Buildings use water filtration and treatment to protect people, plumbing and equipment: removing sediment, reducing hardness and scale, improving taste and odour, and in some cases disinfecting. The right system depends on what is actually in your water and what you need it for, which starts with a water test. Any system you install must then be maintained, or it can make water quality worse.
Start with the water and the goal
Most buildings in Canadian cities receive treated municipal water that meets drinking water guidelines. Filtration in these buildings usually addresses specific concerns: hardness, chlorine taste, sediment from old mains, or water quality for particular equipment. Buildings on private wells have more to consider, since the owner is responsible for treating the water to a safe standard. Health Canada publishes guidelines for drinking water quality, and provinces set their own rules, particularly for public and commercial water systems.
Before choosing equipment, test the water and define the goal. Treating for problems you do not have wastes money and adds maintenance.
Common types of treatment
| Treatment | What it does | Main maintenance |
|---|---|---|
| Sediment filters | Remove sand, rust and particles | Change cartridges or backwash on schedule |
| Activated carbon | Reduces chlorine, some organic compounds, taste and odour | Replace media before it is exhausted |
| Water softeners | Exchange hardness minerals to reduce scale | Keep salt supplied, check regeneration settings |
| Reverse osmosis | Removes a wide range of dissolved substances | Change pre-filters and membranes, manage reject water |
| Ultraviolet (UV) disinfection | Inactivates bacteria and viruses | Replace lamps, clean sleeves, keep pre-filtration in place |
| Iron and manganese filters | Remove staining metals common in some well water | Regenerate or backwash as designed |
Point of entry and point of use
Point-of-entry systems treat all the water entering a building. Point-of-use systems treat water at a single tap, such as a drinking fountain or coffee station. A building may use both: a softener at the entry to protect water heaters, and carbon or reverse osmosis at drinking water points.
Filtration for equipment
Water quality affects mechanical equipment as much as people. Boilers, closed heating and cooling loops, cooling towers, humidifiers, dishwashers and process equipment each have their own water requirements. Scale reduces heat transfer and efficiency; corrosion shortens equipment life. Water treatment for these systems is usually handled by a water treatment provider and should be documented. See Legionella and cooling towers for one important example.
When filters become the problem
Neglected treatment equipment can harm water quality:
- Saturated carbon filters can release captured contaminants and grow bacteria.
- Cartridges left too long can clog, reduce flow and harbour biofilm.
- UV systems with dirty sleeves or expired lamps stop disinfecting without obvious signs.
- Bypassed equipment gives a false sense of protection.
- Softeners that are set wrong can waste salt and water, or fail to soften.
- Removing chlorine at the building entry reduces protection against bacterial growth in the building's plumbing downstream.
Do not remove disinfectant without a plan. Carbon filters at the point of entry remove the chlorine that municipal water relies on to limit bacterial growth in pipes. If you treat at the entry, consider how the building's plumbing will be protected, and seek advice before installing whole-building carbon filtration.
A maintenance routine
- Keep an inventory of all treatment equipment, with locations and model numbers.
- Label each unit with its last service date and next due date.
- Follow the manufacturer's replacement intervals for cartridges, media, membranes and lamps.
- Check pressure gauges before and after filters to spot clogging.
- Check that bypass valves are in the correct position.
- Test water periodically to confirm the system is still doing its job.
- Keep records of service, test results and any problems.
Protecting the public supply
Treatment equipment connected to the plumbing must be installed so that it cannot contaminate the public water supply. That usually means appropriate backflow prevention. Our guide to backflow prevention and testing explains the requirements. Installation should be done by licensed plumbers following the plumbing code and local bylaws.
How ehZee can help
Our air and water filtration system inspections look at your water treatment equipment, its condition and maintenance records, and whether it suits the building's needs. We report what we find and help you coordinate testing and licensed contractors where action is needed.
Common questions
Does our building need water filtration?
Not necessarily. Many buildings on municipal water need little or no treatment beyond what protects specific equipment. A water test and a clear goal tell you whether treatment is worthwhile.
How often should filter cartridges be changed?
Follow the manufacturer's instructions, adjusted for actual water use and quality. Pressure drop across the filter is a useful sign that a change is due.
Is softened water safe to drink?
Softening adds some sodium to water. People on sodium-restricted diets may want an unsoftened supply for drinking. Health Canada and your health provider can advise.