Wells – Drinking Water


by Jerry Trent, Water Quality Committee

We tend to take our drinking water for granted.  City water supplies are managed by full-time, trained, staff and are tested by the Minnesota Department of Health.  All kinds of things are removed from the water if it is taken from lakes and rivers – organic debris and organisms, especially bacteria.  City water is generally safe, but there are substances that are hard to remove – assuming that the facility even tests for them.  That’s another story.

What about those of us on Cross Lake and the Snake River who are using private wells?  There is no skilled operator checking our daily supply for bacteria and chemicals – what do we do?  First of all, we should have our well tested for bacteria and nitrates.  These are of the most concern for our health.  Quite a number of people took advantage of the Pine County SWCD program this spring to have their well water tested for nitrates.  Most wells were fine.  But if you have very young children regularly drinking your well water, you definitely need to have it tested.  Bacteria, of course, are a concern for people of all ages.  Contamination of our wells can occur if it is too close to a pollution source such as a septic system, or the top of the wellhead is flooded, or the casing becomes cracked and allows surface or groundwater to enter from the side.  Shallow wells are always suspect due to contamination from surface water.  Call the Pine County SWCD for advice on testing your well for bacteria.

Recently I had problems with my well water.  The softened water was becoming very rusty and had a strong metallic, almost egg-like odor.  Of course all the sinks, showers and toilets were quickly rust stained.  It turned out that there were several problems.  Does this sound familiar?  The well water had accumulated iron bacteria accounting for the smell and part of the color of the water.  Although iron bacteria are not harmful to ingest, they cause poor water quality and odor.  A second problem was that the water softener system was not operating properly.  A few adjustments of the electronics by the Culligan technician and several quick recyles resulted in crystal clear water again.  I treated the well by removing the cap to the well head and adding pellets of calcium hypochlorite (70% chorine available).  Water softener companies sell this product.  There is a formula for determining how many pellets to drop down the well (in my case 44 for an 80 foot, 4-inch casing well) and a procedure for letting the chemical work (overnight is best), and advice about how to flush the system (always bypass your water softener during this process before returning it to service).  Some prefer to shock the well by using unscented liquid bleach – at least a gallon, perhaps two or three if you have lot of iron bacteria.  A thorough flushing by first pumping through the outside faucet completes the task.  At first this water will be extremely rusty, but it clears as you continue pumping.  Run water through your inside plumbing also until there is no chlorine smell.  Iron bacteria are difficult to remove entirely, and you probably will treat the well from time to time.  Your plumber, or your well driller should also disinfect the well and water system every time the well is opened and every time you have significant plumbing changes.

The moral of the story is simply that you don’t have to put up with poor water quality well water.  You can soften it (remove the carbonates), and remove iron, iron bacteria, tannin, off-color, funny taste and odor.  Your wife will love you for it, and you’ll probably have a better cup of coffee!  I wish that changing the water quality of the lake and river were as simple!

Most Pine County Wells Remain Well 
 By Mary Ann Mills, Pine County Soil & Water Conservation District

This spring, 203 Pine County landowners had their well water tested as part of the “How Well Is Your Well?” program.  Water samples from participating homeowners were tested for nitrate levels and presence of coli form and other bacteria.

Results from the testing indicate that 4 wells or 2% tested over 10 ppm and failed for nitrates, while 33 wells or 16% showed the presence of nitrates between 1 and 10 ppm.  At the 1-10 level, wells are starting to show signs of problems and the reasons for the rising nitrate levels should be explored.  Of the 203 wells tested, only 15 wells or 7% showed presence of coli form bacteria.  The presence of coli form bacteria in a well indicates that the well is receiving contamination from human or animal waste sources, surface water, or other sources.  The source of the contamination should be determined and corrected.  The well should be disinfected and a coli form bacteria retest done.  Comparisons made with a similar testing program in 1994 show that well contamination levels for nitrates may have increased slightly in the last nine years.  Results from 315 samples taken in 1994 reported 3% failed for nitrate levels and 21 percent had nitrate levels between 1 and 10 ppm.  On the other hand, this year’s test results indicate a significant decrease in the coli form bacterial present.  Of the wells tested in 1994, 14% were present with coli form bacteria, compared to 7% in 2003.  Increased public awareness in the importance of safe drinking water and the need to test well water regularly may be a contributing factor in the decrease.

Reprinted from the Pine County Waters, September, 2003