​​Pink Stains - What Are They

Pink residue typically is not a water quality problem. Pink discolorations can be the result of iron found in some well water or older pipes found within the delivery system. However, if this were the case, stains would be found throughout the home, not a single toilet, faucet, or even a room. Most often pink residue is likely caused by airborne bacteria that produce a pinkish or dark gray film on moist surfaces. This film is typically found as a ring at the water line in the toilet bowl or around showerheads, shower doors or curtains, sink drains, bathtubs, tiles, and grout.

Some people have even found the pink residue in their pet's water bowl, which causes no apparent harm to the pet and is easily cleaned off.

Many experts agree that the bacteria that causes this type of stain is most likely Serratia Marcescens, a bacteria that’s found in soil, food, and animals. Serratia, produce a characteristic red pigment, thrive on moisture, dust, and phosphates, and need next to nothing to survive. Serratia spreads easily and will seek a moist location in which to grow. Some people have reported that the residue only appears during certain times of the year, often when their windows or doors are left open. Ironically good ventilation does not help. These bacteria are present in many environments and the wind can carry it or dust in which the bacteria are present.

Serratia Marcescens thrive in conditions that are wet and seek out
materials, such as feces, urine, soap, personal hygiene products such as shampoo, and/or food products.

Bedford Regional Water Authority
1723 Falling Creek Road • Bedford • VA 24523
540.586.7679

Pink Stains