Drinking water quality is an important public health issue because contamination in a single system can expose many people at once. People can be exposed to contaminants in drinking water by
- drinking the water,
- eating foods prepared with the water,
- breathing water droplets or chemicals released from the water while showering, or
- absorbing chemicals through their skin while washing.
The groundwater that supplies a water well can become contaminated through natural processes and human related activities. In addition, Iowa is made up of unique geological settings that can create special construction, maintenance, and water testing needs.
Even if you believe that your well water is safe to drink, it's important to periodically sample and test your water to assess any health related concerns. The information you receive from the test will help you make informed decisions on well maintenance and water treatment. It will also help you determine if you need to call a certified well contractor or seek an alternative source of drinking water.
Arsenic in Private Well Water and Health
Exposure and Risk
The majority of health risks from arsenic in the United States are from long term exposure. Although short-term exposures to high doses may cause adverse effects in people, a high dose of arsenic is about a thousand times higher than the drinking water standard. Arsenic exposures do not occur from EPA-regulated public water supplies in the United States that comply with the arsenic maximum contaminant level (MCL).
Possible health effects include:
- thickening and discoloration of the skin
- stomach pain
- nausea
- vomiting
- diarrhea
- liver effects
- cardiovascular (heart) effects
- pulmonary (lung) effects
- immunological (ability to fight infection) effects
- neurological (brain) effects such as numbness and partial paralysis
- reproductive effects
- endocrine effects such as diabetes and
- cancer
- bladder
- lungs
- skin
- kidney
- nasal passages
- liver and
- prostate
- Prevention
It is recommend that every private well used for any drinking water purpose have at least one arsenic test performed so that the well user understands if arsenic is an issue with the water supply. The local environmental health office can answer questions or assist with testing a private well for arsenic.
Coliform Bacteria in Private Well Water and Health
Exposure and Risk
We are in contact with millions of bacteria every day and nearly all of them are harmless. Yet some of these small organisms are responsible for waterborne illnesses. Coliforms are one group of mostly harmless bacteria that live in soil and water, as well as the intestines of animals. The presence of total coliforms in drinking water can indicate that more dangerous germs, particularly fecal coliforms, have contaminated the water.
The most common source of bacteria is the soil surrounding the well. Fecal bacteria in drinking water are usually the result of contamination by a nearby sewer, septic tank, feedlot or animal yard. Bacterial contaminants may also be introduced into a well during construction or repair.
Prevention
It is recommend that every private well used for any drinking water purpose be tested annually for bacteria. The local environmental health office can answer questions or assist with testing a private well for bacteria.
Nitrate in Private Well Water and Health
Exposure and Risk
Infants under the age of 6 months who drink water containing more than 1 mg/L nitrite, or 10 mg/L nitrate, could become seriously ill and, if untreated, may die. In the body, nitrate changes to nitrite. Nitrite interferes with the oxygen-carrying capacity of blood, so the oxygen you breathe in doesn't get distributed throughout the body. Symptoms, such as shortness of breath and blueness of the skin, can occur rapidly over a period of days.
Read more about Nitrate from the CDC
Infants are at the greatest risk for illness from exposure to high levels of nitrate.
- Short-term: Excessive levels of nitrate in drinking water have caused serious illness and sometimes death. The serious illness in infants is due to the conversion of nitrate to nitrite by the body, which can interfere with the oxygen-carrying capacity of the child's blood. This can be an acute condition in which health gets worse rapidly over a period of days. Symptoms include shortness of breath and blueness of the skin.
- Long-term: Researchers continue to explore if there are associations with long-term exposures to nitrate, including adverse reproductive effects and some cancers. The studies are not conclusive at this time, and health standards are focused on protecting infants.
Prevention
It is recommend that every private well used for any drinking water purpose be tested annually for Nitrate. The local environmental health office can answer questions or assist with testing a private well for Nitrate.