the actual or potential environmental and public health impacts of US Department of Energy (DOE) activities at the INL. Members of our staff conduct monitoring at the INL site, review and comment on DOE planning and decision-making documents, and stay up-to-date on how facilities are managed.
Our INL OP also tracks inventories and handling of nuclear waste at INL. This information helps guide the monitoring and emergency planning efforts.
The INL OP staff serve on the Western Governors’ Association Waste Isolation Pilot Plant Transportation Technical Advisory Group and represent the State of Idaho. This group works collaboratively with DOE to maintain a comprehensive transportation safety program to ensure the safe shipment of transuranic radioactive wastes within the western states.
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Our INL Oversight Program (INL OP) conducts air, water, and terrestrial (soil and milk) sampling for a variety of radiological and nonradiological contaminants.
Water Sampling
Common Ions and Nutrients: Naturally occurring elements and compounds makeup 99% of all dissolved constituents in ground water or surface water, elements. These elements and compounds include calcium, magnesium, sodium, potassium, chloride, fluoride, sulfate, nitrate, phosphorus, and dissolved carbon dioxide. They also make up the vast majority by weight of dissolved contaminants disposed in wastewater at the INL. The ions allow an assessment of the overall health of the ground water.
Trace Metals: Trace metals are present at very low concentrations in ground water. These elements appear naturally but at very low levels. Chromium, zinc, and barium, were also disposed of in INL wastewater.
Technicium-99: This man-made isotope is produced only in nuclear reactors and was historically released into the environment when wastewater was disposed of in ponds or wells. Technicium-99 decays with beta radioactivity.
Iodine-129 and Chlorine-36: Monitored in ground water, these are radioisotopes occur naturally at a very low level but were also produced during worldwide nuclear weapons testing. These isotopes are characteristic of INL wastewater and travel quickly with ground water. Tested for as part of special studies, these isotopes are generally present at very low levels (a million times lower than drinking water standards) and require special testing methods to see them at these atoms-per-liter levels.
Air and Water Sampling
Gross Alpha and Beta Radioactivity: The test for these types of natural or man-made radioactivity is a screening test, measuring contaminants or naturally occurring radionuclides that emit alpha and beta radiation. If measured radioactivity exceeds expected background levels or historic INL operations, then further analyses are done to identify specific radioactive isotopes.
Tritium: A radioactive isotope of hydrogen that is most often found taking the place of nonradioactive atoms in water molecules. It is monitored in precipitation, water vapor in the air, and ground water. Tritium is made naturally in the atmosphere, can be created in nuclear reactors, and is present in spent nuclear fuel. This isotope gives off a low-energy beta particle and is not seen in a gross beta analysis.
Strontium-90: One of the many isotopes created when uranium or plutonium undergo fission in a nuclear reactor. It decays with beta radiation.
Transuranic Radionuclides: Created in a nuclear reactor as a result of nuclear fission, transuranic radionuclides have more protons in their nuclei than uranium. These radionuclides are monitored as particles captured on air filters and dissolved in ground water. Plutonium and americium are among the specific transuranic radionuclides that are monitored. Transuranic elements typically emit alpha-particle radiation and may also be seen with screening for gross alpha radiation or by gamma-spectroscopic analysis.
Air, Water, and Terrestrial Sampling
Gamma-Emitting Radionuclides: Monitored in air, precipitation, water, soil, and milk by examining the energy spectrum of gamma radiation given off by a sample. Cesium-137, Iodine-131, and naturally occurring Potassium-40 are a few isotopes specifically identified by their unique gamma-radiation energies.
Emergencies involving radioactive materials can occur at the Idaho National Laboratory, during transportation, or at facilities that use radioactive material or conduct research such as hospitals, research facilities, technology companies, or engineering firms. To address these potential threats, the Idaho National Laboratory Oversight Program (INL OP) engages in emergency planning and response activities.
Planning
Our INL OP staff gather data, assess potential health and environmental effects, and provide technical assistance to state and local agencies on how to respond to radiological emergencies.
We participate in trainings and exercises throughout Idaho to support responders in identifying, responding to, and minimizing impacts from emergency situations involving radioactive materials.
Response
Our health physicists are on-call year-round to help local communities and the Idaho State Police respond to emergencies involving radioactive material. Health physicists assess potential radiological impacts to human health and the environment, provide information, and recommend protective actions to state and local agencies during their response to emergencies.
