Saltcrete is a mixture of cement with salts and brine, usually originating from liquid waste treatment plants. Its role is to immobilize hazardous waste and in some cases lower-level radioactive waste in the form of solid material. It is a form of mixed waste. [1]
Saltcrete is being replaced by saltstone, which is less permeable and leachable. Saltstone is a mixture of the salt cake (mostly sodium nitrate and other salts) with concrete and fly ash.
An example of a saltcrete site in the United States is The Rocky Flats Environmental Technology Site (RFETS) near Denver, Colorado. Between 1952 and 1992, nuclear weapons components consisting of radioactive and otherwise hazardous materials were manufactured there. By 1989, a government investigation had concluded that many of these materials were being improperly stored and handled, leading to the site being added to the National Priorities List for cleanup by the Environmental Protection Agency. [2]
In June 1997 Kaiser-Hill Company, also known as CH2M Hill, the DOE Integrating Management Contractor for RFETS, contracted with Envirocare of Utah, Inc., also known as EnergySolutions, to transport, treat and dispose of more than 13,000 cubic meters of radioactively and hazardously contaminated mixed waste, including the Saltcrete waste stream. Shipment of Saltcrete began in July 1997. The first phase of 1,705 cubic meters of the Saltcrete waste stream was successfully transported, treated and disposed in less than eight weeks. The second phase of 1,710 cubic meters was completed in the first quarter of FY98 in the same amount of time. [3]
Saltcrete is the result and technique of wastewater processing and was the second-largest mixed waste stream at RFETS requiring treatment and disposition. The majority of wastewater from RFETS production processes is contained in large tanks and then is treated by precipitation, filtration, evaporation, and drying to result in a matrix referred to as "salts". Original waste stream production was rich in nitrates and sulfates, therefore the reference to the dried material as salts; however, current waste stream production has an essentially decreased concentration of inorganic compounds, even though the waste is still considered to as salts. Saltcrete is formed when liquid evaporator concentrates are combined with the salts and Portland cement. The mixture is poured into cardboard and plywood containers to solidify into a monolith.
The process waste water remains hazardous waste Saltcrete is a mixed radioactive waste.[ clarification needed ] [3] [4] Radionuclide contamination principally includes americium, plutonium, and uranium. The waste carries Resource Conservation and Recovery Act, RCRA, Hazardous Waste Codes F001, F002, F005, F006, F007, and F009. RCRA contaminants include specific volatile and semi-volatile organic compounds and metals.
The mutual goal between Envirocare and Kaiser-Hill was to meet the Rocky Flats Cleanup Agreement. The agreement policy was 1,575 cubic meters of non-compliant Saltcrete waste had to be removed from RFETS by September 30, 1997. After agreement award yet prior to shipment to Envirocare, a successful formula had to be developed in time to meet the specified objectives.
Benchscale treatability studies were in progress by experimenting five ‘worst-case’ samples of the Saltcrete waste that were collected by Kaiser-Hill. According to the variability of RCRA Hazardous Waste constituents in the waste population, several treatability samples were required. This sample selection was required to make sure that the formula developed would be sufficiently aggressive to stabilize the hazardous elements known to be existed. Formula development services were subcontracted by Envirocare to InSciTe (a subsidiary of Mountain States Analytical Laboratory, Inc.). Formula development was involving the application of several combinations of chemical reagents in an effort to immobilize hazardous constituents. In accordance with existing permit requirements, Envirocare submitted a copy of the Treatment Formula to the State of Utah, Division of Solid and Hazardous Waste. The State retains this report for its reference.
Kaiser-Hill was successful in expediting sample selection, collection and delivery to Envirocare for the analysis. Envirocare utilized rush analytical services and an accelerated schedule for result in the formula being developed in under one month. Notification for shipment was provided to Kaiser-Hill immediately upon successful formula development. Finally in 1997, Envirocare has won a $7 million contract to handle low-level mixed waste at the former Rocky Flats nuclear weapons plant.
The site-related criteria are used for development of the design for the temporary Reprocessing Facility are also provided in the Process and Project Design Criteria. Numerous of the rules, regulations, guidelines, policies, etc. for a sub-contractor operated, temporary facility have a different principle than those which could be an impact or requirement for a longer-term facility. Furthermore, standards for a processing facility which could be adjusted for a higher variation of feed materials and possibly have the ability to emit different byproduct waste forms such as liquid to solid, are also seemed to be integrated. These new regulations would have to be determined and the well-fitted modifications made to the equipment design criteria, general design criteria, specifications and site-related considerations. These differences would then have to be acknowledged into the construction design. It is similarly that the site-related criteria required for the longer-term plant will not only require a more detailed engineering effort for process design, but also would require greater attention to definition of the site-related factors such as soil bearing pressure, requirements for foundations, vibrational considerations, building criteria, etc.
