WATER FACTS
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State wide ground water usage is about 1.5 billion gallons per day.
Caddo Parish uses: 5 million gallons of ground water/ day 200 million gallons of surface water/ day East Baton Rouge Parish uses: 120 million gallons of ground water/ day 36 million gallons of surface water/ day Caddo Parish’s main aquifer is the Wilcox Aquifer. Other Caddo Parish aquifers are: Red River Alluvial (along the Red River valley) Sparta Aquifer (only in a small area in the North) One square mile with an aquifer 20’ thick with an average permeability contains one billion gallons of water. The average home uses 300 gallons of water per day. Many homes with automatic sprinkler systems in rural Caddo Parish use 12,000+ gallons of water every day in their yards alone during the summer months. The City of Shreveport pumps an average of 36 million gallons of water per day. Peak usage is usually around 45 million gallons per day. During the summer of 1998 pumpage out of Cross Lake exceeded 50 million gallons/day. The Twelve mile Bayou pump station is pumping water out of the Red River into Cross Lake since little or no water is coming down Twelve Mile Bayou from Caddo Lake during drought conditons. An average home water well produces about 10 gallons per minute and pumps an average of 30 minutes a day through out the day. The average size home pump is either a ½ or ¾ horsepower, single phase, 230 volt pump. |
BASIC GEOLOGY |
Water is found in the pore spaces in between the grains of sand.
Aquifers are layers of sand (in Caddo Parish about 5’to 20’ thick) that hold water. Usually the sand bed or aquifer is directly above a clay layer that acts as the bottom of the aquifer and keeps the water from migrating further downward. Sometimes when an aquifer is overlain with clay, the water in the aquifer is under pressure. When a well is drilled into a pressurized, confined aquifer, it is said to be an artesian aquifer. If there is enough pressure in the aquifer to push the water all the way up to the surface; the aquifer is a flowing artesian aquifer. If the pressure is enough to push the water only part way to the surface, the aquifer is said to be a sub-artesian aquifer. The Wilcox aquifer usually runs between 100’ and 350’ in Caddo Parish. The water quality is generally fair to good. However, in places the iron and manganese can be slightly high causing red or brown stains. The quantity can run anywhere between 5 gpm and 200 gpm. The Red River Alluvial aquifer runs between 20’ and 80’ in depth. The water quality is usually poor to downright awful. Most of the water is very high in iron and is very hard. The quantity however, is usually very good. Yields of up to 1,500 gpm are possible in places in the aquifer where coarse sand and gravel deposits can be found. This is usually the aquifer used by farmers to irrigate their crops. |
WELL CHLORINATION |
The typical domestic well should be chlorinated twice a year with a mild chlorine solution. Heavy chlorination is required whenever e-coli is detected in the water. Heavy chlorination is also required whenever the well is serviced and the sanitary well seal is opened to allow the pumping equipment to be pulled and serviced.
State law requires all wells to be tested for contamination any time a home is sold. We recommend that the water be tested once a year. The water can be tested by the Parish Sanitarian or a home test kit can be purchased from CD&S. |
MILD CHLORINATION
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The typical domestic well can be chlorinated by the homeowner in the following fashion.
Purchase 2 gallons of “Chlorox” or “Purex” household bleach. This is a straight 5 ¼% sodium hypochlorite solution. DO NOT use bleach that has scented additives or any extra ingredients. DO NOT use “Chlorox II”. Usually the less expensive the bleach the better. Fill up the bathtub and several gallons of drinking water before you begin because the well will be out of service overnight. Go to the well and remove the well vent. This is the small ½” pipe with a 180 degree fitting on top of the well seal. Notice if the well vent is properly screened. A bug proof screen should be mounted on the end of the breather or well vent. Pour the two gallons of bleach down the well vent hole in the well seal. (You will probably need a funnel.) Refill the containers with clean water and pour two gallons of clean water behind the bleach. Replace the vent and let the chlorine set overnight in the well. CAUTION EVERYONE NOT TO DRINK OR WASH. It is permissible to flush the toilet or wash your hands but try not to run any water until morning. The next morning open all taps and let the chlorinated water run through the piping system. This will also clean out your household plumbing system. Too much chlorinated water in your sewer system could damage the bacterial decomposition in your sewage treatment system. The bulk of the chlorinated water needs to be run outside through a garden hose where it can run off and not pond or create a nuisance. Several hours of flushing may be necessary to assure that all chlorine has been pumped out of the system. DO NOT drink any water until all chlorine is flushed from the system. Do not wash any clothes that are sensitive to chlorine until ALL chlorine is flushed out of the system. Be careful in dealing with the chlorinated wastewater. Some fish and animals are more sensitive to low levels of chlorinated water than humans. |
HEAVY CHLORINATION
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The typical domestic well should probably be chlorinated by a drilling contractor if heavy chlorination is required. Usually 3 to 10 pounds of calcium hypochlorite are used in powder and tablet form. If the tablet form is used the chlorination is usually more effective but it takes much longer to flush the chlorine out of the system. Sometimes multiple treatments are necessary to properly treat the problem.