DEQ’s INL Oversight Program (INL OP) provides real-time radiation measurements to monitor and gauge environmental exposure rates on and around the INL. We collect real-time measurements using high-pressure ion chambers (HPICs) that transmit 5-minute average exposure rates to our Idaho Falls office. Our staff stores the data in a database to determine average exposure rates for 5-minute, weekly, monthly, and quarterly periods currently accessible.
Electret ionization chambers (EICs) provide a cumulative measure of environmental gamma exposure in the field. Results are published in quarterly reports.
Our INL OP conducts independent radiation monitoring for a variety of purposes:
- Independently determine whether INL activities pose a threat to public health and the environment.
- Verify and supplement radiation monitoring conducted by the US Department of Energy’s (DOE) Managing and Operating contractor for INL (Battelle Energy Alliance) and DOE’s offsite monitoring contractor (Environmental Surveillance, Education and Research).
- Provide historical and real-time measurements in the event of an atmospheric radiological release or accident.
Many sources of penetrating radiation are measured by HPIC, including cosmic radiation from deep space, ionizing radiation from the sun, gamma-emitting radionuclides distributed in the soils, and airborne gamma-emitting radionuclides (i.e., cloud gamma) attributed to radon and its progeny, and potential contributions from INL operations.
It is not feasible for INL OP staff to monitor all possible locations. Locations are prioritized by area, climatology, and dose projection model data. HPIC monitoring locations are co-located with National Oceanic and Atmospheric Administration (NOAA) Mesonet towers to provide redundancy in data collection in the event of equipment failure.
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DEQ’s Idaho National Laboratory Oversight Program (INL OP) maintains an environmental monitoring network on and around the INL to verify and supplement monitoring activities carried out by the US Department of Energy (DOE). Our staff take air, water, and terrestrial (soil and milk) samples and external radiation measurements to monitor the environmental impacts of the INL.
Staff also maintain a database of monitoring results covering over 20 years. This information allows staff to track radiation levels and contamination in the Eastern Snake River Plain Aquifer (ESRPA) and determine long-term trends.
Staff conduct monitoring around and within the INL boundaries and at upgradient, background, and distant locations for data comparisons.
Air
DEQ operates 11 air monitoring stations at and around the INL equipped with particulate air samplers, radioactive gas collectors, and water vapor collectors. Six of these air monitoring stations include precipitation collectors and three are community monitoring stations. We collect particulate air samples (filters) and radioactive iodine gas samples (charcoal cartridges) weekly to monitor short-term radiological conditions in the environment. We also collect atmospheric moisture to measure tritium concentrations present in the air and precipitation samples to monitor for tritium and gamma-emitting radionuclides that may be present in the environment.
Water
Contaminants released through infiltration ponds, injections wells, buried waste, 
or spills at the INL have historically reached ground water. Our INL OP staff sample more than 100 water monitoring locations along the Eastern Snake River Plain Aquifer flowing beneath the INL and throughout the Magic Valley to detect for radioactive contaminants and monitor water quality. We sample wells, springs, streams, and selected wastewater sites. Most sites are sampled once a year, although Magic Valley locations are sampled on a triennial basis.
Terrestrial (Soil and Milk)
Radioactive substances can be deposited on soils and foliage where they can be taken up by plants and animals and can concentrate in the milk of cows and goats that graze on contaminated pastures or feed. When people eat contaminated meat, grains, milk, or vegetables the radioactive material can be absorbed in the body.
Following detailed standard operating procedures and using advanced equipment, INL OP staff monitor for radioactive material in the soil at and around the INL. These measurements identify the nuclides and concentrations of radioactivity in the soil and help determine if new sources of radioactivity are being deposited around the INL.
The INL OP conducts monthly milk sampling from sources in southern and southeastern Idaho designed to detect radioactive material such as radioactive iodine from nuclear reactors, which may have accumulated in milk produced by cows and goats.
Quarterly and Annual Monitoring Reports
DEQ compiles reports quarterly and annually to track monitoring results. Quarterly reports provide detailed data, while annual reports focus on long-term trends. Visit DEQ’s Public Records Request web page to request older reports.
