By Larry Mayotte, Operations Manager, Service

Building owners and facility managers are diligently preparing their plans to reoccupy buildings that have been under-utilized or sat empty for weeks or months. In their efforts to ensure occupants can safely return to the workplace, they are tuning up their heating, ventilation and air conditioning (HVAC) systems and implementing physical distancing and other protocol to mitigate the spread of COVID-19.

One area that is often overlooked but is just as critical to safely reopening a building, is a building’s water system (potable, non-potable, cooling towers, evaporative HVAC equipment). Most building owners and operators don’t typically have to deal with health risks from these systems. But, in buildings that have low or no use for extended periods of time, there is significant risk of bacteria such as legionella building up. This build-up puts occupants at risk of exposure to Pontiac Fever, an acute nonfatal respiratory disease, or Legionnaires Disease, a type of pneumonia caused by inhaling bacteria from water and the deadliest waterborne disease in the United States.

The Centers for Disease Control and Prevention (CDC) and Washington Department of Health (DOH) have issued guidance advising building owners to test water before people return and to have a plan in place to test water and maintain water quality. Time and temperature are natural enemies to chlorine levels in water that keep bacteria from blooming. When water is stagnant and warm it is ideal for Legionella growth. Testing can tell you whether your water quality has deteriorated, and whether bacteria is present, but what should your plan be to maintain healthy water quality?

In an overabundance of caution, CDC and DOH recommend building owners take the step of flushing the system to ensure the bacteria, biofilm build-up, and stagnant water is removed, and chlorine levels are appropriate to keep blooms from developing. There are no states mandating this precautionary step yet, but I imagine in the wake of the recent shutdowns that many will take up the cause. In addition to no regulatory oversite, there is no standard guiding building owners or service professionals on when and how to flush a water system.  Washington DOH points to the European Society of Clinical Microbiology and Infections Disease as a guide for appropriate levels of bacteria in water.  

We recently tested the process at McKinstry’s headquarters in Seattle and had an eye-opening experience. Performing the tests is relatively simple – we do spot checks where water comes into the building and a handful of random points – to understand the chlorine and pH levels and temperature, creating a baseline before flushing the system. A reminder that when undertaking this testing, safety precautions, including appropriate PPE, must be used. In our test we discovered a couple of important factors that can impact the results of the test:

1. One would assume water coming in from the main at the street is treated and has good levels of chlorine, but depending on the neighborhood, that may not be the case. Our headquarters are in an industrial part of town that hasn’t seen a lot of activity, so it took quite a bit of flushing the building to get to “acceptable levels” (greater than .2 mg/l or .2 PPM of chlorine).
2. You also must consider how water moves through a neighborhood. Different building types in a neighborhood can also impact the test. In our case, we performed the test on a Monday morning and because there was low use over the weekend, the chlorine levels had degraded. This would be different in an area with significant residential use.
3. Low flow fixtures increase the amount of time to move water through the system. 

In the end, every building is unique and different, which is challenging when trying to develop standards and guidelines, but a plan that takes into account your specific circumstances can be achieved. Testing and flushing water systems are actions you can take to ensure occupants return to work with confidence in the health and safety of their workplace. If you are unsure of how to proceed, seek professional assistance from a licensed and experienced plumbing service provider with testing, and the development and implementation of a water management plan.

McKinstry delivers the assurance needed for your building occupants to return with confidence. Learn more.