Part I: Emerging Trends Affecting Premise Plumbing

Part I of this two-part series examines emerging trends impacting building plumbing

The number of Legionnaires’ disease reported to the U.S. Centers for Disease and Control Prevention (CDC) has been increasing for two decades. As the number of cases continues to rise, so does the need to manage the risks associated with on-site plumbing systems.

In recent years there has been an increase in legionella awareness as multiple stakeholders have entered the conversation – government organizations, water utilities, health professionals, local jurisdictions, model code bodies, industry associations, manufacturers, engineers, academic scientists, legionella consultants, water treatment professionals, etc. These stakeholders hold conferences, attend seminars, create standards, develop guidelines, establish best practices, write research papers, produce products, and make changes to the model code.

Through the individual efforts of stakeholders, enough is known about the bacteria and its transmission to successfully control growth in on-site sanitation facilities; however, with the continued increase in reported cases, it is clear that a comprehensive implementation of multi-stakeholder audit strategies is necessary.

Most available resources and standards focus solely on water management plans and actions by facility personnel. While this is certainly a critical component to managing risk, it overlooks the huge impact that comprehensive plumbing design can have in supporting key water management principles. Design professionals are essential for managing risk. Before delving into risk management in system design, it is important to understand trends affecting sanitation safety.

A perfect storm

The US is experiencing a perfect storm scenario. Both internal and external factors contribute to the increase in Legionnaires’ disease cases.

  1. Outdated water supply infrastructure. There are approximately 240,000 hydrocephalus outages in the US each year. According to the American Water Works Association (AWWA), repairing and replacing old water pipes could cost more than $1 trillion over the next 20 years. The residual effects of water main breaks include bacterial contamination and bacterial corrosion, resulting in a habitat favorable for the spread of waterborne pathogens. Until new infrastructure is installed, the US will continue to experience water pollution in municipal water supply systems and sanitation.
  2. Widespread use of low-flow fixtures. Water use has changed dramatically since the enactment of the US Energy Policy Act (1992). This policy necessitated the production and sale of low-flow plumbing to reduce water consumption. However, the sizing methods for water distribution pipes have not changed. As a result, drinking water supply and water distribution systems are grossly oversized, creating an environment conducive to the growth of biofilm and bacteria.
  3. Building water systems during COVID-19. The perfect storm is fueled by the prolonged vacancy and reduced occupancy buildings are experiencing during the coronavirus pandemic. Recommissioning a building with neglected water systems increases the likelihood of: legionella transfer of bacteria.
  4. More lawsuits. With a better understanding of the causes of legionella, there has been an increase in allegations of negligence and liability claims. With a standard of care enshrined in ANSI/ASHRAE Standard 188, just one Legionnaires’ Disease claim could cost negligent owners millions of dollars in litigation and settlement claims. In the case of the 2015 outbreak at the Quincy, Illinois, Veterans’ Home, families of the victims recently settled with the state of Illinois for nearly $6.4 million.
  5. Insurance coverage. Insurance companies are fighting against their liability for coverage as more lawsuits and claims are filed. Some insurers limit coverage or impose higher deductibles if building systems are outdated. Others ask customers to document how they maintain plumbing and refrigeration systems. As a result, building owners run great financial risks. It is important to point out that owners are not the only ones exposed to charges of negligence or liability claims. Engineers are also exposed to liability given the widespread availability of industrial research and recommendations regarding design strategies to control legionella.
  6. Many buildings do not yet have a water management program. According to the CDC, nine out of 10 Legionella outbreaks could be prevented with more effective water management. In June 2017, the Centers for Medicare & Medicaid Services (CMS) issued a memo requiring healthcare facilities to develop and adhere to an ANSI/ASHRAE Standard 188 compliant water management program to reduce the risk of legionella in their water systems. While this requirement was a great first step to improve public health and safety, it shouldn’t stop there. Unfortunately, facility types outside of CMS jurisdiction are not required to develop or comply with a water management program. Without this requirement, it makes the implementation of proven control strategies in a wide range of building types much more difficult.
  7. Constant increase in construction costs. Construction costs have increased by more than 5% every year since 2017. Architectural, engineering and construction teams are consistently asked to evaluate options for cost savings. Unfortunately, the relentless pressure to cut costs makes effective design concepts and innovative products designed to manage risk constantly vulnerable to removal from project design.

Plumbing design is essential to manage risk

Effectively managing risks associated with building water systems requires a commitment from everyone involved, from owners and operators to engineers and contractors. Plumbers play an essential role in creating safe and healthy buildings. In part two of this article, we’ll look at how plumbing engineers can implement fundamental design principles and execute comprehensive strategies to manage risk.


  • Veteran Disease Rising in United States, National Notifiable Diseases Surveillance System
  • US insurers look to protect against Legionnaires’ Disease as buildings reopen after pandemic closures, Reuters June 18, 2020.
  • Building analysis,
  • US EPA
  • American Water Works Association (AWWA)
  • Centers for Disease and Control Prevention (CDC)

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