November 15, 2001

A cap over troubled waters

  • Local utilities are protecting water supplies by covering open reservoirs and reverting to storage tanks.
    Special to the Journal

    The need to protect water supplies from potential terrorist attacks has uncorked a flood of conversation between engineers and utilities since the events that began Sept. 11.

    "We didn’t discover security last month. As we prepared for the year 2000 ... a lot of steps were taken."

    --Sue Veseth,

    Tacoma Public Utilities

    “I’ve seen an awful lot of e-mail traffic from all sorts of folks,” says Bill Persich, an engineer at Brown & Caldwell. “It’s a hot topic.”

    What’s strange, says Persich, is that everybody’s talking, but nobody’s saying much, especially the utilities. “Clients are ... not going into detail. They’re keeping tight-lipped about everything.”

    Of course, there’s an obvious reason for all the secrecy. Effective security requires keeping the bad guys in the dark.

    “For the protection of our customers, we are not getting into explanations of what we’re doing at each facility,” says Sheila Strehle, spokesperson for Seattle Public Utilities.

    Even so, that’s not the only reason details are scarce. Given its complexity, the issue defies fast — as well as affordable — fixes. While utilities have been quick to heighten surveillance and tighten access at their facilities, they continue to identify their vulnerabilities and weigh what long-term improvements to their systems may be needed.

    “I would suspect it’s going to be an ongoing evaluation,” says Sue Veseth, spokesperson for Tacoma Public Utilities. “I’m not sure we understand the full range of alternatives yet. Before you invest a lot of your customers’ money in capital projects, you want to make sure you’re making the best use of those dollars.”

    Besides, says Veseth, “We didn’t discover security last month. As we prepared for the year 2000 ... a lot of steps were taken.”

    Not overreacting

    Michael Rosenberger, a business development and planning manager for CH2M Hill, says utilities are taking the terrorism threat seriously while at the same time avoiding any overreaction.

    “One of the things they are grappling with is to find the balance between prevention and their ability to respond if something occurs,” says Rosenberger, who specializes in Northwest water projects. “They feel that they are in pretty good shape on the prevention side and pretty good shape on the response side. The question is if there’s enough reason to (go) further.”

    So far, says Persich, utilities appear to be taking security concerns “into their own hands.” He says he’s not aware of any major capital projects in the works solely as a result of the terrorist attacks.

    Of course, that could change as utilities assess where they are most vulnerable and how they can reduce that vulnerability. From physical security to treatment methods to emergency responses, “you’ve got to look at everything,” Persich notes.

    Perhaps the most visible target for sabotage are open reservoirs. Once preferred because it was thought that ultraviolet light improved water quality, open reservoirs already had fallen from favor before Sept. 11 because they are vulnerable to dust, bird droppings and acts of vandalism.

    Today, the fear of terrorism has added another strike against them.

    Tacoma has been gradually replacing its open reservoirs with steel tanks.

    Only two reservoirs remain and one of those is scheduled for replacement this spring. Now, the utility is looking at whether to replace the final tank sooner rather than later, says Veseth.

    Seattle is addressing the problem a different way, choosing to cover or bury all nine of its open reservoirs. The seven reservoirs ticketed for covers will be capped by a sturdy, flexible material that floats secured on the surface of the water. The two buried reservoirs will be protected by concrete lids.

    In the long run, the city hopes to bury all of its reservoirs, but the price tag — 10 times the cost of covering a reservoir — makes that a more distant goal.

    Although the first of Seattle’s nine reservoir projects is expected to be complete by the end of the year, the last is not scheduled to be finished until 2020. But that may change, says Strehle, as the city council is considering accelerating the schedule.

    Protecting watersheds

    As prudent as capping reservoirs might be, the same solution is impossible to apply to watersheds. And while the huge lakes where much of the region’s water supply originates are guarded, the fact is “watersheds are generally accessible to one degree or another,” notes Rosenberger.

    That’s the bad news. The good news is that you’d need truckloads of most biological contaminants to poison a watershed, says Frank Loge, an assistant professor at Washington State University.

    For one thing, the contaminants would have to overcome the dilution factor, explains Loge, whose research focuses on pathogens in the water supply. For another, they would have to survive treatment processes mandated by the federal Safe Drinking Water Act.

    Given the fact that those two barriers have by and large kept the nation’s drinking water safe from natural biological contaminants, they also ought to offer protection from bioterrorism, says Loge, noting terrorists are unlikely to use chemical contaminants because their effects require long-term exposure.

    The trouble is, utilities can bypass some treatment requirements if they can prove certain natural biological contaminants are not a threat, says Loge.

    What’s more, no one knows for sure whether the treatment requirements are actually removing any biological contaminants or whether the contaminants simply don’t exist in sufficient numbers to test the system, he says.

    Loge says the government ought to fund studies to address the question with additional emphasis on potential bioterrorism. “Once we had that study, we could look at some sort of standardized treatment systems” he says.

    Seattle always has disinfected its water, but the utility is in the process of adding a pair of treatment plants to meet or exceed current and expected new federal water standards, says Strehle. A plant in the Tolt River watershed began operations last December while design on a Cedar River facility is currently underway.

    Strehle wouldn’t say what — if any — specific changes in design and operation of those plants or other facilities have been or will be made as a result of the threat of terrorism. “You can safely say at all of our facilities ... security is one of our number one concerns,” she says.

    “Will there be additional improvements as needs are identified? Yes. Will that include additional expense, capital or otherwise? Yes.”

    Indeed, adding further safeguards to the nation’s water supply won’t be cheap and utilities will have to make intelligent choices about the priority of various projects, says Rosenberger. “They don’t have unlimited resources,” he notes.

    With that in mind, says Rosenberger, the Association of Metropolitan Water Agencies already is lobbying Congress for funds to support research and development related to water system security.

    This comes at the same time much of the infrastructure supporting the nation’s water supply is aging and in need of repair, notes Rosenberger.

    “There probably will be a need for federal money,” he says.

    Brad Broberg is a Seattle-area freelance writer for the Daily Journal of Commerce.

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