They say you can’t fight gravity, but there are times when gravity fights the system—a septic system, for example.
    Waste water from a building’s water-using appliances is supposed to be carried to a public sewer main, then on to a treatment plant and ultimately returned to the environment, where it can lead a disinfected yet productive second life. But sometimes a home or business’s sewer line is at a lower elevation than the sewer main, making gravity uncooperative.
    That’s where the grinder pump comes in. It takes the solid waste out of waste water, facilitating a smooth trip through public pipes. The unit is traditionally put in a tank or well and buried outdoors on the property. When water is used, waste water is stored in a holding tank. When it reaches a pre-set level, the unit is activated, grinding the waste and pumping it out into the sewer system. But not surprisingly, the pump is susceptible to certain problems.
    “Failure of grinder pumps can come in different forms, but they all cause the same outcome,” said regional sales manager Steve Ritsema, engineer at Liberty Pumps in Bergen, N.Y. “Waste water from the residence or building stops flowing, an alarm may go off, and back up can occur if the alarm is ignored. For obvious reasons, this is not desirable.”
    So, what exactly goes wrong?    
    The top three difficulties sound like variations on a theme—wadding, jamming and clogging. Materials can get “wadded” up on the cutting mechanism, which can block the flow of water, overheat the pump and eventually burn out the motor. Jamming is worse. When material gets stuck in the mechanism, it can actually stop the motor. On the other side of the blade, ground material can clog up the pump’s housing and block the water or stop the impeller.   
    Liberty is among the manufacturers trying to slash through these problems with innovations. Its new V-Slice cutter technology “provides more cuts per revolution for superior shredding performance in demanding sewage applications,” Ritsema said. “Its special features allow it to do the shredding with minimum motor torque, and it has self clearing features, so it won’t easily wad, jam, or clog.”
    According to press materials for Liberty’s LSG-Series Omnivore, “The hardened stainless steel cutting system provides in excess of 300,000 cuts per minute and aggressively shreds jeans, shop rags, diapers, sanitary napkins, and other difficult solids into fine slurry.”

This Zoeller 6480 submersible pump eliminates ‘roping’ owing to its reversibility. Photo courtesy of Zoeller.

There are, of course, competing solutions. Zoeller Pump Company in Louisville, Ky., is also addressing the issue of wadded up materials—which it calls “roping”—with the “Zoeller 6840” reversible unit. Engineering manager Jason Fletcher explained its significance: “If the pump can reverse, then the amount of time required to clear the material will be greatly reduced. Each time the pump runs, a little more material can be unwound and sucked into the pump.”
    Fletcher claimed the system’s ability to clear within a few cycles would result in fewer service calls and increased pump life.
    “Since the cutter is now using both sides of the cutter blade, the life of the cutter is doubled.”   
    Three other common grinder pump ailments comprise Ritsema’s list: rubber stator failure, caused by macerated waste and pressure; main seal failure, which allows water to get into the motor; and motor burnout, from improperly applied pumps.   
    To better your odds against such breakdowns, Ritsema offered one more suggestion. “Look for pumps that come with longer warranties,” he said. “They generally are better quality.”           
     Another way to sidestep trouble is to avoid dumping too much of a bad thing. Provide end users with a list of items that should be banned from the drain. Grease, kitty litter, aquarium gravel, caustic chemicals, flammable materials, diapers or anything cloth, and all plastic objects should all be on it.