Homeowners who live in rural areas where there is no public water supply system are no longer excluded from the enjoyment of modern plumbing facilities. The installation cost of your own private water supply may be considerable, but once installed the cost of maintenance is small. Your system should be practical, economical, efficient, and hygienic. Generally, a good well, pump, and storage tank are necessary.
There are three basic types of well: the dug well, the driven well, and the drilled well.
The dug well
This is the cheapest but least desirable type. Its disadvantages are obvious. It yields too little water to supply the modern house or farm adequately; it must be built at a low point in the terrain; and it is subject to contamination from surface filth and sub-surface drainage. However, this type has been used for centuries and has served counties rural families.
Digging a well requires the work of at least two men, one to dig and the other to haul up the loosened earth or rocks. When the digging is completed, the walls are generally lined with concrete, with rocks cemented in place, or with bricks. The sides should be sealed tight for a distance of at least 10 feet below the surface of the ground.
The driven well
Like the dug well, this is classified as a shallow well. It is sunk by hammering a well point into the earth. The well point is a hollow, perforated tube with a steel point at its tip. When this tube is almost all the way into the ground, a second length of driving pipe is attached to it and is likewise hammered into the earth. More sections are added and driven down until a water-bearing level is reached. But if the well point hits rock before it reaches water, the entire operation must be started over again at a new location. A driven well is relatively inexpensive, but too often it has a tendency to go dry.
The drilled well
This is the most practical type of well in the long run. It is the only kind to have wherever there is no constant supply of water near the surface. A drilled well is a deep well and may extend down through many layers of rock. It must be drilled by a professional driller with special equipment. A driven well goes down merely far enough to reach water, but a drilled well goes deeper and thus ensures a more consistent supply. A pump cylinder is installed near the bottom of the well. It contains a plunger and valves, and the well pipe, from 1" to 2 1/2" in diameter, runs from it to the surface of the ground.
Location of the well
If you install your own water supply system, it follows that you will also have to have your own waste disposal system, and the two have to be widely enough separated so that your water supply will not be contaminated. The minimum distance between a well and a septic tank should be 75 feet. The well should be not less than 200 feet from a subsurface disposal field, and not less than 250 feet from a cesspool.
These are minimum distances — longer ones are better. The well should also be above the disposal system, if possible, and never below it. Thus, if your home is situated on a slope, have your well above the house and the waste disposal system below it. And do not neglect to consider the boundaries of your property. Avoid locating a well where it would be too near a waste disposal system installed later on by a neighbour.
Another point to consider is the nearness of other bodies of water, such as lakes, rivers, or streams. 'While these may be sources of uncontaminated water at present, you cannot guarantee what the future will bring. So your well should be at least 50 feet, horizontally, from any surface body of water.
The well installation indicates factors that must be taken into consideration. The size of the well must be sufficient to supply water to the pump, and the force of the pump adequate to lift the water and provide pressure at the fixtures. Always be sure to compensate for friction loss when you are installing a well and pump.
If you are having a well drilled, the driller's experience will be valuable in selecting a spot for the well. Neighbours who have wells and pumps should also be consulted. However, it is up to the owner to make the final decision on where the well is to be.
Quality and quantity of water
When you have chosen the location, dug or drilled the well, and obtained water, you should test it for taste, colour, and purity. The water must be free of bacteria and other disease-producing organisms. Wherever you live, there is some state or local health department which will test water for you or tell you where to get it done. It is much better to have the water tested for purity than to take a chance, although you have some assurance if there are nearby wells that have passed a test.
Along with quality, there is quantity to consider. If the supply is satisfactory on both counts, all well and good. However, if it is not satisfactory for drinking, it may be satisfactory in both quality and quantity for washing and other purposes. In this case, the best thing to do may be to provide another, small well for drinking and cooking water. Conversely, if the first well provides water that is pure but in quantity sufficient only for drinking, a second well or other source of supply may take care of additional needs. Many farms have two wells.
