If you're about to have a new deep well pump installed on your property, you know that you have to choose a pump that's the right size for your well. In this day and age of drought and aquifer-use competition, though, you might be tempted to go for a slightly more powerful pump so that you can get that deeper water and have fewer problems with flow. That could be setting you up for an even more spectacular well failure, however.
Overpumping a well, especially if you and everyone else tapping the aquifer are drawing water faster than it can be replenished, can lead to an increase in something called biofouling. And biofouling can kill your pump and make the water you do get unusable.
Biofouling is just what you think it is: Fouling of the water by biological micro-organisms like bacteria. The types of micro-organisms that can show up in a well are hugely varied, but overall, they form a slimy film on the water that eventually plugs up pumps and that can make anyone who drinks the water get sick.
The sources of the bacteria vary as well. Colorado State University Extension notes that the presence of bacteria could indicate that fecal matter has contaminated the well.
That can lead to problems like Giardia and Cryptosporidium -- the types of bacteria that municipal water supplies are usually checked and tested for regularly. Have you ever been on a city water system where you've gotten a boil-water order? Chances are that was due to the detection of one of those bacteria.
But back to overpumping. Another very common source is growth due to an increase in the nutritive value of the water in the underground source. When you open up an aquifer with a well hole, you're letting oxygen and possibly other nutritious minerals into the water. Alberta's division of Rural Agriculture and Development notes that micro-organisms like iron bacteria love these conditions, and the bacteria multiply. The resulting film on the water also draws up sand and silt, and all of these together can jam up your well pump.
It is crucial that you get the right size of well pump. This involves a combination of figuring out the right number of gallons per minute needed and the pressure needed to draw up water from a deep well. Don't try to size it yourself; call in an experienced well-drilling or well-pump company. Letting the experts help you will let you make your water use more efficient and help keep the well in a healthier state for a longer time. And that is gold when you rely on groundwater.