Annual Reports
Quarterly Data Reports
1995 Settlement Agreement
DEQ’s involvement at INL dates back to the Cold War when the INL site was used to dispose of waste materials originating from nuclear weapons production activities outside of Idaho.
The public expressed concern about potential environmental and health impacts resulting from these activities and the state subsequently filed a lawsuit to prevent Idaho from becoming a dumping ground for the nation’s commercial spent nuclear fuel. The landmark agreement is known as the 1995 Idaho Settlement Agreement.
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In October 1995, the State of Idaho, US Navy, and US Department of Energy (DOE) reached an agreement settling a lawsuit filed by the state to require several actions, including but not limited to, the following: prevent shipments of spent nuclear fuel to the INL for permanent storage, remove various forms of transuranic waste from Idaho, treat and remove certain high-level waste streams from the state, and transfer spent nuclear fuel from wet storage into dry storage.
In 2008, the State of Idaho and the US Navy, Navy Nuclear Propulsion Program reached an agreement providing for enforceable commitments governing Naval spent fuel safe storage and ultimate removal, per the addendum, to ensure the ongoing mission of the Naval Nuclear Propulsion Program at the INL.
In 2008, the State of Idaho and the US Department of Energy (DOE) finalized an agreement outlining performance obligations regarding the DOE cleanup of buried transuranic waste at the INL.
In 2011, the State of Idaho and the US Department of Energy (DOE) finalized a Memorandum of Agreement setting out conditions for the safe development of next generation nuclear reactor fuel research capacities using limited quantities of used commercial fuel received at the INL, while ensuring Idaho does not become a defacto national repository for these materials.
In 2019, the State of Idaho and the US Department of Energy (DOE) finalized a Supplemental Agreement setting out conditions for a conditional waiver of sections D.2.e and K.1 of the 1995 Settlement Agreement under which the INL may receive limited research quantities of used commercial fuel.
In 2020, the State of Idaho and the US Department of Energy (DOE) finalized an agreement that provides for handling of spent nuclear fuel generated by operations of the Advanced Test Reactor (ATR), ensuring the commitment for eliminating the use of wet storage facilities for spent fuel is met while providing for the ongoing mission of the ATR at the INL.
In 2025, the State of Idaho and the US Department of Energy (DOE) finalized a Waiver setting out conditions for a one-time conditional waiver of section K.1 and D.2.e of the 1995 Settlement Agreement and paragraph 3(b) of the 2011 Memorandum of Agreement under which the DOE may receive limited research quantities of used fuel.
Regulatory Information
The Hazardous Waste Bureau is responsible for ensuring that hazardous wastes at the Idaho National Laboratory (INL) are managed and disposed of in a manner protective of human health and the environment. Activities include permitting, inspections, compliance assistance, enforcement, and remediation. Learn about the Hazardous Waste Bureau’s regulatory priorities for the INL below.
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DEQ is responsible for administering hazardous waste permits at the Idaho National Laboratory (INL). Many of the wastes managed at the permitted treatment and storage facilities at the INL are “mixed waste,” or waste that is regulated by DEQ under the Hazardous Waste Management Act for its chemically hazardous properties and by the U.S. Department of Energy (DOE) for its radioactive properties.
DEQ’s permitting efforts aim to support both the ongoing mission at INL and the 1995 Settlement Agreement addressing legacy wastes and ongoing site cleanup and closure actions.
Three areas at the INL conduct permitted hazardous waste activity:
- Idaho Nuclear Technology and Engineering Center (INTEC)
- Materials and Fuels Complex (MFC)
- Radioactive Waste Management Complex (RWMC), including the Advanced Mixed Waste Treatment Project
INTEC historically reprocessed spent nuclear fuels, among other research missions. Today, efforts are primarily focused on managing the residuals from this reprocessing effort. Mixed waste managed at INTEC includes calcine solids and approximately 853,000 gallons of liquid sodium-bearing waste stored in underground tanks. Mixed waste is also generated from equipment decontamination and closure, as well as characterization, treatment, and repacking of highly radioactive mixed waste from INL and other DOE sites. These wastes usually require further treatment prior to shipment off site. The site currently has multiple partial permits (meaning less than the entire site) addressing these activities.
