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Protect Your Well

A well isn’t just a hole in the ground that only needs your attention when something goes wrong. It is a direct conduit from the surface to the aquifer that supplies your water. A little TLC will maximize your well’s working life and help protect it and your groundwater source from contamination.

“Be proactive,” says Melissa Orr, agriculture water engineer with Alberta Agriculture. “Just as vehicles need regular maintenance to keep them running smoothly, there are certain things you have to do to keep your well working properly.” That’s the message Alberta’s Working Well Workshops have delivered to some 2,200 well owners since the program’s inception two years ago.

Biofouling is the nemesis of all wells. You’ll know your well is affected if brownish slime forms inside your toilet tank and rust-coloured stains on your fixtures and laundry. The water remains clear, but it may take on a foul taste or that unmistakable rotten-egg odour. A reduction in water quantity could be another sign.

Biofouling is caused by iron bacteria and sulphate-reducing bacteria that are harmless to humans and naturally present in almost all groundwater sources. The slime is actually large populations of the bacteria that multiply as they feed off the oxygen and minerals in the water.

The remedy is to shock chlorinate once a year — whether or not the well is used for drinking water.

Other reasons for a treatment are coliform bacteria in the regular water test, a change for the worse in water quality or quantity, or as a precaution following repair work or a flood that may contaminate the water.

Chlorination is an inexpensive and straightforward preventive measure that involves siphoning a solution of chlorine bleach and water into your well, opening all outlets in the house, outbuildings and yard to draw it through the system, then shutting all of them to let the solution sit in the lines for eight to 48 hours. Be sure to obtain complete, detailed instructions before attempting to carry out the treatment yourself, or hire a professional to do the job. It’s important to consult with a professional before shock chlorinating an old well that hasn’t been properly maintained, Orr adds. The biofouling may be too far advanced for the treatment to be effective and, because chlorine is corrosive, there is a remote risk that the treatment could be too much for equipment that’s on its last leg.

A regular maintenance routine should include testing for coliform bacteria twice a year if the water is used for household purposes. Draw samples from the tap after the water has passed through any iron filters, water softeners, or chlorinators.

The chemistry of groundwater is fairly stable, therefore, a chemical analysis of the raw water every five years or so is generally adequate unless you notice a change in quality or odour. This sample must be drawn from the line before the water enters any treatment equipment.

The same rule of thumb applies for chemical analysis for water used for livestock. If it is a sand-point well, shallow aquifer, or the depth of the water changes dramatically, you should test the water more often as is recommended for dugout water, says Bob Klemmer, regional livestock specialist with Saskatchewan Agriculture.

If the mineral ions of concern in water are on the high side, you may want to test every two to three years to make sure your herd isn’t at risk. The list includes sulphates, iron, sodium, magnesium, nitrates and perhaps molybdenum and selenium. Dugouts fed solely from surface water are more susceptible to fluctuations in mineral ions, particularly when water levels are low and evaporation is rapid concentrating the minerals.

The Internet-based Rural Water Quality Information Tool,www.agric. gov.ab.ca can help interpret water test results.

DON’T CAUSE PROBELMS

People are often surprised to learn that over pumping is a leading cause of well failure, Orr says.

Over pumping occurs when water is removed faster than it naturally flows into the well casing from the aquifer. Once the casing is drained the pump starts pulling water directly from the aquifer creating a depression at the surface of the aquifer. Air rushes in to fill the void and the added oxygen sets the stage for increased bacterial growth that eventually plugs the equipment. As water is pulled into the casing, natural minerals may precipitate out of the groundwater and form a crust on the perforations as well.

Your well drilling report will indicate the maximum safe pumping rate. Contact your provincial Environment or Agriculture Department to find out how to obtain a copy of the drilling report if you don’t have it on file. Drill- ing reports for old wells oftentimes have bare-bones information at best and may not be available at all. In that case, Orr suggests asking your neighbours about the construction and pumping rate of their wells, or talking with drillers who are familiar with your area, because neighbouring wells tend to be of similar construction and are often supplied by the same aquifer. Failing that, licensed drillers can do a pump test to calculate the safe pumping rate.

Dangling a weighted rope down the well to check the water level has been another expensive proposition for many well owners, Orr says. If the weight gets caught on parts inside the well, you will have to hire a driller to remove it.

A dip tube taped to the waterline from the well cap down to the pump just above the perforations will give you clear access to probe the water level. It is usually an extra in a new installation or can be installed in an existing well if the pump is being serviced or replaced.

Regularly monitoring the natural, non-pumping water level and the pumping water level in the well gives a good idea of how efficiently your well is operating. For the best comparison, take your measurements at the same time of day under similar consumption patterns.

Backflow from a livestock, spray or holding tank will contaminate the well and aquifer if the foot valve on the intake line fails to close because of a power outage, slime buildup or corrosion. Frost-free livestock watering systems are made frost free by removing the foot valve so the water will drain back below the frost line.

Backflow occurs when the end of the hose that fills the tank is below the water level in the tank. Creating an air gap between the water in the tank and the hydrant or tap will prevent backfl ow from entering the well, says Orr. One sure way to do that is to install a vacuum breaker on the water outlet before connecting the hose. For frost-free applications, the only way to create an air gap is to ensure that there is space between the surface of the water and the end of the outlet hose.

WELL DESIGN BASICS

A new well should be located up-slope and certain distances from potential sources of contamination. Contact your provincial Environment or Agriculture Department to find out about the regulations and follow the same recommendations when constructing new livestock areas, fertilizer sheds, in areas where there is an existing well.

Build a mound around the casing at ground level so that run-off water flows away from the well. A depression around the outside of the casing where water gathers lets run-off and contaminants seep down the outside of the casing directly into the aquifer.

For the same reason, the anulus (earth between the casing and the bore hole) should be tightly sealed with bentonite chips from the top of the aquifer to the surface. Sealing the anulus is highly recommended in new well construction.

Well pits pose similar risks for contamination and a real danger to people who enter them due to possible toxic gas accumulation or a collapse. If the well in the pit is uncapped, rodents that make their way into the pit can fall into the water that you pump directly into your tap.

Well pits were banned in Alberta in 1993, however, Orr says thousands still exist. They became common when people started using pressure systems instead of windmills and hand pumps. The well casing was cut off below ground level then the pit above the well casing was lined with wood, concrete or steel to provide a frost-free location for the pressure system and access to the waterlines.

If you still have one of these Orr recommends you consider upgrading your design by having a qualified driller install a pitless adaptor to provide a frost-free, watertight connection between the pump and the water distribution line. The well casing can then be extended at least 24 inches above ground level, properly sealed and topped off with a proper mound. Vermin-proof (sanitary) caps should be installed on new wells and can be ordered to fit existing drilled wells.

Always keep records of everything pertaining to the regular testing, maintenance and repair of the well, including testing carried out by other parties. Be sure to pass your file on to the new owner when you sell the site.

For more information about wells and the Working Well Workshops visit www.environment.alberta.ca/01317

or call the Alberta Ag-Info Centre at 403-742-7901; or the Alberta Environment Information Centre at 780-427-2700.

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