Monday, May 2, 2016

Plan Now to Replace Your Well Pump

If you have a private drinking water well you are responsible for maintaining your well and water system to keep the water flowing to your home. There has been limited data gathered on private household water wells over the years, so a lot of what’s out there is hearsay and guesswork. The Virginian Rural Household Water Quality Program out of Virginia Tech through its well testing program is gathering data, but for now the data available is limited.

Both wells and the mechanical components of a well have a limited life. Someday the well components and well its self will have to be replaced- plan and budget for it now because you cannot live without a water supply. To avoid costly mistakes, the time to research well contractors and equipment is before your well fails. While many wells will last decades, it is reported by the groundwater association that 20 years is the average age of well failure that is failure of the well itself. Failure of the well components were not tracked separately. Mechanical failure is impacted by the type of well, the geological conditions, how it is operated and maintained and the materials of construction. In other words, it varies all over the place.

A well may fail through pumping water high in sand or gravel, corrosion from corrosive water (low pH), incrustation of the well by minerals, biofouling of the well by microbial oxidation and precipitation of iron, manganese or sulfur and the slime production, or by a failure or breakdown in the pumping equipment. Often these problems are interrelated and we will discuss that in a later blog entry. Water treatment systems are installed to protect plumbing and improve water quality in the house. Nothing is done to protect the well or keep it operational.

The essential components of a modern drilled well system are: a submersible pump, a check valve (with an additional valve every 100 feet), a pitless adaptor to bring the water to the house below the frost line, a sanitary sealed well cap to keep out vermin and bugs, electrical wiring including a control box, pressure switch, a pressure tank to literally push the water throughout the house and an interior water delivery system known as your plumbing. There are additional fittings and cut-off switches for system protection, but the above are the basics. To keep the home supplied with water each mechanical component in the system and well must remain operational and sooner or later they should all be replaced.

The well has a casing (a metal or plastic liner) that may extend the length of the well, or at least to the bedrock and then have some sort of slotted casing, screen or “sock” around the pump impeller to keep debris, sand and sediment out of the system. Over time these can become damaged by corrosive water, fouled by “iron bacteria” or clogged by sand or clay fines all of which can destroy your well’s mechanical equipment.

When you drill a well, mud and borehole cuttings can partially plug the well. This material must be removed to allow water to freely enter the well during well development. A good well driller will do a better job of this, a less than good well driller will tell you that excess sediment in your new well needs a sediment filter and will happily sell you a new pump when the first one fails prematurely from pumping sand and grit. All wells have sediment, but if the well has not been fully and properly developed the well will often produce excess amounts of sediment or have a low water production yield. Though not every well drilled has the potential to provide enough water for a household, poor choices in well completion design can render even a good well a poor producing well and result in a very short life for the mechanical equipment.

Well casings are subject to corrosion, pitting and perforation. Also, over time the amount of water a well yields can decrease. That can be caused by the water table falling due to extended drought, increased use or building in the recharge area or a deterioration in the equipment efficiency. Mineral encrustation and biofouling can cause plugging of holes in the well casing, well screen or the filling of openings in the geologic formation itself that supply water to the well. The most common encrustation and plugging of a well or its components is from the conversion of calcium bicarbonate which is soluble in water to calcium carbonate which is insoluble and caused by the reduction in pressure by the pumping action.

If you rely on a private well for your water supply, like me and 1.7 million other Virginians, you are completely responsible for routine testing, care and maintenance of that system and you should think about your water supply and equipment and plan for replacement before you have a problem. Some health departments in parts of the country that iron rich recommend chlorinating your well once a year and anytime it has been opened or serviced as a method to prevent biofouling. I chlorinate my well every couple years to address “iron bacteria” that has been a problem in the past. This also serves to keep my well fresh. When I chlorine shock the well I am essentially flushing the water system to remove residue and buildup from the system.

Somewhere in the back of my head is the statistic that the median run time for an immersion pump is about 25,000 hours that gives you about 14-17 years of residential operation depending on how your household operates. My well pump is about 12 years old, while it is my intention to replace my pump, the wiring, the pressure tank and pressure switch before they fail, it is devilishly hard to pick a time to do that. However, I can be prepared to replace the pump and related components by researching that option now. After you pump has failed is not the time to identify a contractor and pick the replacement equipment. Identifying who to call if you have a well problem is something all well owners should do before they have a problem.

The first step is to get a list well contractors where you lie who are licensed to operate in in your state. In Virginia, there have been well regulations in place since 1992 and well contractors are required to have a license from the Department of Professional and Occupational Regulation (DPOR) as a water well system provider. Loudoun County Health Department is kind enough to maintain a public list of licensed well contractors which you can access from their web site.

You should get three proposals to compare, so you will need to narrow the list of contractors based on reputation, size of the organization and references. Call the licensed contractors and ask about availability-when your well fails you do not want to wait a week or more for an appointment. Next get at least three references for pump and pressure tank replacements from each and call them. Get as much information as you can from the references and do not forget to ask if they would use the well contractor again. Also, make sure that the well contractor has the proper equipment to pull your existing pump vertically.

Once you have selected your well contractors you need to call them for a proposal which should include equipment specifications, labor and costs. It might be a good idea to replace the pump, pressure tank and electrical at the same time, I am a big believer in this, but you should discuss this with your selected contractors. Do you want to install a 2-wire or 3-wire model pump? A 3-wire model makes maintenance easier. This is because the starter controls are above ground, wired to the pump. What size pump do you need 1 HP or 1.5, 2.0 or maybe 3.0 HP? How many gallons a minute should it pump? Do you need or want a variable speed pump? Variable speed pumps have been reported in some places to have reliability problems. What size pressure tank do you need? Are you going to replace the electrical wiring? These are all questions you want the well contractor to answer and options you want to price out while you still have water in your house. Your well contractors will not all have the same answers, you will then need to decide what you want. By going through this exercise you will be prepared to deal with both mechanical and well issues when they happen.

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