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Environment
Water Treatment Systems Turn to High-Tech to Harden Security
(enr.com
- 6/18/02)
By Andrew
G. Wright
As the nation's utilities scramble to
complete federally mandated vulnerability assessments to water
and wastewater plants and utilities, system operators are
also eagerly boning up on new high-tech tools designed for
early detection of even minute changes in water quality.
At the American Water Works Association's 121st annual conference
and exhibition, held in New Orleans June 16-20, security-based
sessions drew standing-room-only crowds. Before the opening
session, a day-long workshop on counter-terrorism and security
for water treatment plants was oversubscribed. "They
had 92 registrants and well over 100 showed up. They ran out
of workbooks," said Paul Blair, a Livingston, N.J.-based
engineer with AECOM's Metcalf & Eddy subsidiary.
The next day, water professionals packed another session
on technological advances in drinking water technology to
hear about how U.S. water providers are strengthening security
and about the tools they are using. Immediately after last
Sept. 11's attacks, the Metropolitan Water District of Southern
California earmarked $5.5 million for heightened security,
said Yong H. Kim, an engineer with Palm Desert, Calif.-based
USFilter. "Two-thirds of it is for physical security
improvements, but $1.2 million is for improved analysis and
monitoring," he said.
Early and accurate detection of contaminants in water is
essential, Kim said, especially at three key points of vulnerability
identified by the U.S. Environmental Protection Agency: raw
water intakes, finished water reservoirs and within the distribution
network. While there is no single tool to measure all pollution,
"the more parameters [that are] monitored, the better
chance we have to detect problems," Kim said. Online
monitors can now measure minute changes in pH, conductivity,
dissolved oxygen and other upset conditions–early indicators
that something is wrong with the water supply.
New analytical tools are changing the standard monitoring
practices, Kim said. A potentiostatic measurement device uses
three electrodes to measure chlorine residuals, eliminating
chemical reagents. And particle counters are more sensitive
water quality indicators than turbidity monitors.
The Central Utah Water Conservancy District was working
on water security before 9-11, for the 2002 Winter Olympics.
"Over half the state gets water through our system, said
Gerard Yates, treatment operations manager. Rainfall averages
only 13 in. a year in rainfall, so the water wholesaler collects
water from snowpack in a series of Wasatch Mountain lakes,
then transports it through a stream, river and pipe network
to an 80-million-gal-per-day treatment plant.
After a tractor trailer transporting liquid ammonium nitrate
fell into the river upstream from the plant in 1992, the district
began developing an online early warning system. "We
used an AWWA Research Foundation grant to look worldwide for
the most cost-effective, best available technologies,"
said Yates. The district added monitors at the plant and upstream
to measure temperature, pH and total dissolved solids every
30 minutes.
A German-made toximeter monitors raw water by measuring
its effect on daphinae–a microscopic water flea. If the
fleas die, or even swim in an unusual manner, the device triggers
an alarm to alert the plant operator that something has changed
within the raw water supply. "We learned a lot about
daphinae," said Yates. "We change them every week.
They're very sensitive. Chlorine kills them." The toximeter
cost $43,000, he said. Another tool, an oil and grease spill
monitor, shines a laser on the water surface to detect changes
in reflectance.
The utility also installed security cameras and worked closely
with local law enforcement and regulatory agencies to develop
a spill response plan.
Vendors expect established technology-based tools, such
as surveillance cameras and geographic information systems,
to become commonplace in water treatment systems as they add
features and drop in price. And no matter what tools or security
measures are put in place, there is no substitute for common
sense. Disgruntled employees are a far bigger threat than
terrorists, says Ron Booth, a security consultant in the Atlanta
office of CH2M Hill Cos. "The best way to avoid problems
there is simple–treat your people well," he said.
David W. Coppes, a water supply group operations manager
with the Massachusetts Water Resources Authority. "You
have to balance security improvements with operator inconvenience.
If the operator is going to prop the door open, because you've
designed a system that causes him to do that, you haven't
really made the place more secure."
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