A Texas-sized drought compounds problems in Austin.
January’s 24-inch water main break
in downtown Austin, TX, drew attention to the problem of water loss, symbolizing
issues of aging infrastructure and the urgency of minimizing water loss through
audits, leak detection, infrastructure improvements, and conservation. Although
a substantial amount of water escaped during the lengthy repair, Greg Meszaros,
director of the Austin Water Utility, dubbed it a “run-of-the-mill break that
closed a busy intersection.” He blames an aging distribution system that
consists predominantly of brittle, small-diameter metal pipes adversely affected
by drought and temperature swings, ultimately resulting in leaks, lost water,
and disruptions.
An Austin newspaper reported that
during the most recent fiscal year, the utility repaired 3,927 leaks—an average
of more than 10 per day, with an estimated loss in the billions of gallons each
year. During the 2004–2005 reporting period—the most recent data
available—estimates of water lost through water main breaks and leaks range from
4.5 billion gallons to nearly 7 billion gallons, at a cost of $9 million.
Exact numbers are tricky to
calculate, but Austin’s water loss during that period averaged 14%. The Statesman reported that Houston, TX’s
water utility loses 13% annually, the San Antonio, TX, Water System suffered an
8.2% loss in 2007, and El Paso, TX recorded a 9% loss. Texas is by no means
unusual. The nationwide average is 15%, as indicated by the American Water Works
Association’s (AWWA) report “Plain Talk About Drinking Water: Questions and
Answers About the Water You Drink.”
While a Texas-sized drought
compounds problems in Austin, experts predict more incidents due to aging
infrastructure struggling to meet the demands of expanding cities
nationwide.
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Photo courtesy of San Antonio Water System
San Antonio Water System leak detection specialist Rick Vasquez uses a precision listening device to detect the sound of leaking water. |
Austin Meets Its Waterloo
Experts also concur that Texas
weather has played a significant role in the profusion of water main breaks.
Karen Guz, director of conservation at San Antonio Water System, says Austin and
San Antonio experienced a “perfect storm” in 2007 that led to an increase in the
number of pipe breaks. “We have an elastic soil that responds to changes in
moisture,” she explains. “There are a variety of rock areas, dominated by deep,
heavy clay and some sand, but clay is the main culprit. It absorbs an enormous
amount of water, but contracts when dry.”
After a wetter-than-normal year
with a 5% saturation rate and what Guz describes as “Biblical” rains for 40 days
in the summer of 2007, Texas experienced a 5% drought. The “push-pull” on the
soil makes more breaks likely.
Mark Mathis, water loss specialist
with the Texas Water Development Board (TWDB), explains the effect of drought on
water pipes. “If a pipe isn’t bedded properly, the soil dries and heaves up,” he
says. “The pipe is no longer flat, and can break at the seam or joint—or, the
joint could be stronger than the pipe, forcing a break along the line.”
It depends, in part, on the
material of the pipe. Older pipes are typically metal; new ones are usually PVC,
which not only bends with the earth, but is also faster and easier to
install.
Because 2008 was also a dry year,
Guz anticipates more pipe breaks in 2009. “The soils are incredibly dry and the
ground has shifted; plus, there’s higher demand for water, so you’re forcing
water through the system, putting more pressure on pipes,” she says. “That’s why
we expect a higher number of breaks. I’m curious to see if the ground stabilizes
in a long drought.”
Austin—the state’s capital
originally named Waterloo when it was founded in the 1830s—is located in central
Texas at the intersection of four ecological regions. Situated on the banks of
the Colorado River containing three man-made lakes within the city limits, it
may at first seem ironic that Austin is experiencing a drought. However,
although considered a temperate-to-hot green oasis with moist tropical traits,
it also exhibits some characteristics of a desert climate.
The region’s soils range from
shallow gravelly clay loam over limestone on the western side to deep, fine
sandy loam, silty clay loam, silty clay, and clay on the east. Some of the clays
have pronounced shrink-swell properties that lend themselves to conditions
conducive to pipe breaking. The limestone hills west of the city are covered
lightly with topsoil and during storms, subject Austin to flash floods from
runoff, which is somewhat mitigated by a series of dams that form the Texas
Highland Lakes.
With a population just under
750,000, Austin is the nation’s third-fastest growing city. Because of that
rapid growth, “there’s a lot of added demand on the infrastructure,”
acknowledges Meszaros. “We can’t meet the demand.”
Liquidity
If so much water wasn’t lost,
demands might be easier to meet. Texas water utilities serving 84% of the
state’s population reported in 2007 that enough water is lost annually to meet
the demands of 1.3 million citizens (According to the state Water Development
Board 2007 report, titled “An Analysis of Water Loss as Reported by Public Water
Suppliers in Texas”). In 12 months, from 2004 to 2005, the city of Austin “lost”
enough water to meet the annual needs of 118,000 Austinites. The utility
reportedly pumped 48 billion gallons of water, but dispensed only 41 billion
gallons. What happened to the other 7 billion gallons?
