The Big West Seattle Flush, Week 4: The battle against brown water and what you need to know as it continues

By Tracy Record
West Seattle Blog editor

Three weeks down, “several more months” to go.

Most late nights and early morning, somewhere in West Seattle, Seattle Public Utilities workers are flushing another section of our area’s aged water mains, to tackle the “brown water” problems that have vexed customers around the area.

To get the root cause – rust and sediment – out of the system, however, stirs it up in some spots – so, as was the case for a reader who e-mailed us early today, it gets temporarily worse in order to get better.

Meantime, we’ve checked with SPU for an update on how the project – first previewed here March 31st – is going, including one change in the plan, plus we have a firsthand look at what happens at a flushing scene:

First, for a refresher course – this is the area where SPU is working first, through June:

W Seattle Flush Map Apr 8_FINAL

When they’re on scene, there’s a lot more to it than just opening a hydrant and letting the water run to the nearest drain, we found out one recent night, when SPU’s drinking-water-quality director Wylie Harper joined us at a flushing site in south Admiral.


He was joined that night by SPU communicator Ingrid Goodwin, with whom we checked on Tuesday for an update on the project.

Goodwin tells us that in the fourth week of “unidirectional flushing,” it’s “proceeding well.” They’ve done 21 of the 100 flushes they need to do in the North Admiral area alone. “We’re taking our time, doing it right and making field adjustments as we observe how the system is responding.”

Here’s what you should know about one adjustment. Goodwin says, “One of the challenges of achieving a successful unidirectional flush is achieving sufficient velocity while maintaining adequate pressure within the system. We are learning that this may require temporarily shutting off the water for some customers in the middle of the night (from about 11 pm to 4 am). Impacted customers will receive a door hanger at least 48 hours in advance of the shutdown.”

But even if you don’t have to deal with a shutoff, as mentioned earlier, you might see brown water temporarily as a result of this longterm effort to reduce its cause. Goodwin notes, “We are receiving good feedback from customers about the effectiveness of the flushing. One customer came outside before the flushing began with a glass of water that was discolored. He later returned when the flushing was complete with a glass full of clear water.”

If you notice discolored water, SPU stresses, please don’t just assume it’s the flushing – call them at 206-386-1800: “Information from customers really help us determine where the problem spots are located and how widespread the issue may be.” And you probably won’t know at the time whether the pipe’s been, or being, flushed anywhere near you (last night, for example, crews were at 46th/Stevens, 48th/Stevens, Hanford/Garlough).

The specific hydrants/lines to be flushed are chosen in a way that clears an entire section of pipeline at a time. It can be noisy, crews noticed early on, and the night we joined them in the field, they showed us what they’re doing to try to keep it down and keep it off nearby properties. The night we were out with them near SW Spokane in South Admiral, the first hydrant was right next to a fenced yard:


We were shown the “sound barrier box” the crew – headed by Nick Grover – came up with to muffle things once the flushing began:


What’s in the box besides hoses? The Hose Monster (explained here):


Doing the work overnight had already required a variance from the city planning department.

The goal at each location is to flush water equal to three times the volume of the stretch of pipe they’re clearing. The night we observed, that meant almost a mile of pipe – since the length they were working with was 1,600 feet. As the water discharges, since it’s going into the storm-drain system, it’s treated with vitamin C tablets to neutralize what it had been treated with before going into the residential system – they’re in the orange material you see the water flowing over:


Once they verify they’re at the right volume of water, they flush the water until it’s clear, measuring turbidity – cloudiness – throughout the process, and testing for other water-quality standards.


Meeting that standard means the flush of this section of line might take more than the 17 minutes or so that it should have technically taken to get three pipe volumes out, at five feet per second – more than five times the rate at which it would normally move through pipes. What they try to avoid is running fast and suddenly stopping, to the point where what they stirred up – that rust and sediment – stays in the system, and turns up in a nearby tap.

Everyone on the crew, meantime, has a role, including the person who watches to be sure the flushed water is going into the right place at the bottom of the hill. Overall, “there’s a little bit of an art form to it – just as long as it’s not moving backward,” Grover says.

Once more – even if you think it’s flush-related, if your water turns up discolored, please report it to SPU: 206-386-1800.

9 Replies to "The Big West Seattle Flush, Week 4: The battle against brown water and what you need to know as it continues"

  • John May 11, 2016 (11:46 am)

    This is one way to clean a water main.  Another way is to send a ‘pig’ through the line.  Yup…it’s called a ‘pig’.   You’ll be grossed out when you see how dirty a water main really is. 

    Water mains develop a great deal of growth on them.  I remember about 10 years ago working on a design project where I had to replace the main 30-inch (or 36-inch) steel water main that feeds West Seattle coming in along Spokane Street.  The City send a camera down the line and it looked like it had the same growth on its walls as a piling in Puget Sound. 

  • Diane May 11, 2016 (1:35 pm)

    my apt bldg, right on the border on 37th; still, none of our tenants have received mailer about these flushes; CM Herbold and her staff were responsive when I emailed her office about “are they mailing any notices to renters?”; interesting timing that when I received email from her referral at SPU (who emailed attached map that I already had from wsblog story), just the night before, there was a SPU crew set up half block north of our apt bldg doing flushing, so within about 6 houses of us, and we still have not received any notices; curious if ANY apt dwellers in Admiral received this mailed notice about the flushes

  • newnative May 11, 2016 (2:01 pm)

    We have not had any notices in our condo building nor in the mail.  One day our laundry was affected by the discolored water.  

  • AwakeAtNight May 11, 2016 (2:37 pm)

    They are flushing directly across the street from us, and it’s not the flushing noise that’s loud.  It’s the voices from workers talking, and the “beep beep” when their trucks back up.  We had to close our windows to muffle the beeping noise, which is very loud on a quiet street in the middle of the night.  

  • Kate May 11, 2016 (2:59 pm)

    I’m still not clear about the safety of the drinking water – ours has occasionally been slightly discolored in Seaview. Is it safe to drink?

  • Mike Flynn May 11, 2016 (10:23 pm)

    Hm. We had discolored water two weeks ago, but nowhere near Admiral — we’re between Fauntleroy and Westwood. Probably too late to call about it now, especially since I’m not sure what day it was.

  • WS gal May 12, 2016 (5:07 am)

    Our water is brown. Albeit light brown, but brown. Called the number and Shepperd with spu said to leave it be for 8 hours and it will clear up. Not sure I feel comfortable with that response. Figured something a bit more inquiring, but don’t think it’s a big deal to them :( hope it’s better soon. In the meantime would like to thank the WSB for this story. What would west Seattle do without you! 

  • sbre May 12, 2016 (10:53 am)

    I’m at Admiral & 46th and just found a “NOTICE of WATER SHUT-OFF” hanger on the door informing us that on Tue May 17th from 11pm until 5am is the “maximum anticipated” time we will be without water. 

Sorry, comment time is over.