Stains can show up on fixtures, appliances, laundry and even hair. These stains show up commonly as rust color, black, brown, and blue stains. An occasional pink stain may show up in toilets, which is caused by airborne bacteria and not a subject of this article.
Rust stains: Iron is one of the most common elements in the earth’s crust and is found in many ground waters. The maximum contaminant level (MCL) set by USEPA standards is 0.3 ppm, also referred to as 0.3 milligrams per liter of water. In concentrations above 0.3 ppm, iron in water can cause staining of fixtures and laundry, and impart a bitter, rusty taste to water.
Iron is often found in a dissolved state in well waters, and the water appears clear when first drawn. Upon exposure to air, or after the addition of oxidants (such as chlorine bleach or ozone), this ferrous iron is oxidized (“rusted”) to the ferric state to form insoluble particles. The water then looks orange or yellow, or in the case with manganese, brown or black. This can happen in toilet flush tanks and in the washing machine or dishwasher. An iron test shows if this is the cause of the stain and how much iron is in the water.
Brown stains: Manganese is a common element in the earths crust and is found in many ground waters. Manganese is not considered toxic, although some studies show it causes stomach upset and diarrhea in concentrations over 0.05 ppm. The maximum contaminant level (MCL) set by USEPA standards is 0.05 ppm, sometimes referred to as 0.05 milligrams per liter (mg/L) or 50 micrograms per liter (µg/L).
In concentrations above 0.05 ppm, manganese in water can cause staining of fixtures and laundry, and impart a bitter, asphaltic or oily taste to water.
Manganese is often found in a dissolved state in well waters, and the water appears clear when first drawn. Upon exposure to air, or after the addition of oxidants (such as chlorine bleach or ozone), the clear dissolved manganese is oxidized (“rusted”) to form insoluble particles of manganese oxide. The water then can look tea-colored, brown, or black and have an oily surface or appearance. This can happen in toilet flush tanks and in the washing machine or dishwasher.
Black stains: This can be caused by iron sulfides which are formed by the combination of iron and sulfides in water. This is most common in water that has strong sulfur odor. It can also be caused by manganese and/or manganese sulfides. Test for iron, manganese, sulfates, and hydrogen sulfide to identify the cause of black staining.
Tea colored staining: this can be caused by manganese and/or low levels iron. Tannin in water caused by organic material from decaying vegetation can also leave tea-colored stains and light brown streaks in laundry. Test for tannins in addition to iron and manganese for this problem.
Blue stains: Its starts with blue stains on your fixtures and toilets. You might notice laundry streaked with blue, and the water might have a bitter taste. Eventually the copper pipe corrodes and you start to see pinhole leaks. These problems are all caused by your copper pipes corroding. Copper pipe corrosion can be caused by water that is low on the pH scale, meaning acidic water. It can also be caused by water that is high in pH and total dissolved solids. These problems can be easily fixed only if you can correctly identify what the water chemistry is first. To identify this problem test for copper, hardness, alkalinity, pH, and total dissolved solids. Once you know what these numbers are a Langelier Saturation Index, or LSI calculation can be performed, which will show if your water is corrosive or not.