Everyone wants the water that comes out of their taps to be pure, but sometimes contaminants find their way into it. The Environmental Protection Agency identifies contaminants that it regulates in public water systems. The EPA doesn’t regulate private wells, so if that’s where you get your water from, you’re responsible for making sure it’s safe to drink. Whether you get your water from a well or public water system, it pays to watch out for contamination so you can use one of several methods to get rid of them.
Here are 10 of the most common contaminants you should watch out for:
Aluminium can leach from rock or soil into the water supply and may be found in groundwater. The EPA sets a secondary maximum contaminant level, or SMCL, of 0.05 to 0.2 milligrams per liter (mg/L) for aluminium. Concentrations of more than 0.1 parts per million (ppm) of aluminium can impact the colour of water, and high amounts can cause deposits in water systems.
The EPA has set a maximum contaminant goal level (MCLG) of zero for arsenic, but the maximum contaminant level (MCL) allowed is 0.010 mg/L. Some places in the U.S., especially the western states, may have arsenic levels that exceed this amount. Arsenic can leach from natural deposits or come from wood preservatives, some pesticides or petroleum production. The substance is known to be toxic and can have cancerous effects.
Barium is a metal that can be found in natural deposits and enter water due to the disposal of drilling waste, copper smelting and vehicle part manufacturing. The MCL and MCLG for Barium is 2.0 mg/L. Barium compounds that don’t dissolve well in water typically aren’t harmful, but those that do may cause difficulty breathing, changes in heart rhythm, increased blood pressure and other health problems.
Cadmium is a metal that typically gets into drinking water due to the deterioration of galvanized metal pipes, and also because of industrial waste and certain fertilizers. Exposure to high levels of cadmium in drinking water can cause nausea, vomiting, diarrhoea, muscle cramps and other effects. Long-term exposure can lead to liver, kidney, bone and blood damage. The MCLG and MCL is 0.005 mg/L.
Lead typically enters drinking water because of lead service lines. The EPA MCLG is zero, and the action level set by the EPA is 0.015 mg/L. The setting of an action level means water utilities must sample water and verify that 90 percent of the samples have concentrations below this level. If this isn’t the case, the utilities must take action to correct the problem. Lead is known to be toxic, and it’s more dangerous to children than adults.
Nitrates are compounds of nitrogen and oxygen. The sources of nitrate in water include human sewage, livestock manure and fertilizers. The MCLG and MCL are 10.0 mg/L as nitrogen. Except for in extreme amounts, nitrates are typically only harmful to people younger than six months old. Exposure to water with more than 10 mg/L may cause a temporary blood disorder called methemoglobinemia or blue baby syndrome.
Radium is a natural, radioactive element, and the radiation it emits can cause cancer, birth defects and kidney damage. The EPA has set a MCLG of zero picocuries per liter (pCiL), a unit for measuring radioactive concentration. The MCL for radium is 5.0 pCi/L. A study by the Environmental Working Group performed determined radium levels exceed this amount in 27 states.
Silver may enter drinking water because it’s used in carbon-containing water filters to prevent the growth of bacteria. Silver in drinking water doesn’t cause any health effects but may cause discoloration of the skin, eyes, hair and organs in high amounts. Because of this, the EPA set an SMCL of 0.1 mg/L.
Uranium is another naturally occurring radioactive substance. It may leach into water from natural sources or from releases from processing plants. The presence of uranium in drinking water increases cancer risk and may cause kidney damage. The EPA has set an MCLG of zero mg/L and an MCL of 0.030 mg/L, which equals about 27 pCi/L of radioactivity.
Zinc is a metal that can leach naturally into water or come from mining, metal processing, coal-fired power plants and some fertilizers. In small amounts, zinc is healthy, but ingesting high amounts can cause nausea, vomiting and stomach cramps. Water with high levels of zinc may have a metallic taste and chalky appearance. The EPA set an SMCL of 5 mg/L for zinc.
You can test for contaminants in your drinking water by buying a water purity test or hiring a professional to test it for you. If you get your water from a utility, you can also contact them for information. If you find contaminants, you can install filters to increase the purity of your water to improve its taste and reduce health risks.
Emily is a freelance writer, covering conservation and sustainability. You can read her blog, Conservation Folks, for more of her work and you can read her last post on The Art of Healthy Living here.