Water Well Drilling Basics

In a 1981 York University paper, geography professor Conrad Heidenreich showed how a little knowledge about water can have a big impact on how people live.

After studying archaeological records, he discovered striking differences between 19th century native and European land use patterns in Oro and Medonte, two small rural townships. Despite the fact that both cultural groups possessed similar tools at that time, they showed very different land use patterns. Whereas native settlements were always found near rapidly moving streams that remained open all winter, European settlers could be restricted to 100 acre parcels of surveyed land, often nowhere near open water. The key behind European land use patterns was the knowledge that if you dug a deep enough hole, you’ll usually find water.

You probably didn’t need to know about Heidenreich’s study to recognize that water wells are crucial in rural places. There’s simply no substitute for the water they provide, as the 4 million Canadians who depend on private wells can attest. And of course, nobody needs to be reminded these days that the safety of groundwater can’t be taken for granted. What’s less clear is how to maintain peace of mind when your water comes from what amounts to nothing more than a hole in the ground. How do you really know your well water’s safe? And what can you do to make and keep it that way?

According to the Canadian Ground Water Association, 97 percent of all the earth’s liquid, freshwater is found underground. And of this, more than 99% is safe to drink. That’s better than you might think, but it doesn’t mean you can let down your guard when it comes to safety. Since the most common source of well contamination is a malfunctioning septic system, potential trouble is likely to be close to home. Maintaining a safe drinking water supply depends on three things: a properly constructed water well; a sound pump installation; ongoing water monitoring by analysis; and, in some cases, an effective and reliable disinfection system. Each build upon the other and must be addressed as a group, starting with the well itself.

Keeping the Bad Water From the Good

About 38,500 new water wells are created each year in Canada, and this means thousands of new opportunities for contamination of ground water reserves from surface run-off. Since the purity of sub-surface water is a product of the time it spends percolating down through the earth, anything that short-circuits this process will lead to trouble. That’s why ground water authorities are so careful to promote well construction methods that keep surface water above ground, where it belongs. Any well is a potential breech of the earth’s protective layer and it has to be treated with caution and technical understanding. This becomes an issue for water drawn from the well in question, and for other wells drawing from the same underground reserves.

A crucial part of sound well drilling and maintenance includes a process called sanitization. This refers to the addition of household chlorine bleach added directly to the well as a short-term disinfectant. For large diameter dug and bored wells up to 36 inches in diameter, add 35 ounces of household bleach for every 5 feet of water depth. For drilled wells up to 6 inches in diameter, add 5 ounces of bleach for every 25 feet of water depth. Do this just before going to bed at night, let the bleach do its work until morning, then run a small amount of chlorinated water through all indoor fixtures before turning on an outdoor garden hose until the bleach smell in the water disappears. Although harmful microbes can’t live for long in underground aquifers, they can infect a well from outside sources. That’s why disinfection should occur immediately after every new well is drilled, and after your pump or intake piping is disturbed.

Back in 1993, the United Nations declared March 22 the World Day For Water. But how do you really know if your well water is worthy of praise or suspicion? If your well meets all the mechanical standards, then the next step is laboratory assessment, and there’s more here than meets the eye. One of the things about drinking water safety is that expert opinions about it have grown more cautious, especially after the tragic events in Ontario have proven that the unthinkable can happen.

Although varying provincial regulations are in place to govern the testing of public water supplies, as a private well owner you’re your own testing watchdog. As a rule of thumb, lab analysis should happen twice a year, in the spring and fall, with additional tests whenever you notice changes in appearance or smell. Although government-sponsored testing programs vary across the country, you’ll find private labs that offer more than the basic coliform testing required for minimum health analysis. Regardless of the tests you choose, collecting water samples properly is key. Start with an approved bottle containing a stabilizing agent in pellet or powder form. Remove any aeration screens, hoses or filters from the collection tap, and let the water run for 2 minutes before filling the bottle quickly. Don’t let anything touch the inside of the bottle cap, and hold it face down with your hand while filling. Refrigerate samples immediately after collection and have them analyzed within 48 hours. The time available for accurate analysis drops to just 4 hours if the sample can’t be kept cold in transit.

Water Treatment Strategies

Although there are many kinds of treatment systems that can be connected to a private well, all fall into at least one of three categories: devices for disinfection; devices for chemical purification; and devices to improve taste, odour or appearance.

Since drinking water can carry disease-causing micro-organisms, the issue of disinfection can be crucial. It\’s also essential to have all microbes under control before adding devices that improve chemistry or aesthetics. If not items like carbon filters, for instance, can become microbe breeding grounds. But what if your well consistently tests safe bacteriologically, without the help of a disinfection device? Is it still prudent to install one anyway, just to be sure? That’s unnecessary according to Maurice Lewis, Executive Officer with the Canadian Ground Water Association. “Ground water is naturally free from bacteria that affects human health. If a well is constructed properly, located correctly, maintained diligently and analyzed periodically, then purity can be counted upon.” But since many older wells don’t meet today’s standards of well construction and maintenance, there may be a need for disinfection devices. See “The Disinfection Connection” for details.

Sidebar: Catalytic and Magnetic Water Softeners Don’t Work

According to findings published by the Canadian Water Quality Association, water softeners that use catalytic bars or magnets are ineffective. This position is based on an analysis commissioned in Canada by the Department of Consumer and Corporate Affairs in 1988. Chemistry professors D.W. Larson, Keith Johnson and Hyman Gesser all contributed to the study and all testified that these devices cannot soften water.

