I rent - a few months ago there was a note saying that the water had to be shut off for a bit to do some “work” on it. Ever since then, the cold water at first always comes out cloudy - I have to let it run for a few second before it clears up. Why is that? Thanks!
Take a glass of the cloudy water and let it sit. If it turns clear, then it’s tiny air bubbles. It it doesn’t turn clear, someone needs to be notified.
I don’t know why plumbing does it, but it can get bubbles in it that are so tiny that they stay suspended for longer than you’d expect. It should be a matter of, say, five minutes or less for them to settle up.
Fill up a glass of water and watch it turn clear. Does it turn clear from the bottom to the top? If so then it is just air bubbles.
I get them all the time when they turn the water off. Usually they only last for a day or two. I don’t know why it would still be happening months after the water was turned off.
In my experience, the tiny air bubbles that cause clouding are nearly always associated with ‘noisy’ taps - not sure whether the noise is caused by the bubbles or vice versa though.
Neither causes the other. Both are results of air in the pipes.
Why? Sediment normally collects in pipes and sits harmlessly on the bottom. When the water is shut off and turned back on, the sudden rush stirs up this sediment. After that it will be “looser” for awhile and just turning on a tap will stir up more dirt. If the mains were shut off, a lot of the dirt in them has now moved upstream into your plumbing.
Eventually the loose stuff will either work it’s way out or settle back to the bottom, until next time.
As for sediment, I wonder if the sudden release is caused by pipes stretching? If the crust is very brittle, then the slight change in pipe diameter when pressure is turned off (and then turned back on) might be enough to crack some of it loose.
I had always thought the days of sediment were caused by big bubbles passing through the pipes when the water was turned back on. But if the main valve isn’t opened INSTANTLY, the water won’t rush any faster than during normal use. Then I heard some pipes creaking when the pressure was turned back on, and realized that the whole network must INFLATE slightly when 50psi (or 100) pressure is applied.
Actually, come to think of it, I’m pretty sure there’s a tap in the kitchen at work that can be made to run clear by turning it on fully, or run cloudy (bubbles, not sediment) by turning it to about ¼, wherupon it will emit a sort of whistling/hissing noise. Since it seems unlikely that there is air constantly entering the stream of water (it is under pressure, after all), is it possible that the tiny bubbles are actually gses coming out of solution as a result of perhaps some sort of oscillating pressure effect (that is also causing the noise)?
Well, let me clarify my comment a bit. I’m assuming that the pipes were drained during the maintenance. Normally water flows fastest down the middle of the pipe where the friction is the least, and very slowly along the edges, particularly the bottom where the sediment is.
When the water is turned back on, it moves pretty fast because there’s no pressure ahead of it and it’s pretty easy to push the air out of the way. As the pipe fills, the water first runs along the bottom, where all the muck is, stirring it up. Bubbles, particularly large ones, will also force more current along the bottom than normal.
bbeaty, I think, has a point. I’ve seen this happen when the pipes have been filled with air long enough to dry out. This makes the sediment brittle and little chunks of it show up in the water. The most extreme case is when I first hook up a garden hose in the spring. There can be half a cup of sediment in a 50-foot hose.
Another thing that happens in this area is that the fire department will routinely open the hydrants to flush the sediment out of the lines. This really stirs the dirt up and may drop the pressure enough that when some people open their valves it will suck air into the pipes instead of pushing water out.
Another thing that will temporarily cause excess bubbles is if the pipes were not bled when they were refilled. They get drained, fixed, then the water is turned back on. If the other end isn’t open, the air in the pipes has nowhere to go, and gets pressurized by the water. When you open your tap up the water that comes out is supersaturated with extra dissolved air, which bubbles out of solution once it hits the ambient air pressure of your kitchen; the same thing that causes the bends if you ascend too fast from diving.
Hard to say how long that would last though, depends on how much air was pressurized to what degree and how much the taps get opened afterwords. At my university fish farm there was a big fish-kill when the city plumbers neglected to bleed the air out of the pipes after doing some piping work a few hundred yards “upstream” of our tanks, and we lost lots of fish to gas bubble disease.
I need to retract my post. I mixed up in my mind the air/hammering thing, and what I posted is wrong. My apologies.
Plumbing systems have short vertical sections of pipe that are supposed to be filled with air to act as a shock absorber. It’s when the air cushion is lost from those pipes that you get hammering.
To add to the confusion:
My tap gives out a cloudy white stream of water… if i collect it in a mug and observe it, the white particles rise to the surface and then evaporate… sometimes I can see the white fumes as it leaves the surface of the water… the water is then clear.
Is this characteristic of air bubbles ? Or do I have some sort of chemical in my water ? I’m thinking it has something to do with the white pasty sealant my plumber used for a leak in the pipe.
Anyone have any ideas what this could be ?
I occasionally experience a similar problem, particularly at the beginning of summer when the solar hot water system is really starting to kick in.
Since the cloudiness fades quickly, I’ve always assumed it’s dissolved air.
Still, makes me pretty oogy to brush my teeth with water that looks almost like milk. 
That is very characteristic of air bubbles. In fact that is exactly what my water was doing when I called the water company to come look at it. My problem went away in a couple of days because it was a result of them turning off the water in my neighborhood and air getting into the pipes.
I am sure that what every the plumber used for a leak in your pipe is not going to get into the water or harm you.
So, Robo, was the problem air bubbles?