Stain & Corrosion Issues

Iron (Fe) 
The presence of Iron is a very common water quality problem, particularly in water from deep wells. Water containing even a significant quantity of iron may appear clear when drawn, but will rapidly turn red upon exposure to air. This process is called oxidation, and involves the conversion of ferrous (dissolved) iron, which is highly soluble, to ferric (precipitated) iron, which is largely insoluble. The ferric iron then causes red/brown staining on clothes, fixtures, etc. 

Iron concentration is measured in ppm or mg/l (milligrams per liter, where 1 ppm = 1 mg/l). Staining usually becomes a problem at concentration greater than 0.3 ppm. 

Manganese (Mn) 
Manganese is a metal similar to iron which causes grey/black staining. It can cause staining in concentrations as low as 0.05 ppm. Manganese is removed in a manner similar to iron, although oxidation is more difficult, requiring a pH of at least 8.5. 

Hydrogen Sulphide (H2S) 
Hydrogen Sulphide is a gas which smells strongly like rotten egg odor. It results from the decay of organic matter with organic sulphur and the presence of certain types of bacteria. Even very low concentrations are offensive as well as highly corrosive (silver tarnishes almost immediately upon contact with H2S). 

Because it is in the form of a gas, H2S cannot be collected in a sample bottle for laboratory analysis. Therefore its presence must be reported when a sample is submitted for a treatment recommendation. 

Coliform Bacteria, Fecal Coliform and E coli 
Coliform bacteria are common in the environment and are generally not harmful. However, the presence of these bacteria in drinking water is usually a result of a problem with the treatment system or the pipes which distribute water, and indicates that the water may be contaminated with germs that can cause disease. 

Fecal Coliform and E coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms.

Turbidity 
Turbidity is a measure of suspended particles in water and can range from large particles which settle out of solution rapidly (such as sand), to extremely fine sediment which may stay suspended in solution even after standing for hours. Treatment depends upon size, which is measured in microns. 

Tastes and Odours 
Most tastes and odours are caused by the presence of organic matter and chlorine. The vast majority of these can be removed with activated carbon. 

Volatile Organic Compounds 
The presence of toxic chemicals at various concentrations has been widely documented in many water supplies. Detection can be difficult as these contaminants often have no taste or odour. Treatment depends on type and concentration. These chemicals may be industrial solvents or agricultural pesticides and herbicides. One of the most common is Trihalomethane (THM) which is formed when chlorine in the water reacts with natural organic matter. 

Volatile organic compounds are compounds that have a high vapor pressure and low water solubility. Many VOCs are human-made chemicals that are used and produced in the manufacture of paints, pharmaceuticals, and refrigerants. VOCs typically are industrial solvents, such as trichloroethylene; fuel oxygenates, such as methyl tert-butyl ether (MTBE); or by-products produced by chlorination in water treatment, such as chloroform. VOCs are often components of petroleum fuels, hydraulic fluids, paint thinners, and dry cleaning agents. VOCs are common ground-water contaminants 

Total Dissolved Solids (TDS) 
TDS is the sum of the mineral salts in water and if too high can result in objectionable taste, cloudy ice, interference with the flavor of foods and beverages and scale left behind in cookware. Generally speaking, the lower the TDS the more acceptable the drinking water. TDS of 1,000 ppm or more is unacceptable for drinking water. 

Nitrates (NO3) 
Nitrates are inorganic chemicals dissolved in some water supplies as a result of feedlot and agricultural activities. Nitrate levels over 45 mg/L as actual NO3 (or 10 mg/L as Nitrogen, N) can be a serious health risk to infants and children.