“People think that water is simple, but it is highly complex.” A quote from David LaFrance, CEO of the American Water Works Association (AWWA).

“If you consider the contribution of plumbing to human life, the other sciences fade into insignificance.” A quote from James P. Gorman.

“Second, we must recognize the true value of water. Until society acknowledges that the value of water is more than the money generated from using it and throwing it away, it will be difficult to pursue changes in policy and the behavior of individuals, corporations, and governments.” A quote from Peter Gleick, senior fellow, co-founder and president emeritus of the Pacific Institute, author of “Third Age of Water.”

In my last column, I focused on talking about how engineered plumbing systems were at a crossroads. In the past, we thought plumbing engineering and science was easy. The 21st-century plumbing challenges have shown us otherwise. There is a need for plumbing research and development to occur. And engineering firms that do not have plumbing design professional specialists are bound to fall behind.

In this month's column, I would like to discuss some of the emerging trends in plumbing science.

On Nov. 15, 2022, I was able to participate in a National Institute of Standards and Technology (NIST) plumbing roundtable in Gaithersburg, Maryland. During the all-day workshop, a group of industry experts, which included representatives from NIST, IAPMO, ASPE, PMI and others, discussed initiatives in research and toured NIST’s plumbing research laboratories. A large part of the discussion focused on the NIST plumbing “roadmap” of research needs.

I felt honored to participate, present and lead a discussion during the day’s activities. I was struck by the complexity and vital nature of the work NIST was accomplishing — projects to help us better understand the science of plumbing that would also positively impact society. Since the meeting, I cannot help but keep coming back to that day and look forward to how this work will impact our industry’s future.

I see three emerging trends in plumbing water research:

  • Research Trend No. 1 — Water and Energy Nexus: making plumbing water systems more energy efficient, and safely;
  • Research Trend No. 2 — Water Safety: water quality in premise plumbing systems; and
  • Research Trend No. 3 — Hot water system design, installation, commissioning, and operation as part of the water sustainability and safety nexus.

Research Trend No. 1: Water and Energy Nexus

For more than a decade since I first began as an engineering consultant, there has been a drive toward reducing flow rates of plumbing fixtures and reducing energy usage in buildings. However, in the last five years, a steady drumbeat of experts have continually sought out audiences to speak about the unintended consequences of doing so. Take, for example, the National Academies Of Science Engineering And Medicine consensus report on the management of Legionella in premise plumbing systems indicating the use of low flow fixtures (in essence any rule by any jurisdiction to require plumbing fixture flow rate that is below the legal limit set by the EPA) should not be allowed in any healthcare or long term care facility because of the increased risk of waterborne pathogens to the immunocompromised populations in those buildings. Concerns about lowering water heater temperatures to save energy are also becoming an increased concern for the same immunocompromised populations.

At the NIST workshop, both were discussed at length. NIST has a laboratory focusing on water heater setpoint temperatures on the occurrence and concentrations of opportunistic premise plumbing pathogens (OPPP), like Legionella. An identified need was the relationship between scalding risk, energy costs and OPPP growth. Concerns about the impact of larger storage tanks and volume increasing was a topic that came up several times. Finally, the need to congregate plumbing fixtures more closely and right size piping (such as IAPMO’s Water Demand Calculator) were seen as great solutions.

Research Trend No. 2: Water Safety

Water quality is the great new frontier for plumbing design professionals. Most of us tend to understand hydraulics as well as heat and mass transfer. Water quality presents a different problem. Most ABET-accredited mechanical engineering programs and architectural engineering programs do not spend too much time on water chemistry, or chemistry in general. I know during my schooling, I only had two semesters of chemistry during my freshman year. It's important for us to understand water quality because it does have a big impact on what happens in the realm of public health and safety inside the built environment. The NIST workshop discussed this topic, as well.

The topic of water age dominated the water quality discussions. Trying to understand the impact of flushing or increasing flow rates was identified as a high need. Reducing water age by making more compact designs, in conjunction with collaboration with architects, was seen as a great opportunity. Using building intelligence to reduce water age and repurposing water for other on-site applications was seen as another potential solution.

Research Trend No. 3: Hot Water Systems

If you search the report on the NIST workshop, the words “hot water,” “temperature,” “heat,” “energy,” and “recirculation” occur a total of 179 times over the 95-page report. Clearly, hot water systems and their temperatures and energy usage are a high priority for our industry. Making sure hot water recirculation systems are designed, installed, commissioned and operated in a safe, yet efficient manner, is important. Multiple stories were shared during the conversation about how improperly operating hot water recirculation systems were contributing to waterborne diseases and increased energy usage. As previously mentioned, NIST has an entire laboratory that focuses on water heater temperatures. But further questions remained.

The Plumbing Science Outlook for 2024

So, what do these research trends mean for the plumbing design professional? First, that expertise and specialization will be needed. The above topics in water are not going to have easy solutions; it is going to take dedicated work and effort to learn more about these kinds of challenging and complex problems. Fortunately, there are ways to do so, and a great one would be to attend the 2024 Emerging Water Technologies Symposium being held May 14-15, 2024, in Scottsdale, Arizona. The theme of next year’s symposium will be “The Nexus Between Sustainability and Safety: Avoiding Unintended Consequences.” More details can be found here.


The above topics in water are not going to have easy solutions; it is going to take dedicated work and effort to learn more about these kinds of challenging and complex problems.


As far as putting together a solution, I am excited to report that IAPMO is actively working on these with industry partners such as ASPE, ESPRI, AWWA, and others. A listing of IAPMO-led research that directly addresses these top items can be found below:

  • IAPMO continues to develop the cutting edge right sizing tool — the Water Demand Calculator — while also working with industry partners to try and better understand the impact that right sizing has on cost, sustainability, and safety:
    Studies and Calculator;
    Water Demand Calculator Task Group;
  • IAPMO partnered with AWWA to create a Manual of Recommended Practices to Reduce the Risk of Closing and Reopening of Buildings:
     – Manual;
  • IAPMO partnered with ESPRI to create a manual of Water Quality:
    – Public review period has ended, final document in process;
  • IAPMO has started a task group for Hot Water Recirculation Design, Installation, Commissioning, and Operations to address the need to improve these systems:
    Press release; and
    Sign up page for Task Group.

We have a mountain of research needs ahead of us to get plumbing systems into the 21st century. However, we have already taken the first steps. So how do we get to the top? I’ll refer to this quote from Mark Udall:

“You don’t climb mountains without a team, you don’t climb mountains without being fit, you don’t climb mountains without being prepared and you don’t climb mountains without balancing the risks and rewards. And you never climb a mountain on accident — it has to be intentional.”