Radionuclides pose problems for cities
EPA revises acceptable levels
By DOUG SMITH
Daily Journal Staff Writer
Daily Journal Staff Writer
Published: Wednesday, July 08, 2009
Updated: Wednesday, July 8, 2009 10:27 AM CDT
Updated: Wednesday, July 8, 2009 10:27 AM CDT
FARMINGTON — It’s a big word that can strike fear in the hearts of those who hear it. It wreaks havoc on municipalities with even a minuscule amount of it, and some believe its remedies may be disproportionate to its health risks. The term is radionuclide, and here’s how one area city is handling the problem.
According to the United States Environmental Protection Agency, “Most drinking water sources have very low levels of radioactive contaminants (called radionuclides), most of which are naturally occurring. Most radioactive contaminants are at levels that are low enough to not be considered a public health concern.”
The EPA explanation goes on to say, “At higher levels, long-term exposure to radionuclides in drinking water may cause cancer. In addition, exposure to uranium in drinking water may cause toxic effects to the kidney.”
Farmington is among cities whose water supply has more radionuclides than that allowed. The radionuclides are present in very low amounts and are naturally occurring.
What are radionuclides?
Their source is the extensive deposits of granite, millions of years old, that make up the bedrock of St. Francois County. Granite breaks down very slowly, releasing minute quantities of uranium and thorium into ground water. These further decay to radium particles — radionuclides.
Although the quantities released are generally very small, over a period of millions of years it accumulates and can reach levels the EPA says pose a potential health risk.
Modern technology has made well drilling more common, with deeper wells that may reach ground water that has more radium in it.
Federal regulations governing radionuclides were tightened and went into full effect in late 2007. The first government regulation of radionuclide contamination in public drinking water was by the EPA in 1977. Those rather lax guidelines remained in place for 23 years. Then in 2000 the federal agency “revised” its regulations, requiring new monitoring of community water systems.
The revised Radionuclides Rule went into effect Dec. 8, 2003. U.S. EPA’s revisions to the rule provide standards to ensure all customers served by community water systems receive water that meets the Maximum Contaminant Levels for radionuclides in drinking water, according to an EPA explanation.
Part of that 2003 rule stated that all community water systems “must complete initial compliance monitoring by Dec. 8, 2007. While most systems will be in compliance with the revised rule, systems in areas of the country with elevated levels of naturally occurring radionuclides, and the few systems located near facilities that could potentially contaminate source waters with radioactive substances, might have to install new or upgrade existing treatment to meet these revised standards.”
As mentioned earlier, while drinking water may contain unacceptable levels of radionuclide contamination, that doesn’t mean there is any immediate health risk from drinking the water. The danger is from exposure over long periods of time.
The EPA has set the public health action level for radionuclides at the point where, over a 70-year period, one in 10,000 people drinking a substantial quantity of a given water supply might face an increased risk of developing cancer from the exposure.
Is there a health risk?
While more radionuclides than that is considered unacceptable for the long-term, it does not necessarily mean drinking the water in Farmington poses an immediate health risk. The levels are low enough that the health risk from the radioactive components occur only over a long period of time.
Farmington Public Works Director Allen Welshon uses this scenario as explained by the Missouri Department of Natural Resources and EPA. “If a person drank two liters of Farmington water a day every day for 70 years that person would have a 1 in 10,000 chance of developing cancer (as a result),” Welshon said.
Farmington is not alone in battling to keep the invisible contamination of public drinking water beneath EPA-acceptable levels. Several communities across the Midwest face similar situations. The federal EPA guidelines are being enforced by the Missouri Department of Natural Resources. Cities such as Farmington began looking for the most cost-effective way to treat millions of gallons of water each month.
The problem with the water affects all public water systems in the Farmington area which serve at least 15 connections or a total of 25 residents. That means not only cities were forced to test and treat their water. Rural residential developments sharing a common well or series of wells, along with public drinking water systems like those operated by the Pilot Knob Water Districts, are also required to come in line with the newly lowered standards. At least initially, self-contained systems serving schools or nursing homes or similar uses where either a few people used the system or it was in use for less than six months per calendar year were excused from the updated regulations.
Each community is faced with its own dilemma based on extended sampling and the subsequent results.
City takes steps to reduce levels
Farmington leaders realized that the radionuclide levels of its 13-well system were on the high side of the updated federal and state guidelines. Starting as far back as 10 years ago, when word of the updated EPA regulations were rumored, concerns grew as to how the city would handle bringing its extensive system into compliance. By all other standards, the city had a tremendous potable water system.
To date there had been no need to heavily chlorinate the well water. Residents of other communities in the region voiced valid concerns about foul tasting or smelling drinking water, or of swimming pools which turned bronze or green with a sudden change in temperature or rainfall, or laundry coming out of the washing machine with less than stellar whites. Farmington officials rarely heard complaints about the taste and quality of the public water.
