Water filtering at Fermilab

Rod Walton

Rod Walton

As everyone knows, fresh water is one of the most important substances on the planet. It sustains all life, and all life forms are, after all, mostly water. We are constantly told to drink more water, and “stay hydrated.”

Following this advice at work can be a challenge. Some people prefer to bring water from home in their own bottle, some buy bottled water for work, and some merely drink the water that is provided at faucets or drinking fountains in the workplace.

For Fermilab employees who work in or visit Wilson Hall, an invisible but highly sophisticated system provides clean, safe drinking water. This system provides filtered, sterilized and chilled water to drinking fountains throughout the building.

Filtration is accomplished by fine particulate filters to eliminate rust and sediment particles down to five microns, as well as a charcoal filter, which removes taste, odors, chlorine and a host of volatile organic compounds. A sterilizing unit uses ultraviolet light to control the growth of bacteria, viruses, molds and other micro-organisms. Finally, the water is chilled by a refrigeration unit before circulating throughout the building.

The water filtration unit undergoes regular preventive maintenance, including changing the filters and performing an operational checklist. The particulate filters are changed every month. The large charcoal filter is changed annually. The system is tied into the building automation system, which monitors its status, and sends an alarm when filters need to be changed or for any malfunctions in the unit.

This system provides employees and visitors with high-quality drinking water on demand, so there is no need to re-filter it before drinking. Some building occupants in the past have used commercially available filtering containers to “re-treat” the water from drinking fountains. This is not necessary to get clean, odor-free water, and there may be a slight down side to it, especially if a larger volume of water is filtered for use over multiple days. Because the building system (as well as the filter) removes most of the chlorine to improve the taste, water no longer has antimicrobial properties if it sits longer than a day, and this can actually encourage the growth of microbes.