Depending on your experience with well water, the idea of a private spring on your property might conjure images of sparkling clean, mineral-rich water—or, nightmares of muddy, orange-tinged, sulfurous sludge.
Either way, it’s clear that private wells are a different deal from publicly treated water supplies, which is why it’s essential to always use a whole-house filter for well water.
Here are 10 things you probably never knew about well water:
1. Industrial and agricultural runoff often find their way into shallow wells
The quality of well water depends a lot on what’s happening in the environment surrounding the well. When private wells are situated in areas with lots of factories, refineries, or large farms, there’s a good chance that their water could be at risk of contamination (this is especially true in hand-dug or shallow wells).
When contaminants spill from these industrial or agricultural operations, they can seep into the soil and quickly enter streams, rivers, and groundwater sources. Heavy rain can also wash pollutants like fertilizers and pesticides directly into wells.
While bacteria are always a concern, organic chemicals are the main threat from these areas of activity. Organic chemicals are used in household products like dyes and cleaners, as well as in industrial substances like pesticides and solvents.
If a well becomes heavily polluted with organic chemicals over a long period of time, those drinking the water become vulnerable to kidney and liver issues, as well as nervous system disorders. Be sure to test well water for any contaminants at least once per year, or if you notice any differences in taste or smell.
2. Sometimes wells need “shocking”
‘Shocking’ a well isn’t a particularly pleasant term, so it’s unsurprising that the process is only done when a water supply becomes inundated with nasty bacteria that present a threat to health.
To shock a well, gallons of chlorine or other chemical disinfectants are added to the well, well pump, and other fittings for a prolonged period of time. During and after well shock, households attached to the well run their faucets continually to flush out the system, but need to find another temporary drinking water source, as the chlorine levels are far too high to drink.
3. Well water is corrosive and can leach lead from pipes
Due to recent events in the US, lead poisoning is probably the most high-profile health issue associated with contaminated drinking water. But most people consider lead contamination a public water problem. Actually, lead corrosion is also a threat to well water, where acidic or changeable groundwater can erode the buildup of sediment inside old piping, releasing lead.
Lead can also find its way directly into aquifers through mines, refineries, facilities that produce things like cement and electrical goods. Some types of bedrock also naturally contain a small amount of lead.
There is no agreed safe level of lead consumption, and people that repeatedly consume the heavy metal can become at risk of cancers, liver and kidney issues, as well as anemia.
4. Iron bacteria can turn well water into a swamp
Iron is one of the most common elements in the earth surrounding water sources, so it’s not surprising that most wells have some iron contamination. And when this contamination occurs in a dissolved form, it’s not necessarily a big issue.
However, iron bacteria are microorganisms that are also often found in the soil near-surface water and shallow groundwater. When these bacteria exist in places with high levels of iron, they can begin to combine with the metal to produce large, slimy, often orange or red-colored deposits.
As they build, these deposits can cause stagnation and clog the inside of wells and pipes, leading to some pretty nasty drinking water. While iron bacteria in themselves are not thought to be directly harmful, they can create conditions where other pathogens and diseases thrive.
5. Well water is affected by the water shelf
One aspect of well water that can sometimes be a drawback is its reliance on the health of the water shelf. Depending on the amount of rain an area has, the condition of its rivers, and other environmental factors, water reserves can increase or decrease. When decreases become extreme during the summer or other times of drought, there’s a chance that water reserves will become insufficient to supply every well in the area.
More likely, though, is that a low water shelf affects the quality of well water, where a great level of silt and grit can enter the supply.
6. EPA drinking water regulations do not apply to privately owned wells.
A critical thing for any private well owner to know is that the US government does not help with the treatment or maintenance of private wells. Even though many Americans in rural areas rely on wells, and the EPA estimates up to 15 million households draw their water from a private source, there are no official regulations that apply to most well water.
Because of this, it’s important to regularly test any well for major contaminants and always use the right filtration device. Some of the most harmful contaminants, like lead, may have not detectable taste or smell.
Many people take lots of precautions with their own well, but forget that other properties may not be as vigilant with their water supply. For example, when was the last time you considered whether your favorite rural restaurant uses safe well water?
7. Well flow rates often depend upon rock permeability
It’s possible to drill a functional well pretty much anywhere, but the quality of water flow depends in large part on how permeable the surrounding earth is. Permeability refers to how easily water can move through the rock surrounding the water source.
In areas with very permeable earth made of limestone or clay, wells often have to be drilled much deeper to achieve a standard flow rate of around 5 gallons per minute.
8. Freshwater aquifers can extend underneath the oceans.
It really is possible to drill a well almost anywhere—even the ocean. groundwater aquifers are rarely connected to seawater and instead lay under the surface of the earth in long layers. As a result, fresh water can be found extending miles out into the ocean. According to the USGS, the state of Georgia has a series of large, coastal paper mills that take advantage of this very fact to source plentiful groundwater.
9. Even domestic activities can contaminate your well
It’s not just the obvious sources of contamination that private well owners need to be thinking about. According to the CDC, more domestic activities and objects like fuel and skeptic tanks, swimming pool chemicals, sewer lines, and lawn fertilizer can all contribute to a buildup of unwanted pollutants in drinking water wells.
There are also those infrequent events that can cause extra chemicals to enter suburban and urban areas. For example, when roads are de-iced, or when flooding causes drains to overflow.
10. Many well water filters need replacing every few months.
Depending on the type of water filter a person uses on their well, cartridges and tanks may need regular maintenance. According to Clean Cool Water, most people leave filter cartridges in for so long that they risk unnecessary contamination.
Always read (and trust!) the instructions for your filter. Devices that include large tanks may need regular backwashing, while replaceable cartridges usually need cleaning or throwing away after 3-6 months. Perform regular visual inspections to check for contamination build-up—a filter with a clear plastic casing can make this task easier. Many modern water filter systems also come with mobile apps that allow for automatic backwashing.
Often, performing a well water test is the best way to fully understand your water profile, and gauge how frequently you’ll need to service your filter system.