Hydrant flushing is the quick release of water from fire hydrants. It's a controlled procedure that is vital to the general maintenance of the City's water distribution system. It ensures adequate water flow is available to fire fighters, residents and businesses. It also helps maintain the City's water quality by clearing iron and mineral deposits from the water mains (distribution pipes).

Hydrant flushing helps ensure consistent water quality and helps avoid random incidence of rusty water if there is a high demand for water, such as a major firefighting effort or high usage during a sustained drought.

Sometimes hydrant flushing can make makes the water temporarily appear rust-colored because the iron and mineral deposits in the water get stirred up.

Sometimes hydrant flushing can make the water temporarily appear rust-colored because the iron and mineral deposits in the water get stirred up. Water is safe to use and consume during hydrant flushing, however it may stain laundry.

The main component of the discoloration of the water during hydrant flushing is caused by iron deposits from inside the water mains. The source of the iron is naturally occurring from groundwater wells and deposits in the ductile iron pipe that make up the underground water distribution system.

IWA is required by the U.S. Environmental Protection Agency and the California State Water Resources Control Board to test the water in the system at various times throughout the year according to mandated parameters. The results of these tests are outlined in the annual Water Quality Report available on this website. (The report is sometimes called the Consumer Confidence Report.)

Although the water is discolored during hydrant flushing and may look unclear or tinted, the water is not harmful or contaminated. To ensure the highest possible quality of water and in accordance with state and federal drinking water standards IWA collects samples from 21 separate collection points (by Code, IWA is required to have 20) every month from areas all over of the water system. This sampling takes place even during hydrant flushing operations. These samples are then analyzed for bacteriological contamination and other testing parameters at an independent laboratory.

Sometimes residents who live beyond the limits of the area where hydrant flushing is being performed will notice discolored water. We assure you that IWA is making every attempt to keep these impacts to a minimum, while continuing to maintain safe drinking water.

If you were home when the flushing was going on and you turned on your water, your water may be discolored because you are drawing in the water as the distribution system flushing stirs up the minerals and iron.

If your neighbors were not home all day and returned home in the evening and turned on their tap when no flushing was occurring, they most likely will not notice any discoloration.

Wait until flushing has subsided in your area then run the cold water tap until the water runs clear. If you have a water softener and are experiencing discolored water, place the unit into regeneration or cleaning mode after hydrant flushing is completed in your area. Remember discolored water is safe, but it may stain laundry. If this happens, keep clothes wet and treat them with stain remover.