But about 2005, the question of what might be required in the near future became a major concern. Possible expenditures including multi-million dollar treatment options were routinely mentioned in council sessions. Officials, including City Administrator Greg Beavers, former Public Works Director Jeff Blue and current Public Works Director Welshon met repeatedly with DNR officials in Jefferson City to keep informed on how the radionuclide concern was being handled by other cities, and what new technology was being developed and introduced to make future treatment as palatable as possible.
City leaders discussed studies which had shown that geological surveys could reveal bedrock less prone to radionuclide contamination. If such areas could be found within the city limits then it might be possible to drill new wells to replace others which were troubled by elevated radionuclide levels.
Pilot program
In about 2007, the city joined with DNR to participate in a pilot program to explore a way of blocking off the most troubled portion of bedrock and only draw water from depths above most of the contaminants. The goal was to probe the depth of a well with testing equipment and develop a footprint of just what level was producing the most contamination. Once that was determined, a concrete “plug” would be installed in the bedrock to block off the well from that point down. Water would then only be drawn from that point up to the surface. It was confirmed that much of the volume of water produced by the well was drawn from the deepest points. Relying on the most shallow groundwater rendered the well as much as useless to meet the city’s daily water needs.
Fortunately, companies such as Dow Chemicals were busy working on their own solution for the radionuclide problem facing much of the Midwest. Dow developed a self-contained “treatment plant” which uses man-made sphere-shaped pellets to attract and draw out radionuclides as water passes through. The device uses ions that have an opposite charge to attract the radionuclide ions. The company went a step further in developing a maintenance plan that was cost effective for cities and other public drinking water entities.
The cost of the new “plants” is about $100,000 each, including the ongoing maintenance agreement. For that price Dow agrees to help with the initial installation, and then return periodically to remove and dispose of the contaminated pellets in one of two disposal locations in Western states.
How it works
The best description of how the treatment plants work is to compare them to a swimming pool sand filter. By EPA standards, water must be treated at the source — or as soon as it leaves the ground and before it enters the water main system. The water is piped from the ground and through a large cylinder containing the absorption pellets. Active radioactive contamination is drawn out of the water and “sticks” to the pellets. Another major difference from the treatment plants and a swimming pool filter is that there is no way to “backwash” the contaminants out of the filter material. The radionuclide contamination remains bonded to the pellets, which are then routinely removed and disposed of and replaced with new matter by Dow Chemicals.
Total cost to treat the city’s entire 13-well system will be in the neighborhood of $1.3 million. The DNR has agreed to allow the city to install one treatment plant initially and experiment with its effectiveness for a few months.
Once the treatment plant has proven effective, the city will consider installing six identical plants. When those are completed, the final six will be installed bringing the entire 13 wells into compliance.
The city has until Dec. 31, 2011, to comply with the EPA regarding radionuclide contamination.
To better explain the quality of Farmington’s drinking water system, the annual “Water Quality Report” was mailed to all drinking water customers this past week. The four-page report outlines the source, assessment and any concerns regarding the public drinking water system.
According to the United States Environmental Protection Agency, “Most drinking water sources have very low levels of radioactive contaminants (called radionuclides), most of which are naturally occurring. Most radioactive contaminants are at levels that are low enough to not be considered a public health concern.”
The EPA explanation goes on to say, “At higher levels, long-term exposure to radionuclides in drinking water may cause cancer. In addition, exposure to uranium in drinking water may cause toxic effects to the kidney.”
Farmington is among cities whose water supply has more radionuclides than that allowed. The radionuclides are present in very low amounts and are naturally occurring.
What are radionuclides?
Their source is the extensive deposits of granite, millions of years old, that make up the bedrock of St. Francois County. Granite breaks down very slowly, releasing minute quantities of uranium and thorium into ground water. These further decay to radium particles — radionuclides.
Although the quantities released are generally very small, over a period of millions of years it accumulates and can reach levels the EPA says pose a potential health risk.
Modern technology has made well drilling more common, with deeper wells that may reach ground water that has more radium in it.
Federal regulations governing radionuclides were tightened and went into full effect in late 2007. The first government regulation of radionuclide contamination in public drinking water was by the EPA in 1977. Those rather lax guidelines remained in place for 23 years. Then in 2000 the federal agency “revised” its regulations, requiring new monitoring of community water systems.
The revised Radionuclides Rule went into effect Dec. 8, 2003. U.S. EPA’s revisions to the rule provide standards to ensure all customers served by community water systems receive water that meets the Maximum Contaminant Levels for radionuclides in drinking water, according to an EPA explanation.
Part of that 2003 rule stated that all community water systems “must complete initial compliance monitoring by Dec. 8, 2007. While most systems will be in compliance with the revised rule, systems in areas of the country with elevated levels of naturally occurring radionuclides, and the few systems located near facilities that could potentially contaminate source waters with radioactive substances, might have to install new or upgrade existing treatment to meet these revised standards.”
As mentioned earlier, while drinking water may contain unacceptable levels of radionuclide contamination, that doesn’t mean there is any immediate health risk from drinking the water. The danger is from exposure over long periods of time.
The EPA has set the public health action level for radionuclides at the point where, over a 70-year period, one in 10,000 people drinking a substantial quantity of a given water supply might face an increased risk of developing cancer from the exposure.
