Sunday, October 7, 2012

Chloramine in our Water

If you are a customer of Pennsylvania American Water (PAW) living in Washington County or southern Allegheny County, since March of this year your water has been disinfected using chloramine. Perhaps like me you are wondering why PAW switched from chlorine to chloramine for disinfection, and if there are any reasons to be concerned about the use of chloramine in the water flowing into my home and from my faucets.


Chlorine creates toxic disinfection byproducts (DBPs) when it reacts with certain chemicals and organic matter in water. These DBPs have been linked to cancers and birth defects.

One of the class of chemicals with which chlorine reacts to create dangerous DBPs are called bromides. In 2010 and 2011 the Monongahela river, from which PAW draws its water supply, was found to have elevated levels of bromides, threatening the safety of our drinking water. Bromides get into our rivers from various sources, including power plant, conventional oil and gas drilling wastewater, and Marcellus Shale drilling wastewater discharges.

From 2008 until the spring of 2011, natural gas drilling companies brought millions of barrels of chemically tainted shale drilling wastewater to municipal water treatment plants. These plants, which were not equipped to properly treat this wastewater, discharge directly into the rivers from which hundreds of thousands of us get our drinking water. This practice did not stop until the state Department of Environmental Protection asked the drilling companies to voluntarily stop it. Nevertheless, at the end of 2011 bromide levels remained high in our rivers. Nobody appears to have a definitive answer as to why levels remain elevated; one possibility seems to be that wastewater from power plants, as well as from conventional oil and gas drilling (all of which contain bromides) is still being discharged into our rivers.

The combination of chlorine disinfection and elevated bromide levels caused the water supplied to many western Pennsylvania homes to exceed permitted levels of certain DBPs. Specifically, in 2011 some samples of the drinking water that PAW supplied to its customers exceeded the maximum allowable levels of some of these DBPs by nearly 30%. (You can access the 2011 Water Quality Report for the Pittsburgh, McMurray, Mon-Valley service area here). In previous years, some samples contained nearly double the maximum allowable levels of these toxic substances.

PAW made the switch from chlorine to chloramine in order to comply with new, stricter federal regulations, to go into effect this year, governing levels of chlorine DBPs in drinking water. Chloramine produces lower levels of certain DBPs regulated by the EPA.


Unregulated Disinfection Byproducts

However,  "[c]ompared to water treated with chlorine, water treated with monochloramine may contain higher concentrations of unregulated disinfection byproducts." This is from the EPA's statement on Chloramines in Drinking Water. In other words, our water may now contain different, even more dangerous DBPs that are simply not monitored and not regulated by the EPA. The best the EPA can give us is that it and other organizations are conducting research into potentially dangerous but currently unregulated DBPs.

The EPA acknowledges that the use of chloramine with source waters with high bromide, high iodide or high total organic matter may lead to the formation of unregulated disinfection byproducts such as iodoacids and nitrosamines.

Studies have shown that chloramine can indeed react with bromides, iodides and organic matter to create DBPs that are highly toxic, yet are not regulated by the EPA. These unregulated DBPs include iodoacids, discovered in water treated with chloramines in a 2004 study. One of the scientists conducting that study said iodoacids "may be the most toxic family of DBPs to date." He went on to note that the study demonstrated that switching from chlorine to chloramines " . . . may be opening a Pandora's box of new DBPs, and these new DBPs may be much more toxic, by orders of magnitude, than the regulated ones we are trying to avoid."

Another chloramine DBP of concern is NDMA (it is also a chemical used in the manufacture of rocket fuels). NDMA is a nitrosamine and is classsified by the EPA as a probable human carcinogen. The World Health Organization, on the other hand, says it is "clearly carcinogenic." But even though NDMA is clearly dangerous, and has been detected in our drinking water, the EPA does not regulate it, so it is permitted in our drinking water at any concentration.

Leaching of Lead

The EPA acknowledges that changes in water chemistry from chloramine use may impact lead levels in water. Chloramines can make water more corrosive, which can lead to pipe corrosion (in the distribution system or in the home) and an increase in lead levels in water. This happened when Washington, D.C. switched from chlorine to chloramine in 2001, causing lead to leach from aging pipes into drinking water. Between 2001 and 2004 tens of thousands of children were exposed to extremely high lead levels; in some homes lead levels in the water were hundreds of times higher than the amount the federal government considers a level of concern. Blood tests revealed that hundreds of young children had potentially damaging amounts of lead in their blood.

Closer to home, West View began using chloramine in its water in 2009. Testing in 2010 revealed high lead levels in water supplied to older homes with lead pipes. West View stopped using chloramines in 2010, but started using it again this year.

As my house was built in the 1930's, I am extremely concerned about the possibility of chloramine causing lead to leach into our water. PAW states that it practices "corrosion control" at its water treatment facilities. However, this is a complex science and the details of all the related environmental chemistry are not fully understood.

Removing Chloramine from Your Water

So, are there ways to remove chloramine and its dangerous byproducts from our water? Chloramine is not easy to remove from water; it is much more difficult to remove than chlorine. According to the EPA you cannot remove chloramine from water by boiling it, allowing it to sit at room temperature, or by using a reverse osmosis filter.

While it appears that some products claim to remove chloramine from drinking water or from shower water, the NSF only certifies certain products for chloramine reduction.

I am continuing to research ways to reduce or remove chloramine and chloramine DBPs, and will follow up in a future post.

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