People get sick from Legionella by breathing in small water droplets containing the bacteria, not from drinking the water or contracting it from other people. Legionella can grow in plumbing systems when the water is warm and has low levels of disinfectant. Common ways people breathe in water droplets with Legionella are in a large building that uses a cooling tower, during showering, hot tub use, or exposure to decorative fountains. The risk of exposure to Legionella in a single-family home is low. Large buildings that have complex plumbing systems are at a much greater risk to Legionella growth.

Learn more about what you can do to prevent harmful bacteria like Legionella at your home or business:

• Information about Legionella and Legionnaire’s Disease

Providing safe water is our number one priority and a responsibility we share with you. Although the drinking water we deliver to your property meets all federal and state water quality standards and requirements, the quality of that water can be affected once it leaves our pipes and enters a building or home, due to the unique interior plumbing system at your property. For example, in certain conditions, harmful bacteria can grow in your pipes, or other water-using devices in your home or business, if they are not properly cleaned or maintained. A very common bacterium found in pipes and water-using devices in homes and businesses is Legionella.

Whether you are a homeowner or a large facility manager, you have an important role in maintaining the quality of water on your property after it leaves the public system. Please see links at the end of this document for more information.

Has Tigard’s municipal water been tested for Legionella?
While Tigard doesn’t specifically test for Legionella, our water is delivered from a highly advanced water treatment process (Lake Oswego-Tigard Water Treatment Plant) that uses ozone and chlorine as a disinfectant to kill harmful pathogens, including virus and bacteria.  Legionella is bacteria.  The water is routinely tested by a certified laboratory throughout the Tigard Water Service Area to ensure that no pathogens are detected.

What are common causes and sources of infection?

• Cooling towers (structures that contain water and a fan as part of centralized air cooling systems for building or industrial processes)
• Hot tubs that aren’t drained after each use
• Decorative fountains and water features
• Showerheads and faucets
• Hot water tanks and heaters
• Large plumbing systems

How can you prevent Legionella in your building’s internal plumbing system?
To prevent the growth of bacteria like Legionella in your plumbing, there are actions that you can take that vary in complexity depending on what type of water system you have. Although the risk is low for a healthy person to contract Legionnaires’ Disease (in the home), there are simple precautions you can take to prevent the growth of Legionella. 

• Showerheads and Faucets
  • Clean showerheads and faucet aerators at least four times per year to minimize the growth of the Legionella bacteria.
  • Clean them more often if your home has high risk occupants or if there is build-up of minerals or slimy film.

• Water Heaters

  • Setting the Water Heater Temperature
    • Keeping your home’s water heater at 140°F will reduce the growth of Legionella.
    • However, to reduce the risk of scalding, the temperature of the water leaving the showerhead or faucet should be no higher than 120°F.
• Gas and Electric Water Heaters

  Homes with high risk individuals may consider installing tankless water system, set at 122°F, which both reduces the risk of scalding and prevents the growth of Legionella bacteria.

  • Flushing the Water Heater
    • Emptying and refilling (flushing) the hot water tank is a good practice.
    • If you are not completely familiar and comfortable with this task you could contact a licensed or qualified plumber to do it for you. 
  • Water Filters
    • Water filters that are installed at any faucet, also called point-of-use (POU) filters, should be changed according to the manufacturer’s recommendations because if not, Legionella bacteria can grow on the filters and lower the water quality.
  • Humidifiers
    • Humidifiers create fine mists of water that can host and transport Legionella bacteria into your lungs, if they are not cleaned properly. Humidifiers can be complex appliances, so it is best to follow the manufacturer or the supplier’s instructions for cleaning and maintaining them.
  • Hot Tubs/Jacuzzi®s/Spas, and Pools
    • Legionella grow best in warm water, like the water temperatures in hot tubs and spas. Warm temperatures also make it hard to keep disinfectants at the levels needed to kill germs like Legionella. Therefore, hot tubs, spas and pools should be periodically inspected to ensure they are operating properly and adequately cleaned. Disinfectant levels and the pH should be checked regularly. 

Additional information from the CDC for large buildings, apartments, and facilities

• For more information about Legionnaires’ disease or the ecology of the Legionella bacteria, check out the CDC website

No. Tigard Water Service Area residents do not receive a fluoridated supply of tap water.

If you are concerned about the quality of water in your home, you may want to have your water tested. For a fee, private laboratories will test your tap water. Not all labs are certified to test for all contaminants.

In the case of an emergency, it is important to know the location of the water shut-off valve for your home. If you are unable to locate or operate the shut-off valve in your home, another alternative is to shut off the water main valve at the street. View detailed instructions:

Instructions for Turning Off and On Water

Water lines between the meter and the home are the responsibility of the home owner and there are companies that offer insurance to cover repair or replacement of those lines. The City of Tigard does not endorse or have any partnership with any organization offering this service. You are not obligated to purchase this insurance.

