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| Arsenic in well water |
Recently I was asked to do a presentation, at a networking meeting, about our company and the services we provide along with a particular topic to discuss. It's easy to discuss one particular water treatment issue and how to solve it but there are twelve other people at the table that don't necessarily have that particular problem. They have a whole different perception of their water problems and water concerns or just want to know what the heck that contraption is in their basement (water softener) and how it works. So instead of doing a typical presentation, I said how about we go around the table to each person and they can ask a question pertaining to their water or water treatment system. This way we can help everyone with their water concerns. It worked out very well. Everyone was happy with the presentation. I helped everyone with their water questions and we all learned something about each other (which is the objective for networking). We actually ran over by ten minutes. But during all these discussions the one topic that came up more than any was Arsenic!
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| The first family in Michigan, diagnosed with arsenic poisoning. |
Arsenic is naturally occurring in Southeast Michigan and has become a big concern for those living with water drawn from private and community well water supplies. In 2001 The World Health Organization lowered the arsenic standard from 50 ppb (parts per billion) to 10 ppb. In part due to the increased incidence of health-related problems at the previous levels of 50 ppb. In 1999 I happened to work with the very first family in Michigan that had been diagnosed with
arsenic poisoning. Their water had been tested and the Arsenic levels were at 43 ppb, well below what was perceived to be the threshold for health problems at the time. The whole family had become sick, three young children and the parents, with various symptoms that seemed totally unrelated. Their water was the last thing tested and arsenic was found to be the basis for all their health problems. The entire family had elevated levels of arsenic in their systems. Their health issues sparked renewed interest in the arsenic levels and what is really a "Safe" level for human consumption. Doctors finally stood up and took notice and started testing their patients for elevated arsenic levels and to everyone's dismay, the arsenic problem was much more widespread than anyone could have conceived. One doctor that became proactive in testing his patients for arsenic, and searching for solutions for them, is in Southfield, MI. Southfield (located in the middle of a city water area outside of Detroit, MI), actually has many homes still on private wells. It was discovered that many of the wells have extremely high levels of arsenic.
This map, released by the U.S.G.S, shows the incidence of arsenic occurring across Michigan counties. As you can see southern Michigan is especially high in arsenic.
The family these arsenic problems came to light over, in 1999, lived in northwest Oakland County. In our water treatment business, we have run into arsenic levels as high as 250 ppb in southern Michigan. Obviously, that is extremely high and absolutely needs to be treated for removal. But in my opinion "NO Arsenic" is the level everyone needs to be at. The only reason the arsenic levels are currently set at 10 ppb is the level was negotiated by municipalities to 10 ppb because it would be almost impossible for these municipal water suppliers to guarantee they could keep the arsenic levels at "0 ppb" all the time. The federal government was really pushing to have the standard set at 0 ppb but that was just not practical or cost-effective for these water supply companies.
Livingston County Michigan has taken a proactive approach to this arsenic issue and now requires water treatment if the arsenic levels are above the 10 ppb standard for any real estate transactions. Typically most homeowners want the whole house treated for arsenic removal and there are several ways to accomplish this. Many water treatment companies have decided not to pursue the arsenic removal business as they find the liability associated with treating these problems too high. It has been my experience that a strong education in the arsenic removal processes, a proper water analysis, and experience in the application provides the acumen for arsenic removal solutions for the growing number of concerned homeowners and prospective home buyers.
Arsenic types: There are two types of arsenic. AS-5 and AS-3. These are referred to as "valences". Both types of arsenic can and frequently do appear in the same well. In southern Michigan, AS-5 is the most prevalent type we find but any application method has to take into account the possibility of AS-3 being present also. Testing for arsenic can be done by a certified lab, or by a water treatment professional that is educated in arsenic testing. Real estate transactions will need a water test performed by a certified lab to determine the arsenic levels. Determining the "valence" is difficult, even for a lab, and generally is not necessary as the treatment method will determine the proper water treatment method for removing both types of arsenic.
Arsenic Removal Methods
There are two approaches to arsenic removal. POE (Point of Entry) which is whole house treatment or POU (Point of Use) treatment at a specific spot in the home. Usually at the kitchen sink.
1.
Water Softener; In the presence of
ferrous iron even a water softener will help remove some arsenic from the water supply. But this is not the recommended method for arsenic removal. Typically only small amounts of AS-5 are removed with this process and the arsenic levels removed are very inconsistent.
2.
Reverse Osmosis; Reverse osmosis systems can be an option for arsenic removal. These systems are typically only for POU (point of use) and have a dedicated faucet at the kitchen sink and can be tied into the refrigerator also. This is good for AS 5 removal and will need a separate AS 3 filter to assure all arsenic is removed. This would only be for drinking water, not the whole house.
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| Under sink POU reverse osmosis drinking water system. |
3.
Oxidation and Precipitation; Fortunately AS 5 (arsenic five) has a strong affinity to bind to iron. So the most practical method of removing arsenic is with an oxidation/precipitation filtration system, With this method AS 3 is converted over to AS 5 and consequently, a much higher success rate of total arsenic removal is achieved. This method can be accomplished by either "Air Induction" or "Chemical Injection". In a residential home, depending on water chemistry, arsenic levels and water usage. Air Induction is the most practical approach.
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| Air Induction system |
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| Chemical Injection system |
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Adsorption; There are also adsorption media that attract and hold the arsenic on the media. These type arsenic removal/reduction filtration systems generally have a specific amount of gallons that can be run through the media before it needs replacing. This type of arsenic removal process usually has a "lead" and "lag" tank set up. The first or "lead" tank takes the brunt of arsenic removal. The second or "lag" tank is used as a polishing tank to assure arsenic is still being removed when the lead tank starts to become exhausted. The number of gallons able to run through the system, before replacing media, is strictly dependent on the arsenic levels, which can fluctuate seasonally, and the amount of water used. This is referred to as the "load factor". Arsenic tests are performed from the sample ports annually. There should be three sample ports. before, middle and after the lag tank. When the lead tank becomes exhausted (arsenic starts to leak to lag tank) it is replaced with fresh media. The "Lag" tank is moved in front and the new tank becomes the polishing or "Lag" tank. To track water usage and get a better idea when tank changes should occur. There should always be a totalizing meter after the lag tank to record annual water usage. Tank replacement literally could be on a yearly basis for up to seven years, depending on the factors mentioned above.
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| Adsorption system with "Lead" and "Lag" tanks and sampling ports. |
It is recommended to seek out a seasoned water treatment professional and water treatment company experienced with arsenic removal to assure you have the best and most practical water treatment solutions for your household. I hope this article has been helpful in answering some of your questions and concerns regarding arsenic and the options you and your family have to treat your water and be healthy and happy for years to come. Yes, you can drink up with peace of mind!
Good Water, Good Life!
Ray McConnell
Beauchamp Water Treatment and Supply
872 N Old US 23 Brighton, MI 48114
810 632 200
Please see the links below for more information regarding the topics discussed in this article.
