How Water Wells Work

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Note: This podcast transcript has been edited for clarity and length.

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

Thanks for listening! In 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 are important, and 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

My name is Gerry Bulfin. I’m a water treatment contractor and WQA-certified Master Water Specialist.

I’m the owner and founder of cleanwaterstore.com, and I would like to welcome you to the podcast. 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’ve had your water tested and it came back positive 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 divided into an area or topic. 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 touches on rainwater and spring water.

Download FREE Well Water Guide

In this episode, we’ll cover the basics of how water wells work and how to disinfect and sanitize your well. I also 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 it has an exploded view of how a typical well works.

It also has a flow rate calculator guide so you can easily estimate your well water flow rate. And a step-by-step guide on how to sanitize your well. If you’d like to get your free copy, text the word “wellwater” all one word, wellwater- to 44222 or go to cleanwaterstore.com/podcast, 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 owned several companies in the water business. I’m the founder and CEO of cleanwaterstore.com, 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 and a certified installer.

I also trained and worked for many years as a state-licensed water treatment plant and distribution operator. We operate numerous small community water systems around Northern California. I also wrote a book on well water treatment, the Definitive Guide to Well Water Treatment. 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 installations and projects involving water treatment in many countries as well. The US government, embassies, and military bases worldwide use our custom systems. We’re also in other states and national parks, and we have donated many systems and worked on many projects. We worked with charities and church groups, supporting small communities, hospitals, schools, and mostly in Mexico, Central South America, and Southeast Asia.

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

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 have fabulous water with tremendous rain. We are coming out of a drought, and so our aquifers are being recharged now. This is true for other states that are also coming out of a long drought.

Groundwater vs Surface Water

Groundwater is one of our most abundant natural resources. Excluding the ice caps, about 95% of all freshwater is stored underground as groundwater, while surface water—like rivers and lakes—makes up just 3%. In the U.S., scientists estimate that groundwater reserves total at least 33 trillion gallons, which is equal to the amount of water the Mississippi River has discharged into the Gulf of Mexico over the past 200 years.

Rain and snow contribute to this system in three main ways: some water evaporates or is released by plants, some flows across the land into rivers and oceans, and some soaks into the ground to recharge aquifers. As it travels through the soil and rock, groundwater dissolves minerals like limestone, iron, or manganese, which give it unique chemical characteristics.

Though groundwater is naturally filtered by the earth, it can still become contaminated by pollution from the surface. Its quality depends heavily on the geology of the region and the types of minerals it encounters along the way.

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 those are actually very common in the world. Sometimes it’s called boreholes, but they’re just hand-dug and might be shallow. Those are highly prone to contamination. So, in the US and Canada, drilled wells are the most common, consisting of a borehole in the ground with the upper part lined 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 the lower section of it, has slots in it, or what they call a well screen. The well driller will pick out what type of screen to use depending on the formation of the rock. Your submersible well pump is down inside this casing. That is why it’s called a submersible well pump, because it’s submerged underneath the water. So the intake may be an open hole in solid bedrock or a screen and gravel pack; this depends again on the geologic conditions. Once the well is completed, it’s pumped to determine the yield.

Well Yield

The yield is the quantity of water measured during the development of the well. They usually do it for at least one hour, measuring how much water the well can yield in an hour. They start out by measuring how deep the water is, and then they pump it for an hour. At the end of the hour, they measure it again, and they can figure out how fast the water is recharging or filling 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 shock it with some chlorine bleach. They sanitize the well because when drilling it, they can introduce bacteria into the ground with their well-drilling rig and tools. So sanitizing is very important. Also, if you ever have your well worked on, you want to make sure that it’s sanitized when they’re done.

Most wells use submersible pumps that are down in the water in a casing and pumped out to the top. But you might have a pump that is on top of the ground, which is often called a jet pump and those pumps are usually sucking water from a shallow depth. So if you hear a pump on top of the ground and you hear it running, it's probably pulling from a shallow well. These shallow wells are more prone to contamination. You have to be careful about that. Most folks that we deal with are customers with submersible well pumps.

Sources of Groundwater or Well Contamination

Private well owners are largely responsible for protecting their water source. One of the most common contamination sources is a nearby septic system—this should be at least 50 to 100 feet from the well, depending on local regulations. Other risks include improper disposal of paints, pesticides, and fertilizers near the well.

Abandoned wells are another concern. If not properly sealed, they can allow contaminants like oil or fuel to seep into groundwater. We’ve seen cases where hidden underground tanks from decades ago eventually corroded and leaked into a property’s water supply.

