Piped water: two edged sword

If you want to know what advances in public health and medicine in the last 150 years have done the most for the overall health of the community a major contender for the top spot would have to be the provision of safe and abundant drinking water. The first piped water supplies for major American cities date to shortly before the Civil War (mid nineteenth century) and disinfection with chlorine didn't start until the end of the first decade of the 20th century. The results for major waterborne infectious diseases like typhoid fever and various maladies just categorized as diarrhea and dysentery was immediate and dramatic. Evidence at the time suggested that it wasn't just waterborne disease that was affected either. A claim variously called Hazen's Theorem or the Mills-Reincke Phenomenon said that for every life you save from a waterborne disease by providing a clean water supply you save another two or three from non-waterborne disease, like pneumonia. If the claim is valid, presumably the mechanism was a general improvement in host defenses. If you aren't shitting your guts out all the time you are less likely to succumb to another disease. In any event, a piped water supply proved to be a remarkably efficient way to distribute a life giving substance, clean water, to the entire community. But there is a corollary: it is also a remarkably efficient way to distribute poisons to the same community. This week the residents of a small Colorado town are finding out first hand:

It could be three more weeks before residents of a southern Colorado town can drink water straight from the tap after dozens of cases of salmonella poisoning were linked to municipal water, putting seven people in the hospital.

An analysis indicates the municipal water system in Alamosa is the source of the bacterial outbreak, as suspected, said Ned Calonge, chief medical officer for the state health department.


The city and county also have declared emergencies as officials scrambled to provide safe water and disinfect the system with chlorine.

The earliest the city water system could be flushed is Tuesday, and disinfecting it and making sure it is safe could take many days, said James Martin, executive director of the state health department. Water agencies from Denver, Aurora and Fort Collins were helping.

As of Friday, 138 cases of salmonella linked to the outbreak had been reported in people from infancy to age 89, of which 47 were confirmed by lab testing, Calonge said. The conditions of those hospitalized weren't released.

Alamosa, with about 8,500 residents, gets its water from a deep well system. The water is pure from the aquifer and is not chlorinated. (AP)

This large outbreak is actually pretty unusual. Salmonella infection (which Salmonella species wasn't specified) used to be a common waterborne disease. Typhoid fever, for example, is Salmonella typhi). But waterborne disease outbreaks are now quite rare. In the last 30 years CDC has identified Salmonella as a waterborne disease agent only a little over a dozen times. Non typhoid Salmonella infections take a fairly hefty inoculum to make someone sick, which means a really bad contamination. In this case the source of the Salmonella hasn't been identified, but I'd put my money on a cross-connection with a wastewater system. This can happen more easily than you'd suspect. Often subtle hydrostatic pressure conditions will suck wastewater from a washing sink that has a faucet sticking below the surface of the wash water will do it, although the plumbing code is supposed to prevent that kind of thing. Sometimes wastewater gets suck back from sprinkler systems or in really bad cases, the sewer line gets connected to the water line.

Water - wastewater cross connection control is a difficult but very interesting problem -- more interesting than you'd expect. If you want to know more about it, take a peek at the EPA's Cross-connection Manual which is online here.

Meanwhile, no water supply for these folks. Sure they can drink bottled water but if the supply is turned off, then flushing the toilet, cooking, cleaning and personal hygiene become a challenge. One thing for sure: these folks will have a real appreciation for what most of us take for granted.

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But there is a corollary: it is also a remarkably efficient way to distribute poisons to the same community.

Including, inter alia, deliberately introduced poisons such as fluoride and chloramine.

I live in a place where the tap water quality is some of the best in the world, delivered from a pristine mountain watershed. Or at least the quality would be among the best in the world, if the water were not, two kilometers from the house, then adulterated with chemicals in the name of a highly dubious public health agenda.

I can't put that "healthful" tap water in my car engine without instantly voiding the warranty. I can't fill the fish pond with that "clean, sanitary" water because it'll kill the fish in seconds. And yet I'm expected to put that stuff down my neck?

If they left out the fluorides, and went back to simple chlorine instead of chloramine, I would happily drink the tap water. As it stands, I instead must buy, at substantial additional expense, artificially distilled water. Thanks!


Not to mention drugs that poison the system incidentally, likely excreted by people taking these drugs, and which may affect fertility and behaviour. Of course, nobody really knows because our public health departments do not even study the effect of these drugs in the water supply, since god forbid, if there were negative effects they would need to do something. Of course, if the effects are reduced fertility and make people docile and easier to control, they might think this a good thing and let it be. Might even add some of these things to our water.


"A vast array of pharmaceuticals -- including antibiotics, anti-convulsants, mood stabilizers and sex hormones -- have been found in the drinking water supplies of at least 41 million Americans"

Reminds me of the recent Nokia water criss in Finland.

Fascinating. Although I read the European press, I had no inkling of this event.

The last time I had a look at a water system where sanitary and sewer water were in proximity, it was pointed out to me that clean water is used to rinse the dirty water system, but only via a gravity air gap: clean water comes out of a pipe and falls several meters into a basin, from whence it goes to the rinse system. Backflow cannot occur. An elegant, simple safety model.

But any foolproofing scheme must take into account the infinite power of foolishness. We ended up with contaminated water after a fool with a backhoe dug through a sewer pipe and then, continuing to dig even though the trench was filling with waste, nailed the nearby drinking water pipe.


Public water supplies can have their problems, but try the fun thought experiment of being the person to propose laying pipes to every home in a city. Do you think that was an easy sell? Did it look practical? Do you suppose there were some people who said it wouldn't work and would be too expensive?

Do big solutions to big problems ever look practical before they're in place?

But it's also a remarkably efficient system to clean out all at once; I can imagine the majority of the world--which doesn't have the routine of clean municipal or well water--reading this and saying, "So what? Three weeks of bottled water? And the problem would be ....what?"
I'm not saying that three weeks of bottled water isn't a pain in the neck, if you're used to turning on the faucet. But, shucks, most of the world would be thrilled to trade places, and thrilled to be only three weeks away from clean tap water. AnnieRN, apparently feeling rather Pollyanna-ish today...:)

Annie, Mark: If you note at the beginning of the post, I recognize that provision of clean water is perhaps the single most important public health advance of the late nineteenth and early twentieth century. The way the post should be read is that it is so important that more should be invested in maintaining it. It should not be taken for granted, because the very feature that makes it so valuable, the ability to distribute a health giving resource to everyone, is also the one that can make it dangerous, the ability to distribute poisons to everyone. You are on the end of a long lever and you shouldn't screw it up.

Absolutely, and I wasn't trying to be flippant or to minimize the problem. I was a young child in the "PBB zone" in northern Michigan when some yahoo decided that pouring a bag or two of polybrominated fire-retardent into animal feed "won't hurt the damn cows" (exact quote), so I completely understand your point about the long lever and how it can cause problems for an entire population at once. But, my point was that while salmonella is a terrible condition to have introduced into any size population's water system, it is fixable--and relatively easily--and needs to be taken into context for what the rest of the world has to deal with. I remember returning from a third-world country sick for months with dysentery from their water, and have had friends in similar situations. (It was so unremarkable for people in that country, that they expected that when they went out for dinner and drank the water, they knew that they would be sick as a result, but went out for dinner anyway.) My point was only that we are fortunate to have such consistently dependable water supplies--serving approximately 300 million people--that a salmonella outbreak actually makes it into the news when it happens. Nothing more than that, and I didn't mean to minimize your point. AnnieRN