The same precautions should be taken overnight and the next day when flushing the well as with the procedure in “light chlorination” only it may take much longer to completely flush all of the chlorine out of the system. Remember that your well is chlorinated for your protection. Clean, safe water has done more to increase the actuarial lifespan of mankind than all medical research combined. The drilling contractor as well as the homeowner are all working together to keep drinking water safe for human consumption. A few items that you as a homeowner can do are: 1. Make sure your well casing is properly cemented. State law requires a minimum of 10 feet of grout around the outside of the casing to prevent surface water contamination from yard wastes, herbicides, etc. Continental Drilling recommends full depth grouting all the way down to the top of the aquifer if possible. 2. Make sure your casing is extended at least 12” above ground level (State sanitary code rule). In areas of flooding make sure your casing is at least 12” above the 100 year flood plain. 3. Make sure your well seal on top of your casing is water tight and sealed properly. Make sure that the electrical wires coming out of the well seal are sealed with either a compression rubber fitting or silicone. Make sure the vent pipe is 12” above the well seal, turned down and properly screened with bug proof screen wire. 4. Make sure that any old or abandoned wells not in use are properly plugged and abandoned (DOTD state law). These old wells can provide a direct conduit for contamination to enter your aquifer. NEVER use an old well to dispose of anything- especially those items listed in below in section #5. (I have seen items listed below stored in an old shed with an abandoned well. The well casing was cut off flush with the floor, the pump had been removed and no cap was over the casing. Several containers that no longer had labels were leaking on the floor!) 5. Sensibly dispose of old paint, motor oil, herbicides, fertilizer, etc. Remember that the well house should not be a storage place for hazardous chemicals! (Unfortunately many are used for just such a purpose.) Remember that a good well is your most important asset at your home. Take care of it. If you have any questions, contact Continental Drilling & Service, Inc. 318-221-4273. |
BASIC WATER DISINFECTION |
Ground water in its natural state is usually pure to drink 99% of the time. Most of the problem results from contamination of the water while removing it from the aquifer or transporting or storing the water.
The most common form of disinfection is chlorination. Other forms of disinfection include hydrogen peroxide, ozone, iodine, ultra violet light and a few others. Chlorine is the easiest to handle, store & use. The most common form of chlorine is ordinary household bleach such as Chlorox. This is 5 ¼% sodium hypochloride. This means the mixture contains 5 ¼% of chlorine by weight. If you use ordinary bleach be sure to use plain bleach. Do not use anything with special “whitening agents”, “scents” or any other additives. Just use plain bleach, the least expensive item of the shelf. To disinfect small quantities of water use the following mixture: 25 ppm Mix one teaspoon of 5 ¼% bleach with 5 gallons of water. Shake or mix and wait over night before drinking (at least 4 hours). 50 ppm Mix two teaspoons of 5 ¼% bleach with 5 gallons of water. Shake of mix and wait over night before drinking. Use the “25 ppm“ mixture if the water seems to be from a relatively safe source such as a properly constructed water well and you want to put it in a clean container and save or transport it. Use the “50 ppm” mixture if the water is of a more questionable source such as a City water system that has been off and lost all pressure and then come back on line or after a water main has been broken and repaired. If the water still has a strong chlorine smell after it has set all night the excess chlorine can be removed by running the water through a small carbon or charcoal filter. These are available at a number or outlets. Be aware that the carbon will have to be replaced from time to time. Another source of chlorine is HTH or swimming pool granular chlorine. This has a long shelf life and can be mixed up as required. To obtain a 5 ¼% solution mix 3 1/3 pounds of 65% active granular chlorine with 5 gallons of water. Mix thoroughly and you now have chlorine with the same strength as regular Chlorox. If it is determined that an aquifer is deep enough (below the Alluvial) but not too deep (into the salt water) then the next consideration is the thickness. The thickness (along with the grain size) determines how fast the water will travel through the sand bed (aquifer). Usually a minimum of 10’ is required. The hole is then enlarged and a casing pipe is run down to the top of the aquifer. The annular space (the space between the earthen borehole and the outside of the casing pipe is then filled with grout from the top of the aquifer all the way back up to the surface. This is necessary to prevent contamination. Contamination can come from; surface water, septic systems or shallow aquifers such as the Red River Alluvial aquifer. After the casing pipe has been installed down to the top of the aquifer and the grouted in place the aquifer is drilled and washed out. A special screen is placed down in the aquifer and special graded coarse filter sand is installed around the outside of the screen. The screen holds back the special graded coarse filter sand and the special graded coarse filter sand holds back the fine grained sand in the aquifer. The well is then developed to remove the drilling mud from the aquifer and to settle the filter sand. A submersible pump is then installed in the casing and is connected to a pressure demand switch. This automatically turns the pump on and off as required by the pressure sensing switch. |
BASIC WELL CONSTRUCTION |
The whole object of a properly constructed well is to remove water and leave the sand without contaminating the water along the way.
