Purdue University assistant professor Andrew Whelton is leading a project to help address potential health hazards posed by low-flow building water systems, which may cause an increase in disease-causing organisms and harmful chemicals. (Purdue University image/Erin Easterling)
Do you know what’s in your water? How certain are you that it’s safe?
In mid-December 2017, researchers from across the United States specializing in various disciplines came together at the annual meeting of the Society for Risk Analysis to present reports on a range of problems in American water infrastructure. This plumbing safety research illuminates a disturbing litany of failures in water safety all over the country—but also highlights a commitment to fixing problems and taking a proactive approach to keeping water infrastructure safer.
In 2001, the American Water Works Association (AWWA) released a report entitled, “Dawn of the Replacement Era: Reinvesting in Drinking Water Infrastructure.” This report described the unprecedented needs to rebuild and replace water infrastructure across the US faced, even back then. Since that time, additional reports from AWWA, the Infrastructure Report Card from the American Society of Civil Engineers (ASCE), reports and presentations from Purdue University’s Center for Plumbing Safety, and various other authorities have taken up the same message: there is an urgent need to repair and replace drinking water infrastructure.
Sadly, these reports and research from experts are not the only confirmation Americans have gotten concerning this problem. The Centers for Disease Control (CDC) has reported an uptick in waterborne illnesses and deaths from drinking water. Towns like St. Joseph, Louisiana have been unable to use the water coming from their taps and have relied upon water buffaloes for their survival. And the stunning, ongoing tragedy in Flint, Michigan has driven home the terrible consequences of unsafe drinking water and what failure to respond in the “replacement era” will mean.
Historically, the focus of water treatment has centered upon the water as within the treatment plant. However, in recent years, plumbing systems inside buildings have been the sources of growing numbers of waterborne disease outbreaks and other public health crises in the US. The toxic lead problem in Flint and outbreaks of Legionnaires disease in New York City, for example, shove public health risk management in the context of aging water infrastructure to the forefront of risk analysis.
According to the AWWA, to maintain and expand service in line with conservatively projected demands for drinking water over the next 25 years it will cost an estimated $1 trillion. The ASCE Infrastructure Report Card for drinking water grades our national drinking water systems with a “D.” The report cites an estimated 240,000 water main breaks annually in the US, which are responsible for wasting more than two trillion gallons of treated drinking water. In short, our water infrastructure is in trouble, and policymakers will need to take action.
This is where the work of researchers like Dr. Andrew Whelton of Purdue University’s Center for Plumbing Safety comes in. Scientists like Dr. Whelton can conduct the research, but in the end they can only provide the information to policymakers, who must then act on it.
“Yes, we have seen policy makers act upon information we already have given them—and believe they will take further action.,” Dr. Whelton asserts. “Drinking water safety has a profound impact on our health, economic vitality, and security. As incidents in the past five years have shown, plumbing in homes, schools, and office buildings as well as hospitals, hotels, and other structures can become chemically and pathogen contaminated.”
Dr. Joan Rose is the co-director of Michigan State University’s Center for Water Sciences and an international expert in public health water microbiology. Her work focuses on the relationship between human health and water quality, with an eye toward water and wastewater treatment, water pollution, and public policies.
“When Cryptosporidium came on the scene the Information Collection Rule was developed to gather information on the occurrence of the protozoan in US water supplies,” Dr. Rose explains. “This is what is needed for Legionella: a national study that focuses on distribution and premise plumbing. Our work will assist in examining sampling strategies.”
Dr. Janice Beecher, director of the Institute of Public Utilities, Michigan State University, highlights the importance of an interdisciplinary approach.
“It is about responding in an informed and intelligent way,” comments Dr. Beecher. “Water usage patterns are changing, and this should be considered when making infrastructure decisions to both save costs and ensure public health protection. Members of the research community are interacting with policymakers through various networks and will also be working to disseminate the findings to other academics, students, and practitioners.”
Even more importantly, risk management in the context of public health can be proactive or reactive—and high quality research provides the tools for a more proactive approach.
“Some risks are identifiable and manageable,” Dr. Beecher elaborates. “By the time we are in reactive mode, damage has been done. A proactive approach can avoid the costs and damages associated with a failure. We cannot avoid all risks, but some basic measures can be used to manage risks efficiently and effectively. Another thing we can look for are ‘co-benefits’ that come from effective risk management, meaning that we can see positive spillover effects. This might include, for example, strategies that save water and energy while improving the quality of life and protecting public health.”
