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How Does Well Water System Work? (Pumps, Pressure Tanks)

Scott Winfield
Written by Scott Winfield
Last Updated on

A well water system is comprised of several components, but once you break them down, it’s pretty easy to understand how they all interact.

The components in question are the following:

  • Water pump
  • Pressure tank
  • Water container tank
  • Pump pressure switch
  • Cut-off switches
  • Filtration units

Drilling Your Own Well

Drilling Your Own Well
Drilling Your Own Well

There are essentially two different types of wells – handmade and drilled.

Handmade wells are a rarity nowadays, and they can usually be found on older properties. The main benefit of handmade wells is that you can build them yourself, which can save you between $3,000 and $8,000. However, the drawbacks are way too numerous.

If you don’t have drilling equipment, you won’t get too deep before you start running into rocks and soil that are too hard for hand tools to be able to handle. Additionally, groundwater is usually found at least 50 feet underground, and some areas need the well to be at least 100 feet deep. Needless to say, that’s a pretty tall order if you don’t have a drill.

But let’s say that you manage to dig a hole deep enough without any professional equipment, and you even manage to build the walls of the well and make a structure capable of collecting water at the bottom.

If you do all of that, you still need to put in the gravel screen, install the pump system, connect the pressure tank, and connect all of the water lines to the house. Installing wells usually requires a team of individuals with a specialized set of skills, so it’s very rare to find any one person with all of those necessary skills, especially if you don’t have a background in construction.

If you’re going for a handmade well, depending on your skill set, you might be able to get an old-school bucket and pulley well since they’re just holes filled with water. You’ll still need specialized tools and regular water inspections to make sure that what’s coming out of the well is drinkable, but we’d say that it’s a manageable project.

However, if you want to cut yourself off from the municipal water supply and be self-sufficient, then you’ll need to spend a bit of money and get professionals to handle the job for you.

Driven Wells

There’s also a third type called driven wells. However, it’s not all that common, so it’s really just a special mention.

Driven wells are made using a piledriver to make a hole in the ground. They can’t make a hole as deep as a drill, so they only reach around 50 feet underground. This puts them at a disadvantage since you might not have a body of water so close to the surface that you can tap into.

They’re almost universally considered the worst well-digging option, but they’re also cheaper.

If you did a soil test and found that there’s water on your property relatively close to the surface, then a driven well can be a viable option, otherwise, we’d stick to drilling.


A well will cost you between $3,000 and $8,000. This is the sort of price that you’ll likely be looking at if the well you’re digging is between 50 and 100 feet underground.

The price will vary depending on the diameter of the well, and it’ll increase substantially the deeper the well needs to be. Generally speaking, wells don’t go past the 200-foot mark, but that still means that you’ll need to pay between 7k and 17k, so it’s quite a price hike.

Additionally, these prices aren’t universal and some states might charge you more depending on the type of soil that you have and how long the digging and installation is going to take.

We should also say that this is just for the well, the casing, and the pump. Most well systems will usually come with a pressure tank, but any water storage tanks and water filtration units count as additional expenses.

How Does Well Water Work

Well water
Well water

Not many people know the basics of how wells work. While the simplest explanation would be that they tap into underground water reserves, that’s not much of an explanation.

First of all – no, you don’t have a lake under your house. Wells are essentially massive holes in the ground that go into aquifers. Aquifers are layers of soil and rock that have enough space between them so that they can hold water.

It’s much easier to find aquifers near lakes and rivers. However, the reason isn’t that water seeps into aquifers from these bodies of water. It’s that the rivers and the lakes are a good indication that there’s already a sizable amount of water under the ground layers that can be tapped into.

These underground aquifers are constantly being replenished thanks to rain and precipitation, but they can also dry out if the terrain changes, the water is pumped out faster than it’s replenished, or if the weather stays dry for long periods of time.

The good news is that, a lot of the time, you can find another aquifer if you dig a little deeper, so you probably won’t even need to make a new hole if this happens to you.

Finding the Aquifer

As we’ve already mentioned, figuring out if you live next to an aquifer is pretty easy if you have a lake or a river 100 miles or so away from you. There’s a lot more water under our feet than we think, and you don’t even need to dig too deep to find it sometimes.

