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How Water Wells Work

How Water Wells Work

How Water Wells Work

Welcome to the Clean Water Made Easy Podcast, Episode One: How Water Wells Work. My name is Gerry Bulfin, WQA Master Water Specialist and Water Treatment Contractor in  Santa Cruz, California.

Thanks for listening! During this inaugural episode of “Clean Water”, I will cover the basics of how water wells work, including environmental considerations and sanitation. Proper installation and maintenance of your well is important; hopefully, this podcast will help guide those looking to safely use well water on a daily basis.

I have worked as a well water treatment specialist for twenty-five years. Though I generally work in Northern California and am a certified installer there, I have also worked all over the world. I have left behind many satisfied customers. Through this work, I have gleaned a lot of important information regarding clean water and hope to pass on this information to my listeners.


Topics Covered Include:

  • Groundwater explained
  • Drilled wells explained
  • Possible well contaminants
  • Considerations for areas near hydro-fracking
  • Dealing with cracks and loose fittings
  • The first step of proper well management
  • Sanitizing your well

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My name is Gerry Bulfin. I’m a water treatment contractor and WQA certified Master Water Specialist. I’m owner and founder of and I like to welcome you to podcast. Hey thanks for listening.

You’re in the right place if you want to learn more about well water, well water treatment systems, and how to improve the quality of your well water. If you’re experiencing stains, sediment, scale build-up, corrosion or odor in your water, or if you’d had your water tested and it came back with the positive tests for coliform bacteria, this podcast series is for you. Or maybe your water tastes and smells great but you just want to find out more about wells and water quality.

Each episode in this series is broken down into an area or topic that you can listen to each one individually or you can jump around and listen to the ones that pertain most to your application. This series is primarily about well water treatment but also touch on rainwater and spring water as well.

Download FREE Well Water Guide

In this episode, we’re going to cover the basics of how water wells work. It also go over how to disinfect and sanitize your well. Also I have a free gift for you, a well water cheat sheet and resource guide that I can send you. I created this guide as a companion to today’s podcast to make it easy to follow along with and has a well water treatment cheat sheet as well as an exploded view of how a typical well works.

Pretty nice diagram illustration. Also has a flow rate calculator guide so you can easily estimate what your well water flow rate is. And a step-by-step guide on how to sanitize your well. If you’d like to get your free copy, just text the word “wellwater” all one word, wellwater, to 44222 or go to and you get it there, we’ll get it going to you.

The Host/Resource Person

Okay a little bit about myself. I started in well water back in 1989 and I’ve own several companies in the water business and I’m the founder and CEO of where we sell custom water treatment systems. I have a California state contractor’s license for water treatment and I’m certified by the Water Quality Association as a master water specialist as well as a certified installer.

I also trained and worked for many years as state license water treatment plant operator and distribution operator. And we operate numerous small community water systems around Northern California. I also wrote a book on well water treatment, it’s called the Definitive Guide to Well Water Treatment. And I guess I just really love well water and talking all about well water and well water quality.

You know, we have customers on well water in all fifty states and I’ve had the fun and good fortune to be involved with installation and projects involving water treatment in many countries as well. Our custom systems are used by the US government and various embassies and military bases worldwide. We’re also in all other state and national parks and also donated many systems and worked on projects. We raised water charities and church groups, supporting small communities, hospitals, schools and mostly Mexico, Central South America, and South East Asia.

I’d been a member for many years of American Water Works Association, the National Groundwater Association, the Water Quality Association, and other water-related groups.

Groundwater /Surface Water

Okay, what is groundwater? It’s kind of amazing to think about it but according to the National Groundwater Association, 47% of the US population depends on groundwater for its drinking water supply. Of that 47%, many get the water from private wells. You know, groundwater is just the water that soaks into the soil from rain or other precipitation and moves downward to fill cracks and other openings in beds of rock and sand. It’s a renewable resource. Although the rate at which it can be renewed varies greatly.

You know here in California we sell fabulous water with a tremendous amount of rain coming out of the years of drought and so our aquifers are being recharged now and these two and all about the other states as well that is coming out of a long drought.

Groundwater vs Surface water

Groundwater is really an abundant natural resource. Of all the freshwater in the world, not including the icecaps, 95% is groundwater. Surface water, like some rivers make up only 3% of our fresh water.  Scientists estimate US groundwater reserves to be at least 33 thousand trillion gallons. That’s equal to the amount of water discharged at the Gulf of Mexico by the Mississippi river over the past 200 years. Groundwater is naturally filtered by the earth that holds it. It can however become contaminated by pollution that comes into contact from the earth’s surface.