Water may disappear, but demand
doesn’t. “We have the same amount of water since Adam and Eve, but now six
billion people want it,” expresses Mathis.
Between 70–75% of the earth’s
surface is covered by water—the same water that was created shortly after the
earth formed, roughly 4.54 billion years ago. Supporting increasing populations
with the same amount of water is the challenge facing utility companies.
“Water loss is a problem that
we’re becoming more aware of due to the cost and availability of water,” notes
Mathis. The cost of 2007’s statewide water loss is estimated between $152
million and $513 million, an admittedly large span.
But leaks aren’t the only cause of
loss. Theft, faulty meters, and other uses account for considerable amounts of
so-called lost water. The Austin Water Utility suspects 142 million gallons were
stolen through meter tampering or unauthorized use of fire hydrants.
Legitimate use of hydrants is
another source of unaccounted water usage. Water used to fight fires or clean
streets is rarely calculated. Nor is the water wasted during main flushing,
which is a task being performed more frequently in some areas, says Dana
Nichols, manager of outdoor water conservation program for the San Antonio Water
System (SAWS). “Cul-de-sacs and dead ends mean a dead-end main, which needs
flushing more often for health reasons,” she says.
“Loss is costly, but loss through
mainline breaks is not as bad as through meters,” reflects Mathis.”
With the exception of line breaks
and leaks, the biggest source of water loss is due to faulty meters. Because of
faulty meters and metering errors, Austin water customers were not billed for
2.1 billion gallons used during the 2004–2005 reporting period.
A meter is a mechanical device
that is affected by age and water chemistry. An old or an improperly sized meter
reads wrong. “Meter application is a science,” believes Mathis. “If it’s too big
for the application, it doesn’t read all the water received. If it’s old, it’s
slowing down and isn’t recording all the water received. If water is at the
customer’s house but the meter isn’t accurate, that means free water. But there
are marginal production costs for the utility to buy, secure, acquire, treat
with chemicals, and get water to the customer. Every unrecorded gallon
represents a loss to the utility.”
Meszaros says he’s “comfortable”
with Austin’s large retail meters, but the utility is conducting a study on the
accuracy of residential meters. Nichols recommends testing meters based on
“mileage” around 15 years or earlier if there’s heavy usage. She says SAWS knows
many of San Antonio’s meters are outdated. To combat the problem, they initiated
a change-out program.
In addition, Guz says they’re
considering “the next step: automatic meter reading.” Traditionally, meters are
read on a monthly basis, but with an automatic meter, readings could be taken
remotely as frequently as 3–4 times a day. “It provides better accuracy,” and
alerts the utility and the customer to changes in consumption, she says. “It’s
probably the way we’ll go; most utilities are going to them.” Her hesitation
stems from the logistics of changing 300,000 meters and the sheer cost to put in
the network of software and replace meters. “We’re analyzing
the ROI.”
Staunching the Flow
Although costly, identifying worn
out meters is easier than finding leaky underground water pipes. “It’s hard to
find leaks underground,” confirms Mathis.
Typically, they’re discovered
through loss of water pressure, questionable meter readings, or customer
reports. SAWS maintains a 24-hour report system for reporting potential leaks,
as well as waste.
When a leak is suspected,
acoustical detectors are often used to locate the source. “Basically, we walk
above and listen for the leak,” describes Mathis.
Equipment can help in hearing
water going through pipes—particularly metal pipes. Guz says when they hear an
apparent leak they conduct a survey, sending out special trucks with an
experienced leak detection team using listening equipment. “The leak could be
far away from where it’s coming through the ground, so we walk the area to
locate it and decide where to dig,” she explains. “It’s complex and can be an
extensive process. It requires constant effort to pinpoint the source.”
In older, densely populated parts
of San Antonio, cast iron pipes are common. Mathis says it’s easier to hear
leaks in metal pipes when using acoustic equipment, but Nichols cautions that
it’s never an easy job because many are service line leaks that occur in little
lines between the main and customer.
Mathis mentions correlators that
use information to narrow the source between two points, and devices that mount
on the flush valve or inside on the main line to record data and determine how
far the leak is from the device, sending signals to a radio tower. “It’s like a
ball on a tether for a big main,” describes Nichols. “It picks up rumblings.”
SAWS doesn’t use it, but Nichols
says they’re looking at a new version with a butterfly valve for a 60-inch
diameter line. Mathis says Fort Worth, TX has a lot of them, “but they’re
pricey.”
