Depending on the type and age of the well, there could be several reasons that well water suddenly becomes dirty or contaminated. Routine maintenance and water testing to check for chemical balance and unwanted contaminants will help ensure clean water and a longer well life.
Broken Pipes
The most common cause of dirty well water is simply a broken well pipe that is allowing dirt and surface run-off water to enter the well water. This can leave the water with an odor, bad taste and dirt in the bottom of your drinking glasses.
Mineral Deposits
Mineral deposits can break down in well pipes, leaving behind sediment, grit and grime in the well water. Using a filter and cleaning it regularly will help reduce the chance of this "dirt" from entering your home.
High Iron Levels
Well water with high levels of iron, can leave behind red stains in toilets, sinks and washing machines. Adding improved filtration will remedy the problem.
Organic Matter
Well water with a musty, earthy smell and black or yellow stains on clothing, toilets and sinks are most likely contaminated with organic matter or decaying vegetation. This problem requires better filtration and chlorination procedures to correct.