The safety of bottled water depends on its source and the treatment it has undergone. Using bottled water is a personal preference. If you are using bottled water for health reasons, we suggest that you thoroughly research the product that you are selecting to assure that is offers the level of protection that you are seeking.

Our water is very soft for most of the year. During the summer, some customers receive a blend of groundwater from our aquifer storage and recovery wells. The water from these wells is moderately hard.

Low pressure in one area can be because of a faulty plumbing fixture. For instance, if the kitchen sink works fine but the clothes washer takes a long time to fill, the problem is probably in the line to the washer or the washer itself. The same can be said of individual problems with showers, toilets, sinks, etc. If this sounds like the problem you are having, you'll want to contact a plumber or make the repair yourself.

One common problem is low flows in sinks due to clogged faucet aerators. We get a lot of phone calls from residents reporting small white or gray particles plugging their faucet aerators and strainers. This problem is not unique to Tigard’s water – it is the results of the dip tube in many home water heaters installed between 1993 and 1997. Faucet aerators can be cleaned to keep the water flowing. For a permanent fix, you’ll want to contact a plumber. 

If pressure is low throughout the house, air might be caught in the lines. This can happen if there has been construction at your house or in the area. Signs of air pockets include water "spitting" out of the faucet, cloudy or milky looking water, and possibly water that appears rusty. If you experience any of these things turn at least two faucets on full blast for 5-10 minutes; it's helpful if the faucets are located at different ends of the house. This should pull the air pocket through the water lines.

Another common pressure problem can be attributed to a bad pressure regulator. If the pressure seems unusually low throughout the house or if your pipes tend to rattle when certain fixtures are used, you may need to repair or replace your regulator valve.

Tigard’s water is treated to reduce lead release in the distribution system. Lead in drinking water does not usually come from the water source – it is released into the water from piping systems and household plumbing. Sampling in 2020 showed Tigard’s lead levels were well within regulatory limits, with 100% of testing locations having no detectable lead concentration. For more information, download our Lead Fact Sheet.

The odor is just chlorine doing its job to keep our water safe. The simplest way to get rid of the odor is to pour a pitcher of water and let it sit in the refrigerator. Overnight, the chlorine will have dissipated and the odor will be gone.

Water naturally varies in taste and odor at different times of the year. Taste and odor problems can come from new or old pipelines, plumbing fixtures, or changes in water quality. Customers may notice changes predominately during weather changes. These changes are closely monitored to ensure that they do not affect the safety of the water.

Occasionally you may see a decrease or increase in the water pressure. These are many possible causes of this problem, including air in the water lines, faulty plumbing fixtures, or a defective pressure regulating valve (many houses do not have a pressure reducing valve).

We regularly flush the water distribution pipes to remove sediments and keep the system clean. Residents in an area being flushed may temporarily receive discolored water. The water is safe to drink, but unpleasant for consumption and use. If you find discolored water, run the cold taps for five to ten minutes, or until the water runs clear.

Why are we flushing fire hydrants?

Flushing is a proven method that discharges a large volume of water through the main and out the hydrant. During flushing activities, water quality is disrupted due to scouring of pipes and the removal of sediments.  This is a short-term event. In addition to improving the quality of water, this process provides Tigard with the opportunity to assess the general condition of the hydrants. While we understand that this is an inconvenience to our customers, flushing provides beneficial, long-term water quality.

Will my water be shut off during flushing?
No. If you are without water contact us immediately.

Can I drink from the tap during hydrant flushing?
During flushing, it is possible you may receive discolored water. We ask customers to avoid using discolored water.  The water is safe from harmful bacteria, but unpleasant for consumption and use.  While it may not be visually appealing, it is safe to drink and continues to meet all federal and state drinking water standards. There are no health hazards associated with the discolored water.

What should I do if flushing is happening in my neighborhood?
The main impact of hydrant flushing is discolored water. Here is what you should do if hydrant flushing is taking place in your neighborhood:

• If possible, avoid using water while the hydrant flushing is taking place. By not taking water from the tap or running appliances that use water (dishwashers and washing machines), you can prevent discolored water from entering your household plumbing altogether.
• Do not do laundry while hydrant flushing is taking place. The discolored water can sometimes stain fabrics. Wait until water runs clear at the tap before using your washing machine. After your water clears wash a load of dark clothes first.
• If you encounter discolored water following hydrant flushing, run the cold water taps throughout your home (bathroom sinks and tubs, kitchen faucets, etc.) for five to 10 minutes or until the water runs clear. This allows discolored water to work its way out of your household plumbing.
• If, after hydrant flushing, your water pressure or volume seems low, clean faucet screens to remove silt and mineral sediment that could be obstructing water flow.

For more information: If you experience water quality problems lasting more than four hours following hydrant flushing, we want to know and provide immediate assistance. Contact the City of Tigard at 503-718-2591.