Treated byproduct will be placed mixed waste cell for permanent disposition. The mixed waste cell is engineered with a triple high-density polyethylene (HDPE) liner system. Collected layers between each line provide leak liquid management and leakage detection for the cell, while a foundation of engineered clay stabilizes the liner system. The waste is buried in a 7 ft clay radon barrier, a rock filter zone, and a coarse rock erosion barrier. [5]
Hazardous waste is waste that must be handled properly to avoid damaging human health or the environment. Waste can be hazardous because it is toxic, reacts violently with other chemicals, or is corrosive, among other traits. As of 2022, humanity produces 300-500 million metric tons of hazardous waste annually. Some common examples are electronics, batteries, and paints. An important aspect of managing hazardous waste is safe disposal. Hazardous waste can be stored in hazardous waste landfills, burned, or recycled into something new. Managing hazardous waste is important to achieve worldwide sustainability. Hazardous waste is regulated on national scale by national governments as well as on an international scale by the United Nations (UN) and international treaties.
Industrial waste is the waste produced by industrial activity which includes any material that is rendered useless during a manufacturing process such as that of factories, mills, and mining operations. Types of industrial waste include dirt and gravel, masonry and concrete, scrap metal, oil, solvents, chemicals, scrap lumber, even vegetable matter from restaurants. Industrial waste may be solid, semi-solid or liquid in form. It may be hazardous waste or non-hazardous waste. Industrial waste may pollute the nearby soil or adjacent water bodies, and can contaminate groundwater, lakes, streams, rivers or coastal waters. Industrial waste is often mixed into municipal waste, making accurate assessments difficult. An estimate for the US goes as high as 7.6 billion tons of industrial waste produced annually, as of 2017. Most countries have enacted legislation to deal with the problem of industrial waste, but strictness and compliance regimes vary. Enforcement is always an issue.
The Rocky Flats Plant was a United States manufacturing complex that produced nuclear weapons parts in the western United States, near Denver, Colorado. The facility's primary mission was the fabrication of plutonium pits, which were shipped to other facilities to be assembled into nuclear weapons. Operated from 1952 to 1992, the complex was under the control of the U.S. Atomic Energy Commission (AEC), succeeded by the Department of Energy (DOE) in 1977.
The Resource Conservation and Recovery Act (RCRA), enacted in 1976, is the primary federal law in the United States governing the disposal of solid waste and hazardous waste.
The Waste Isolation Pilot Plant, or WIPP, in New Mexico, US, is the world's third deep geological repository licensed to store transuranic radioactive waste for 10,000 years. The storage rooms at the WIPP are 2,150 feet underground in a salt formation of the Delaware Basin. The waste is from the research and production of United States nuclear weapons only. The plant started operation in 1999, and the project is estimated to cost $19 billion in total.
Low-level waste (LLW) or low-level radioactive waste (LLRW) is nuclear waste that does not fit into the categorical definitions for intermediate-level waste (ILW), high-level waste (HLW), spent nuclear fuel (SNF), transuranic waste (TRU), or certain byproduct materials known as 11e(2) wastes, such as uranium mill tailings. In essence, it is a definition by exclusion, and LLW is that category of radioactive wastes that do not fit into the other categories. If LLW is mixed with hazardous wastes as classified by RCRA, then it has a special status as mixed low-level waste (MLLW) and must satisfy treatment, storage, and disposal regulations both as LLW and as hazardous waste. While the bulk of LLW is not highly radioactive, the definition of LLW does not include references to its activity, and some LLW may be quite radioactive, as in the case of radioactive sources used in industry and medicine.
The Savannah River Site (SRS) is a U.S. Department of Energy (DOE) reservation in the United States, located in the state of South Carolina on land in Aiken, Allendale, and Barnwell counties adjacent to the Savannah River. It lies 25 miles (40 km) southeast of Augusta, Georgia. The site was built during the 1950s to refine nuclear materials for deployment in nuclear weapons. It covers 310 square miles (800 km2) and employs more than 10,000 people.
According to the United States Environmental Protection Agency, mixed waste (MW) is a waste type defined as follows; "MW contains both hazardous waste and radioactive waste. It is jointly regulated by NRC or NRC's Agreement States and EPA or EPA's RCRA Authorized States. The fundamental and most comprehensive statutory definition is found in the Federal Facilities Compliance Act (FFCA) where Section 1004(41) was added to RCRA: "The term 'mixed waste' means waste that contains both hazardous waste and source, special nuclear, or byproduct material subject to the Atomic Energy Act of 1954."