Although the response in Flint has become a very public case study in some sense, New York City has also been responding to the ongoing Legionnaire’s disease threat.
Dr. Tiong Gim Aw of Tulane University is a public health microbiologist whose research touches upon the ways water quality, molecular microbial ecology, and human and environmental health intersect. Currently, his focus is in part on using biological big data to study the microbiome in water systems and their impacts on health. One result of this kind of research is developing the ability to detect waterborne pathogens rapidly using advanced molecular techniques, including those that thrive in urban water catchments—like Legionella.
“My understanding for New York is that the city started regular, mandatory inspections of cooling towers after the outbreaks in the Bronx in 2015,” Dr. Aw explains. “New requirements for owners of buildings with cooling towers were passed. The rules require owners to create routine and long-term maintenance procedures for their cooling towers and for owners to register their towers with the city. There will be more monitoring, but it will be focused on cooling towers.”
Legionellosis is currently the most common waterborne disease outbreak in the US, and its incidence is increasing, despite our awareness of the problem. This is in part because of aging infrastructure.
“Although Legionella bacteria are often found in natural water environments, water systems in the built environment are the main reason for the emergence and increase in Legionellosis in the US and many other developed countries,” Dr. Aw clarifies. “Increasing use of engineering products that create aerosols has increased the risk of human exposure to the pathogen. For example, cooling towers, spas, water fountains, showers and humidifiers are among many man-made water systems that have been identified as sources of Legionella bacteria. Other factors include steady increases in the age of the US population, better diagnostics and increased awareness of the disease resulting in more cases being reported, and environmental factors, particularly a warmer climate.”
Furthermore, a lack of information is still thwarting public health efforts in many ways.
“There is very limited data about the occurrence of disease-causing organisms in building plumbing,” comments Dr. Whelton. “Analytical methods have improved over the years too. In our ongoing testing for example, we have found predicting drinking water quality in plumbing may be even more complex than buried water distribution systems. As complexity increases and data are lacking, so does the difficulty in answering questions about why a certain ‘effect’ occurs.”
An additional complicating factor is that existing regulations are, of course, based on the incomplete information we have—and sometimes regulations vary from place to place.
“The rules governing the control of Legionella were focused on just maintaining a chlorine residual under the Surface Water Treatment Rule,” Dr. Rose points out. “Thus, there are really no federal regulations governing the control of such biofilm related bacteria in distribution systems, premise plumbing or other potable waters.”
Researchers are working to create a better quantitative microbial risk assessment (QMRA) model to close the information gap and eliminate the conditions that allow Legionella to thrive. This research involves evaluating infection rates under a variety of conditions.
“The QMRA framework and a dose-response model are available,” Dr. Rose explains. “What is still needed is more information on the exposure pathways. Our work will help support fill in the data gaps.”
In the context of toxic lead in Flint and Legionnaire’s disease in New York City, it’s easy to feel uncertain about safety. The challenge moving forward is more than ensuring that our drinking water is safe; it is also going to include rebuilding confidence in our national water infrastructure. This is one aspect of the “Right Sizing Tomorrow’s Water Systems for Efficiency, Sustainability, and Public Health” project, an EPA collaboration in which Drs. Whelton, Beecher, and Rose are participants.
“Today, when you go to a faucet, you cannot tell if the drinking water is unsafe or safe,” Dr. Whelton states. “There is no blinking light telling you to be cautious or avoid the water from a certain fixture and choose a different one. Ideally, that is where technology could be headed, but today we have no such ability. Through this project we are focused on helping the building construction, plumbing industry, public health, and utility communities better understand how to predict drinking water quality (safety) at the tap.”
“As incidents have shown over the past five years, there are real human health, economic, and public confidence consequences associated with our inability to predict drinking water safety at the faucet,” Dr. Whelton adds.
While some consumers have taken water testing into their own hands, there are many reasons why this is an area that public entities must not yield.
“One of the reasons we have uniform protective standards, accepted practices, and appropriate technologies in water treatment and distribution is because in many respects, people should be able to take the safety and quality of their water for granted,” argues Dr. Beecher. “New monitoring methods throughout the system may be helpful. But there are advantages of scale and expertise that argue for professional utility management of water services.”
Dr. Juneseok Lee, a professor of civil and environmental engineering at San Jose State University, is also working on the EPA project. Dr. Lee’s work centers on protecting public health by enhancing the integrity of drinking water infrastructure.
