Well Water Testing Analysis and Contamination in MA and NH – Arsenic in water

The second post in our series highlighting some of the contaminants that can be found in water wells.   Northeast Water Wells is available to collect samples and test your well water for contaminants anytime.

If you have a private well, regular water quality testing is very important.  Northeast Water Wells recommends testing your well at least every two years.   Many contaminants cannot be identified by taste or odor, making it difficult for homeowners to know if the water quality of their well has changed.

What is Arsenic?

Arsenic is a naturally occurring mineral found in soil and bedrock.  Arsenic works its way into groundwater through erosion.  Arsenic is present in throughout parts of  both Massachusetts and News Hampshire and is particularly present in the Merrimack River Valley.  Drinking water from bedrock wells, also called drilled or artesian wells, and less frequently from shallow or dug wells, may contain arsenic.  Arsenic is currently present in the U.S. as a wood preservative, and also in paints, dyes, metals, drugs, soaps, and used as a semi-conductor.

Arsenic can be present in well water as Arsenic III (arsenite), Arsenic V (arsenate), or a combination of the two.   Arsenic III is more toxic and more common in groundwater than Arsenic V.

What are the health effects of Arsenic?

Arsenic ingestion can result in both chronic (long term) and acute (short term) health effects.  Arsenic exposure can easily go undetected because many of its symptoms point to a number of other illnesses.   Acute effects can include nausea, vomiting, neurological effects such as numbness or burning sensations in the hands and feet, cardiovascular effects and decreased production of red and white blood cells which may result in fatigue.  Chronic effects include changes in skin coloration and skin thickening and small corn-like growths that can develop especially on the palms of the hand and soles of the feet.  Chronic exposure to arsenic is also associated with an increased risk of skin, bladder, and lung cancer.  There is also evidence that long-term exposure to arsenic can increase risks for kidney and prostate cancer.  Your health risks are determined by the following factors:

  • the concentration of arsenic in your water,
  • the amount of water you consume each day,
  • the length of time you have been consuming the water,
  • your dietary intake of arsenic (in the foods that you eat), and
  • your individual sensitivity to arsenic.

What is the regulatory standard for arsenic in the drinking water?

The current drinking water standard or Maximum Contaminant Level (MCL) set by the U.S. Environmental Protection Agency (EPA) is 0.010 mg/L or parts per million (ppm).  This is equivalent to 10 ug/L (micrograms per liter) or 10 ppb.  In 2001, the U.S. Environmental Protection Agency (EPA) reduced the regulatory MCL from 50 ppb to 10 ppb on the basis on bladder and lung cancer risks.  The MCL is based on the average individual consuming 2 liters of water a day for a lifetime.  Long term exposure to drinking water containing arsenic at levels higher than 10 ppb increases the chances of getting cancer, while for lower arsenic water levels the chances are less.

If your water has arsenic levels above 10 ppb, you should obtain drinking water from another source or install a home treatment device.  Concentrations above 10 ppb will increase the risk of long-term or chronic health problems, the higher the level and length of exposure, the greater the risk.  It is especially important to reduce arsenic water concentrations if you have children or are pregnant.  Children are at greater risk (to any agent in water) because of their greater water consumption on a per unit body weight basis.  Pregnant women may wish to reduce their arsenic exposures because arsenic has been found at low levels in mother’s milk and will cross the placenta, increasing exposures and risks for the fetus.  If your water has arsenic levels above 200 ppb, you should immediately stop drinking the water until you can either obtain water from another source or install and maintain treatment.

What about bathing/showering, or other uses?

Unless your arsenic level is over 500 ppb , showering, bathing and other household uses are safe.  Arsenic is not easily absorbed through the skin and does not evaporate into the air.

What can I do if my water has high arsenic levels?

If the arsenic level in your well water is above 10 ppb there are a number of treatment methods available.  However, before selecting a treatment method, there are a number of factors that need to be considered.  If the arsenic level in your well water is above 10ppb Northeast Water Wells recommends another test called speciation.   Speciation will determine which of the two varieties, or species or arsenic are present in your well water, Arsenic III or Arsenic V.   Arsenic III is more difficult to remove from water and needs to be oxidized to Arsenic V before it can be removed.  This can be done with Chlorine Treatment to the well water.

There are different systems available to treat Arsenic in well water.  Point of use treatment at the tap, this is installed under the kitchen sink with a special tap for drinking water.  Whole house treatment, point of entry treatment, will treat all of the well water that enters the house.

Northeast Water Wells offers a variety of testing packages to take care of all of your water needs.   Call today to set up a time for us to collect a sample of your water.  All of our testing is done through a state certified analytical lab.

Article written by Karen Provencher, Northeast Water Wells