Water Well Drilling: FAQs
1. How much will a new well cost?
The cost of drilling a new water well is derived from the amount of casing (20 foot minimum) to bedrock and the amount of drilling needed to find water, plus the cost of the drive shoe and the well cap. In unstable formations we use our underreamer system, which drives the casing and drills at the same time. This requires the use of a more expensive drive shoe. Our per-foot well drilling prices sometimes change due to the fluctuating cost of casing and other materials. Although it is impossible to tell exactly how much a water well will cost beforehand, our average well in 2011 was about $3500.
2. How do you know where to drill?
Typically, the first consideration in determining the location of the well is to maintain enough distance from the septic system to prevent contamination. With previously existing septic systems the State of Maine Well Drillers Rules require the well to be at least 60 feet from the septic tank and 100 feet from the leach field. However, for new septic systems the Maine Subsurface Wastewater Disposal Rules require that both the septic tank and the leach field be installed with 100 feet of setback from the well. Property lines also must be considered. Contact your local town office for set-back requirements from adjacent property lines, and be sure of their exact location when drilling close by. If your property is in a township, plantation or other unorganized area, contact the Land Use Regulatory Commission for information about setback requirements in your area. Finally, the well must not be within the right of way of any roads adjoining the property. As a general rule of thumb the right of way extends 35 feet from the center of the road, but check with your town office for any location-specific requirements. Be sure to contact DIG SAFE before digging or drilling to avoid striking any underground utilities. We prefer to meet with the customer at the job site to determine the best location for the well, so feel free to contact us if you need assistance.
3. What determines the depth of a well?
Because most wells in Maine are fractured bedrock wells, the size and location of water-bearing fractures encountered during drilling determines the depth of the well. The amount of casing needed depends on the depth to bedrock in a given area, since the casing seals off unwanted contaminants above the bedrock. Both of these factors can vary drastically in different areas. In fact, a well on one property could be hundreds of feet deeper than the well on an adjacent property.
4. How do you know when you have enough water?
During drilling, compressed air continuously cleans the hole and lifts out any water entering the well through fractures in the bedrock. This allows us to measure the water flow rate of the well at any time. When deciding whether or not a given flow rate will adequately supply a house, we must first consider the depth of the well.
A typical well holds about 1.5 gallons of water per foot and will usually fill up to within 25 feet of ground level. As such, at a depth of 300 feet the flow rate can be significantly lower than at a depth of 100 feet because of the greater storage capacity of the well. In fact, the water stored in a 300 foot well will supply the average house for a day.
5. How do I know that my water is safe to drink?
There are no laws requiring private wells to be tested in the state of Maine, so it is up to you to ensure that your water is safe for consumption. Wells are usually high in natural contaminants when they are first drilled so you should run your well pump for two to four weeks before getting your water tested. If your well tests high for contaminants after your first water test, test it again after two weeks of use before considering a water filtration system. Additionally, well water should be tested once every year because normal groundwater flow and other changing conditions can alter the quality of your water. Test kits are available from Northeast Laboratory Services.
Annual chlorination of your well is also a good idea. For best results have this done by a professional, but for the do-it-your-selfers out there, read on.
6. How do I chlorinate my well?
* When handling chlorine or any potentially harmful chemicals, be sure to wear rubber gloves and safety glasses. *
Before you start it will help you to know the well’s depth, diameter, and pH level. You can find the well depth stamped on the underside of the well cap or on a label affixed to the expansion tank. If not, try calling the company who drilled the well. Most wells are six inches in diameter, but you should measure the inside of the casing to be sure. The pH level can be found on water test results or by using test strips purchased at pool supply stores. The pH scale measures the acidity or alkalinity of water on a scale of 1 to 14, 1 being most acidic, 7 being neutral and 14 being most alkaline. Chlorine is most effective in water with a low pH; in fact, a chlorine solution in 7 pH water has a 75% greater biocidal efficiency than a solution in 8 pH water. If your well water has a pH that is greater than 7, you can add vinegar to your well before adding the chlorine and allow it to mix for 30 minutes to lower the pH.
1. Shut the power off to the pump.
2. Remove the well cap and carefully move the pump wires out of the way so that they are hugging the side of the well casing.
3. Run a hose from an outside faucet or from the drain valve on the expansion tank to the well. *Be sure to bypass all softeners, filters, and other water treatment equipment. Introducing chlorine into these systems can permanently damage them.* Stick the hose a few feet down the well.
4. Double check that the electrical connections are out of the way. Turn power on to the pump and with the water running pour the required amount of bleach into the well and away from the wires. The normal range of recommended concentration is 50-100 parts per million (PPM), which is about 20 to 40 ounces of bleach for every 100 feet of depth in a 6 inch diameter well.
5. After about 15 minutes of water circulation a strong chlorine odor should be present at the well. At this point, turn on all faucets in the house starting with cold water and then hot until a chlorine odor is present at all taps.
6. Allow the chlorine to stand in the system for at least six hours, preferably overnight. Flush the system from an outside faucet until no chlorine odor can be detected. Repeat on each faucet in the house.
7. Return all water treatment equipment to the service position and enjoy your water!