A Path for Improved Building Water Quality

As the daily occupancy in public and commercial buildings continues to rise, an unintended consequence of many stay-at-home orders during the COVID-19 pandemic has emerged relating to the quality of building water systems.

All the “work from home” activity and virtual schooling has in turn led to the underutilization and stagnation of building water systems. These factors can result in lower residual disinfectant (such as chlorine or chloramine) concentrations, growth of microorganisms like Legionella, and accelerated pipe corrosion. They can also create unsafe levels of lead and copper in water.

To help clients meet the water safety needs of their returning tenants, STV’s team of environmental engineers and scientists is providing guidance and design solutions that are aiding the re-occupancy process.

“One of the biggest concerns our clients have about their buildings’ water systems is that they don’t often know there’s a specific problem until something happens, like the water turns blue, or someone gets sick,” said Robert Fields, P.E., ENV SP, LEED AP, an associate and environmental engineer in STV’s New York office. “We are helping to identify preventive measures clients can take that adhere to best industry practices, such as the Centers for Disease Control and Prevention (CDC) guidance, while also tailoring solutions to each client’s specific needs.”

STV already has extensive experience supporting clients who own facilities where building water systems are more vulnerable to stagnation and water quality issues, such as large institutional buildings and schools.  Over the past seven years, STV has investigated and addressed corrosion and bacteriological conditions affecting water quality in more than 20 large-scale building water systems.  Fields is currently providing recommendations to clients that include designs for remedial measures and improvements to building potable water systems.

“Although official guidance from several sources is still being developed, there are measures that owners and building staff can take now to maintain their plumbing water systems until the buildings are fully re-occupied”

Robert Fields, P.E., ENV SP, LEED AP,
STV Associate and Environmental Engineer

In most instances, systemic water quality issues are caused by a combination of contributing factors.  For example, a recent industry-wide push to install more efficient, low-flow water systems in public buildings, as well as nearby construction activities, can lead to conditions that degrade water quality over time. The lower flows can contribute to water stagnation and reduced velocities in system piping which prevent sediment from being purged through flushing. In response, STV has developed a suite of mitigation measures and design enhancements for building plumbing infrastructure. Fields is now leveraging that experience for clients dealing with similar issues for the re-occupancy phase of the pandemic.

Steps recommended by Fields and his team include upgrades to potable water systems and developing and implementing procedures to simulate normal use while the buildings are vacant or have reduced occupancy and for preparing dormant systems for re-occupancy. The aim of these procedures is to flush all the water in a building’s potable water system and replace it with fresh chlorinated water from the municipal distribution system. 

As a member of several committees focusing on water quality, Fields has been working with the American Water Works Association (AWWA) and others since April 2020 to develop best practice recommendations to combat building water system stagnation. One of these documents, “Responding to Water Stagnation in Buildings with Reduced or No Water Use,” was released late last year.