On the other hand, if you don’t have a large body of water anywhere near your home, it’s still pretty easy to find out if there’s an aquifer near you.

The best way to do this is naturally going to involve hiring a professional excavation company that does well installation so that they can test the soil and the area for you. However, if you want to make sure that you live in an area that has a decent supply of groundwater before getting professionals involved, then the information is easy enough to find online.

There are plenty of aquifers in the US that can be tapped into, but unfortunately, there are also quite a few dry zones as well. Our recommendation is to get a professional opinion regardless.

Making the Hole

The hole itself is made by a heavy-duty drill, and the diameter will depend on your specifications. They usually come in three sizes, those being 4, 6, or 8 inches. While this might sound too narrow, most water pumps can easily fit into a 4-inch wide well, so there’s nothing to worry about.

The bottom of the well is generally going to need to be at least 100 feet or more underground. The actual depth will depend on the location of the aquifer and the quality of the water itself. Most common soil contaminants like gasoline and pesticides penetrate the soil and cause the water to be undrinkable.

The solution to this issue is to test the soil and calculate how deep the well needs to be so that the contaminants that are present in your area aren’t in your drinking water supply. The water in the well will, of course, also need to be tested to make sure that it’s clean before you can start using it.

And finally, we’d also recommend testing your water once a month, or at least once every two months, using a water testing kit to make sure that it’s clean and the filters are doing their job properly (we’ll get more into those a little bit further in the article).

Putting In the Casing

After the hole has been completed, it’s time for the casing to be put in. The casing is otherwise known as the wall of the well, and it can be made out of different materials, but most commonly, it’s made out of plastic, carbon steel, or stainless steel.

The choice is yours, and plastic is always going to be the most cost-effective option, but if the soil in your area is rougher or prone to shifting, you might want to get something a bit more sturdy.

The casing will then be lowered into the hole, but it won’t be lowered all the way down since a few feet near the bottom need to be left free. Once that is done, a gravel screen will need to be poured into the hole. This is exactly what it sounds like – a large amount of gravel that will serve as the bottom of your well.

The function of this screen is to increase the surface area at the bottom of the well through which water can seep in. This will increase the draw of the well, and make it so the reservoir that the pump is drawing from will get replenished a lot quicker.

The gravel also provides a more stable ground for the casing to be placed on, and it also works as a basic filter that can keep out a lot of the soil. You’ll still need an actual filter, of course, but the larger chunks of sediment will get stuck in the gravel and won’t go into the pipes, thanks to the gravel screen.

How Do Well Pumps Work

Well pump
Well pump

Well pumps are placed at the bottom of the well near the gravel screen, and their job is to push the water from the well into the pressure tank. The pumps use the force generated by the spin of the internal fan to propel the water up the pipe and toward the pressure tank.

There are submersible pumps that go directly into the water and need to be fully submerged to work, and there are standard pumps that are placed inside the well but not in the water itself. Most wells use submersible pumps, but you can get whichever one you prefer since the differences are minor and easy to work around.

The well pumps have a water line that’s connected to the pressure tank and an electrical line that connects the cable to a power source somewhere in the home. Once all the components are connected, a well cap is placed on top of the well to prevent insects or debris from falling down into the water, and the system is turned on.

Well pumps operate via pump pressure switches that are located somewhere near the pressure tank. They’re incredibly easy to operate, and all you need to do is turn the dial to one side to start the pump and turn it to the other if you want to stop it.

How Does a Well Pressure Tank Work

Well Tank Pressure Tank
Well Tank Pressure Tank

The pressure tank is a large spherical container made out of metal that has something called a membrane inside. This membrane uses pressure to collect the water from the well and store it inside the tank until it needs to be distributed throughout the house.

Larger pressure tanks are capable of storing dozens of gallons of water and distributing them throughout the house; however, smaller pressure tanks usually get connected to large water storage tanks.

If your system uses a water storage tank, the water from the well passes through the pressure tank and goes into the storage tank.

Filtration Units


We already mentioned that many contaminants can be found in the soil even if the well is located relatively deep underground. To avoid these contaminants ending up in your faucet, you’ll need to have a filtration unit that can get rid of them.