So, how’s it get there? Water from rain and snow fall three main paths. Some water evaporates from the earth’s surface into the air or as breathed out by vegetation and returns near atmosphere. But some water runs off in a streams likes an ocean. Some water filters into the ground. There, it can float to the surface as springs and move into surface water or importantly to recharge the groundwater deep in earth. Then groundwater moves into these large underground natural storage areas known as aquifers.

As the groundwater moves through the ground, it dissolves into minerals that comes in contact with. So if you think about it, rain is mostly pure water but as it’s falling in the atmosphere it picks up carbon dioxide and this carbon dioxide when in water forms carbonic acid which makes the rainwater slightly acidic.

So as this rainwater penetrates the ground, it soaks down into the aquifer, it comes in contact with the rock in the ground such as, could be limestone or different material such as iron or manganese and so it can dissolve some of these minerals out and that’s what gives water its unique chemical characteristic. It varies in the ground depending on what type of minerals it can come in contact with.

Drilled or Hand-dug Water Well

So, what exactly is a drilled well? That’s mostly what we’ll be talking about. There are hand-dug wells and it’s actually very common in the world and sometimes it’s called boreholes but they’re just, they’re hand-dug, they might be shallow. Those are highly prone to contamination. So in US and Canada what’s most common is there we have drilled wells which consists of a bored hole in the ground with the upper part be aligned with casing. This casing prevents the collapse of the borehole walls and prevents surface water from entering the water supply.

And this casing is near at the lower section of it, has slots in it or what they call a well screen and the well drill or wall up when drilling while we pick out, decide what type of screen to use depending on the formation of rock. But what it is, is that that’s where your submersible well pump is down inside this casing. So that is why it’s submersible well pump ‘cause it’s submerged in the water underneath the water. So this, the intake maybe an open hole in solid bed rock or maybe screen and gravel pack depends again on the geologic conditions. Once the well is completed, it’s pumped to develop the well and determine the yield.

Well Yield

The yield is the quantity of water which they measure during the development of it. They usually do it for at least one hour and that they’re measuring how much water the well can yield and they start out at observe and measure how deep the water is at the end of the hour and they can figure out how fast the water is recharging or filling in the well.

Well Sanitation

The important step when the well is drilled or serviced is to sanitize the water. So, this is what the professional well drillers will do when they’re done developing the well and the last thing they often do is they shot it with some chlorine bleach, a specific amount and so that they sanitize well because when they’re drilling the well there’s a chance that they can introduce bacteria into the ground by their well drilling rig and tools. So the sanitizing is very important. It’s true also if you ever have your well worked on you want to make sure that it’s sanitized when they’re done.

So as I see in most wells using submersible pumps, pumps that are down in the water in the casing and pumped out to the top but you might have a pump test on the top of the ground which is often called a jet pump and those pumps are sucking water  usually from a shallow depth. So that you see a pump on top of the ground, you hear it running then you’re running them shallow well and these types of shallow wells are more prone to contamination. You have to be careful about that. Most folks that we deal with are costumers all in submersible well pumps.

Sources of Groundwater or Well Contamination

One thing you keep in mind, most states and provinces don’t regulate or have jurisdiction over your private wells serving a single home or farm. This puts responsibility for protecting the private well squarely on us the well owner. Wells have a number of potential sources of groundwater contamination. The foremost of them is the septic system, the septic tank. You don’t want that obviously near the well. They’re by law, they have to at least 50 feet away and this varies based on the counting but a hundred feet is even better but they have a certain amount of feet that is got to be set back from the well.

But one thing you can have control over is improper waste disposal such as paints, lubricants, cleaning products, pesticide, fertilizer storage. It’s a big one you don’t want any of that near your well. Lawn and garden chemicals, these are all things and oil.  These are all things that you want to avoid anywhere near your well.

The other things is, it can be a little trickier to figure out is, is there an abandoned well nearby? This can be contaminating the water as well. Pretty unusual, but it does happen there’s a lot of abandoned wells. If they are not properly sealed and filled with, usually they’re filled with concrete to seal them off, then that can cause serious problems.

Underground storage tanks, underground fuel storage tanks, in particular, we’ve seen it happen several times where folks will say “yeah I’ve got this, all of the sudden I’ve got oil in my water” and it’s literally petroleum oil you know, that comes back from lab it’s actual oil.

And so, it’s kind of a mystery while it turns out they have an underground fuel storage tank from say, the 1950’s or many years ago they didn’t even know it was there and finally corroded and leaked, now they’ve got the problem. So that’s something that, that can be a little harder to determine but those are all things that can cause some issues with contamination.

