How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Brian Your Own Question
Brian, Architect
Category: Home Improvement
Satisfied Customers: 3123
Experience:  Licensed Architect- 17 years, L.E.E.D. AP
Type Your Home Improvement Question Here...
Brian is online now
A new question is answered every 9 seconds

What causes black soot in my water system

Resolved Question:

What causes black soot in my water system
Submitted: 9 years ago.
Category: Home Improvement
Expert:  Joseph replied 9 years ago.
Do you happen to have a well?
Customer: replied 9 years ago.
Reply to Joseph's Post: No I don't have a well system. When I turn on the water for a shower or bath I see black water coming out from time to time and clears up for a while.
Expert:  Joseph replied 9 years ago.
Im going to opt out of this one. If you had a well I could help you. But since you dont - ill let another expert take over. Good luck.
Customer: replied 9 years ago.
Reply to Joseph's Post: ok, thanks.
Expert:  Brian replied 9 years ago.
Hello ,

Welcome to Just Answer.

If you see it in all faucets:

When hydrants are flushed (our town does annually in the overnight hours), the high volume and pressure clean out our old iron water mains like a steel brush would, sending rust and loosened deposits to the end of the line where the hydrant is. Although a lot of that water is run out of the hydrant, the remaining sediment in the line will always run to the hydrant for a few days afterward, and the area homes will get the discolored water. This is also true when there is a water main break (many in the cold northeast with old water systems), and some sediment from the soil around the broken pipe could get in as well. We also saw this problem when the town reversed flow direction for some neighborhoods while repairing gate valves in the mains.

If it is just the tub/ shower:

I know when changing a toilet flapper(after we tampered with it) it will sometimes leave bleed black. Perhaps one of the washers in your faucet(if it has black washers) is bad. Does it have any problems turning off? I doubt it has anything to do with the water heater if its only that faucet and not others that is causing the problem. If it is hot side only, it is probably the washers within the hot side of the faucet. They are deteriorating. Hot water is harder on them then the cold side. Remove the valve and replace it with a new valve insert. Do not forget to replace the valve seat within the valve housing. If you do, you are wasting your time. Replace both hot and cold sides.

If you should need further help on this question, please reply to this post.

It is my objective to make sure that your question is answered to your complete satisfaction.

Best of Luck,


Please click the green "ACCEPT" icon, if you feel that I have met this requirement.

This is a FEE based website & your payment allows us to be here for you.

PLEASE LEAVE FEEDBACK; it is important to me

BONUSES are appreciated.

Brian, Architect
Category: Home Improvement
Satisfied Customers: 3123
Experience: Licensed Architect- 17 years, L.E.E.D. AP
Brian and 4 other Home Improvement Specialists are ready to help you
Customer: replied 9 years ago.
Reply to Brian's Post: I have noticed the problem in all 3 bath rooms. Using the faucet or shower. I noticed this problem about 2 years ago. It seems to happen when the weather is cooler and I'm using the hot water. The soot that was left over in the bath tub was black and had very small Granular sand type stuff. The house is 6 years old, so fairly new. Your response about the flushing of water by the city sounds promising.