Is there a health risk?
While more radionuclides than that is considered unacceptable for the long-term, it does not necessarily mean drinking the water in Farmington poses an immediate health risk. The levels are low enough that the health risk from the radioactive components occur only over a long period of time.
Farmington Public Works Director Allen Welshon uses this scenario as explained by the Missouri Department of Natural Resources and EPA. “If a person drank two liters of Farmington water a day every day for 70 years that person would have a 1 in 10,000 chance of developing cancer (as a result),” Welshon said.
Farmington is not alone in battling to keep the invisible contamination of public drinking water beneath EPA-acceptable levels. Several communities across the Midwest face similar situations. The federal EPA guidelines are being enforced by the Missouri Department of Natural Resources. Cities such as Farmington began looking for the most cost-effective way to treat millions of gallons of water each month.
The problem with the water affects all public water systems in the Farmington area which serve at least 15 connections or a total of 25 residents. That means not only cities were forced to test and treat their water. Rural residential developments sharing a common well or series of wells, along with public drinking water systems like those operated by the Pilot Knob Water Districts, are also required to come in line with the newly lowered standards. At least initially, self-contained systems serving schools or nursing homes or similar uses where either a few people used the system or it was in use for less than six months per calendar year were excused from the updated regulations.
Each community is faced with its own dilemma based on extended sampling and the subsequent results.
City takes steps to reduce levels
Farmington leaders realized that the radionuclide levels of its 13-well system were on the high side of the updated federal and state guidelines. Starting as far back as 10 years ago, when word of the updated EPA regulations were rumored, concerns grew as to how the city would handle bringing its extensive system into compliance. By all other standards, the city had a tremendous potable water system.
To date there had been no need to heavily chlorinate the well water. Residents of other communities in the region voiced valid concerns about foul tasting or smelling drinking water, or of swimming pools which turned bronze or green with a sudden change in temperature or rainfall, or laundry coming out of the washing machine with less than stellar whites. Farmington officials rarely heard complaints about the taste and quality of the public water.
But about 2005, the question of what might be required in the near future became a major concern. Possible expenditures including multi-million dollar treatment options were routinely mentioned in council sessions. Officials, including City Administrator Greg Beavers, former Public Works Director Jeff Blue and current Public Works Director Welshon met repeatedly with DNR officials in Jefferson City to keep informed on how the radionuclide concern was being handled by other cities, and what new technology was being developed and introduced to make future treatment as palatable as possible.
City leaders discussed studies which had shown that geological surveys could reveal bedrock less prone to radionuclide contamination. If such areas could be found within the city limits then it might be possible to drill new wells to replace others which were troubled by elevated radionuclide levels.
Pilot program
In about 2007, the city joined with DNR to participate in a pilot program to explore a way of blocking off the most troubled portion of bedrock and only draw water from depths above most of the contaminants. The goal was to probe the depth of a well with testing equipment and develop a footprint of just what level was producing the most contamination. Once that was determined, a concrete “plug” would be installed in the bedrock to block off the well from that point down. Water would then only be drawn from that point up to the surface. It was confirmed that much of the volume of water produced by the well was drawn from the deepest points. Relying on the most shallow groundwater rendered the well as much as useless to meet the city’s daily water needs.
Fortunately, companies such as Dow Chemicals were busy working on their own solution for the radionuclide problem facing much of the Midwest. Dow developed a self-contained “treatment plant” which uses man-made sphere-shaped pellets to attract and draw out radionuclides as water passes through. The device uses ions that have an opposite charge to attract the radionuclide ions. The company went a step further in developing a maintenance plan that was cost effective for cities and other public drinking water entities.
The cost of the new “plants” is about $100,000 each, including the ongoing maintenance agreement. For that price Dow agrees to help with the initial installation, and then return periodically to remove and dispose of the contaminated pellets in one of two disposal locations in Western states.
How it works
The best description of how the treatment plants work is to compare them to a swimming pool sand filter. By EPA standards, water must be treated at the source — or as soon as it leaves the ground and before it enters the water main system. The water is piped from the ground and through a large cylinder containing the absorption pellets. Active radioactive contamination is drawn out of the water and “sticks” to the pellets. Another major difference from the treatment plants and a swimming pool filter is that there is no way to “backwash” the contaminants out of the filter material. The radionuclide contamination remains bonded to the pellets, which are then routinely removed and disposed of and replaced with new matter by Dow Chemicals.
Total cost to treat the city’s entire 13-well system will be in the neighborhood of $1.3 million. The DNR has agreed to allow the city to install one treatment plant initially and experiment with its effectiveness for a few months.
Once the treatment plant has proven effective, the city will consider installing six identical plants. When those are completed, the final six will be installed bringing the entire 13 wells into compliance.
The city has until Dec. 31, 2011, to comply with the EPA regarding radionuclide contamination.
To better explain the quality of Farmington’s drinking water system, the annual “Water Quality Report” was mailed to all drinking water customers this past week. The four-page report outlines the source, assessment and any concerns regarding the public drinking water system.
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