Water Quality


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Frequently Asked Questions

My well water smells like rotten eggs, what is the cause of the odor?

The odor you are smelling is hydrogen sulfide (H2S). This gas is often associated with relatively shallow wells that have dissolved iron in the water. Iron in the water can come from several sources. More information on iron and manganese in water can be found in WQ1030 iron and Manganese Removal (https://www.ag.ndsu.edu/publications/environment-natural-resources/iron-and-manganese-removal-1). Often, only the hot water in the home has a rotten egg smell. This is a result of the well water chemistry reacting with the anti-corrosion anode in the hot water heater. This can be corrected by removing the anode but it may shorten the life of the hot water heater. Hydrogen sulfide can be greatly reduced by using a whole house activated carbon filter. More information on filtration can be found in WQ1029 Filtration: Sediment, Activated Carbon and Mixed Media (https://www.ag.ndsu.edu/publications/environment-natural-resources/filtration-sediment-activated-carbon-and-mixed-media).

 Why does a well in constant use suffer a loss in pumping capacity?

There are several reasons for reduced pumping capacity. The most common is that over time the part of the well where water enters becomes partially clogged. Dug wells (shallow and large diameter) may have tree roots and broken pieces of casing and accumulated clay in the bottom. Drilled wells (small diameter) can have clogged screens due to minerals or iron bacteria. Clogging usually happens in wells that have been in use for more than 10 years. Pumping capacity can also decrease due to a drop in the water table. This can happen during a drought or if a new high volume (irrigation, rural water, municipal) well is installed nearby. Although not common, disturbances on the landscape can reduce the recharge to the aquifer supplying the water. Many household wells tap into shallow groundwater aquifers. Some symptoms of land disturbance could be a change in taste, color or odor of the water.

Where can I find answers to common drinking water problems?

Many sites offer water testing services.  It is a good idea to periodically have your water tested. Well water should be tested for the presence of coliform bacteria every year. The presence of coliform bacteria in the well is an indicator that the water is contaminated and could contain other water borne diseases. In North Dakota and Minnesota, water should be tested periodically to determine nitrate and arsenic concentrations exceed EPA maximum contaminate levels. Before installing new water treatment units, have the water tested and analyzed. More information on drinking water definitions along with testing laboratories can be found in WQ1341 Drinking Water Quality: Testing and Interpreting Your Results (https://www.ag.ndsu.edu/publications/environment-natural-resources/drinking-water-quality-testing-and-interpreting-your-results). 

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