First a drilling rig is set up and a pilot or exploration hole is drilled. This is to find out if an aquifer exists, how deep the aquifer is and how thick the aquifer is at the particular location. If it is determined that an aquifer is deep enough (below the Alluvial) but not too deep (into the salt water) then the next consideration is the thickness. The thickness (along with the grain size) determines how fast the water will travel through the sand bed (aquifer). Usually a minimum of 10’ is required. The hole is then enlarged and a casing pipe is run down to the top of the aquifer. The annular space (the space between the earthen borehole and the outside of the casing pipe is then filled with grout from the top of the aquifer all the way back up to the surface. This is necessary to prevent contamination. Contamination can come from; surface water, septic systems or shallow aquifers such as the Red River Alluvial aquifer. After the casing pipe has been installed down to the top of the aquifer and the grouted in place the aquifer is drilled and washed out. A special screen is placed down in the aquifer and special graded coarse filter sand is installed around the outside of the screen. The screen holds back the special graded coarse filter sand and the special graded coarse filter sand holds back the fine grained sand in the aquifer. The well is then developed to remove the drilling mud from the aquifer and to settle the filter sand. A submersible pump is then installed in the casing and is connected to a pressure demand switch. This automatically turns the pump on and off as required by the pressure sensing switch. |
HOW DO I ADJUST THE AIR IN MY BLADDER TYPE PRESSURE TANK?
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Why do I need air in my tank anyway?
The air cushion is necessary to maintain pressure on your household plumbing while the pump is not running. Think of the air cushion as a coil spring pushing on the water in the tank. If the tank looses the air pressure or air cushion it becomes water-logged. This will cause rapid cycling of the pump motor and will either trip the circuit breaker, trip the overload relay in the motor or eventually burn up the motor windings. How often do I need to check my pressure tank? We recommend that you check the air in your pressure tank twice a year. If you notice the pressure switch clicking on and off quickly or if you notice the pressure surging high and low every few seconds you need to stop and check the air pressure very soon. How do I check the air pressure? You first have to know where your system pressure is set. Watch the pressure gauge in the bottom of the tank and see how low the system pressure goes before the pump turns on and then notice how high the system pressure goes before the pressure switch turns off the pump. The high and low pressure readings (20/40 or 30/50 or 40/60) is the system operating pressure range. If you have been putting off replacing your old pressure gauge this is a good time to install a new one. Once you have determined your system operating pressure range subtract 2 psi from the cut on pressure (the small number). This is the air pressure number that goes in the top of the pressure tank in the air chamber. (If your system is set on 30/50 then your air pressure number would be 28 psi.) Write this number down on the top of the pressure tank near the air fill valve. Turn off the electricity to the pump (circuit breaker) and drain all of the water out of the tank. Open a hose and drain every last drop of water out of the tank. If there is not a hose at the base of the tank then simply use the closest hose outlet and drain the entire system. If there is water trapped in the top of the tank and sloshing around then the bladder is ruptured and the tank needs to be replaced. If the tank feels empty then check the air pressure in the top of the tank with an ordinary air gauge such as you might use to check the air in your car tires. If the air is less than your air pressure number (see previous paragraph) then add more air. After the air pressure is up to your air pressure number wait 5 or 10 minutes and check it again to make sure there are no air leaks into the water chamber. (Keep the water drain valve open.) If the pressure will not stay up at your air pressure number than the tank needs to be replaced. If the air pressure number remains steady, then close the hose, turn on the electricity and everything should be operating properly. Make sure the pump turns off at the high pressure setting. Run some water until the pressure drops to the low setting and the pump turns on. Close the valve and see if it takes about 60 seconds or more for the system to pressure back up to the cut off pressure. If so, pat yourself on the back and you are finished until the next time. This seems so confusing? If you would like, we will be happy to send you written instructions or send a service man to check your system and go over the procedure with you in person. If my old tank is bad where can I get a new one? Glad you should ask! Just call us at 318-221-4273 for a tank quote. We have all size tanks in stock ready for installation by our service crews. If you would like to install it yourself, we will be glad to help you size the proper tank for you system and get back home with all the parts you will need. All of our bladder tanks have a five year warranty. (cheat sheet) 1. Check your system pressure and write it down. 2. Turn off the electricity and completely drain your tank. 3. Make sure the tank feels empty by gently rocking it. 4. Put 2 psi less than you system cut on pressure in the air chamber. 5. Wait a while and check the air pressure again to check for leaks. 6. Close water valve, turn on electricity and test system. |