Terri’s RURAL RUMBLINGS #4 - Well Tidbits
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ESTIMATING YOUR WATER NEEDS
Once you know ground water is available, you must estimate how much water you need. To estimate your daily peak water demand, add the appropriate quantities of water for all uses which would likely occur on the day of the year in which water needs would be highest.
Peak demand in the home normally occurs at the beginning of the day, at bedtime, or during laundry or irrigation uses. The following guide will help you determine peak demand.
Type of UseGallons per Day
Dwellings: Single family (per person)..............50-75
Multi-family apts (per person)..........40
Estate units (per person)...............65-150
Lawn and garden.........................50-1,000
Livestock (drinking per animal):
Dairy (plus maintenance)................35
Chickens (per 100).....................5-10
Turkeys (per 100).....................10-18
Some domestic water systems are designed to store water during times of low demand. The stored water can be used later to supply water during peak demand. An experienced pump installer or plumbing contractor can plan a water system based on your needs and water source.
In contrast to a domestic well, an irrigation well must be able to produce water at steady high rates for extended periods of time. Irrigation systems must be carefully designed to minimize pumping costs and to prevent excessive drawdown of the well’’s water level.
FINDING GROUND WATER
The amount and quality of ground water in an area can depend on yearly rainfall, geologic conditions, topography, distance to nearby wells, and surface water supply.
WATER WELL REPORTS (WELL LOGS)
You can learn about the quantity and quality of well water in your area from local water well constructors and neighbors. Water well reports are required by Oregon water law and are a basic tool used in checking for ground water availability. Well reports provide information on geologic formations encountered in a well and list details concerning well design, construction and yields.
The Water Resources Department has drilling records of most water wells drilled in Oregon since approximately 1955. You may examine water well reports in your district watermaster’’s office or at the Water Resources Department’’s central office at 158 12th Street NE, Salem. District watermaster offices are listed at the end of this brochure.
A local water well constructor can a lso help you estimate well depth, yield, and cost.
Water witches or "dowsers" claim to predict the presence of water with hand-held tools such as forked twigs or metal rods. Since there is no scientific basis to dowsing, most geologists do not recommend the practice. Although most water witches charge only a modest fee, the U.S. Geological Survey and National Ground Water Association advise against employing a water witch to search for ground water.
LOCATING YOUR WELL
Water well constructors have local knowledge and experience with state regulations. They can help you select your well site. The main consideration in locating your well is convenience. If conditions allow, try to locate the well near where you will use the water and near a power source. The following standards apply to the placement of wells.
•• Locate the well away from septic tanks, sewage disposal areas (such as a drain field), and other sources of contamination such as stock yards, storm sewers, privies, or refuse dumps. The minimum distances of 50 feet from septic tanks and 100 feet from sewage disposal areas are required by the well construction rules. Research suggests greater distances may be even more appropriate, depending on soil type and topography.
•• Increase the distances in areas of highly permeable formations, such as sand and gravel.
•• Run drainage away from the well on all sides; divert up-slope drainage away from hillside wells.
•• Locate the well upgradient of disposal areas if possible.
•• Locate the well far enough from buildings to allow easy access during maintenance, repair, testing, or redrilling. Remember to plan future well construction or repairs before building a shelter around the well.
•• Locate the well in an area free from flooding or plan extra precautions to protect it.
•• Site your well as far as possible from neigh- boring wells. When wells are close together, they can interfere with each other and produce less water.
•• Site your well a safe distance from your property line. This will prevent difficulties with neighboring septic systems and boundary line inaccuracies.
Contact your county health and planning departments for additional well location and permit requirements before you drill.
OBTAINING WATER RIGHTS
Oregon statutes declare ground water to be a public resource. With some exceptions, any person intending to use ground water must obtain a permit from the Water Resources Department. In general, a ground water permit must be obtained before using water from any of these sources:
•• A well;
•• Any artificial opening in the ground;
•• An artificially altered natural opening (this may not include development of a natural spring);
•• Tile lines placed beneath the surface;
•• A sump.
The following uses of ground water do not require a water right permit.
