|My well in its safety enclosure next to the driveway|
As a well owner you need to know your well. Start with the “Water Well Completion Report” that must be filed when a well is drilled in Virginia. This report can tell you the age of the well, the depth of the well and casing, the approximate water zones and the yield at completion. These are the most basic facts needed to evaluate a well and water system. These reports are housed at the County Health District offices. From my report I know that my well is 150 feet deep and was grouted to 60 feet below grade. Back in the fall of 2004 when the well was drilled, the water zones were at 121-122 feet and 143-144 feet below grade. The static water level is listed at 30 with the units illegible and the stabilized yield is 60 gallons per minute after 2 hours. You read that right, 60 gallons per minute recharge rate. The property in a fractured rock system overlying the Culpeper groundwater basin has amazing groundwater flow.
The Prince William Health District rule of thumb is 5 gallons/minute is a safe yield to supply on-demand water for a typical household, but homes can have much lower yielding wells and still serve a household. However, be aware that over time the static yield of most wells fall. Groundwater typically enters a well through fractures in the bedrock and overtime debris, particles, and minerals clog up the fractures and the well production falls. According to Marcus Haynes at the Prince William Health District that drop could be 40-50% or more over 20-30 years. A low yielding well might have a functional life of only 25 years. My well is unlikely to have a noticeable reduction in yield because the fractured rock system does not typically clog with debris. The functional life of my well could easily exceed my lifetime.
If you have an older well, or you are buying a home with an older well having a well driller perform an accurate assessment of the well’s capacity would be important. A well recharge can be estimated by running water from the pump and measuring the top of the water level in the well. If it does not change, then the well recharges fasters than the pump rate. If the level is falling then the each foot in a typical 6 inch cased well represents about 1.5 gallons. A more accurate rate to determine the recharge rate is to use a compressor to blow all the water (and deposits at the bottom of the well) out of the well and time how long it takes the well column to recharge. When I last chlorine shocked my well, the water level was visible less than 2 feet down and even with running both hoses, I could not drop the water level. The recharge was too fast to clock. It costs about $200-$300 to have a well driller to do a flow test on your well and determine the water level. Since I could see my water level, and the recharge was faster than I could clock I passed on having that done and was pleased that the well itself was in good condition.
I had Bell Pump & Well examine the condition of the casing, wiring, replace the cap pump and check the well components in the house- the pressure tank and switch. The check-up cost under $200, the well cap replacement was extra. The pump should be checked for amp load, grounding, and line voltage, and the pressure tank checked for psi, a functioning pressure switch (check the contacts for corrosion), and checked for leaks.
I received a one page report from Bell Pump & Well that tells me I have a ¾ horsepower submersible pump. The pump is probably a Goulds’ Pump since the pressure tank installed at the same time is labeled Goulds and when sold together they usually label the pressure tank with the pump brand. (Gould Pump does not actually manufacture pressure tanks.) It is a good brand of pump, but there are cheap versions with plastic fittings and I would assume that my pump was “builder grade” like everything else in this house and will only have an average lifespan. The pressure switch is functioning properly cutting on a 55 psi and off a 75 psi. The higher range setting is to up the water pressure slightly. The pressure tank had a good cycle and the pressure switch was in good condition.
Out at the well, Bell Pump & Well noted that the well is a 6 inch drilled well that the well meets code. The pump amperage load was within the normal operating range and the line voltage was normal. There were no signs that the pump motor was wearing out. The most likely pump failure I am likely to see is from a lightning strike- Steel sticking out in the lawn and running sixty feet below ground is a very attractive lightening target. Based on my well check-up, I’m good to go for the winter. I will be testing my water quality in the spring when the Virginia Cooperative Extension (VCE) Office will be hosting a drinking water clinic for well, spring and cistern owners in Prince William County as part of the Virginia Household Water Quality Program. When a well is drilled the only water sampling that takes place is for a coliform bacteria test. There are many chemicals and naturally occurring contaminants that could make water unpalatable or unhealthy. The Virginia Household Water Quality Program recommends that water be analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria (if coliform is present). That can add up to quite a bill, but the analysis is subsidized by the state program and will cost only $49.