Meszaros isn’t a big proponent of
sound equipment, observing that it “hasn’t produced unknown leaks.” His
preferred method of detection is “eyeballs.” The Austin Water Utility hired a
company to go through one-fourth–one-third of the system, checking valves and
hydrants for leaks escaping through underground pipe that aren’t coming to the
surface.
When chasing a known leak, Guz
says utilities must choose their top priorities. The Austin utility classifies
water main breaks and leaks in three categories: Category one gets immediate
attention, because of the threat of property damage or the risk to public health
and safety; category two should be fixed within 48 hours, because it could
become critical; and category three is a leak that needs to be repaired, but
isn’t urgent. Wait time on repair of category three leaks averages three to
seven days, depending on the availability of crews. Austin Water Utilities
claims that 98% of leaky pipes are repaired within seven days.
Once a leak is discovered, Guz
says the real challenge is how a response is managed. Like Austin, SAWS has
infrastructure teams look at patterns to determine priorities. It’s not based on
just age first, she indicates; it depends on the type of pipe and the type of
soil.
Nichols refers to long discussions
on types of pipe. “There are studies on foundries [that made] older cast pipes:
pre-1921 are fine,” she says. Generally, new pipe of PVC and AC also protects
against leaks, but if there are any, they’re harder to find because using sound
detection methods isn’t as effective
on them.
Because leaks are costly, utility
companies try to get to them as quickly as possible. There’s no exact science
able to determine exactly how much water is coming out of a leak or how long the
leak has existed, but Mathis uses four pieces of information: size, thickness
and depth of the pipe, and velocity of the water. The Austin Water Utility
estimates the volume of water loss similarly, measuring the size of the hole,
the size of the line, the average operation pressure of the line, and the
estimated duration of the leak. “There are calculations for the length of break,
but time is difficult to determine,” says Mathis. “We also consider when there’s
a drop in pressure and if the pumps come on more frequently.”
Legislating Leakage
While many water utilities are
buying leak detection equipment and monitoring illegal usage of hydrants and
meters in order to reduce water loss, a state law passed in 2003 is designed to
help them determine exactly where they should focus their efforts. The law
requires utilities to submit a water loss audit every five years to account for
where the water is going.
Because the law is so new, most
utilities don’t yet have multiple audits for comparison, so judging the
effectiveness of the law’s intention is difficult. However, Mathis, who often
serves as a consultant to utility companies, thinks the law will lead to a
decline in water loss, although he says ongoing monitoring is costly.
Nevertheless, “more utilities are adding technology,” such as supervisory
control and data acquisition, which can run a system and send an alert when a
problem arises—in effect, monitoring itself.
Pinpointing the source(s) of loss
is an important first step; so most utilities have embraced the new audit law.
“Finance departments in utilities across the US see the light,” says Mathis.
“They used to look at raising rates to cover costs, but if you minimize loss, it
saves money and keeps rates stable.”
Watching the bottom dollar is as
critical for public utilities as it is for the public. Meszaros carefully weighs
the expense of leak detection versus the cost of loss. “There is a point of
diminishing return,” he realizes. “You don’t want to chase water loss if it’s
not worth it.”
The importance of the audit law is
that, as Meszaros says, it “encourages us to know where the water is going. It’s
too early to say loss is reduced, but we have a better sense of where loss and
opportunities are.” He says Austin has taken the law a step further, with the
goal of yearly calculation to improve data.
The downside, Meszaros continues,
is that economics affects what they can do. “Water is a capital-intensive
utility.”
The Austin Water Utility produces
60 billion gallons of water a year—water that passes through 3,000 miles of
water main. Knowing that infrastructure needs upkeep, he calculates that if the
pipes last 100 years, under a typical maintenance program, the utility would
replace 1% per year (30 miles) at a cost of $200 per foot. As Meszaros
concludes, “The numbers get big pretty rapidly.”
Mathis explains that the TWDB
serves as a funding agent for utilities, its mission to distribute loans to
utilities and projects such as leak detection, infrastructure replacement, and
such. “We evaluate audits and management plans,” he says.
Currently, they employ best
management practice, which he considers better than the percentage method,
because it shows where the loss occurs. “The percentage method just shows the
amount of loss, not the location,” he adds. That’s why he believes real loss is
underestimated. “There are main line and service line breaks, storage tank
overflows … It’s difficult to determine the duration of small breaks.”
“The water law has a format
regulated by Texas and a report based on new methodology,” states Nichols. “It’s
standardized to compare systems worldwide and try to put a dollar value on water
loss, but it’s misleading to talk about water loss percentage without knowing
what was charged and what was delivered. You have to include flushing mains and
hydrants, fighting fires, et cetera. Our per capita is calculated differently.
We take the total amount of water pumped divided by the total number of people
served; that includes lost water, not just billed water.”