The amount of water needed depends on the size of your family, plus the number of livestock, if you live on a farm. And you should make a sensible allowance for future increases in demand. You must also remember that wells tend to yield a decreasing amount of water over the years. With the passage of water underground, sediment is swept along and collects around the well, eventually reducing or blocking the flow of water. This is a point many forget to take into account. After a time, it may be necessary to drill a second well some distance from the first so that both will supply enough water.
It may be possible to supplement the non-drinking supply with rain water drained off the roof and stored in a cistern. Rain water is soft, as it lacks the minerals that water flowing through the ground may pick up, and it is especially good for laundering. However, rain water is often far from pure. It picks up dust from the air and often contains moulds, yeasts, and bacteria which multiply in cisterns and reservoirs. So if you wish to collect and store rain water, it would be wise to plan on a charcoal filter system and enclosed storage tank. Many rural families use hard well water for drinking and cooking and soft rain water for washing.
If a plumbing system is to be installed and the well supplies hard water in abundance, it may be cheaper to omit the cistern and install a commercial water softener.
No hard and fast rules can be given on private water supplies as the possibilities and combinations are so numerous. In most cases, however, a pump and storage tank will be needed. There are several types of pump — some more suitable than others for particular conditions — and many manufactured brands of each type. The types described below can all be operated electrically.
The five main types of pump are: the plunger, the turbine, the centrifugal, the rotary, and the ejector. They may also be divided into shallow-well and deep-well pumps. Lift pumps and suction pumps are the same thing as shallow-well pumps. The plunger pump: This type is also called a reciprocating pump. It works by the action of a plunger and valve in a cylinder. When the plunger is forced into the cylinder chamber, the air is forced out. When the plunger is withdrawn, the vacuum created draws up water from the well.
The water is forced by the next stroke of the plunger to go through the one-way valve into the pipe. A constant flow of water is built up and the water in the pipe is forced to the surface. The plunger pump is a positive-displacement pump. It builds up pressure as long as it operates.
The rotary pump: This type uses a set of closely meshed gears rotating toward the centre of their housing. This action forces water from a suction pipe into a discharge pipe. Like the plunger, the rotary is a positive-displacement pump. Usually its capacity is too limited for normal household requirements, but many portable pumps are the rotary type and find frequent use on farms to supplement the primary supply. One objection to this kind is that it is particularly subject to wear if the water carries abrasive material.
The centrifugal pump: The centrifugal pump has an "impeller," which is a disc with radiating blades. When the impeller rotates, water is forced from the inlet pipe to the discharge pipe. This pump is not a positive-displacement one; it ceases to build up pressure after a certain limit fixed by the pump's design. Conventional centrifugal pumps, like rotaries, have poor resistance to any abrasive materials in the water.
The turbine pump: The turbine type also has an impeller, but in this case it is a slotted disc. Otherwise, it works in much the same way as the centrifugal pump.
The ejector pump: The newer pumps of this type—also called jet pumps—operate efficiently at depths down to 100 feet or more. The action is somewhat complicated. Water is forced down through a pressure pipe and leaves an ejector at the bottom. The water leaves the ejector nozzle at high speed and enters a chamber known as a venturi tube. The passage of the water creates a partial vacuum that sucks up water from the well. The water goes up the tube to the centrifugal pump at the top. A small amount of water is directed back down the pressure pipe to continue the process, and the rest goes to a storage pipe. A trouble peculiar to these pumps is the possibility of the ejector's clogging and requiring removal for cleaning.
Selecting a pump
Selection of the proper kind of pump depends on various factors, such as the depth to water, the location of the well, whether the pump is to be mounted directly over the well, the head of water required, and so on. The four chief considerations are the well size, the pumping level, the discharge pressure, and the rate of demand. Obviously, the maximum size of the pump and well pipe is controlled by the diameter of the well.
