The world as we knew it changed recently with the spread of COVID 19. On top of that was the directive to close
all “Non-essential” businesses. This rapid closure inevitably caused many locations to drastically reduce or
completely stop the routine water flows that these facilities usually operated. Facilities that are included in this
group of “non-essential” businesses are hotels, malls, colleges, school districts and many other very large and
small businesses that have temporarily closed for a period of time.
Systems in these facilities that are of major concern are water systems that have hose bibs with stagnant water
being stored, tubs, showers, faucets, ice machines, process water if pumps have been stopped, and any other water
system with interrupted flow. Concerns are with respect to scale, corrosion and most importantly – biofilm and
microbiological activity. Biofilm and microbiological activity are even more dramatic in waters that are warm – a
condition that many buildings will experience, and many hot water potable systems operate in.
Proper re-implementation of these systems will be critical to avoid any potential for potential catastrophic events
with this water as the systems come back online. There must be communication with facility personnel (both
maintenance and health), a reputable water treater that can assist and guide the re-integration of the water
systems, and any guidance that may come from the federal, state and local levels. The communication must be
frank and very thorough so that proper practices can be implemented. It is critical to understand that a small
“dead leg” could inoculate an entire water system. A “dead leg” is generally defined as any length of pipe that is
6x the diameter of the pipe (i.e.. if a 1-inch pipe has a length of pipe that is 6 inches on a stub, it is a “dead leg”.
This short dead leg is the source for potential microbiological growth – think of a system with no flow for a period
of weeks (hundreds of feet of pipe with warm water, nutrients and little flow to offer turbulence) – what kind on
microbiological activity will be in that length of pipe. Staggering!! Very Scary!!
A plan of action should be considered that incorporates communication (up and down, side to side) with all
pertinent personnel about:
1. The system and all information as to changes made in piping in recent years, or changes that occurred
due to the current shutdown.
2. Documentation of all data pertinent to the system. What was known prior to the shutdown, what are
those parameters now (temperature, pH, free halogen, scale/corrosion issues, etc.).
3. If necessary – recruit a quality water treater to assist with this “system startup”. It might be the wisest
investment you can make.
Please also remember that many of these practices may be in place due to efforts to minimize the proliferation of
Legionella Pneumophila in potable water or in a cooling tower. These same good practices will further assist in
minimizing that pathogen, but it will also demonstrate a complete understanding of proper practices to minimize
other pathogens that may be in this water as building owners/managers restart their businesses and water
systems, after the sudden and unexpected shutdowns of these critical water systems ordered by the Federal
Mark Botsford, CWT #995
THE METRO GROUP, INC.