Monday, November 18, 2013

Identify and Solve Problems with an Older Well

After a wet summer it has been an unusually dry fall. These are the perfect conditions to discover if your old well is failing. Unlike machinery wells failure can be a slow and gradual process, for a small household that thoughtfully conserves water an old well can be nursed through several dry spells before having to address the problem. Natural groundwater levels usually reach their lowest point in late September or October, but the oddly dry fall has resulted in declining water levels into November. The highest groundwater levels tend to be during March and April, but the unusually dry fall has produced a slew of failing wells around here. Remember, a mechanical component is much more likely to fail than the well itself. If your water supply has lost pressure, and seems to be drizzling out of your faucet your problem could simply be a loss of pressure in the pressure tank or damage to or a leak in the bladder in the pressure tank. If your water pulses as it comes out of the faucet, the most likely cause is short cycling of the pump, which could be caused by inadequate water supply or another faulty component in the pump system. However, there are times that the problem is the well and the water supply.

A well that is going dry may produce water that looks muddy or here in Virginia with so much red clay it may look rusty. The water flow might sputter as air comes through the line instead of water as the pump draws air. If you have water first thing in the morning and again when you get home from work, but the supply seems to run out especially after doing a load of laundry or taking a shower. Then you may have a groundwater problem. According to Marcus Haynes of the PW Health District the effective yield from a well can fall 40-50% or more over 20-30 years, so a low yielding well ( a well that recharged at under 5 gallons a minute at completion) might have an effective life of only 25 years. Over time sediment and mineral scale build up inside the well closing the fractures that allow water to flow into the borehole.

To avoid be penny wise and pound foolish the first thing you need to do is figure out what is going on with your well. Do not call a plumber. A plumber is not trained to ascertain what is wrong with your well and the first thing that must be determined is if the problem is with the well or the mechanical components. Make sure that the service provider is licensed to service wells in Virginia (not all states require well drillers and well repair companies to be licensed). In Virginia a well driller should have at least a Class B contractor license and the service provider must be Department of Professional and Occupational Regulation, DPOR, certified Well Water Providers. Since 1992 private drinking water well construction has been regulated in Virginia and well drillers have to be licensed. In many other places well drilling and water wells are still not regulated.

You can waste a lot of money if you do not understand what is going on with your well and implement the wrong repairs. You will need to spend money to test the well, test the well equipment and test the water quality. When you have a private well you pay for your water in the maintenance of your well and pump system. To isolate the problem with your water supply both your well and pump system need to be tested and examined. It costs about $200-$300 to have a well driller to do a flow test on your well and determine the water level. The flow test will tell you how quickly a well is recharging essentially telling you if your well has water and how much. You also need to know the condition of your pump and pressure tank which will cost about $200 to have those checked. 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. Call the County Health Department to get a copy of your well completion report that will tell you how deep your well is, how old, the location of the water recharge zones and flow rate at completion. Ask the well specialist about the geology in your immediate location to know what can be done to restore the flow. Finally, you should test your water quality. At a minimum test of your water for iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria, appearance, taste and anything else of local concern. Virginia holds a series of subsidized water testing clinics at various locations throughout the year at a cost of $49 privately this analysis could cost $100-$200. To identify the problem with your well and water supply will cost $500-$700.

At this point you should know what is wrong with your well, but the best way to fix your well is not always black and white. If the problem is the well, you have more options than just drilling a new well. Generally speaking, a new well costs $12,000-$20,000 plus other costs for piping to the house, a new pump and pressure tank. However, drilling a new well is not always the best answer. Cleaning a well or hydrofracking a well may restore the flow to a usable rate, but this can only be accomplished in bedrock. Hydrofracking can cost $3,000-$4,000, cleaning is cheaper.

Hydrofracturing, commonly referred to as hydrofracking, is a well development process that injects water under high pressure through the well into the bedrock formation. This process is intended to flush and remove fine particles and rock fragments from existing bedrock fractures and/or increase the size and extent of existing fractures, to increase the flow of water to the well. This technique can be used for older wells and can be very successful in parts of the Piedmont and other bedrock rock formations, but the improvement may not last beyond a few months. In diabase geology hydrofracking may do nothing and in siltstone it is unpredictable what may happen to the fractured system. I could not find statistics on long term failure rates for hydrofracking (only the impressions and experience of the VA DEH and USGS), but hydrofracking could work at least for a period of time- whether that time is months or years cannot be predicted. It is a good first step in trying to restore a well with a viable aquifer, and that is structurally sound.

There are times that the water table has fallen and lowering the pump or re-drilling a well might restore the well to a lower aquifer. Lowering the pump is the cheapest fix, for several hundred dollars you might be able to restore water to your home. However, there is generally only about 50 feet below the initial pump level to the bottom of the well. With the right equipment, an existing well can be re-drilled to a lower aquifer. Re-drilling a well can cost $10,000-$20,000 depending how deep you have to go to hit a viable aquifer, and not every well hits water. Not every well driller has the expertise and equipment to hydrofrack or re-drill wells, and locally based well drillers are familiar with the geology of a region. Well drilling equipment is expensive to move great distances- if your hire an out-of-town well driller, chances are they will subcontract the actual drilling anyway. Stay local when hiring well drillers.

If the well testing you performed tells you the well is still reliably producing water in the neighborhood of 0.5 gallons, there are ways to deal with it. First is water conservation and the second is to increase water storage within the system. Water conservation involves changing water–use behavior such as taking shorter showers, but usually involves installing water saving devices like a front-loading washer (saves over 20 gallons of water for each load- about half), low flush toilets, flow restricting faucets and shower heads. Installing water saving appliances can reduce household water use by up to 30%. Disconnect any water treatment systems that consume water. Water softening systems typically use 25 gallons in the 10 minute for each backwash cycle. Reverse osmosis systems use a lot of water. They recover only 5%-15% of the water entering the system. The remainder is discharged as waste water. A reverse osmosis system delivering 5 gallons of treated water per day may discharge 40 to 90 gallons of waste water per day to the septic system. Also, check for plumbing leaks. According to the U.S. Environmental Protection Agency one out of every 10 homes has a leak that is wasting at least 90 gallons of water per day.

Water conservation may solve the problem of a 4 gallon a minute well, but increasing water storage can make a reliable 0.5 gallon a minute well viable for a modern household. An intermediate storage system can either be the well itself if deep enough or a storage tank, reservoir or cistern that can be installed between the well and pressure tank. The reservoir or storage serves as the primary source of supply for the pressure tank supplying peak demand. Ideally, the storage tank or cistern should be able to hold at least a day’s water supply and be regulated by a float switch or water level sensor. A 0.5 gallon a minute well can pump 720 gallons per day more than adequate for a household, you just need to capture it. The rule of thumb is to size a storage tank or cistern at 100 gallons per person in the household. Every two feet of well below the static water level holds almost 12 gallons so that 120 feet of well below the static water level will hold 720 gallons. It is important to use disinfection if you have a cistern.

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