Energy-Efficient and Water-Wise Buildings Can Put Water Safety at Risk

Temperature and chemicals are the two most common ways to kill pathogens in water. However, cutting energy use may require lower temperature settings on hot water tanks. And water conservation measures may mean it stands longer in plumbing systems while disinfectant strength rapidly decays.

As a result, pathogens like Legionella pneumophila and Pseudomonas aeruginosa can amass in nooks and crannies in water pipes and colonize distribution systems. Legionella bacteria cause Legionnaires' disease, a severe form of pneumonia that's often found in hospitality venues. Pseudomonas germs cause blood and lung infections, particularly in hospitalized patients with weakened immune systems.

But owners and managers can have it both ways—water and energy-efficient buildings with safe and high-quality water are a possibility. Here's a closer look at how water safety management plans can ensure buildings keep water distribution systems within control limits and protect occupant health.

Energy-Efficient Buildings Require Frequent Water Quality Testing

Water heating uses about 8% of the total energy consumption in commercial buildings, according to the LEED® Core Concepts Guide. To reduce energy consumption, managers may need to restrict water use and reduce water heater temperatures.

Another option is to run a solar water heater using renewable energy. Active solar water heater systems have circulating pumps and controls. Passive systems don't, and they may be less efficient. One concern is that intermittent activity in solar thermal storage tanks may cause lower water temperatures. And water that isn't scalding hot may introduce the risk that pathogens survive.

In a study reported by the National Institutes of Health, researchers observed a higher risk of Legionnaires' disease in residential buildings with solar thermal systems. So, it's critical for building managers to safeguard water quality by testing often for pathogens from the point of delivery by the water supplier to points of use by consumers.

Water Conservation Measures Call for Regular Monitoring

The operation of buildings, including landscaping, accounts for approximately 12% of total water use, according to the Green Building Council. Keeping demand for potable water in check—whether for residential, commercial, industrial, or other uses—reduces the strain on supplies and the need for rationing. In addition, excessive amounts of water going down the drain can overwhelm wastewater facilities. Water pumping and treatment also require energy use.

But strategies that reduce water demand can result in water stagnation, according to the American Water Works Association. Water that sits in pipes due to lower flows may increase chemical and microbiological contaminants that pose health risks to occupants. Keeping water safe requires maintaining a consistent residual of disinfectant, such as chlorine, throughout the system.

Water flowing at higher volumes with primary and secondary disinfectants eliminates waterborne pathogens most successfully. Otherwise, the disinfectants can expire before the water reaches the point of use. A report published in Chemistry World showed that chlorine disinfectant in water decayed as much as 144 times faster in buildings with strict water conservation measures because of increased water age.

Of course, the health and safety of building occupants must be managers' top priority. Routine monitoring for residual disinfectant, temperature, and turbidity, and regular water quality analysis are critical to understanding the impacts of low demand.

Water Safety Management Plans Need Lab Support

Building owners and managers should put a comprehensive water safety management plan in place to handle all potential waterborne pathogen hazards. Avoiding contamination not only reduces disease risk but also litigation and liability concerns. Testing that's sensitive to pathogens of concern and appropriate for submitted samples helps determine if control measures in water distribution systems are adequate.

Water labs play a vital role in water safety management plans. You handle the validation step of a water safety plan—ensuring control measures work effectively to reduce or eliminate waterborne pathogens—and provide the data for the water safety team to take actions necessary to keep occupants safe.

With the help of water test labs, building owners and managers can deliver a hat trick—increasing water and energy efficiency while ensuring high water quality that protects occupant health and safety.