“Regarding predicting water quality and safety, water distribution systems such as utility water mains that bring drinking water to individual premises, are quite well developed,” Dr. Lee explains. “We can predict critical water quality parameters such as water age and chlorine concentration within these systems. This information can help water utilities take actions such as systematic flushing at the appropriate time and locations. Typically, dead-end zones have higher water age—which can be translated as possibly deteriorated water quality.”
Unfortunately, the approximately one million miles of American premise plumbing systems—those that feed water directly into homes and businesses—are less well understood.
“The water quality predictive capacities in premise systems have not been well addressed in the research community,” Dr. Lee states. “The stochastic nature of water use patterns, as well as complexities in configuration and materials used in the piping systems, make the predictive capacity a challenging but interesting problem that needs to be developed. At this point, the typical advice for residents is to flush their faucets if they have not used water for a longer period—say about 10 to 15 days.”
Dr. Whelton interjects, “I would add to Dr. Lee’s assessment that the role of the newer plumbing materials themselves on drinking water quality is quite complex and poorly understood.”
Meanwhile, Dr. Whelton and the Purdue team of researchers found problematic levels of bacteria and organic carbon increasing inside the plumbing systems of even green buildings within a 72 hour period.
“What we believe took place is that the utility water traveled through the building plumbing to the faucets,” Dr. Whelton explains. “At the same time, a biofilm developed in the plumbing. It is likely that organic carbon and bacteria levels will increase in a newly commissioned plumbing system.”
Dr. Whelton underlines the significance of one aspect of these results in particular.
“Unlike the current understanding of lead and copper inside building drinking water, there have not been any large-scale studies to determine if increasing chemical and microorganism levels are common in new buildings of certain types, locations, or designs,” Dr. Whelton emphasizes. “A large-scale water testing study, focused on building drinking water, would help answer some pressing questions that cannot be addressed by focused efforts underway.”
In fact, there is so much uncertainty about fixtures inside buildings that this is a research area in need of attention.
“In terms of fixtures, we found drinking water chemical and microbiological quality differed across fixtures even in a single building,” Dr. Whelton explains. “This finding was also discovered many years ago in that different parts of a water distribution system had different drinking water quality. Water quality at the tap can be influenced by the environmental conditions such as temperature, flow rate, use frequency, biofilm, and pipe materials.”
Does this mean that increasing levels of things like bacteria and organic carbon are unavoidable? If drinking water is so sensitive even to fixtures, should we be more careful about materials we use in conjunction with water? Dr. Whelton answers these questions with questions of his own.
“If we do not know what chemicals are released from new or aged plumbing materials and what are the worst-case conditions, how can we make material selection decisions that best protect drinking water safety?” queries Dr. Whelton. “The commonly used plumbing material chemical leaching test method is not representative of actual plumbing conditions, its test results are not publicly released, and the existing product evaluation process does not consider the impact of plumbing materials on biofilm growth or disinfectant byproduct generation inside buildings, among other issues. Without this information, how does someone choose a plumbing pipe that will not cause unsafe drinking water in their home, school, office, or hospital?”
One answer the Purdue team has formulated is the innovative Whirlpool Corporation-Purdue University RENEWW House. The completely renovated home is heavily outfitted with the latest plumbing technologies engineered to conserve water and energy. It is also equipped with extensive online monitoring equipment, which allows in-depth monitoring of water that exits every faucet.
“We know what temperatures it was exposed to, how long it’s been in the house, where in the plumbing the water traveled before exiting the faucet, when the fixture was last used, the duration of that use, and the flow rate during use,” Dr. Whelton describes. “Coupled with this information, our team is developing a hydraulic model for predicting water quality at each faucet—chemical and microbiological quality.”
And, of course, the interdisciplinary work that the EPA project and others produce was inspired by past missteps as much as triumphs.
“One of the hard lessons of failure is that we need to be working together in an interdisciplinary way, as our team reflects,” states Dr. Beecher. “There is relevant knowledge on these issues coming from very different perspectives, drawing from the physical and the social sciences. Water quality has become more complex and old assumptions might not hold. It is more critical than ever to engage scientists, engineers, and researchers in the policymaking and policy evaluation processes.”
Top image: Purdue University assistant professor Andrew Whelton is leading a project to help address potential health hazards posed by low-flow building water systems, which may cause an increase in disease-causing organisms and harmful chemicals. (Credit: Purdue University/Erin Easterling.)