Seems to me installing check vavles at the mains going into buildings and residences would make this type of terrorism more difficult, but it would take years to accomplish.
Also, how would you prevent terrorists from disabling them?
The scariest water terror scenario I've heard so far would be to take a few grams of plutonium and toss it into a reservoir. Easier than making a bomb, and a coordinated attack could poison a large region. Chlorine would be useless.
Just as scary: Lysergic acid diethylamide would render an entire city insane, would take only minute amounts thrown into a reservoir to be effective, and is much easier to acquire than plutonium (can be homemade). Scary, eh?
Backflow valves at every branch in the water mains are going to be needed to localize any problem. Something else to worry about.
In the end, when this and other anti-terror measures are installed, we will have a safer nation---but the cost will be high.
Still, experts have long feared that a terrorist would try an intentional attack. As Gay Porter DeNileon - a journalist who serves on the National Critical Infrastructure Protection Advisory Group, a water-industry organization - put it in the May issue of the journal of the American Water Works Association, "One sociopath who understands hydraulics and has access to a drum of toxic chemicals could inflict serious damage pretty quickly."
Sounds scary.
Calm down, my friend. This article, and your comment are both...well...unfounded in reality.
Plutonium is heavy, and if tossed into a body of water, would sink to the bottom and into the mud, where it would remain forever, doing absolutely nothing to anybody.
Don't believe me? Then try your own experiment. Toss a chemically-similar metal, "a few grams of lead" [a shotgun pellet would do] into a lake, and let me know when folks start showing symptoms of lead poisoning.
Backflow preventers have vacuum breakers - that's the difference from simple check valves.
If you're really worried about this stuff, use bottled water, distill/filter your own, collect rainwater, or better yet, move to the country.
This whole scare is just union propaganda to scare the gullible into clamoring for more union workers to "make their water safe".
Yikes!
What's the difference between a "backflow preventer" and a check valve?
Also, how would you prevent terrorists from disabling them?
See this article. I think it will answers those questions of yours.
D'Angelo refers to the ABPA's policy statement that says that a single check valve will not be construed to be an adequate backflow prevention technique. He asks: "What about two check valves? Detector check and alarm check? Detector check and wafer check? Are two check valves an adequate backflow prevention technique? What is an assembly?" Of course, D'Angelo hits the nail right on the head.
This is the question that has never been answered by any legislator or backflow preventer manufacturer. And the reason for this is that there is nothing to be accomplished by a backflow prevention assembly that is not accomplished just as well with two weighted check valves. Both configurations represent "double-check" backflow protection.
All of the "backflow preventers" I've seen have been vacuum breakers, required to prevent chemicals from being sucked into the supply lines if the water pressure fails, which would create a siphon effect. A vacuum breaker will open up when pressure drops, letting air be sucked into the system instead of chemicals. (You see these things on darkroom sinks, they look like a flat-bell-kinda thing at the top of a pipe.)
A check valve, on the other hand, is a one-way valve, i.e., a spring-loaded ball. Water can go one way because it pushes the ball into the spring, away from the valve seat. It can't go the other way, because it pushes the ball into the valve seat.
"Also, how would you prevent terrorists from disabling them?"
With the former, you don't. With the latter, you bury them outside the building, between the water mains and the distribution pipe to the building.
IMO the article paints an overly optimistic picture of the threat. What? Yeah, overly optimistic.
That stuff about "a sudden drop in water pressure in a targeted neighborhood as terrorists stopped the flow of water into a home or business" is IMO feel-good nonsense. If the bad guys hooked up a high pressure pump to a water faucet, opened the faucet, and started the pump injecting concentrated toxin into the pipes at a low rate of volume, I dunno, off the top of my head, a gallon or two a minute, they'd be able to effect a considerable amount of havoc with zero detectibility. I mean, hell, there'd be less pressure change from that than there'd be from someone turning on (or off) the faucet to wash his hands.
And where they got that stuff about a vacuum cleaner, I have no idea.
The problem, in a nutshell, is that our infrastructure -- from top to bottom -- was not designed for survivability in hell. It was designed to perform OK in a normal country, populated with normal people. You don't put a half-million dollars worth of bomb and radiation hardening around a ramshackle outhouse in the backyard. You put a hook-latch on the wooden door. IOW, you build the "security" measures to be commensurate with the anticipated level of threat.
We're facing the kind of nightmare that can only occur when a free society is attacked by a group of sociopaths. And the solution is to either retrofit an ever-increasing amount of safety measures (i.e., checkvalves on every supply line to every house and business in the country -- and mind you, that will only address the "poison into the pipes" problem, all other weak points will remain unprotected), or, to deal with the perpetrators of the crimes, and deal with them quickly, and mercilessly.
It's either that, or we let them win.
All the more reason to continue to pray that President Bush is a man of his word -- and of quite incredible resolve -- and that as the consequence of that resolve and determination -- and of Our Beloved FRaternal Republic's ability to project our immense power far beyond our borders -- that the manifestation of the forces of evil that we call "terrorism" and that and those who drive it -- will be chased to the edges of Hell and beyond -- and be eliminated from the Earth.
Not a good decade, one must hope and pray, for being an inciter, an enabler, a facilitator or a Hitlerist-Marxist-gangster-bastard member of "fatah" or "islamic jihad," the "plo" -- or the much-vaunted "ira!" Etceteras .....