The audit law isn’t the only
attempt to legislate better water management. In 2007, the US Senate unanimously
passed the National Infrastructure Improvement Act to address the country’s
deteriorating infrastructure, including drinking water systems. The bipartisan
bill created the National Commission on Infrastructure to produce a federal plan
detailing priorities, along with recommendations for legislation deemed
necessary for the next five, 15, 30, and 50 years.
More recently, the AWWA lobbied to
include drinking water infrastructure in the recent economic stimulus
legislation. Although the association’s Government Affairs Office estimated that
nationwide projects totaling $10 billion were awaiting funding, the Recovery Act
signed by President Obama included only $4 billion for water quality and
wastewater infrastructure improvement and $2 billion for drinking water
infrastructure needs.
Water infrastructure stimulus
funds will be distributed via the state revolving loan fund (SRF) program,
divided between all 50 states according to the existing SRF allocation formula.
At least 20% of the funds are earmarked for “projects that address green
infrastructure, water or water efficiency improvements, or other environmentally
innovative activities.”
Legislation has been an uphill
battle because, as research indicates, the biggest hindrance to action on
infrastructure issues is the old “out of sight, out of mind” attitude. Awareness
is necessary to motivate change and action. Crises, ranging from levee failures
in New Orleans to the I-35W bridge collapse in Minneapolis, MN, to smaller
incidents like the main break in downtown Austin, are often the only way to draw
attention to the need for repair and improvement of aging infrastructure and
waterway systems.
Reducing Loss by Reducing
Us
Awareness has led many utilities
to plans of action that address aging infrastructure and bad habits. Austin is
focused on more infrastructure replacement, using plastic pipes because they are
more flexible and less likely to leak than cast iron. In some cases, pipes are
being upsized from a 4- to a 9-inch main. “The service is better,” insists
Meszaros. “The quality is better. We currently have a lot of 4-inch cast iron
mains in service that create a lot of problems hydraulic-wise.”
Another water-saving measure
Meszaros implemented is mandatory conservation. With more awareness, however,
comes more expectation. If a utility is asking customers to conserve, it’s
imperative to lead the way. “Our conservation campaign is very effective, but
the citizens expect the same from the utility,” he acknowledges.
Illustrating the point that it
“takes a lot of power to move water,” he admits that the water utility uses half
the city’s electricity. “Water and energy are deeply connected.” But money is
only one aspect.
“We want to reduce our carbon
footprint; it’s all about climate protection,” claims Meszaros. “The most
important step is to reduce water usage.”
With that goal in mind, the
utility is using reclaimed water—treated wastewater—where it can: for irrigation
on golf courses, and such. There’s also a commitment to help customers lessen
the impact of their carbon footprint by way of reduced water usage. In addition
to a toilet exchange program, the utility will inspect irrigation systems for
free. “It helps customers save money and helps reduce water usage,” he adds.
Higher rates can be a good thing,
however, because that
encourages conservation. “Treatment costs went up
dramatically because of fuel costs last summer,” says Mathis. “They’re as much
as three to four times higher than the previous year.” Whether from an
ecological or economic point of view, it pays to conserve resources.
San Antonio’s water resources
issues came to a head in the ‘90s, Guz recalls, when a lawsuit initiated by the
Sierra Club over a shared aquifer and endangered resources let to a highly
regulated environment. “Our city leaders decided conservation was the answer,”
she says. SAWS’ goal is to save 1 billion gallons through reduction, retention,
and conservation.
Nichols believes SAWS’ proactive
education program is working. “The community embraces it—even if there’s no
direct financial impact,” she says.
SAWS looks at water as a resource
to be protected by implementation of a daily program. “Everyone can
participate,” adds Nichols. “Everyone can buy in to conservation.”
They are. The 150 reports of waste
per week demonstrate that San Antonio citizens will not tolerate wastefulness.
Because they’re accustomed to conservation measures, they don’t balk during
droughts when mandatory restrictions are put into place.
Guz says, “The city council can
trigger drought restrictions sooner because we’re not suddenly resorting to
crisis management mode. People understand.” But, she admits that they might not
be as understanding if SAWS failed to pursue non-revenue loss or conserve water.
The Riverwalk, for example, uses
recycled water to augment its spring-fed source, and teams follow up on reports.
“It maintains community support,” says Nichols.
Preserving support is important.
She reports that Austin is number one and San Antonio is number two in the
housing market, explaining it by saying, “conservation enhances our image. We
have increased the number of customers 50%, but we’re using the same amount of
water.”
Meszaros believes Austin is making
progress in its battle against aging lines, inaccurate meters, theft, and waste.
“Our water loss rate is pretty good,” he says. “As a rule of thumb, if you’re
under 10% loss, that’s pretty good. We’re in the 8–12% range.”
Still,
he says, they’ll continue to work on improving infrastructure, metering, and
water usage.