- Liquid Waste Management System
- Idaho Nuclear Technology and Engineering Center Storage and Treatment
- Idaho Nuclear Technology and Engineering Center Postclosure
- Calcine Solids Storage
MFC supports INL’s ongoing mission and management of legacy waste from past activities. These activities include storage; storage of waste for radioactive decay; treatment by neutralization of mixed waste; and waste characterization, treatment, and repackaging. MFC has a single partial permit addressing activities at the site.
RWMC received, disposed of (before the early 1970s), and stored Cold War wastes. To date, over 60,000 cubic meters of mixed waste has been retrieved, characterized, treated, repackaged, and shipped to the Waste Isolation Pilot Plant or other suitable disposal locations. The Advanced Mixed Waste Treatment Project and the RWMC component of the Volume 18 permit address waste management activities at RWMC.
DEQ is authorized by the US Environmental Protection Agency (EPA) to regulate hazardous waste in Idaho. EPA still remains involved in how the state regulates hazardous waste. Proper hazardous waste management is an integral part of protecting human health and Idaho’s air, land, and water. Many of the wastes managed at the INL are “mixed waste,” or waste that is regulated by DEQ for its chemically hazardous properties and by the US Department of Energy (DOE) for its radioactive properties.
The Hazardous Waste Bureau seeks to achieve compliance through a number of tools including technical assistance, inspections, and enforcement actions. Some or all of the facilities at the INL are inspected at least once a year to see if permits and regulations are being followed. If violations are found, the Hazardous Waste Bureau may issue an enforcement action. The enforcement process focuses on working with DOE and its contractors to identify and correct problems and prevent them from reoccurring. DEQ sometimes issues civil penalties as part of this process. Highlighted below are two of the most significant INL compliance agreements that the Hazardous Waste Bureau oversees.
- INL Site Treatment Plan. In 1992, the Federal Facility Compliance Act (FFCA) was signed into law. The law required DOE to prepare a plan for developing treatment capacities and technologies for each facility at which DOE generates or stores mixed waste. To fulfill the requirements of the FFCA, DOE prepared a Site Treatment Plan (STP) providing a schedule with milestones to treat mixed waste at the INL, in consultation with DEQ, EPA, the public, and other affected states. This far-reaching document covers the treatment of mixed waste streams, including high-level, transuranic, and low-level waste. The STP is enforceable via a Consent Order signed by DEQ and DOE. No penalties have been assessed under the STP.
- Notice of Noncompliance Consent Order. DOE and its predecessor agencies formerly reprocessed spent nuclear fuel at the INL. Reprocessing operations and associated decontamination activities resulted in the generation of high-level radioactive liquid mixed waste. These liquid wastes were stored in eleven 300,000 gallon belowground tanks (known as the tank farm facility). The waste is very acidic and highly radioactive. It also contains chemicals that make it a hazardous waste. The storage tanks were built in the 1950s and do not meet current regulatory standards.
In 1989, EPA and DEQ conducted the first hazardous waste inspection of the INL. EPA was the lead agency as Idaho was not yet authorized to implement the hazardous waste program. In 1990, EPA issued a Notice of Noncompliance (NON) to DOE for violations of the hazardous waste regulations. Among many other violations, the NON cited the INL’s tank farm facility, and the associated piping and valve boxes, for not having adequate secondary containment. The liquids are a concern because the tanks sit above the Snake River Plain Aquifer, critical drinking water, and agricultural resource for much of southern Idaho.
In 1992, the NON-Consent Order (NON-CO) became effective, signed by DEQ (then the Idaho Department of Health and Welfare), EPA, and DOE for resolution of the violations contained in the NON. The NON-CO contained a phased compliance schedule for upgrading the tank farm piping and valve boxes, as well as a deadline by which DOE would permanently empty and close the tank farm tanks, or achieve compliance with all secondary containment requirements.
DOE initially treated some of the liquid waste in a facility that existed at the time known as the “Calciner” and eventually emptied and closed seven of the tanks. Due to the high sodium content of the liquid waste generated during later phases of spent nuclear fuel processing, the remaining “sodium-bearing waste” was not as amenable to treatment in the existing Calciner facility. A total of 853,000 gallons of waste are currently stored in three of the tanks. One additional tank is empty and could be used as a back-up tank if needed. DOE has completed construction of the Integrated Waste Treatment Unit (IWTU) to treat the liquid sodium-bearing waste in order to empty and close the tanks, but delays during testing have prevented DOE from meeting deadlines to achieve full facility operation.
