Progress being made on water filtration
Wednesday, October 28, 2009 1:06 PM CDT
A specialist was in town Tuesday to try to rectify a problem with the city’s first radionuclide filtration system.
It was reported during the monthly city council session Monday evening that a problem had been found when workers tried to start up the new filtration system last week. The tiny man-made media used to filter radionuclide contamination from the water was escaping one are of the equipment and making its way past a filtering screen into another portion of the mechanism.
The filtration system being utilized by the city operates similar to a standard swimming pool sand filter. Water is cycled through a filtration tank full of media, which then separates impurities and allows the clean water to pass out of the system. The impurities are kept in the system.
In the case of filtering radionuclides, the tank houses man-made particles which are about the size of sand and have an oily feeling. The particles collect radionuclide contamination as groundwater passes through on its way from a ground well to a storage tank or water main. Unlike a pool sand filter, the media in this pump is never backwashed and used again. Service technicians remove and replace the media on a regular maintenance schedule. Currently there are two locations in the United States which accepts such waste — facilities in Utah and Washington.
Radionuclide contamination is a naturally-occurring breakdown of minuscule radioactive particles within the bedrock of the Earth’s crust. As groundwater is pulled through the bedrock containing the particles a tiny portion of the contamination attaches itself to the water molecules.
Starting several years ago the federal Environmental Protection Agency tightened restrictions on radionuclide contamination in the public water system. After years of trial and error to find the most cost-effective solution to the problem, city officials opted to install a series of treatment plants at the locations where the water is pumped from the ground.
City staff explored other possible solutions. They tried to raise pumps higher in the bedrock and block off the more contaminated bedrock. In the end a decision was made to install the media filtration system at each well.
The units cost about $100,000 each, and were developed and are manufactured by Dow Chemical Company.
Public Works Director Allen Welshon said the city will have to change a portion of the media material every couple years. The purchase agreement includes the maintenance plan where the supplier collects and disposes of the contaminated material.
While the government has mandated cities treat drinking water for radionuclide contamination, the amount found in Farmington’s water system poses no immediate health risks.
Welshon has used the scenario as explained by the Missouri Department of Natural Resources and EPA. “If a person drank two liters of Farmington water a day everyday for 70 years that person would have a 1 in 10,000 chance of developing cancer (as a result),” Welshon explains.
The city has had 13 wells in its water system. A new well off Route H was recently added and an older well off Karsch Boulevard was taken out of the system due to a low flow rate. The first radionuclide treatment unit was installed in the base of the water tower at U.S. 67 and Business 32. Once this plant is operational work will start to install six more units. Once the second round is complete, the final six units will be installed.
The city must be in compliance with the EPA regulations governing radionuclide contamination by Dec. 31, 2011.
It was reported during the monthly city council session Monday evening that a problem had been found when workers tried to start up the new filtration system last week. The tiny man-made media used to filter radionuclide contamination from the water was escaping one are of the equipment and making its way past a filtering screen into another portion of the mechanism.
The filtration system being utilized by the city operates similar to a standard swimming pool sand filter. Water is cycled through a filtration tank full of media, which then separates impurities and allows the clean water to pass out of the system. The impurities are kept in the system.
In the case of filtering radionuclides, the tank houses man-made particles which are about the size of sand and have an oily feeling. The particles collect radionuclide contamination as groundwater passes through on its way from a ground well to a storage tank or water main. Unlike a pool sand filter, the media in this pump is never backwashed and used again. Service technicians remove and replace the media on a regular maintenance schedule. Currently there are two locations in the United States which accepts such waste — facilities in Utah and Washington.
Radionuclide contamination is a naturally-occurring breakdown of minuscule radioactive particles within the bedrock of the Earth’s crust. As groundwater is pulled through the bedrock containing the particles a tiny portion of the contamination attaches itself to the water molecules.
Starting several years ago the federal Environmental Protection Agency tightened restrictions on radionuclide contamination in the public water system. After years of trial and error to find the most cost-effective solution to the problem, city officials opted to install a series of treatment plants at the locations where the water is pumped from the ground.
City staff explored other possible solutions. They tried to raise pumps higher in the bedrock and block off the more contaminated bedrock. In the end a decision was made to install the media filtration system at each well.
The units cost about $100,000 each, and were developed and are manufactured by Dow Chemical Company.
Public Works Director Allen Welshon said the city will have to change a portion of the media material every couple years. The purchase agreement includes the maintenance plan where the supplier collects and disposes of the contaminated material.
While the government has mandated cities treat drinking water for radionuclide contamination, the amount found in Farmington’s water system poses no immediate health risks.
Welshon has used the scenario as explained by the Missouri Department of Natural Resources and EPA. “If a person drank two liters of Farmington water a day everyday for 70 years that person would have a 1 in 10,000 chance of developing cancer (as a result),” Welshon explains.
The city has had 13 wells in its water system. A new well off Route H was recently added and an older well off Karsch Boulevard was taken out of the system due to a low flow rate. The first radionuclide treatment unit was installed in the base of the water tower at U.S. 67 and Business 32. Once this plant is operational work will start to install six more units. Once the second round is complete, the final six units will be installed.
The city must be in compliance with the EPA regulations governing radionuclide contamination by Dec. 31, 2011.
Reader Comments (
Member Center
E-mail updates