The pumping level is the vertical distance from the pump to the water level while the pump is operating. Do not confuse this with the standing water level—the distance from the top of the well to the top of the water when the pump is not operating. Inmost cases, while the pump is working the water level is drawn down, and it is this level that you should use.
The discharge pressure is the pressure required to overcome friction loss, and to deliver the rate of flow demanded at the fixtures (the service pressure). The average discharge pressure is 30 lbs. when tank and fixtures are on the same level as the pump. If the tank is higher than the pump or the fixtures are higher than the tank, a greater pressure—and thus a larger pump—will be needed.
The rate of demand or flow required governs the discharge capacity of the pump. Figure on the basis of the maximum demand at any one time. It is usually safe to use the demand of the fixture requiring the greatest flow plus 10 per cent. A pump with the proper capacity should have to work, on the average, a total of two to three hours a day.
The pump's maximum total head, which is the maximum pressure it can develop, must be greater than the total discharge head ( service pressure and friction loss) plus the pumping level (from water surface at operation to pump).
Pumps shouldn't give much trouble. Serious troubles are usually the result of using the wrong kind of pump or having a faulty installation. Installation should be done with great care, following the manufacturer's instructions precisely. For instance, suction lines must be at a correct pitch if you are to have proper operation. Anchor the pump to its foundation, and protect pipes from freezing.
The most common cause of pump trouble is really not the pump but the motor. Pump motors are unusually liable to damage by frost and dampness. The dampness also makes the electrical equipment additionally dangerous to work with or repair. So protect the motor well, have the pump house well drained and ventilated, and make the rim of the foundation for pump and motor slope slightly outward and downward.
The motors are usually started and stopped automatically by a switch. If water is pumped into an elevated tank, a float switch should be used, set to stop the motor when the tank is full and to start it at a certain low level of water. If the water is pumped into a hydro-pneumatic or automatic tank, a pressure switch will be used.
Motors should be equipped with overload and undervoltage controls to prevent their burning out. A motor mounted on a shallow-well pump or on the head of a deep-well pump is usually effectively grounded by the pipe extending into the well. You can, however, easily install a specific ground by looping one end of a #4 copper wire under the head of one of the studs that hold the motor frame and the other end under a nut or bolt head on the pump.
Most shallow-well and some deep-well pumps must be primed on occasion. Follow the manufacturer's instructions for his type of pump.
Keep the pump strainers clean and the valves tight. Keep the pump lubricated according to directions, and check occasionally for leaks and proper switch operation. If the pump is properly maintained and still does not operate the way it should, check these possibilities: water level too low; valves stuck or worn; suction lift too great; not fully primed; motor too fast or slow; loose drive belt; offset lines too small; piping sprung or bound; shaft out of line; pump rod wrong size; air leak in delivery lines.
You can check for leaks in lines by plugging the discharge from the pump, having the system nearly filled with water, and pumping air in with a tire pump until you reach a pressure of 70 to 80 pounds.
Many modern private water supply systems have an automatic pressure tank, or hydro-pneumatic tank, which starts and stops the pump motor. This is a great convenience and is almost like being connected to a public water supply system. This tank is also the storage tank. It must be air-tight and large enough to hold a supply of air in addition to the water. The air expands or compresses with the changes in the water level in the tank. The air pressure not only helps to deliver water to the fixtures but it also operates the switch. When the pressure falls to a certain point, the motor is started; when the pressure builds up to a certain point, the motor is turned off. Small tanks provide so little storage that whenever a faucet is turned on, the pump starts almost immediately.
It used to be the custom to place water-storage tanks on the roof or some other high point so that gravity would deliver the water where needed. But with efficient modern pumps and air-pressure tanks, it is not necessary to lift water so high, and storage tanks can often be placed in the cellar. With some types of pump, it is better to have the tank close to the well, either above or below ground. If it is above ground or partially so, house it so that it will be dry and protected against freezing. If it is below ground, it should be in a concrete-lined frost-proof pit with a cover and should be large enough for the equipment plus room for making adjustments and repairs.