Harrowsmith – June 2019

Harrowsmith Summer 2019 | 53

HOME & DESIGN: WATER WELLS

Wells can be deep or shallow, as

well as drilled, dug, bored or driven.

Drilled wells are typically smallish in

diameter (10 to 20 cm/four to eight

inches), more than eight metres

(25 feet) deep and are the only option

for accessing water from bedrock.

Drilled wells like the one you see here

include a steel tube (called a “casing”)

pushed into the hole far enough to

extend down past any soil that might

be present, and into bedrock. Casings

also extend several feet above the

surface to keep out surface water

and dirt. Even when you need to drill

30 metres (100 feet) or more through

bedrock to get water, modern drill

rigs do the job in a day or less. My

own drilled well is 44 metres (143

feet) deep, with the first 2.5 metres

(eight feet) going through soil.

The rest is limestone bedrock.

Drilled wells are the only kind

with a metal casing that extends

above the ground. All drilled wells

have (or should have) some kind

of cap on top of the casing. Visit

harrowsmithmag.com/4137/how-to-

drill-a-water-well to see a water well

being drilled in the limestone bedrock

of a Canadian island.

Dug wells are as the name sounds.

They’re holes dug into soil only (no

bedrock), to a relatively shallow

depth. Traditionally, dug wells were

shovelled out by hand and lined with

stones, but today they’re usually

created with a backhoe or excavator.

Dug wells can be created only in

soil of some kind, they’re typically

61 to 91 cm (24 to 36 inches) in

diameter, and usually less than six

metres (20 feet) deep. These days,

tubular concrete well tiles, instead of

hand-laid stonework, keep soil and

surface water out of the hole. A dug

well could have a wood, metal or

concrete cover.

Bored wells are just like the

dug well you see in the illustration

above, except deeper. Created by

specialized equipment that augers a

round hole in soil only, this lets bored

wells go deeper than dug wells (up

to 15 metres/50 feet deep). The

boring operation is less disruptive

to the surrounding landscape than

using a backhoe or excavator too.

Bored wells also use concrete well

tiles to line the hole, plus a cover to

keep surface water, dirt and critters

out of the hole.

Understanding water well systems

Your first task is to learn to recognize what kind of water well you have, and to recognize the type of

wells other people you might need to help have. As with any technical knowledge, you need to start

with an understanding of the basics before anything else.

Driven wells are unique. They’re

made by fitting a sharp, rigid,

screened attachment that threads

onto the end of rigid steel pipe.

This attachment is called a sand

point, and it allows a pipe to be

pounded into the ground using a

sledge hammer or jack hammer

for extracting groundwater from

abundant, relatively shallow sources

in coarse soils. Sand points are the

simplest and cheapest option for

getting a well, but they only work

in sandy or gravelly soils with water

fairly close to the surface. If all you

see coming out of the ground is a

metal pipe a couple of inches

in diameter, then you’ve got a

sand point.

STEPHEN HUTCHINGS (DRILLED WELL, DUG WELL)