builditnow
Civil/Environmental
- Oct 1, 2004
- 5
1 of the 20 wells in our system required the pump to be pulled due to flow flucuations of 20 to 40 gpm, normally pumps 35+ gpm, and the pump finally failed. When pulled the drop pipe, pump and motor had a thick (1/4")black sludge on it. This same well pump was replaced in Oct 04 ( very thin black film at that time and did not seem abnormal for our sources), the well sat idle from Jan 06 through May 06 during testing of another well in the same aquifer (1000 ft away). I don't have recent tests of soluable iron or managanese in the well water but most of our wells have both but significantly less then EPA limits. I collected samples of the sludge and dug what appears to be flakes of rust out of the pump screen with a screw driver. The dried sludge cake when rubbed between fingers is fine and looks like lamp black, when washed off leaves a brown stain on fingers. I am wondering if this is manganese bacteria problem due to the bulking characteristic? and iron bacteria problem? or if anyone has had this experience. The well is 450 ft deep and the pump is at 340ft. Has been online for a minimum of 6 years and is located in Central MD.