Well water sometimes brown

[srsmith]

Summer cottage used 4 months/year. Well was drilled 75 years ago. 6" iron casing. 125 feet deep. Jet pump is 75 feet deep in casing. We have a tank with chlorine/water mixture. That solution is added by feeder pump before a holding tank. The water is carbon filtered. The cottage has kitchen sink, bathroom wash basin and toilet. We carry in our drinking water. Cottage is used primarily on weekends. We manually trigger the backwash on the carbon filter every 2nd or 3rd weekend. Regardless of when we have backwashed, the water will run clear then turn brown. Later it will run clear again. We have never poured chlorine into the well.

Cause/solution for the brown water?

 

[Valveman]

Sounds like rust from the old steel casing. You might be able to pump it out. Try running a large amount of water for several hours and see if it cleans up. You need to run enough faucets or a large enough faucet that the pressure stays low and the pump does not cycle off.

 

[Sponsor]

 

[Reach4]

I wonder if your backwash of the carbon tank has enough gpm for your diameter of tank. If you have a flexible drain line, you can measure the backflow rate by timing how many seconds it takes to fill a 5 gallon bucket.

To measure the diameter of your tank, you can measure the circumference, and divide by pi. Then round down.

10 minute backwash?