•• Group and single-family domestic use up to 15,000 gallons per day;
•• Stock watering;
•• Watering any lawn and/or non-commercial garden totaling one-half acre or less in area;
•• Down-hole heat exchangers; or
•• Any single industrial or commercial develop- ment up to 5,000 gallons per day.
WELL CONSTRUCTION STANDARDS
Oregon's well construction standards are designed to protect the ground water resource and the public. They help prevent contamination of the well or aquifer by surface and subsurface leakage which may carry harmful chemicals or bacteria, and they help prevent physical injury and waste of water.
You should check the constructor’’s performance and materials to be sure they meet each item in your contract, if you have one.
WELL DEPTH - The depth of a well can be measured by using a weighted line or by measuring the drill pipe in the hole when the drilling is completed. The depth should be close to the depth recorded on the required water well report.
CASING - Casing is steel or plastic pipe installed to prevent borehole cave-in and to seal the upper portion of the well. The total length of casing used should be the same as that recorded on the well log.
SEALING - Sealing the space between the borehole and the casing helps prevent con- tamination of the aquifer. The seal should be placed in one continuous operation from the bottom upward. The seal consists of neat cement (cement and water) or bentonite (a dry clay) which extends from the ground surface to the depth required by the construc- tion standards that apply to the particular well.
DEVELOPMENT - Development involves vigorously pumping the well to help clean out drill cuttings and to maximize production of the well. Development should result in a well which produces sand-free or mud-free water unless over-pumped.
OPENINGS IN THE FINISHED WELL - All wells must have an access port for measuring the water level or a pressure gauge for measuring artesian pressure. The access port must be unobstructed. If an air line is installed for measuring the water level, it must not block the access port. Make sure the access port is capped and that all other openings are plugged, sealed, or designed to prevent surface water from entering the well casing.
TOP TERMINAL HEIGHT- The casing head or pitless unit of any well must extend twelve inches above the finished ground surface or pumphouse floor, and not less than twelve inches above the local surface runoff level.
YIELD TEST - The driller can explain the yield test to you. Make certain the data is recorded correctly on the well log. The driller reports the static water level, the date, the drawdown at the end of the test period, the pumping rate, and the length of the test period. Note whether the water level stabilized during the test. Oregon law requires owners of wells requiring a water right (usually large industrial or irrigation wells) to conduct a well pump test once every ten years and report the results to the Water Resources Department.
WELL IDENTIFICATION NUMBER - A stainless steel label, preprinted with an assigned number, should be attached to the well casing within 30 days of well construction. This unique number identifies your well and will be used to track any future modifications to the well. Please do not remove this label.
WELL LOG - You should receive a copy of your water well report from the water well constructor. You may also be able to obtain a copy by contacting your district watermaster or the Salem office. Keep your copy of the well log. This is one of the more important records of your property.
PURCHASING AND INSTALLING A PUMP
Well pumps are sold by pump dealers, some water well constructors, plumbing supply dealers, and various retail outlets. The water well constructor can tell you the well production and drawdown of the yield test. Using this information and the well diameter, a pump can be selected to meet your water needs. The delivery system design should produce enough water while using as little energy as possible. Selection of a pump with a capacity greater than the well yield can cause problems, such as muddy or sandy water, pump failure or well failure.
Several types and sizes of pumps are used in domestic wells. Each has certain advantages, depending on the depth to water, the size of the well, and the amount of water needed. Your pump supplier can recommend the best type and size for your needs. Selection of a pump too large for your well has no advan- tages and may damage your well.
MAINTAINING YOUR WELL
Some simple well maintenance steps are advisable. Carry them out for your own protection and keep careful records of all the work completed.
1. Have a water sample analyzed for bacteriological quality at least once a year. Have a sample checked for chemical quality (such as hardness or specific conductance) every five years. Changes in water quality provide early warning of defective surface casing, seals, or contaminated aquifers. Many local water treatment or conditioning businesses, and some local health Department offices or independent laboratories will perform these tests for a reasonable fee.