Another one, which we get a lot of calls on are hydro-fracking, hydro-fracking operations. Fracking operations drill very deep so they’re usually way below where your, where the aquifer is, thousands of deep below actually. So on one hand, theoretically, they shouldn’t cause any problems because they’re drilling so deep. But in, because there is so many of them now, in fact there are problems with some of them.

It’s probably a very small percentage, it varies by state and area I’ve no idea exactly what the percentage is. It’s a small percent but there are quite a few folks that have problems that started after the hydro-fracking where they have methane, hydrosulfide, or they have other water quality issues that come up. So that’s something to watch out for it.

If you have a well into the area of hydro-fracking, that’s something that’s really panic over but it’s something you might want to do — periodic testing of your well for the petroleum products and heavy metals.

Older wells and shallow aquifers are more likely to be contaminated. I can say that if you have a jet pump that’s probably old and you have a shallow well, those are more likely to be contaminated. Deeper wells pass through a restrictive or impermeable layer that decrease the rate that which the surface water reaches the aquifer. How do you figure out what you’ve got?

Well, a really good way to go about it  is talk to the well driller especially if you’d bought your home and you see a sticker on your well control box you can call them, look and get your well log. You probably have the well log that came with the deed. If you don’t, you need to get your well log and have it with you and I mean have it in your, in your records. Because that gives you a record of what happened when the well was drilled, how deep it is, what sort of strata they went through and what the yield test was, that’s, that should all be in that well log.

So most of the well drillers are very nice if they’re happy to give it to you, if they don’t have a copy of it you can often get it from your state or county, department, they all often have a copy of it too because it’s, it has to be submitted with the permit. There, it varies depending on the state but there’s a state department natural resources but I would start by just calling your local or county health department and ask them what can I do to get more information on my well and where can I go.

There’s also the coop extensions, but I would first start with the well drillers and then go from there. So, having the well log gives you a really good idea and something that’s you get additional information on especially if you’re having problems with your well,  you can this all information from your well, well drill and get like a background information like maybe the water was great originally but developed iron bacteria over time or the water quality deteriorated. Its very common because wells get old and different things happen.  There’s drought, there’s floods too, to access waters and other problems with contamination but, so it’s a good thing to do.

Okay, so in terms of the actual contamination of your well we talked about that a little, bit you want to make sure you septic tanks and sewer lines  are at least 50 feet away and some counties have greater actual stuff requirements. One very common thing to do is to, is to have a problem with coliform bacteria in your well because your well cap is missing or it’s cracked or broken or there’s some lose fittings on top of your well.

So this is something you can easily do yourself and if you don’t want to get a professional involve and talk to your well driller contractor, you can just literally look at the top of your well there shouldn’t be any lose fittings around the well. Of course that there’s lose wires you have to be careful because there’s high voltage there 220 volt usually. So, but if you see like the top of the well has cracks in it or there’s caps missing, that’s very serious so that’s where, very common to get coliform bacteria in your water from that.

Managing your private well

So the first step in proper management of your existing private well is to do an annual test for total coliform bacteria. This is, the EPA recommends this, World Health Organization recommends this, and most well professionals recommend an annual test for bacteria and nitrate.

There are home kits available. You can’t use a home kit if you’re going to submit this information in any kind of like for banks, for financing, it’s not certified but if you just want to  get an idea, yes you can get an, a home test kit for that. But especially if you’re new to the home or if you’re testing and has been testing some years, a local certified lab is very good. If you can’t find a local certified lab to do the testing, you can also send the test away to a lab.

We use national testing labs, their water check is really good value. Concerning what you get for it is pretty low cost and they, you can test for bacteria, a complete general mineral, physical along with pesticides, herbicides, heavy metals so it gives you a really good idea of all kinds of different contaminants. But sometimes local labs are good to get tests too because you can talk to those guys and they have a lot of experience in your area.

Now if your well test positive for coliform bacteria, a sanitary well cap might help solve the problem. But you need to find out what the source of the bacteria is. You can’t just test for bacteria and then shock chlorinate  it and just forget about it. You’ve got to, you know, you can determine that there was a problem with contamination like maybe your well that you worked on recently and so you can sanitize your well and then retest for bacteria after that. Then if you test it periodically you’re good to go.

Importance of Sanitizing Your Well

You know, there’s a lot of well professionals I know they, National Groundwater Association and some county, state association. They don’t recommend folks doing their own well sanitizing even though it’s like, it’s commonly done but the reason they don’t like you to do it yourself is because sometimes people put too much bleach in or they don’t put enough in they don’t do it right.

So you have to do it basically correctly so, if you put too much chlorine bleach if you just dump gallons bleach on your well, that can really have a negative effect on your well. It can wreck your pump, your check bound, it can corrode wires, it can do different things.

