If your well begins to pump sand or grit this can be an indication of a serious problem with your well.
Sand or Grit in your water well can lead to abrasive wear of the pump, clogging and premature replacement of fixtures, appliances, and your water system.
In private well systems, often, what appears to be sand can actually be sediment or other particulate material from various sources.
Be sure to determine if what you are observing is coming from your well or within your home, try to run the water directly from the well into a white bucket to see if you’re able to identify some sand or sediment.
Consider getting your water tested for contaminants, especially if there is a foul odor or taste present.
This particular article addresses sand or grit determined to be coming directly from the water well.
There can be many causes for the sudden appearance of sand in your water well. It is usually best to seek advice from a well-driller or pump-contractor to determine the source or cause.
Nonetheless, here we discuss some of the most common causes of sand or grit in your water well and our knowledge on approaching the problem.
Common Causes of Sand In Your Water Well
- Well Pump is Set Too Low in Well: If your well suddenly starts to pump sand, this may indicate that the well is filling with sand or your pump is sitting too low in the well near the bottom of the well..
Most wells use submersible pumps that are down in the water in a casing.
Typically the well pump is set so it’s at minimum 10 – 20 feet higher than the base of the well. But if the pump is down near the base of the well, sand or grit and sediment can be drawn in.
In old wells, the well shaft can fill up with fine sand and silt so much that the pump may start to suck in sand from this build-up.
2. Well Screen Degraded: When the well is drilled, it is lined with steel, iron, or PVC plastic which is called a casing. The casing in the well shaft is installed by the well driller.
The well casing has grooves that allow water to penetrate the well from the surrounding groundwater and at the same time keep out sand and grit. This is called the well screen.
Your submersible well pump is down inside this casing and over time the well screen can become degraded or corroded, allowing silt and sand to get into the well and pumped into your water system.
3. Well Pump is Too Large: In some cases, the well pump can be too powerful or strong for the well and consequently pulls sand in from the surrounding aquifer.
This sand can cause a rapid deterioration in the valves of the pump and cause a build-up of sand at the bottom of the well.
In any case, a sudden presence of sand or grit is not a good symptom and the source or cause should be inspected.
What Should I Do?
If your begins to pump sand or sediment it is often best to contact your well driller or local well professional to discuss the problem and possible ways to fix these issues.
Sometimes the well contractor can simply pull up the pump 10 to 20 feet to eliminate sand uptake. A well professional can put a camera down your well and inspect the well screen to see if it has deteriorated or needs repair.
In some serious situations, a new casing may be advised.
However, there are also special screens a well contractor can install over the pump to keep out sand.
Although these are not feasible for some wells if the casing is very old or if the well’s diameter is too small. If it is not feasible or possible to repair, a new well may be recommended.
Centrifugal Sand Separator
Another solution is to install a centrifugal sand separator on top of the ground before the pressure tank to filter the water before it enters your home plumbing system. Centrifugal sand separators are effective in removing over 98% of all 200 mesh sized particles (74 microns) and greater.
These remove sand and sediment through centrifugal force which slings large particles, sand, debris, and sludge outward to the separator wall and downward by the gravitational force which pulls the separated solid particles past the spin trap plate into the solids holding chamber.
Cleaned water then rises through the vortex locator and returns back to the plumbing system. Once in the solids-holding chamber, the sand can be easily drained out through a small ball valve opening at the bottom of the device, manually or automatically by an auto flush valve.
No other maintenance is required as there are no moving parts to wear out and no screens, cartridges, cones or filter elements to clean or replace. If finer filtration is needed, this should be followed by another type of secondary filter to take out the finer particles.
Filter Screen with Flush Valve
An alternative to the centrifugal sand separator is a spin down filter which comprises a filter screen and a small valve found at the bottom of the filter. The screen filters out the sand and grit and can be cleaned out by opening the ball valve and flushing the filter.
These filters must not be too fine because they can result in a pressure drop. Generally, a 60 or perhaps a 100 mesh screen works well in straining out most sand and grit. These types of spin-down filters are installed after the pressure tank.
Both the centrifugal sand separator and the screen filters have manual ball valves that allow you to flush out the sand.
If you use a lot of water or have a lot of sand in your water, it may require frequent cleaning in which case an automatic flush valve can be installed.
These valves turn on for a few seconds and flush out the accumulated sediment and keep the sand trap clean.
A combination of different types of well water filters can also be used to maximize performance and minimize maintenance.
If there is some sand but also sediment such as clays, soil or rust particles a combination of a large mesh (60 mesh) spindown filter first, followed by a backwashing sediment filter can eliminate most sediment and not require constant maintenance and filter changes.
The automatic backwash filters using turbidity filter media such as Chemsorb or Turbidex can filter down to the 3 to the 5-micron range and then backwash out the accumulated sediment to drain once or twice a week as needed.
In some cases, if there is very fine sediment less than 5 microns a final stage dual-grade 1-micron depth filter is recommended. However, since most of the sediment is removed by the spin-down filter and sediment backwash filter, the cartridge lasts many times longer.
Do you have sediment or sand in your well water? If your well begins to pump sand or grit get our free guide or call us for more information.