2. Keep a permanent record of the depth to water from a reference point such as the top of the well casing. These measurements will provide an early warning of water supply problems. Measure the water level at least twice a year and record the time and date. Measurements should be made on approximately the same dates each year, usually in the spring and fall. Let the well sit without pumping for one to two hours before measuring. If you have any questions about how to do this, ask your constructor.
3. Do not store poisons, pesticides, petroleum products or other hazardous materials in your pumphouse or near your well. It is foolish to risk pollution of the well and aquifer.
4. Do not use the pumphouse to shelter animals.
5. The landowner carries the ultimate responsibility for maintenance of wells. If well construction problems are discovered that may contribute to contamination or waste of the resource, the Department may require repairs to eliminate the problem. The Department will look first to the well constructor if the standards were not adhered to, but if the constructor is unable or unwilling to perform the repairs, the landowner must assume the costs. Over time, well casings and seals may fail and prompt the need for repairs.
ABANDONING YOUR WELL
Unused wells that are not properly abandoned can cause ground water contamination, waste, or loss of artesian pressure. Ultimately, landowners can be held responsible for harm to the ground water resource resulting from old or unused wells. Oregon’s well abandonment standards are designed to prevent contamination of the well or aquifer by surface and subsurface leakage which may carry harmful chemicals or bacteria. The standards also seek to prevent physical injury, waste of water and loss of artesian pressure.
The Water Resources Department has minimum standards that describe the accept-able methods for two types of well abandonment.
Temporary Abandonment: A well is considered temporarily abandoned when it is taken out of service for a short time. Owners of tempo- rarily abandoned wells intend to bring them back into service at a future date. A temporarily abandoned well must be covered by a watertight cap or seal. This prevents any materials from entering the well from the surface.
Permanent Abandonment: A well is considered permanently abandoned when it is completely filled so that movement of water within the well is permanently stopped. Unless otherwise stated below, a permanent abandonment must be performed by a licensed water well constructor, or the landowner under a Landowner's Water Well Permit.
The appropriate permanent abandonment method will depend on information obtained from an examination of the well log and an onsite investigation of the well. Generally, a drilled well with steel or plastic casing will be abandoned by either removing or ripping the casing and filling the well bore with cement from the bottom up. Any pump, pump wiring, or debris in the well must be removed before the cement is placed.
If a review of the well log indicates that the well is a filter or gravel-packed well (where pea gravel is used to screen out loose geologic material in the well), the Department must pre-approve any abandonment method. A greater potential exists for harm to the ground water resource from incorrect abandonment of this type of well due to the artificial gravel-pack material. If a dug well is to be abandoned, you must notify the Water Resources Department prior to beginning the abandonment, and the proposed method must be approved. Typically, a hand-dug well free of debris may be abandoned by filling the well with cement or concrete to above the water producing zone and then clean fill (not gravel) to land surface. In some cases, hand-dug wells containing debris may be subject to other abandon ment methods. For more specific information concerning well abandonment, contact a drilling constructor or the Water Resources Dept.
If you plan to construct a well to serve more than one household, a carefully drawn agreement should be negotiated. Generally, legal advice is sought for such an important document between water users and well owners. A sound agreement should address these questions:
•• Who will maintain the well?
•• Who has access to the well for maintenance?
•• Under what conditions can the property on which the well is located be bought and sold?
•• How will power costs and water availability be shared?
•• What is each party’’s interest or right to use the water? Be sure to talk to your lending institution about their restrictions on lending for shared wells.
If the well serves more than three households, it is considered a public water system. Public water systems are regulated by the Oregon Health Division, Department of Human Resources. The Health Division should be contacted for further requirements. The Health Division is located at 800 N.E. Oregon St., Portland, Oregon 97201. Phone: 1-800-422-6012
If you need help financing your new well, check with lending institutions in your area before you look for a well constructor. Some lenders have specific requirements for well production, water quality, and well depth, and may have standards for sharing wells with one or more neighbors. Several types of loans for well construction are available. The cost of a well may be included in a loan for construction of a home. Sometimes interim loans are needed to cover the cost of the well until you receive financing for home construction. These are available from a variety of lending institutions.
FOR ADDITIONAL INFORMATION CONTACT:
Oregon Water Resources Department
158 12th Street NE Salem, OR 97310