So the important thing is, you want to have between 1 and 200 parts per million of bleach. It’s not that hard. If you know your well depth or you can estimate it, it’s not that hard and you follow the chart it’s not that hard to do your own well sanitizing. But, just to get an idea what it is, you’re adding enough bleach so that you have 1 to 200 parts per million of chlorine residue on the water.

Then you’re recirculating this water by running your garden hose until it gets going through the household pipe and you run it back down the well. You put it over to the well where you added the bleach to begin with and so you got water circulating in the well, going to the pipes, and going back down the well.


Once you’ve got the, this chlorine, chlorinated water circulating, you turn everything off, shut the well pump off and let it sit for at least 8 hours, 12 hours is good. And then you retest at that point. If you have less than 10 parts per million of chlorine left, then you want to do the procedure over again. So that means that there’s extreme high chlorine demand in the water and use up all that chlorine so you probably back to your problem or some kind of serious demand.

So they have those high level chlorine test kits they’re inexpensive so that makes it very convenient. A lot of folks just, you know they often add like say half a gallon or one gallon of bleach inside into like 30, 40 gallons of water and pour that down the well.

So, it’s a good idea to follow the chart and to know how much chlorine you can use, powdered bleach too, but the, we find the liquid bleach works good. Peroxide doesn’t work well for sanitizing well so really bleach is the way to go and you can run the water out on the ground out of a hose bib so you don’t want to have to suffer through days or weeks of heavily chlorinated water in the house and also you don’t want to run a lot of chlorinated water down in your septic tank either.

So you can just flush the water, run it till it test 0, personally now there’s no odor or smell of chlorine in there or taste of chlorine and then you can wait like a couple weeks and then retest for coliform bacteria and see where you’re at. In the meantime, if you do have a positive test for coliform, either regular coliform or e-coli which is more dangerous fecal coliform, obviously you don’t want to drink the water. You could boil it but you have to even be careful bathing in it and if you have kids especially, you get infection.

Testing your Water

So, what other things do we test for? Well, what we recommend is that you want to take a look around where you live. If you live in a remote area and there’s no heavy agriculture or industry, freeways, highways you know nearby your home then you can do nitrate bacteria in just a general mineral analysis.

Like I’ve said before, if you’re new to the well, it’s not a bad idea to do a exhaustive test for pesticides, herbicides, and also heavy metals, arsenic and then also radon. Radon is a gas that’s odorless that, it’s very dangerous. So that’s another test, it’s a good idea to do it at least once. This again you can find out, maybe your area there is no radon, maybe you’re in an area where there’s a lot of radon. So it just depends on the strata, what’s down on the ground to determine if you’re going to have much radon or not.

So you want to get your well tested or test it yourself at least once a year for coliform bacteria, nitrate, dissolved solids, pH and hardness. We recommend those because you can keep a baseline every year. You do your test for coliform, nitrate, dissolved solids, pH and hardness, that’s the minimum number of test you want to  do.

But if you do that once a year over a period of years you can start to track “hey what’s happened? My dissolved solid is going up in my ground or the water is getting harder” you know in other words the ground water is changing, so that’s good to know. If you see a decline in water quality or you speck contamination local sources like I said, you may need to do a more thorough investigation.

Flow Rate Test

The other thing you want to do is do a flow rate test. A  flow rate test tells how many gallons per minute your well pumps yield and that’s the thing we’re going to talk about in the next podcast episode. It’s very easy to do, it’s really good to know how many gallons per minute your well pump is pumping. Especially if you’re looking into water treatment systems in order to size them or you want to  get a water filter, you’re really good to know how many gallons you’ve got.

Okay so let’s go over the most important points in this episode. One, check your well cap. Make sure there’s no crack or lose fittings Check around the top of your well. Make sure there’s no potential source of contamination. Try to keep your any potential source of contamination 50-100 feet away at least. Test your water annually for bacteria and nitrate.

But also test for a general mineral analysis such pH, hardness, dissolved solids and then keep a record year to year so you can spot changes in your groundwater. If you suspect more serious contamination, get an exhaustive test on for pesticides, herbicides their price are really come down. It’s not as expensive as it used to be. And if you want to get a copy of our well water treatment cheat sheet and resource guide then just text the words “wellwater” to 44222 or you can go to the and get a free copy there.

Next Podcast Episode

In the next episode we’re going to go over how you can get a good idea of how many liters or gallons per minute your well pumps. Knowing and periodically measuring the flow rate from your well, it’s important to know and it’s also just good to know how well, how your well is working and help for troubleshooting pressure and flow problems in the house.

So thanks again for listening. Talk to you soon.


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