An interesting insight into some of these
differences is the approach to fire hydrant
management taken in different countries.
For example, one U.K. utility is currently
working to reduce the number of fire
hydrants in its network (in conjunction with
rehabilitation of water mains), which is
possible due to changes in technology used
by fire fighters. A risk-based approach to
assessing hydrant location is being applied
to aid this process. This contrasts strongly
with case studies in the United States where
the approach to hydrant provision and
management is driven by issues relating to
fire insurance premiums.
Depending on predominant issues and
drivers, condition assessment practices
also vary widely between different
utilities. Even for the same asset class,
practices ranged from “do nothing” to “do
everything on a planned cycle.” A key factor
in determining the strategy adopted is
resourcing. For example, one utility in the
United States has dedicated crews for each
type of appurtenance, which “ring fences”
resources to ensure maintenance tasks
are undertaken. In contrast, a case study
partner in Australia noted that maintenance
is undertaken by non-dedicated crews,
so tasks like valve exercising are often
deprioritized in the face of other demands.
At the extreme, one U.K. case study partner
had undertaken no formal inspection for
more than a decade even though it was
known there were a range of issues with
non-functioning isolation valves.
Similar problems had been noted by one
of the U.S. case study partners. In response,
the utility has implemented a phased
management approach intended to address
the backlog in valve condition assessment
and maintenance. In the first phase, the
utility focused on assessing isolation valves
with the highest consequence of failure. The
initial effort, which began in 2005, focused
on large valves (> 12 inches). By 2010, most
of the utility’s 2,000 large valves had been
assessed and inoperable valves restored.
The second phase is to focus on valves
of any size associated with critical pipes
(i.e., pipes with a potentially high failure
consequence). The condition of these
valves will again be assessed and efforts will
be made to improve their reliability.
Deb, A. K., J.K. Snyder, J.O. Hammell, Jr., and S.B. McCammon. 2006. Criteria for Valve Location and System
Reliability, order #91136/project #2869. Denver, CO: Awwa Research Foundation (AwwaRF).
USEPA (U.S. Environmental Protection Agency). 2005. Drinking Water Infrastructure Needs Survey and Assessment:
Third Report to Congress. EPA 816-R-05-001. Washington, DC: Office of Water, Office of Ground Water and Drinking
Water, Drinking Water Protection Division. http://water.epa.gov/infrastructure/drinkingwater/dwns/needssurvey.cfm.
USEPA (U.S. Environmental Protection Agency). 2007. Distribution System Inventory, Integrity and Water Quality.
Washington, DC: American Water Works Association, Office of Water, Office of Ground Water and Drinking Water,
Total Coliform Rule Issue Paper. http://www.epa.gov/ogwdw/disinfection/tcr/pdfs/issuepaper_tcr_ds-inventory.pdf.
MacLean, R. and K. Keane. 2007. “Distribution System Valve Management: Leveraging Technology & Equipment to
Deliver Results.” Presented at the American Water Works Association’s Annual Conference & Exposition (ACE) Toronto,
Ontario, Canada, June 26, 2007.
Schumi, P. 2009. “Criticality of Valve Operability.” Presented at the MI-AWWA/MWEA Joint Conference. Lansing, MI,