Mineral And Metal Contamination

Not all minerals found in your well water can harm you and your family. Some minerals may only cause a discolouration of your water, plumbing, and clothes. However, some metals and minerals may react with your well lining and cause health problems. In Newfoundland and Labrador there are certain minerals and metals that can be found in your water. The “ Guidelines for Canadian Drinking Water Quality ” set by Health Canada state what the concentration of a particular mineral or metal can be in your water before it will be harmful or esthetically displeasing. These may include:

• Lead
• Copper
• Uranium
• Arsenic
• Manganese
• Nitrates
• Chlorine
• Iron
• Sulfur/Hydrogen Sulfide

Minerals and metals are more of a concern for drilled well owners than dug well owners. This is because the water in drilled wells comes from deeper aquifers. Water in deeper aquifers move more slowly through the ground and have been in contact with rocks that contain minerals and metals longer. Because of the contact between water and minerals and metals, traces of the minerals and metals may be found in the water.

Below is some information compiled from the Canadian Drinking Water Quality Guidelines and Buying a House with a Well and Septic System, CHMC, 2003. This is for initial information only. If you suspect you have any of these chemicals in your water, test immediately.

Lead

Lead in your water can come from the pipes or from the soil. Lead concentrations of 0.01mg/L can cause long-term health effects.

Copper

Copper occurs naturally occurring in soil and can also get into your drinking water from copper pipes. Copper enhances the corrosion of aluminum and zinc. Also, water with high copper content may have a bitter taste. Stains will appear on laundry and plumbing when the concentrations exceed 1.0mg/L. Copper is also necessary for the functioning of the human body, so concentration below 1.0mg/L are good for you.

Uranium

Uranium is a naturally occurring radioactive metal in the soil and can also come from mine tailings. A concentration above 0.020mg/L in drinking water is above the Drinking Water Quality Guidelines. Uranium is easily released from the body if ingested. The chemical properties of uranium are more of a concern than the radioactivity.

Arsenic

Arsenic is poisonous to humans and does not produce a smell or taste. The concentrations are higher in drilled wells than dug wells, and higher in wells than surface water. The drinking water guideline is 0.025mg/L. Arsenic is easily soluble in water. Many of the locations in Newfoundland and Labrador where arsenic is found are documented. If you are concerned get your water tested or contact the Dept. of Environment and Conservation.

Manganese

Manganese in your water can appear as black staining of your pipes, faucets, sinks, and bathtub. You may also find black specks and a metallic taste in your water. This will happen when the concentrations are above 0.05mg/L.

Nitrates

Nitrates that are found in your water may come from residential and agricultural fertilizers, or seepage from a septic system. It may not be a problem for adults, but will make infants less than six months old sick if their formula is made from well water with concentrations exceeding 5mg/L.

Chloride/salt

You may know you have chloride in your water if it tastes salty and if the concentration is above 250mg/L. Also, high chloride concentration may corrode your pipes.

Chloride in the form of salt can be found in well water. The ground consists of varying layers, when your well is drilled or dug into a layer containing salt, your water will have a high salt content. Also, if a well is drilled near the ocean, over time you may get salt water in your well. This occurs when you are using more water from a freshwater aquifer than is being placed back into that aquifer resulting in water being pulled in from the surrounding area which is the ground near the ocean. This is also called salt water intrusion.

Another source of chloride in your water is from the use of water softeners. The water softeners use sodium chloride to reduce the metal in your water. The sodium chloride can be harmful for people who are on sodium-reduced diets.

Iron

If you have a concentration of iron above 0.3mg/L, you may notice a metallic taste on your water. Also, your pipes, sinks, and bathtub will be stained a rusty colour. Another symptom of iron is that your clothes will be stained a rusty colour. There may also be a thin, oily layer on the surface of the water in your well.

A high iron concentration may also be associated with iron bacteria. These bacteria will form a red/brown jelly-like substance around the pipes in your well and on filters. You can get rid of the bacteria by disinfecting your well. If the use of regular household bleach does not work, you may have to use a stronger bleach, like the bleach used to clean pools.

Bathroom fixtures stained from severe iron deposits

Sulfur/Hydrogen Sulfide

If you turn on your tap and get a rotten egg smell, then there is a good chance that there is sulfur in your water. At the concentrations it is found in groundwater it is generally not harmful, but at high concentrations it can make you sick. You know you may have Hydrogen Sulfide in your water if your water is bitter and have a laxative effect. The guidelines state the maximum limit of sulfates is 500mg/L and for sulfides is 0.05mg/L.

Hardness