Water Well Journal
Issue link: http://read.dmtmag.com/i/440561
C ar owners know preventive maintenance—like oil changes— can extend the life of their vehi- cles and keep them running longer. "Most don't wait until their engine is knocking to change their oil," says Neil Mansuy, vice president of Subsur- face Technologies in Rock Tavern, New York. "They change their oil every so many miles or months before a problem develops." Water systems managers are begin- ning to look at their well systems in the same way. They're turning to regular, preventive maintenance to extend the life expectancy of their wells, reduce lifecycle costs, and maintain maximum productivity. "When you follow the operate-to- failure maintenance cycle, you often have to do more extensive rehabbing," Mansuy notes. "You end up getting to a point where you're not able to maintain that asset." A time-based well cleaning cycle Subsurface Technologies prefers to put its municipal and industrial cus- tomers on a time-based preventive maintenance schedule rather than rely- ing on water quality tests or specific capacity to tell them when a well needs cleaned. By using a time-based maintenance schedule, they're able to remove any plugging materials from the wells while it's still soft. After all, the longer you wait, the more likely it is to become encrusted in the well and more difficult to remove. Most of the company's customers have their well maintenance performed every year. But if a well is known to foul more frequently, preventive clean- ings are scheduled every six months or even four months, depending on the severity of the fouling. "I don't have confidence that specific capacity can detect problems early enough," Mansuy thinks. "That's why we prefer time-based maintenance." Specific capacity is useful for select- ing the right pump, but it is less accurate in catching the early stages of plugging. When one zone begins to clog, other zones may make up for some of that lost production in the well for a while. "Therefore, many years can pass where you are effectively clogging your well, clogging your filter pack, and clogging your formation before you even have the beginning stages of losses in specific capacity," Mansuy says. Pumped water samples are also not always a good indicator of biological growth because there are many variables that can affect the results. These could include the starting and stopping of the pump, surging, or even earthquakes. "You can have quick changes in water quality," Mansuy observes. "These changes don't necessarily indi- cate the well is becoming fouled or bac- teria is growing more aggressively." During a scheduled preventive main- tenance, Subsurface Technologies uses a carbon dioxide–based approach to clean the plugging materials in the well. Carbon dioxide is injected into the well with pumping equipment in place. "We're using the energy of carbon dioxide to effectively clean the plugging materials in the well. The existing pump is in place to pump off the debris you've detached during cleaning," Mansuy explains. Chemical approaches, including acids or acid blends, can also be used for preventive cleaning, but those would need to be neutralized and discharged appropriately. Preventive mechanical maintenance While Subsurface Technologies' preventive maintenance focuses on well cleaning, annual preventive maintenance on a system's mechanical components can be beneficial too. "Something as simple as keeping air in the bladder tank can really increase the longevity of the system," says Brian Lane, CPI, operations manager for Joe Samples Well Drilling Inc. in White Pine, Tennessee. "We see the failure of the bladder tank being the root cause of switch failure, control box failure, and a lot of other problems." The air to water ratio in the bladder tank can be checked annually as part of a well system check. Lane's annual checkup includes an amperage test and voltage test. He also checks the continu- ity down the well. Lane uses a megohm reading to check the wiring and cabling and looks at the wellhead to make sure the well cap is secure. "We're making sure everything is running the way it should be," Lane points out. Efficiency testing Downey Drilling Inc. in Lexington, Nebraska, offers its clients periodic effi- ciency testing. These tests help their clients—who are mostly agricultural— save money on energy costs. "More people are conscious of energy costs," says Thomas Downey, CWD/PI, owner of Downey Drilling Inc. "If we test the system and find it's only running at 48 percent, that means they're spending a lot of money and not getting much for the money." Downey's company uses testing equipment to test the flow rate of the well. They also check the amperage, voltage, and power factor. If the system runs on diesel, they test horsepower and torque. All of the data is input into engineer- ing software to determine the system's efficiency. The data is also compared to any previous tests to see if the well's performance has changed over time. These efficiency tests can give the indications of problems in the well. "Maybe production is off some, but the pump looks like it's still performing. Then we check specific capacity and our drawdown water level," he says. "We can pinpoint if it's a pump issue through our efficiency testing." If it looks as though it's a well issue rather than a pump issue, they may pull the pump, video the well, and determine a plan of action. Efficiency testing can be completed on time-based intervals, but Downey more commonly runs the tests when his clients are making changes or upgrading their irrigation systems. He admits many times his company only does testing when one of its agri- MAINTENANCE continues on page 16 WWJ January 2015 15 Twitter @WaterWellJournl "We have some who just do not want to have a problem, and they're willing to pay for us to do that service."