Water Woes

by Sara Mead

I just received the following letter from the Washington Acqueduct and the District of Columbia Water and Sewer Authority. I’m totally perplexed by it:

An equipment problem cause elevated turbidity on December 22, 2008 in water produces by the McMillan Water Treatment Plant. Continuous monitoring enabled us to detect and resolve the problem within 14 miutes. The problem began when in the automatic mode, the filter effluent valves opened wider than expected. It was resolved by the operator assuming manual control of the filters and closing the effluent valves to the proper setting. The short duration of the elevated turbidity reduces the public health risk, but it is very important to read the following information. This is not an emergency. It is had been, you would have been notified immediately. You do not need to boil your water or take other actions. 

Normal turbidity levels at the McMillan Water Treatment Plant are less than 0.1 turbidity units. A water sample taken December 22 showed levels of greater than 1 turbidity unit. This was above the regulatory standard of 1 turbidity unit. Because of these high levels of turbidity, there is an increased chance that the water may have contained disease-causing organisms. 

Turbidity has no health effects. However turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. 

Individuals with extremely compromised immune systems may have been at an increased risk of gastrointestinal illness. Anyone that has concern should contact their health care provider. 

Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools and businesses). You can do this by posting this notice in a public place or distributing copies by hand or mail. 

For more information, please write to Mr. Thomas acobus, General Manager of the Washington Acqueduct, 5900 MacArthur Boulevard, NW, Washington, DC 20016. The phone number is 202-764-0031. e-mail: thomas.p.jacobus@usace.army.mil

This notice is being sent to you by Washington Acqueduct, Public Water System ID3: DC 0000001.

Date distributed: December 30, 2008. 

I suppose posting this fulfills the instruction to share this information with all other people who drink this water, but I’m really doing so because–WTF? Is this some kind of bizarre chain letter (It’s on DC WASA and Army Corps of Engineers letterhead)?  If there really was a minor problem that was resolved in 14 minutes several weeks ago, why are they telling me about it now? What is turbidity anyway? If I don’t need to boil my water or take other action, and the situation is resolved, why did an accompanying letter from DC WASA insist that “It is important that you read he enclosed notice” (doesn’t seem to have told me anything useful!)? Is it really safe for me to drink DC water? Or is this another reason I should ignore Mark Bittman? 

FWIW, I’m going to continue in my normal water consuming practices, which include drinking refrigerated DC tap water on a regular basis, and pretend I never got this letter. But–wtf?


5 responses to “Water Woes

  1. I used to live in Morgan Hill, a very small community just south of silicon valley. Every June, they would send a notice around with your monthly water bill (early nineties, ran about fifty five bucks a month) with the results of their federally mandated (I think, maybe it was state mandated) water quality testing.

    They always came up with HUGE Benzene numbers, way above what’s allowed by law. In the early days of Silicon Chip Fabrication in Santa Clara county, they just dumped everything, and it left a HUGE residual Benzene contamination problem in the water table, and nobody has clue one what to do about it.

    But I was always baffled by the notification. Ok. The water is highly contaminated with Benzene. Um. Thanks for sharing. No advice, no suggestions for filtering, no INFORMATION about mitigation strategies. No suggestions to not drink the water, nothing.

    I was always left feeling like there was another page of the notification letter they forgot to put in my envelope…


  2. Verplanck colvin

    Turbidity is more of a measurement than a substance. Turbidity is the measure of how cloudy water is. 1 NTU is pretty low, you could barely tell that there’s something in there.

    Basically, they let some dirt get into the pipes. No need to worry. I wonder what the actual level was, that was odd that they didn’t specify.

  3. hopefully, on december 22nd, you were drinking eggnog and eating marzipan….and not having turbid tapwater and a peanut butter sandwich.

  4. As Verplanck Colvin says, this is really nothing to worry about. They sent you the letter because they are obligated by law to inform the public when there is any problem, no matter how small. This is supposed to ensure accountability by the provider and also make sure that if there are health consequences of any treatment problem, they can be tracked to specific dates, times and causes.

    The majority of cases, like this one, will be trivial. On the other hand, there was a major treatment failure in Milwaukee in 1993 that led to more than 400,000 people getting sick, and elevated turbidity levels were the key piece of evidence of the problem (which was actually caused by a waterborne parasite called Cryptosporidium). You can read about it on Wikipedia: http://en.wikipedia.org/wiki/Milwaukee_Cryptosporidium_outbreak

    If you’re interested in other issues related to drinking water contamination, this online interview with Barbara Minsker of the University of Illinois is worth reading.


    Bottom line, there are trace levels of contaminants in the drinking water, as there are in air and food, and we don’t know the human health effects of all of them, and there’s no reason to believe bottled water is any safer than public water supply (actually it is not regulated to the same extent). Some of these effects are not yet known and require more research, but we also don’t have any direct evidence of an imminent hazard and we don’t know any way to avoid them at this point. Go ahead and keep drinking your refrigerated tap water unless there is some new revelation about a serious hazard. Almost everything else you do in life (eating a hamburger, taking a walk down the street, riding a bicycle or driving in a car) poses a greater threat to your health than the water you’re drinking.

  5. LiberalTarian

    Hey, at least this time it wasn’t lead, with the DC folks in charge knew about the problem for quite some time before they did anything. (http://ncseonline.org/NLE/CRSreports/05Jan/RS21831.pdf)

    Now, lots of people out there sleep plenty well at night without worrying about their water. Me? I use an activated carbon filter.

    Why? Because even if you have relatively new water works in your city, what about the plumbing in your house? Is the water main that delivers your water contaminant free? Sure, the chlorine or whatever they put in water now will probably provide protection against pathogens all the way to the tap (unless you have a situation like Milwaukee’s).

    I don’t have the resources for a reverse osmosis system, but I can buy an activated carbon filter. Activated carbon filters need to be changed regularly, say monthly or every 6 weeks, but the will still adsorb organics (like benzene), metals (like copper and lead) and anions (like nitrate and perchlorate) from your drinking water.

    Take home message: when you hear them talk about crumbling infrastructure, they are also talking about city plumbing. Take care.

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