Bacteria, Viruses, and Parasites in Drinking Water
Bacteria are everywhere in our environment, including Minnesota’s surface waters and groundwater. Some of these bacteria can be harmful to human health. Drinking water with disease-causing bacteria, viruses, or parasites (collectively called pathogens) can make you sick. It is not practical to test drinking water for every type of pathogen, but it is simple to test drinking water for coliform bacteria. The presence of coliform bacteria can indicate there may be harmful pathogens in the water.
How to Protect Yourself and Your Family
The U. S. Environmental Protection Agency (EPA) requires public water systems to regularly test water for total coliform bacteria and E. coli. Safe drinking water does not have E. coli or other pathogens in it.
If you have a private well
Here are some recommendations on how to prevent and address coliform bacteria contamination:
- Protect Your Well by constructing it in a safe spot.
- Regularly inspect your well for damage. Contact a Licensed Well Contractor if you find any damage.
- Test your well water every year for coliform bacteria. You are responsible for keeping your well water safe and testing it as needed. All well testing should be done through an accredited laboratory. Contact a Minnesota Department of Health (MDH) accredited laboratory to get a sample container and instructions on how to submit a sample. You can also contact your county to see if they have any programs to make testing your water easier.
- Disinfect your well with a chlorine solution if floodwaters come within 50 feet of your well; your water changes in taste, appearance, or odor; or your well is opened for servicing. Follow these steps for Well Disinfection or hire a Licensed Well Contractor.
- Conduct routine maintenance of potential sources of contamination, such as household septic systems.
If coliform bacteria are detected in your water, follow these steps:
- Stop using the water for drinking and preparing food, unless you boil it at a full rolling boil for a full minute before using it. You can also use bottled water or water from a known safe alternative source.
- Disinfect your well with a chlorine solution, using the same Well Disinfection steps as above.
- Test your well water again after disinfection to confirm there are no coliform bacteria.
- You can use the water again, without boiling, once the well has been disinfected and the water no longer tests positive for coliform bacteria.
If you are on a public water system
Your public water system is regularly tested for coliform bacteria. The system will issue a public notice within 24 hours if it detects E. coli. The public notice will tell you what you should do to stay safe.
You can find the coliform bacteria test results for the system serving where you live by reading the system’s Water Quality Report (also known as a Consumer Confidence Report [CCR]). You can call your public water system to get a paper copy of your CCR, or you may be able to find it online at Find Your Local CCR. You can find the coliform bacteria test results for the systems serving places other than where you live by contacting the water system.
The recognition that microbial infections can be waterborne has led to the development of methods for routine examination to ensure that water intended for human consumption is free from excremental pollution. Although it is now possible to detect the presence of many pathogens in water, the methods of isolation and enumeration are often complex and time-consuming. It is therefore impractical to monitor drinking water for every possible microbial pathogen that might occur with contamination. A more logical approach is the detection of organisms normally present in the faeces of man and other warm-blooded animals as indicators of excremental pollution, as well as of the efficacy of water treatment and disinfection. The presence of such organisms indicates the presence of faecal material and thus of intestinal pathogens. (The intestinal tract of man contains countless rod-shaped bacteria known as coliform organisms and each person discharges from 100 to 400 billion coliform organisms per day in addition to other kinds of bacteria). Conversely, the absence of faecal commensal organisms indicates that pathogens are probably also absent. Search for such indicators of faecal pollution thus provides a means of quality control. The use of normal intestinal organisms as indicators of faecal pollution rather than the pathogens themselves is a universally accepted principle for monitoring and assessing the microbial safety of water supplies. Ideally, the finding of such indicator bacteria should denote the possible presence of all relevant pathogens.
Indicator organisms should be abundant in excrement but absent, or present only in small numbers, in other sources; they should be easily isolated, identified and enumerated and should be unable to grow in water. They should also survive longer than pathogens in water and be more resistant to disinfectants, such as chlorine. In practice, these criteria cannot all be met by any one organism, although many of them are fulfilled by coliform organisms, especially Escherichia coli as the essential indicator of pollution by faecal material of human or animal origin.
Exposure to Chemicals in Water
Everyone has a role in protecting the water supply. Before you throw away unused medicines, birth control pills, paint, motor oil, pesticides, cleaners, and other chemical-based products, talk to your local health or hazardous waste departments about how to safely dispose of these products. You also can visit the U.S. Food and Drug Administration for more tips.
Steps you can take
In general, filtered tap (municipal) water is as safe as or safer than bottled water from the store, because bottled water is less regulated.