Sidebar: The Disinfection Connection

When it comes to killing critters in your well water, you’ll find a handful of options. And since none are perfect in every way, you’ll need to know to pros and cons of each before making an informed choice. Here are three of the most popular options:

Chlorination: Chlorine treatment of municipal drinking water began in Chicago and Jersey City in 1908 and remains in use today because it’s so effective. At the turn of the 20th century, large North American city populations typically suffered more than 100 typhoid deaths per year per 100,000 people — a figure that dropped as water treatment plants were constructed. Not only is chlorine useful for killing micro-organisms upon application, but it also provides residual disinfection as water travels through long municipal distribution pipes.

Although Health Canada described chlorination as “one of the greatest achievements of public health protection” in a November 1999 publication, the process is not without concerns. The greatest of these is the formation of disinfection by-products such as trihalomethanes (THMs). These compounds are created when chlorine reacts with organic matter in water. In published animal studies, THMs have been associated with adverse pregnancy outcomes and bladder/colon cancer. Activated carbon filters, reverse osmosis units and aeration will reduce the concentration of disinfection by-products, including THMs.

Distillation units: Water is boiled with the unit, the vapour collected and condensed, then transferred to a holding tank. Besides killing all microbes, distillation removes some toxic chemicals and all minerals.

Ultraviolet disinfection: This is a widely-accepted method of treatment that’s well-suited to domestic situations. Ultraviolet units include a long, electric bulb housed within a metal case. UV rays kill microbes in the water as it passes through the unit, without the need to add chemicals. Taste, smell and acidity remain unchanged. On the downside, it’s usually necessary to replace UV bulbs every year. UV treatment also does not offer residual disinfection.

Sidebar: Sulphur Water Treatment

Does your well water smell like rotten eggs? Food-grade hydrogen peroxide can eliminate the stench. Although it won’t work in all situations, H202 is a surprisingly useful and inexpensive solution to the problem. Injected into your incoming water stream at about 30 parts per million by an electric pump, hydrogen peroxide reacts with the sulphur compounds that cause the odour, converting them into a form that can be removed by an activated carbon filter. Cost for the system runs about $1200 for the pump (including 20 litres of H2O2), and another $1000 for a whole-house carbon filter. That much hydrogen peroxide will last the average household three or four years and costs less than $200.

Sidebar: Canadian Water Help

Jurisdiction over ground water and water well issues is a provincial matter in Canada. Your provincial office will have info on well regulations and technical requirements for where you live.

Ground Water Information Centre
10th Floor Oxbridge Place, 9820-106th St
Edmonton AB, T5K 2J6
Ph: (780) 427-2770
Fax: (780) 427 -1214
[email protected]

British Columbia
Communications Branch
Ministry of Environment, Lands and Parks
Victoria BC V8W 9M2
Ph: (250) 387-9422
Fax: (250) 356-6464

Box 44, 200 Saulteaux Crescent
Winnipeg, MB, R3J 3W3
Fax: 945-7782

New Brunswick
Department of Environment and Local Government
P.O. Box 6000, Fredericton, NB E3B 5H1
Ph: 506 453-3827
Fax : 506 453-2893
E-mail : [email protected]

Newfoundland and Labrador
Department of Environment and Labour
4th Floor, West Block
Confederation Building
P.O. Box 8700
St. John\’s, NF A1B 4J6
Ph: 709-729-2664
Fax: 709-729-6639

Northwest Territories
Department of Resources, Wildlife and Economic Development
P.O. Box 1320
Yellowknife, NT X1A 2L9
Ph: (867) 873-7654
Fax: (867) 873-0221

Nova Scotia Department of Environment and Labour
Civic Address:
5151 Terminal Road, 5th floor
Halifax, NS

Mailing Address:
PO Box 697
Halifax, NS B3J 2T8
Ph: (902)424-5300
Fax: (902)424-0503

The Department of Sustainable Development
Ph: 867-979-5822
Fax: 867-979-5833
Email: [email protected]

The Ministry of the Environment
135 St. Clair Avenue W.
Toronto, ON
M4V 1P5
Ph: 416-325-4000
Toll free: 1-800-565-4923

Prince Edward Island
Jones Building, 4th Floor
11 Kent Street
PO Box 2000,
Charlottetown, PEI
C1A 7N8
Ph: (902) 368-5028
Fax: (902) 368-5830

Centre d\’information
675, boulevard Ren\xe9-L\xe9vesque Est
\xc9difice Marie-Guyart, r.-d.-c.
Qu\xe9bec (Qu\xe9bec)
G1R 5V7
Ph: (418) 521-3830 ou 1 800 561-1616
Fax: (418) 646-5974
E-mail: [email protected]

Sask Water
Fourth Floor, Victoria Place, 111 Fairford Street East
Moose Jaw, Saskatchewan
S6H 7X9
Ph: (306) 694-3900
Fax: (306) 694-3944

Department of Renewable Resources
Box 2703
Whitehorse, Yukon
Y1A 2C6
Ph: 867-667-5652
Fax: 867-393-6213

Canadian Ground Water Association (403) 749-2331; www.cgwa.org

  • a national industry association that promotes education, guidelines and strategies to preserve ground water resources.

Canadian Water Quality Association (416) 695-3068; www.cwqa.com

  • a not-for-profit trade association that promotes education of the public and of water quality professionals.

Environment Canada Freshwater Website: www.ec.gc.ca/water

  • includes an enormous collection of water-related links and downloadable reports from federal, provincial and municipal agencies