While scanning for water-related news stories this morning we found a few articles announcing hydrant flushing and figured today a good day to talk about… hydrant flushing.

Iron in Water Visual Test Kit
Iron in Water Visual Test Kit

When the water department (or fire department) flushes hydrants in your neighborhood, discoloration of your water and issues with pressure may occur — BUT for the most neither of the issues really ought not pose health risks.

Experts in the field do, of course, suggest letting faucets run to allow discoloration and any trapped air pockets to pass before collecting water for use, though.

Why flush hydrants?

Not all water lines in a system get equal use and that means sediment may have the ability to collect in less used lines. Over time that sediment could possibly build up to the point where it forms an obstruction. In the event of a fire that obstruction could stop much needed water from flowing through firemen’s hoses.

What is the discoloration?

Metals in Water Test Strips
Metals in Water Test Strips

Typically we have seen the discoloration come from rust formed in the pipes between the water treatment facility and the hydrant. Remember: The water typically contains chlorine (an oxidizer) and that water sits idle in metal pipes… so certainly rust can form over time.

As stated previously, the flushing of hydrants helps to keep that rust from building up in ways that would impair the water system’s flow rate.

Should I test my water for metals after hydrant flushing?

We have not heard of incidents where drinking water absolutely needed testing for metals after hydrant flushing but it does stand to reason (in our opinion) that a homeowner may want to test for things like metals (and possibly coliform bacteria) after any event that disrupts the water supply.