Maintenance Guidelines

Always use an Arizona licensed well driller and pump installer when a well is constructed, a pump is installed, or the system is serviced. A properly constructed water supply system should require little routine maintenance, and these simple steps will help protect your system and water quality:

Be aware of the geology of your aquifer. Know that a well installed in consolidated (fractured) rock is more vulnerable to contaminant transport, whereas an unconsolidated aquifer retains more water filtering capacity. In other words, if a known contaminant release occurs in your neighborhood, the geology of your aquifer may protect your water supply, or may make your supply more vulnerable to contamination.

Keep hazardous chemicals, such as paint, degreasers, fertilizer, pesticides, kerosene, and motor oil away from your well head. Do not spill or discard any liquids in your yard. Instead, reuse them or take them to a recycling center.

Periodically check the well cover or well cap to ensure it is in good repair. Do not allow surface water to puddle near your well: if necessary construct berms around the well to divert surface runoff away from the well head.

Always maintain separation between your well and buildings, septic systems, chemical storage facilities, garage, or car maintenance area. Your professional contractor will know the rules on appropriate distances for new construction.

Don’t dispose of chemicals in your septic system, and read the label of any cleaners or additives advertised for septic systems. De-greasers contain industrial solvents that persist in the environment and may seep into the aquifer.

Do not allow water to siphon back into your well. Install a back-flow preventer on outdoor hoses. When mixing pesticides, fertilizers, or other chemicals don’t put the hose inside the tank or container and leave air space between the hose and the contents of the container.

When landscaping, keep the top of the well at least one foot above the ground. Slope the ground away from your well for proper drainage.

Be careful when working or mowing around your well. A damaged casing could jeopardize the sanitary protection of your well. Do not pile landscaping or construction materials near your well.

Be aware of changes in your well, the area around your well, or the smell, taste, or color of your water.

Monitor the sediment build-up in your toilet tank: If the sediment is soft and does not feel gritty if rubbed between your fingers, this is not of concern unless you notice a significant increase in volume. If the sediment is gritty, or if you notice sand in the tank, contact a licensed well pump installer.

If the flow rate slows and you have not observed any sediment, scale build-up may be sealing the well screen or blocking the sand pack. A common iron bacteria or slime may also be growing on your well screen, causing a biofilm to build up (biofouling) that clogs the screen. A licensed well driller will be able to inspect your well with a down-hole video camera to diagnose the problem and rehabilitate your well. Typical methods to rehabilitate the well include using chemicals to dissolve incrusting materials, cleaning the well with a brush attached to a drilling rig, and high pressure jetting and surging to dislodge fine materials and open the gravel pack. In a bedrock aquifer exhibiting reduced flow, the contractor may inject water at extreme pressures to induce more fracturing of the rock.

An annual well maintenance check, including water quality testing, is recommended. The water quality should be checked any time there is a change in taste, odor, or appearance, or anytime a water supply system (such as pump replacement) is serviced.

Keep your well records in a safe place: These records include the construction report (well log), as well as any water well system maintenance and water testing results.

When your well has come to the end of its serviceable life (usually 20 to 30 years), have a licensed water well contractor assess your system. You may have to have your well properly decommissioned and a new well installed. If ground water elevations have dropped and air is entering your system, you may need to have your pump lowered, or the existing well deepened.

Shock Chlorination: Proceed with Caution

Shock chlorination is used to disinfect wells during, or right after, construction and thereafter as needed to remove microbial contaminants from the well casing, holding tanks, and even delivery pipes, as needed. It is recommended that this procedure be done by qualified personnel since strong bleaching chemicals must be handled during the process. For guidelines on how to proceed see the Arizona Cooperative Extension Water Facts Number 5 by Hassinger et al., (1994) “Shock Chlorination of Domestic Wells, available online at http://ag.arizona.edu/pubs.

Note of Caution: Recent preliminary research done outside Arizona suggests that in some instances shock chlorination may result in the release of arsenic from aquifer minerals near the well screen. Arsenic trapped in pipe scale deposits may also re-dissolve when exposed to strong chlorine solutions. As previously mentioned, changes in the water chemistry (for example, raising or lowering the water pH) may result in the release of arsenic in the water. The effect has been observed in some aquifers with minerals high in arsenic and has prompted the Wisconsin Department of Natural Resources to publish a bulletin titled “Well Chlorination in Arsenic Sensitive Areas” which cautions about using chlorine solutions (WDNR, 2008).

Well owners that shock chlorinate their wells in regions of Arizona known to have arsenic, should follow shock chlorination steps carefully. Avoid the use of either acid or alkaline bleach solutions (pH 6-7 is best), and do not leave chlorine solutions inside well casings for longer times than those prescribed. Well casings, tanks, and pipes should be flushed thoroughly until no residual levels of chorine are found. Well water used for drinking should also be tested for arsenic after shock chlorination.