Pondcrete
Encyclopedia
Pondcrete is a mixture of cement
and sludge
. Its role is to immobilize hazardous waste
and, in some cases, lower-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
.
Because the blocks were classified as mixed waste, Rockwell International
was unable to store the blocks in the Nevada Test site. The site did not have a permit to store mixed waste, so the blocks were temporarily stored at Rocky Flats
. Due to problems in production, many of the blocks did not harden correctly and eventually began to seep from the boxes and cause large scale environmental damage to the area. The blocks, containing radioactive waste with a half-life of 24,000 years had failed in a year. Despite warnings by engineer Jim Stone that the blocks would most likely fail earlier than expected, the blocks were still produced. Later it would be Jim Stone which would file a lawsuit against the company, claiming that they had concealed environmental, safety and health problems from the United States Department of Energy
. The contaminations lead to an investigation of the Plant by the Federal Bureau of Investigation
and the Environmental Protection Agency which eventually resulted in its shutdown.
Cement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...
and sludge
Sludge
Sludge refers to the residual, semi-solid material left from industrial wastewater, or sewage treatment processes. It can also refer to the settled suspension obtained from conventional drinking water treatment, and numerous other industrial processes...
. Its role is to immobilize hazardous waste
Hazardous waste
A hazardous waste is waste that poses substantial or potential threats to public health or the environment. According to the U.S. environmental laws hazardous wastes fall into two major categories: characteristic wastes and listed wastes.Characteristic hazardous wastes are materials that are known...
and, in some cases, lower-level radioactive waste, in the form of solid material. The material was used by the United States Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
and its contractor, Rockwell International
Rockwell International
Rockwell International was a major American manufacturing conglomerate in the latter half of the 20th century, involved in aircraft, the space industry, both defense-oriented and commercial electronics, automotive and truck components, printing presses, valves and meters, and industrial automation....
, in an attempt to handle the radioactive waste from contaminated ponds in the Rocky Flats Plant
Rocky Flats Plant
The Rocky Flats Plant was a United States nuclear weapons production facility near Denver, Colorado that operated from 1952 to 1992. It was under the control of the United States Atomic Energy Commission until 1977, when it was replaced by the Department of Energy .-1950s:Following World War II,...
for burial in Nevada desert. Portland cement
Portland cement
Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout...
is mixed with sludge
Sludge
Sludge refers to the residual, semi-solid material left from industrial wastewater, or sewage treatment processes. It can also refer to the settled suspension obtained from conventional drinking water treatment, and numerous other industrial processes...
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
Mixed waste
Mixed waste can refer to any combination of waste types with different properties.Typically commercial and municipal wastes are mixtures of plastics, metals, glass, biodegradable waste including paper and textiles along with other nondescript junk....
.
Because the blocks were classified as mixed waste, Rockwell International
Rockwell International
Rockwell International was a major American manufacturing conglomerate in the latter half of the 20th century, involved in aircraft, the space industry, both defense-oriented and commercial electronics, automotive and truck components, printing presses, valves and meters, and industrial automation....
was unable to store the blocks in the Nevada Test site. The site did not have a permit to store mixed waste, so the blocks were temporarily stored at Rocky Flats
Rocky Flats Plant
The Rocky Flats Plant was a United States nuclear weapons production facility near Denver, Colorado that operated from 1952 to 1992. It was under the control of the United States Atomic Energy Commission until 1977, when it was replaced by the Department of Energy .-1950s:Following World War II,...
. Due to problems in production, many of the blocks did not harden correctly and eventually began to seep from the boxes and cause large scale environmental damage to the area. The blocks, containing radioactive waste with a half-life of 24,000 years had failed in a year. Despite warnings by engineer Jim Stone that the blocks would most likely fail earlier than expected, the blocks were still produced. Later it would be Jim Stone which would file a lawsuit against the company, claiming that they had concealed environmental, safety and health problems from the United States Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
. The contaminations lead to an investigation of the Plant by the Federal Bureau of Investigation
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
and the Environmental Protection Agency which eventually resulted in its shutdown.