Fall 2023 - Flipbook - Page 6
Aging Water Infrastructure & Effects on Water Quality
Lauren Redfern, Florida Gulf Coast University
Phong Tran, California State Polytechnic University, Pomona
During the early twentieth century, the appearances
of new towns and cities across the nation grew as the
population of the United States began to expand.
City planners designed the urban infrastructure for
these booming cities to ensure that the residences
had access to clean water and sewage disposal. To
this day, the majority of those systems built almost a
century ago are still in use. Unfortunately, the water
and sewer mains that were used as the initial infrastructure for towns that have evolved into urbanized
cities have reached their life expectancies and,
in some cases, their capacities. As a result, aging
subsurface infrastructure has become a dilemma
amongst cities throughout the nation, where the
aging systems may have negative effects on
distribution performance and on the environment. In
the latest American Society of Civil Engineers (ASCE)
Infrastructure Report Card (2017), the grade given Figure 1: Construction crew work to repair a broken water main in
for America’s drinking water infrastructure was D.
New York City. Source: Metropolitan Transportation Authority of
The American Water Works Association (AWWA)
the State of New York
states that the current industry is entering a new
era called the Replacement Era, which involves rebuilding the nation’s aging water systems (AWWA, 2012). These
increasingly deteriorating water systems have resulted in costly negative effects on water quality and human health,
making rehabilitation crucial.
Densely populated cities such as Los Angeles, California, have active water mains that were built as early as 1900.
Similarly, in New York City, over 1,000 miles of pipeline are over 100 years old (NYC Emergency Management).
These urbanized cities still utilize pipelines that were designed during times when the cities were smaller and had
much lower infrastructure demands. In addition to potential capacity issues, pipe materials such as cast iron, lead,
and asbestos cement were widely used for water mains as they were considered stable and available. Over time,
these materials are known to deteriorate (e.g., corrosion), permit entry of microbial contaminants through cracks and
holes, and/or release toxic chemicals. Today, most of those materials are considered obsolete and/or are banned
based on current standards and regulations, including heath regulations such as those associated with lead and
asbestos. Municipalities and water purveyors prefer water main materials to be either ductile iron or polyvinyl
chloride due to durability and anti-corrosive characteristics. Currently, there is a large amount of existing pipeline
that needs to be upgraded due to its material and age. Miles of these pipelines are still active, and many have
reached or are reaching the end of useful life; Many water agencies have taken proactive steps to avoid failures
within their systems. For instance, between 2012 and 2018, the rate of water main breaks in old pipes within the
United States and Canada increased by 27 percent. The majority of these pipelines were made of old materials
(e.g., cast iron, lead, etc) (Folkman, 2018).
One crucial point of concern with aging pipelines is the effect on water quality. Leaks and breaks within these mains
are common due to pipe deterioration. Environmental factors such as soil characteristics, water properties, and stray
electric currents from underground electrical cables can also play a role in pipe deterioration. For example, cast iron
www.asce.org/ewri • EWRI Currents • Volume 21, Number 4 • Fall 2019
