Module 4 Intro

Humic Acid Discolouration.This discolouration can be caused by humic acid, which is present naturally in soil and vegetation. At the current time, it is assumed this substance has no significant effect on human health. Research is being done to see whether the chlorination process reacts with humic acid to create toxic by-products or whether the presence of humic acid correlates to the presence of heavy metals in the drinking water.

Iron Discolouration. Iron can naturally enter drinking water from soil and rocks or from being leached out of pipes. In low doses iron is a nutrient required by the body, so there is no significant health risk.

Reddish-brown water can also occur if rust-coloured sediments are disturbed during water main repairs. This discolouration can often be remedied by letting the tap run for several minutes.

Copper Discolouration. On rare occasions, specific conditions arise that allow copper to be leached out of pipes into the drinking water. This is not typically a hazard since copper in trace amounts is an essential nutrient. However, in older homes, lead may have been used in some of the pipes. The same conditions that can leach copper can also leach lead, which is very toxic and not easily detected.

If you suspect your home may be of the age where lead pipes were used during construction, you may want to contact your regional health authority to ask them to test your water.

Manganese Discolouration. Much like iron, manganese can naturally enter drinking water from soil and rocks. In addition to tinting the water, it can sometimes be found as small black specks in a glass of water. Manganese is an essential nutrient, and in small qualities it does not have any negative health effects.

Chlorine. Chlorination is used in the water-treatment process.

To keep water free of bacteria all the way to your tap, some chlorine must be allowed to remain in the water. Occasionally, there may be enough chlorine that an odour can be detected. This low quantity is non-toxic, and you may drink the water. If the taste and smell of chlorine are not appealing you, simply let the water stand and the chlorine will dissipate.

Hydrogen Sulfide Gas. This can occur in cases where tap water is coming from a well. Decomposing deposits of underground organic matter produce this gas, which may then enter the well water. Hydrogen sulfide gas can also enter well water that is near coal deposits or oil fields.

In some cases, the water itself is not the cause of the rotten-egg smell; rather it is coming from the drain. Anaerobic bacteria can thrive in this environment, producing hydrogen sulfide gas that accumulates underneath the food trap. When the water is turned on, the gas is forced out of the drain, yielding the rotten-egg smell. This problem can be fixed by pouring a cup of household bleach down the drain to kill the bacteria.

It is also possible that the smell is coming from the hot water heater, which has a magnesium rod that can interact with sulfates in the water to produce hydrogen sulfide gas. This is likely the problem if the rotten-egg smell is present in hot water but not cold water.

Hydrogen sulfide gas is not harmful at the levels you would find in tap water, and the bacteria that produce it pose no known health risk. However, if the smell is indeed coming from the water and has appeared for no previously known reason, it would be a good idea to call your water supplier to inform them of the problem. Hydrogen sulfide gas can, in rare cases, result from pollution or sewage contamination.

Algae Growth. There are many different tastes and odours that are the result of algae growth in reservoirs. Depending on the type of algae, the water can taste and smell fishy, swampy, grassy, and even like cucumber! There are no health risks associated with smells related to algae growth.