In January 2015, DEQ issued a Notice of Violation to DOE. On March 3, 2015, the Fifth Modification to the NON-CO became effective. The Fifth Modification required DOE to pay a civil penalty and establish a new compliance schedule for treating the sodium-bearing waste and emptying the tanks. Due to ongoing delays with the treatment facility, DOE failed to meet the new milestones. Pursuant to the Fifth Modification to the NON-CO, DEQ began assessing a daily stipulated civil penalty on October 1, 2016. The daily penalty continues to accrue at the current rate of $6,000 per day. DOE satisfies the penalty on an annual basis, through a cash penalty payment and/or completion of various supplemental environmental projects.
Since its inception in 1949, the Idaho National Laboratory (INL) has fulfilled numerous US Department of Energy (DOE) missions, including designing and testing nuclear reactors; reprocessing spent nuclear fuel to recover fissile materials; managing spent nuclear fuel; and storing, treating, and disposing of a variety of wastes. Some of these activities resulted in suspected and confirmed releases of contaminants to the environment, and INL was added to the US Environmental Protection Agency’s (EPA’s) National Priority List of Superfund Sites in 1989.
Environmental cleanup of the 890 square-mile site began in 1989, and the majority of the cleanup work is driven by regulatory compliance agreements, including the Comprehensive Environmental Response Compensation and Liability Act (CERCLA)-based Federal Facility Agreement and Consent Order (FFA/CO). The FFA/CO is a legally binding cleanup agreement that was signed in 1991 by DEQ, EPA, and DOE.
The cleanup work is funded through the DOE’s Office of Environmental Management and focuses on reducing risks to workers, the public, and the environment—particularly the Snake River Plain Aquifer, which serves as the sole agricultural and drinking water source for much of eastern Idaho. The past use of unlined wastewater disposal ponds, industrial injection wells, accidental spills, and waste discharges created contaminant plumes underneath INL. As a Superfund Site, DOE conducts risk-based cleanup, which is subject to DEQ and EPA approval. This means that if a confirmed contaminant release to soil and/or ground water poses an unacceptable risk to either humans or the environment, it requires cleanup or the establishment of controls to keep people, plants, or animals from coming into contact with the waste. If a site poses little to no risk, either limited action or no action is taken.
Since 1991, EPA, DEQ, and DOE have signed 25 Records of Decisions on individual contaminant release sites and entire facilities at INL. Cleanup actions continue at Test Area North, the Idaho Nuclear Technology and Engineering Center, and the Radioactive Waste Management Complex. The FFA/CO subdivided INL into 10 waste area groups (WAGs) to facilitate remediation. These groups contain individual sites that are organized into operable units based on proximity or similar characteristics. WAGs 1-9 comprise the major facilities at INL, while WAG 10 encompasses the remaining portions of the site and site-wide ground water issues. Each WAG has a comprehensive Record of Decision that addresses human and ecological risk and has actions to restore or protect ground water within 100 years.
Resources
- Overview of the Idaho Cleanup Project
- History of the cleanup at INL
- Federal Facility Agreement and Consent Order (12-04-1991)
- Federal Facility Agreement and Consent Order Action Plan
- INL Citizens Advisory Board
- INL CERCLA Administrative Record and Information Repository
DEQ’s Hazardous Waste Bureau
DEQ’s Hazardous Waste Bureau performs various tasks at INL to safeguard human health and the environment:
- Monitor and evaluate the effectiveness of completed and ongoing CERCLA remediation activities, including Records of Decisions and nontime-critical removal actions. This action involves retrieval of buried radiological and hazardous substances and contaminated soils, limiting anthropogenic infiltration, treating specific zones of the eastern Snake River Plain Aquifer, and overseeing operations at the Idaho CERCLA Disposal Facility landfill.
- Evaluate newly discovered sites for environmental impacts.
- Provide for inspections of institutional controls, operation and maintenance requirements, and long-term stewardship of CERCLA sites contaminated with radionuclides and hazardous substances.
- Evaluate risk and the proposed alternatives for the decontamination and decommissioning of facilities proposed by DOE as excess and no longer supporting the INL mission.