Chlora what?

Chloramine. There’s a small but vocal group of city residents fighting to prevent Rutland from switching its water disinfectant from chlorine to chloramine (a compound of chlorine and ammonia). They have an active Facebook presence. I can’t remember if it’s an open or closed group right now (its status has moved back and forth), but if you went there and asked nicely, I’m sure they would let you in. They are trying to get the aldermen to a) reject a chloramine system and/or b) put a carbon filtration system on the ballot.

The background, in five points:

1) The EPA tracks haloacetic acid levels in water, among many other potential health risks.

2) Haloacetic acids are created when free chlorine reacts with organic material (think decomposing leaves, deer poop, etc., etc.), and Rutland’s are stubbornly higher than allowed.

3) The city considered two main methods of getting its haloacetic acid levels under EPA-mandated levels: Carbon filtration and chloramine, choosing the latter because it would be orders of magnitude less expensive, based on a study from Otter Creek Engineering.

4) The EPA doesn’t track some byproducts of chloramine reactions in water, including haloacetonitriles, halonitromethanes, haloacetaldehydes and nitrosamines. The link to an article used by the concerned citizens by a scientist name Stuart W. Krasner that discusses the potential dangers of these chemicals (warning: contains science) is here. There are also several articles on the city website, including for the brave of heart, a 447-page statewide study on water systems. Oddly, I can’t find the actual study from Otter Creek anywhere.

5) The Krasner article says the amount and type of byproducts varies by site (makes sense … not every stream has the same naturally occurring organic matter in it). He further states that the order you treat with chloramine, chlorine and filter is important in terms of the number of disinfectant byproducts in the resulting drinking water. You have to read past the abstract to find this information, and I doubt many people on either side have done so.

6) I’m going out on a limb and saying that you won’t get more than half the voters to support a multimillion dollar carbon filter that costs $1.5 million annually to run, in addition to the present sand filter and chlorine treatment when a chloramine system can be set up for $100,000, and I think that’s the consensus of the concerned citizen group, which is trying to find a much cheaper version of the carbon filter system. The problem then becomes how to minimize the creation of the harmful byproducts.

So here’s my open question for the aldermen, Mayor Chris Louras, and Evan Pilachowski:

Did the Otter Creek Engineering study take into account not only using chloramine but testing where in the process to add the chloramine to minimize both the creation of chlorine and chloramine byproducts that are known carcinogens, including testing the various combinations of chloramine, chlorine and the existing sand filter to provide water?

Followup question: If not, why not?

Second followup: If you don’t know the answer to these questions or if the answer to the first question is “no,” should you be voting on a new system?

One comment

  1. Mr. Smathers,

    Before I get to your open question, thank you for pointing out that the report from Otter Creek was no longer on our website. For some reason the report was removed, but it is now back on the DPW website. Had the report been available when you did your research, I’m sure you would have seen that the City investigated and pilot tested far more than two options to bring our system into compliance. We started with every method and technology that we were aware of and worked our way to two viable options. I say viable, because both options are safe, have long histories of use, do not use proprietary technology, and we are reasonably assured that the technologies would bring the system into compliance.

    You raise another point that should be addressed as well. There are disinfection byproducts that form with the use of both chlorine and monochloramine that are unregulated and minimally studied. Some of these disinfectants form more readily with the use of chlorine and some with the use of monochloramine. Nearly all of these unregulated disinfection byproducts form in concentrations that are fractions of the regulated disinfection byproducts. Many of these byproducts are tested at parts per trillion and require very specific precursors and conditions to form. The unregulated disinfection byproducts that are of the greatest concern when using monochloramines require precursors that are not present in our water source. However, in order to be extra cautious, we are testing for the precursors and unregulated contaminants currently and are awaiting the results from the lab.

    As to your open question, yes we did test various disinfection protocols and locations to minimize the formation of all disinfection byproducts. The best solution would have been merely switching the location of chlorination to reduce disinfection byproducts. The first step of our pilot study was to investigate potential operational changes we could make in the water system to reduce disinfection byproducts. If we could have made changes that would not involve adding additional chemicals or adding a process to our water treatment plant, that would have been the best case scenario. Unfortunately we have already made the operational changes that have a measurable impact to disinfection byproducts, and further tweaks will not bring us into compliance.

    Our water system, throughout the decades, has reduced chlorine levels as much as possible to minimize disinfection byproduct formation. We have also abandoned prechlorination, a common practice that was used to control plant growth in our raw water storage area, and with these and other steps, we have greatly reduced the formation of disinfection byproducts. However to be thorough in our pilot test, we tested different disinfection locations and found that haloacetic acids form frustratingly quickly in our water system. We found that we could not simply shift the chlorination point downstream, reducing the time chlorine reacts with naturally occurring organic matter. With the pilot test, we learned that the water age, the distribution system, the reservoir, and the slow sand filters are not the controlling factors that lead to haloacetic acid formation in excess of the regulatory limit. The naturally occurring organic matter in our source water is the primary culprit for our disinfection byproduct problem. The two ways to address that problem are removing the organics or using a disinfectant that will not form disinfection byproducts as readily. Those options are using a granular activated carbon filter or switching to monochloramination respectively.

    As far as looking at chloramination locations, we would have to strike a balance between disinfection and disinfection byproduct formation. Under this treatment method, we would still provide primary disinfection with chlorination. This means that water entering the distribution system would be disinfected to the regulatory standards provided by the State and Feds. After this chlorine contact time that provides primary disinfection, we would add ammonia to convert the chlorine into monochloramine. If this is done too quickly, we would not have adequate disinfection prior to the distribution system. If this was done with too much delay, we would form too many disinfection byproducts. It is less of a question of where to disinfect with chlorine and monochloramine, and more of a question of how long to allow free chlorine to remain in our water.

    Thank you for your question and for raising the other points.

    Evan Pilachowski, P.E.
    Commissioner of Public Work for Rutland City

    Like

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