Hydrofracking is also something to monitor. While most fracking takes place deep below aquifers, some wells in fracking regions have developed issues like methane or hydrogen sulfide. It’s a good idea to periodically test for petroleum byproducts and heavy metals if you're in a fracking area.

Older and shallower wells are more likely to be affected by surface contamination. Jet pumps and shallow aquifers, in particular, are at higher risk. Deeper wells that pass through a protective layer tend to stay cleaner longer.

Get to Know Your Well

If you’re unsure about your well’s construction, contact the original well driller or check your well log, which often comes with the home deed. The log provides useful details like depth, flow rate, and geologic layers passed through. If you can’t find it, your state or county health department may have a copy on file.

Make it a habit to inspect your wellhead. A cracked or missing well cap can allow bacteria like coliform to enter. If you see gaps or loose fittings, take it seriously. And always be cautious—wells often carry high voltage wiring.

Routine maintenance and regular testing are your best defenses against contamination.

Managing your private well

So, the first step in proper management of your existing private well is to perform an annual test for total coliform bacteria. The EPA and the World Health Organization recommend this, and most well professionals also 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 to a bank for financing because it’s not certified, but if you just want to get an idea, then you can get a home test kit for that. But especially if you’re new to the home or if you haven't tested for 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 a really good value. Considering what you get, it is pretty low cost, and they can test for bacteria, a complete general mineral analysis, pesticides, herbicides, heavy metals, and many other things, so it gives you a really good idea of all kinds of different contaminants. But sometimes local labs are good for getting tests too because you can talk to those guys, and they have a lot of experience in your area.

If your well tests 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 forget about it. For example, maybe your well was worked on recently, 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 are a lot of well professionals I know who recommend that folks don't do their own well sanitizing, even though it’s commonly done. But they don’t like you to do it yourself because sometimes people put too much bleach in or they don’t put enough in, and they don’t do it right.

If you put too much chlorine bleach, if you dump gallons of bleach in your well, that can really have a negative effect on your well. It can wreck your pump, your check-bound, corrode wires, and do other things.

The important thing is that you want 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, and you follow the chart, it’s not that hard to do your own well sanitizing. But just to get an idea, you’re adding enough bleach so that you have 1 to 200 parts per million of chlorine residual in the water.

Then, you recirculate this water by running your garden hose until it passes through the household pipe and runs back down the well. You put it over to the well where you added the bleach to begin with, and so you have water circulating in the well, going into the pipes, and going back down the well.

Chlorination

Once you’ve circulated chlorinated water, shut off the well pump and let it sit for 8–12 hours. After that, retest the water. If chlorine levels are below 10 ppm, repeat the process—this usually means there’s a high chlorine demand due to bacteria or other contaminants.

A high-range chlorine test kit is affordable and helpful. Many people mix a gallon of bleach with 30–40 gallons of water to treat the well. Liquid bleach works best—peroxide isn’t effective for well sanitizing.

To avoid running chlorinated water into your home or septic system, flush it from an outdoor hose bib until the chlorine smell and taste are gone. Wait a couple of weeks and retest for coliform bacteria. If the test is positive—especially for E. coli—don’t drink the water. Boiling can help short-term, but avoid bathing in it, especially for kids.

Testing Your Water

What should you test for? Start by looking at your surroundings. If you live in a remote area without agriculture, industry, or highways nearby, test for nitrates, bacteria, and do a basic mineral analysis.

If you’re new to using a well, consider a more complete test. This includes checking for pesticides, herbicides, heavy metals, arsenic, and radon. Radon is an odorless, dangerous gas. Even one test is helpful. Some areas have none; others have high levels. It depends on the ground beneath your home.

You should test your water at least once a year. Look for coliform bacteria, nitrates, total dissolved solids (TDS), pH, and hardness. These five tests create a helpful baseline.

Testing yearly helps you track changes. For example, if TDS or hardness increases, your groundwater may be changing. If water quality drops or there’s nearby contamination, it’s smart to do more in-depth testing.

Flow Rate Test

The other thing you want to do is a flow rate test. A flow rate test tells how many gallons per minute your well pump yields, and that’s what we will talk about in the next podcast episode. It’s very easy to do, and 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 to size them or want to get a water filter, you want to know your well flow rate.

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

However, you can also test for a general mineral analysis such as pH, hardness, and 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 for pesticides and herbicides. It’s not as expensive as it used to be. If you want a copy of our well water treatment cheat sheet and resource guide, just text the words “wellwater” to 44222, or you can go to cleanwaterstore.com/podcast and get a free copy there.

Next Podcast Episode

In the next episode, we’ll discuss how to 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 is important. It’s also just good to know how well your well is working, which can help you troubleshoot pressure and flow problems in the house.

So, thanks again for listening. Talk to you soon.

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