Protect your groundwater when servicing your windmill.

If proper precautions are not followed, regular maintenance of windmills, turbine pumps and other oil-lubricated water pumps can result in an oil-contaminated well, a New Mexico State University water quality specialist warns.

"Just as most people wouldn't drain their car engine oil onto the ground, well owners should take care not to drain pump oil onto the ground, particularly near the well casing," said Craig Runyan of NMSU's Cooperative Extension Service.

Some wells provide more protection than others. Properly-cased, drilled wells offer much better ground-water protection than handdug or driven-point wells, Runyan said. Even greater protection is gained when a concrete slurry is poured between the casing and bore hole. A concrete pad or grade sloping away from the casing will prevent runoff from entering the bore hole.

"The casing should be a minimum of 12 inches above grade to keep run-off water from entering into it, and it should also be capped and vented," Runyan said.

Review all activities that occur near a well to determine their potential threat to groundwater. Recommended practices include restricting livestock access to the wellhead, controlling burrowing animals, avoiding manure or chemical storage near the wellhead and providing sufficient distance from dead animal pits and leach fields.

Runyan stressed four main areas to consider in wellhead protection: well location, well construction, well management or maintenance, and proper well abandonment. Owners should follow correct closure procedures for an abandoned well to be sure it is properly sealed and poses no threat to groundwater.

Most windmill manufacturers recommend changing gear oil every year, said James Dean, associate professor with NMSU's agricultural and extension education department. "Changing windmill gear oil is critical, but it is the most often overlooked windmill maintenance practice," Dean said. "I've seen windmill motors in service that had run so dry I had to use a hammer and scraper to remove packed dirt from the drain hole."

Change pump oil completely every year, instead of simply topping it off. "By completely draining the oil, any dirt or corrosion which may be in the gear box will be removed with the old oil," Dean said. "This also is a good time to look for other areas that may need servicing such as stuffing box leaks, dry grease fittings and dry furling ring bearings."

Turbine pumps require oil changes based on recommended hours of usage. Too often the used oil is allowed to simply drain out directly from the drain plug, risking groundwater contamination. To change pump oil, use a drain tube or valve to drain the oil into a bucket. This reduces the risk of oil entering the groundwater down the well casing or between the casing and the bore hole. Take used oil to an oil collection center.