Water filters use many methods to get rid of contaminants, but generally speaking, reverse osmosis systems are considered to be some of the most effective ones that you can get. The size and power of the system that you settle on will depend on the size of your home and the quality of your water.

There are plenty of systems to pick from, so regardless of what your requirements are, you’re more than likely going to find a water filter that can meet all of your needs.

Additionally, groundwater also has a lot of minerals in it, which isn’t a surprise seeing as how it’s drawn from aquifers. These minerals are the reason why you have hard water in your pipes. This hard water makes it more difficult to wash off soap in the shower, causes clothes to come out of the washer looking more worn out, and causes a lot of other issues as well.

To counteract these issues, it might also be a good idea to install a water softener after your filtration unit. Similarly to water filters, water softeners come in many different shapes and sizes, and there’s bound to be a model that’s perfect for your needs.

Cut-off Switches

Cut-off switches are valves that you turn to stop or re-enable water flow through certain parts of the system. They’re vital for water systems, so they’re replaced after every component in the event that the water needs to be immediately stopped.

This means that you’ll need to have a valve on the pipe leading out of the well, on the pipe leading out of the pressure tank, and on the pipes that lead out of the storage tank, the water filter, and the water softener.

Strictly speaking, it’s not necessary to have that many valves, but they’re incredibly cheap items, and they serve the vital role of dividing your system into several sections.

This helps with maintenance and repairs since you can shut off certain sections and work on them without having to tear down the entire system.



When it comes to maintenance, well systems are pretty difficult. You can’t really look into the well and diagnose any issues, and you can’t pull out the pump to check for any issues either. This essentially means that the pump, the casing, and the main body of the well itself don’t get maintained.

The pump can be removed for repairs, but the whole procedure is long and requires you to disassemble your entire well system, so we’d recommend only doing it when absolutely necessary. Additionally, you’re likely not going to know how to fix any pump issues anyways, so you’re going to want to get a professional to handle any problems for you.

The pressure system will need to be checked every two months or so to make sure that the pressure is right. Most already have a pressure meter on the top that tells you the working psi, but if yours doesn’t, then there’s still a way that you can check. There should be a cap at the top of the tank where you can place a pressure measurement tool to check the psi.

The psi varies between systems; however, the pressure should be around the 40 – 60 psi range when the pressure tank is working and a few psi below that when it’s not.

Pipe maintenance is pretty straightforward. Run a visual inspection of the pipes that lead from the well to the storage tank and ensure they’re not damaged or rusted. Check to see if there are any puddles on the ground or if the pressure tank isn’t running properly. If you can’t see any visible damage, there’s no water leaking, and the pressure is as it should be, then the pipes are fine.

And finally, the filtration and water softener systems. This maintenance procedure is pretty long, so we’d recommend reading our article on the subject  if you want to know more.


At the end of it all, here’s what everything should look like.

The bottom of the well should be 100 feet deep on average, and the casing should be supported by a gravel sheet that helps increase the water flow. The pump goes into the well and connects to the pressure tank and a power source inside the house.

The pressure tank will take in the water from the well, and, depending on its size, it’ll either store it or immediately transfer it into a larger water storage tank. The stored water will then go through a water filtration unit, and ideally, a water softener unit, and then it’ll be transferred throughout the house.

That’s a well-water system in a nutshell.

Link to “Water Softener Maintenance Tips” when live

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Scott Winfield
Scott Winfield
My name is Scott Winfield and researching and writing about water filters and other strategies to purify water has become my full time passion in recent years. I'm glad that you found our site and you can look forward to authoritative and well researched content here to help you get the best in water.
  1. I like that this post underlined that when we are looking to have a water well dug in our backyard, it is important that we are mindful of the size to ensure that it has ample volume. My wife and I are planning to have a new well dug. I will definitely keep this information and mind and look for reliable contractors.

  2. Thanks for helping me understand that well water pumps would be pushing the water from the bottom of the system to the pressure tank. It seems that this kind of equipment is a must if we want to have proper pressure for our faucets, showers, and garden hose. We might not be able to enjoy the shower experience if the flow is not strong enough to even climb up the pipes.

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