Welcome to our new Magazine format! All new content will now be brought to you in this easy, new format. All our older content can still be found by scrolling below. Simply click the ">" to start the magazine and navigate via your arrow keys.

Tuesday, December 28, 2010

Concrete Well Lining

The course of history hasn’t changed much when it comes to our drinking water supplies. We either get it from standing water, such as a pond or cistern, or we get it from a hole in the ground. One thing that has changed is how we make that hole in the ground. Nowadays we usually hire a well drilling company to do the job, but sometimes the situation calls for an old fashioned hand dug well. One key factor in any well is protecting it from contamination, and hand dug wells are especially prone to problems if you do not take steps to prevent problems from occurring. There are many ways to do that today, from using corrugated culvert to precast concrete caissons to line the well. But to some extent you can also pour in place your own concrete well lining.
Here’s a piece from the old days that tells you one way to line your well;

One of the most necessary appointments of the farm is a well to furnish a supply of good, pure drinking water, and a well should be so located and lined that the water will be protected against all possibility of contamination from outside sources.
The old wooden well lining and cover not only permits particles of soil and vegetable matter to drop into the water but soon reaches a state of decay when it becomes a source of danger to life and to limb from contamination and possibility of accidents. The top covering becomes loose, boards are pushed into or dropped down the well and the opening is a serious menace to farm animals and children about the place.
A concrete well lining and platform will overcome and for all time prevent these dangers. The concrete well lining should extend down into the well from 6 to 8 feet or sufficient depth to prevent burrowing of animals and seepage through the upper layers of soil.

In localities where an underground water stratum of undesirable quality is found at greater depth than this, the lining should be extended down far enough to exclude such water. In lining a well with concrete first remove the top cover as well as the old lining down to the desired depth. At that depth a platform must be built to form a stage on which to work. This platform may rest on the old lining or else be supported against the soil within the well. With this platform in place and all of the old lining thoroughly removed, forms for the new lining may be built. These should consist of 1 by 4 inch strips beveled at the edge to permit their being placed around in a circle with tight joints facing the concrete.

One of the accompanying illustrations shows this in the sectional plan of forms. These boards should be braced by 2 by 4′s at sufficient intervals to insure that they will not bulge or give way under the pressure of the fresh concrete. These forms are 4 feet long as shown in the sketch of the vertical section and are so bolted together that they are easily collapsible when necessary to take them down. As a rule only interior forms will be needed if they are braced and blocked sufficient distance from the earth wall when concreting. After the form section has been filled with concrete the forms should be left in place until the concrete has thoroughly hardened. Then they may be removed and a support or platform built for casting the concrete cover slab or if this is not too large to be handled in place by three or four men, it may be cast separately in a form made for that purpose and when it is hardened be moved to its position over the well curb.
A platform not less than 4 inches thick and reinforced with 1/4 inch round rods 8 or 10 inches center to center should be made. An opening must be provided for inserting the pump and another one to serve as a manhole which may be necessary if the well has to be cleaned out at some time.

A tight fitting concrete cover should be made for this manhole, provision being made for it when the cover slab or platform is cast. The edges of the manhole opening should be beveled and the cover for the manhole opening correspondingly beveled to fit into this opening.

Plan of concrete pavement on ground around well lining or curb.
Concrete for a well lining platform should be mixed not leaner than 1:2:4 although a 1:2:3 mixture is preferable. The pebbles or broken stones used should not exceed 1 inch in largest dimension.