Underground Construction - April 2018 - 32

Study Warns Pipe Failures are
Cause for Concern

Break Rates for Almost 1/2 U.S. Water Mains Up More Than 40% in 6 Years

APRIL 2018 | UConOnline.com

service life assumptions
BREAK RATES OF EACH PIPE MATERIAL FROM THE BASIC SURVEY
used in the past.
35
Water main break rates
are an important calculation to assess pipe perfor30
mance and durability, and
are the most critical metric
25
used in water infrastructure asset management,
as well as pipe repair and
20
replacement decision-making. "This report provides
greater insight into the
15
drivers of the aging water
infrastructure crisis, and
10
offers data which utilities
can use to benchmark pipe
material performance. It
5
will be a valuable asset
management planning tool
for water utilities," said
Folkman.
Overall, break rates
AC
CI
CSC
DI
PVC
Steel
Other
have increased 27 percent
in the past six years. Utilpipes. Utilities across the country rehabilitation requirements,"
ities should be concerned that
Folkman added. "Larger municwould need to rapidly accelerate
break rates for cast iron (CI) and
ipal utilities, however, are not
their
pipe
replacement
schedasbestos cement (AC) pipes, tofaring much better, since the rate
ules to avoid potentially serious
gether representing almost half
at which they are replacing the
economic and social impacts. If
of the installed water mains in
pipes that are now beyond their
a break rate doubles, one would
North America, have increased
useful lives is inadequate."
need to double the number of
46 and 43 percent, respectively,
According to the survey, an avpersonnel repairing failures,
since 2012, making them prierage of 0.8 percent of installed
along with supplies and materimarily responsible for the spike
pipe is replaced each year across
als, while loss of treated water
in total pipe failures. These types
increases. Societal impacts would the country. This equates to a
of pipes are no longer manufac125-year national pipe replacebe devastating if the break rates
tured and are now reaching the
ment schedule. Pipe replacement
reached exponential levels," said
end of their expected lives.
rates should be between 1 and
Folkman.
1.6 percent, equivalent to 100A critical new finding is that
Increased failure
year and 60-year replacement
smaller municipal utilities have
The study also discusses how
twice the water main break rates schedules, respectively, Folkman
water main failure rates for CI
pointed out.
as larger utilities. "With less
and AC pipes could increase
A reconfirmed major finding
revenues and resources, smallexponentially over time. "One
is that polyvinyl chloride (PVC)
er municipalities will need to
could envision a rapid increase in use the most cost-effective and
pipe has the lowest overall break
rate when compared to cast iron,
break rates in the near future for durable pipe materials available
ductile iron, concrete, steel and
to address pipe renewal and
cast iron and asbestos cement

Break Rate (break/(100 mi-year))

Utah State University's (USU)
Buried Structures Laboratory
has published a second, comprehensive study on break rates of
the most commonly used water
pipe materials titled, Water Main
Break Rates In the USA and Canada: A Comprehensive Study. The
Buried Structures Laboratory has
a large-scale testing facility for
pipes and underground structures. USU is also home to the
Utah Water Research Laboratory
(UWRL), which has been a world
leader in environmental research
and water policy for over 50
years. UWRL is the oldest university-based water research facility
in the U.S.
Dr. Steven Folkman, co-author of Buried Pipe Design and
author of a 2012 USU water
main break report, has completed a new pipe materials survey in
which over 300 utilities responded, representing approximately
200,000 miles of installed water
mains. The 2018 respondents
came from 48 states in the U.S.
and seven out of 10 provinces in
Canada - a 49 percent increase in
survey responses and 45 percent
more miles of pipe compared to
the 2012 study, increasing its
statistical validity. Utilities that
provided data serve a population
of over 52 million people, or 14.5
percent of the total population of
the U.S. and Canada.
The survey recorded 23,803
pipe failures that needed repairs,
which is a significant basis for
break data. This is one of the
largest surveys conducted on water main breaks and the results
give an accurate representation
of water pipe condition and operation in North America. The
report can assist in revising pipe

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Underground Construction - April 2018

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