High-level waste (HLW) is a type of nuclear waste created by the reprocessing of spent nuclear fuel. It exists in two main forms:
Pondcrete is a mixture of cement and sludge. Its role is to immobilize hazardous waste and, in some cases, low-level and mixed-level radioactive waste, in the form of solid material. The material was used by the United States Department of Energy and its contractor, Rockwell International, in an attempt to handle the radioactive waste from contaminated ponds in the Rocky Flats Plant for burial in Nevada desert. Portland cement is mixed with sludge to solidify into “pondcrete” blocks and placed into large, plastic lined boxes. The sludge is taken from solar evaporation ponds which are used to remove moisture from waste materials, therefore reducing their weight. To do this, liquid waste is poured into artificial, shallow ponds. The waste is heated by solar radiation and any moisture is evaporated, leaving behind the waste. These ponds contained low level radioactive process waste as well as sanitary sewage sludge and wastes, which categorize them and the Pondcrete as a mixed waste.
Remediation of contaminated sites with cement, also called solidification/stabilization with cement is a common method for the safe environmental remediation of contaminated land with cement. The cement solidifies the contaminated soil and prevents pollutants from moving, such as rain causing leaching of pollutants into the groundwater or being carried into streams by rain or snowmelt. Developed in the 1950s, the technology is widely used today to treat industrial hazardous waste and contaminated material at brownfield sites i.e. abandoned or underutilized properties that are not being redeveloped because of fears that they may be contaminated with hazardous waste. S/S provides an economically viable means of treating contaminated sites. This technology treats and contains contaminated soil on site thereby reducing the need for landfills.
A waste pond or chemical pond is a small impounded water body used for the disposal of water pollutants, and sometimes utilized as a method of recycling or decomposing toxic substances. Such waste ponds may be used for regular disposal of pollutant materials or may be used as upset receivers for special pollution events. Often, chemical ponds themselves are addressed for cleanup action after their useful life is over or when a risk of groundwater contamination arises.
Under United States environmental policy, hazardous waste is a waste that has the potential to:
The Energy Technology Engineering Center (ETEC), was a government-owned, contractor-operated complex of industrial facilities located within the 2,850-acre (11.5 km2) Santa Susana Field Laboratory (SSFL), Ventura County, California. The ETEC specialized in non-nuclear testing of components which were designed to transfer heat from a nuclear reactor using liquid metals instead of water or gas. The center operated from 1966 to 1998. The ETEC site has been closed and is now undergoing building removal and environmental remediation by the U.S. Department of Energy.
Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product's value above zero.
Municipal solid waste (MSW) – more commonly known as trash or garbage – consists of everyday items people use and then throw away, such as product packaging, grass clippings, furniture, clothing, bottles, food scraps and papers. In 2018, Americans generated about 265.3 million tonnes of waste. In the United States, landfills are regulated by the Environmental Protection Agency (EPA) and the states' environmental agencies. Municipal solid waste landfills (MSWLF) are required to be designed to protect the environment from contaminants that may be present in the solid waste stream.
Waste management laws govern the transport, treatment, storage, and disposal of all manner of waste, including municipal solid waste, hazardous waste, and nuclear waste, among many other types. Waste laws are generally designed to minimize or eliminate the uncontrolled dispersal of waste materials into the environment in a manner that may cause ecological or biological harm, and include laws designed to reduce the generation of waste and promote or mandate waste recycling. Regulatory efforts include identifying and categorizing waste types and mandating transport, treatment, storage, and disposal practices.
Waste Control Specialists LLC (WCS) is a treatment, storage, & disposal company dealing in radioactive, hazardous, and mixed wastes. Developed and controlled by Texas billionaire investor Harold Simmons until his death at the end of 2013, the company was founded in Dallas, Texas in 1989 as a landfill operator, and awarded a unique license for disposal of low level radioactive waste in 2009. Its main operations are in Andrews County, Texas.
Solid waste policy in the United States is aimed at developing and implementing proper mechanisms to effectively manage solid waste. For solid waste policy to be effective, inputs should come from stakeholders, including citizens, businesses, community-based organizations, non-governmental organizations, government agencies, universities, and other research organizations. These inputs form the basis of policy frameworks that influence solid waste management decisions. In the United States, the Environmental Protection Agency (EPA) regulates household, industrial, manufacturing, and commercial solid and hazardous wastes under the 1976 Resource Conservation and Recovery Act (RCRA). Effective solid waste management is a cooperative effort involving federal, state, regional, and local entities. Thus, the RCRA's Solid Waste program section D encourages the environmental departments of each state to develop comprehensive plans to manage nonhazardous industrial and municipal solid waste.
There are many exemptions for fracking under United States federal law: the oil and gas industries are exempt or excluded from certain sections of a number of the major federal environmental laws. These laws range from protecting clean water and air, to preventing the release of toxic substances and chemicals into the environment: the Clean Air Act, Clean Water Act, Safe Drinking Water Act, National Environmental Policy Act, Resource Conservation and Recovery Act, Emergency Planning and Community Right-to-Know Act, and the Comprehensive Environmental Response, Compensation, and Liability Act, commonly known as Superfund.