You may want to consider the following tips to ensure your water is the safest it can be:
- If you get your water from a private or small community well, you may want to have your tap water tested. Well water can become contaminated with bacteria, pharmaceuticals, and other toxins. City water supplies and municipal wells that serve large numbers of people are regularly tested for contamination. Private and small community wells are not tested, unless you arrange to have it done. If you don’t get a water bill, you most likely have a private or small community well. To find a state-certified water testing lab, contact your local state health or environmental department.
- Install a filter on the taps in your house or store drinking water in a pitcher with a filter. Check the box label to make sure you’re buying a filter that removes E. coli and Cryptosporidium bacteria, as well as pharmaceuticals. Both Brita and Proctor & Gamble (maker of PUR filters) say their filter pitchers remove both E. coli and Cryptosporidium, as well as more than 96% of pharmaceutical contaminants. These companies also claim that their plastic pitchers are made without bisphenol A. Change the filter at the recommended times. The National Sanitation Foundation website has information on how to choose water filters for your home.
- Reverse osmosis systems and ion exchange pour-through filters can remove contaminants that tap filters can’t. Certain contaminants, such as hexavalent chromium, a metal used in metal processing, steel and pulp mills, and the tanning industry, aren’t removed by standard tap filters. Hexavalent chromium in drinking water has been linked to certain stomach cancers. In December 2010, the Environmental Working Group released a report that found hexavalent chromium in the tap water of 31 of 35 U.S. cities tested. Hexavalent chromium can be removed from drinking water by using reverse osmosis systems and ion exchange pour-through filters. Still, these systems are much more expensive than installing a tap filter. If you suspect the water in your area is contaminated with hexavalent chromium or other heavy metals, you may want to consider taking a tap water sample to a lab for specific heavy metal testing before you invest in a reverse osmosis or ion exchange pour-through filter system.
- Boil your water if you think it might be contaminated with bacteria. Bring water to a rolling boil for 1 minute before using it. Boiling kills bacteria and other organisms, but doesn’t remove pharmaceutical residues.
Ways to Know Whether or Not You Should Have Your Water Tested for Contaminants
Many ways to access water are available today. You may prefer to stock your home with water bottles, use a filtered pitcher or drink from the water dispenser in your fridge. However, problems can start to arise depending on where that water comes from. People get water from one of two places — public water systems or wells. Either way, sometimes things can go wrong, and you might need to test your water.
Your Water Tastes Bad
People like to say water is water — but you’ll taste a big difference between different water qualities. It’s why people prefer certain brands of bottled water over others. Whatever water you use at home should always be pleasantly neutral. You should never have to wonder if you’re tasting something in your tap water when sipping on a drink poured from your tap. The same goes for shower water or the water you use to brush your teeth. Immediately follow any bad taste by a water quality test, just to ensure you aren’t drinking contaminants.
Your Water Fixtures Are Stained
You may never think about the quality of your sinks and tubs until you notice a pink mould on them that grows slowly over time. You should be able to easily wipe away this mould with cleaning solution — and if you can’t, your utilities may be stained. Stains can appear brown, yellow, red or black. Those colours indicate high concentrations of harmful minerals that shouldn’t be in your water. Test your water if you see any stains on the water fixtures in your house. A professional can easily treat your water, and the stains will disappear.
Your Stomach Is Upset
Just as your stomach can get upset when you eat something unhealthy, the same thing can happen if you drink bad water. Drinking water can irritate your stomach in a few ways. First, you might experience an upset stomach after local and natural chemicals infiltrate your water source. Arsenic is a naturally occurring toxin found in water that a professional can filter out if they identify the substance through testing. Infections like gastroenteritis also follow the minerals that contaminate water. You may experience stomach cramps, diarrhoea and vomiting as symptoms of this virus. These symptoms are also associated with salmonella and E. coli. If you’re having symptoms like these and don’t think you’ve consumed any bad food, test your water right away.
Your Soap Doesn’t Lather
Groundwater filtered through soil is called hard water. It’s less likely to react well with soaps and create a lather, although hard water that passes a filtration test will make minimal suds. If your dish or hand soap won’t lather or produces only minimal suds, your water has become hard and needs to be tested for contaminants like hardness, iron, pH, nitrates and chlorine.
Your Water Smells Foul
Water shouldn’t have a taste or smell — so it’s a bad sign if you’re wincing when you bring a cup of water to your lips. Hydrogen sulphide is a common cause of foul-smelling water. Many people note a rotten-egg-like smell when they sniff this contaminated water or turn the tap on.
Trust your nose and test your water if it smells bad when you use your sinks or showers.
Your Plumbing’s Corroded
A bad taste and smell in your water could also be a sign your plumbing has started to corrode. Pay attention to whether your water becomes discoloured early in the morning. If so, it may have settled in the pipes overnight and absorbed the metals from the corroded pipe. Replacing corroded plumbing will be a project, but it’s worth testing for so that you can start as soon as possible.