A sewage grinder pump
macerates sewage so that it can be pumped through a (usually
smaller-diameter, perhaps 2") force main to an uphill septic tank or sewage
pumping station or to a municipal sewer line, all of which are in this case
located higher than the pumping location. Where a lot of vertical lift is needed
( head pressure), a submersible sewage grinder or effluent
pump will be used and will be installed at or near the bottom of the holding
tank. Though we can't see the pumps in this photo - they are below the
sewage level in this pumping chamber - that's what we'd expect to find
installed in this municipal sewage lift station.
Many subdivisions were located outside of
existing municipal sewage pump systems. Often, the most desirable lots presented
physical constraints on traditional septic or sewage handling systems. Some of
these constraints were: waterfront locations, hilly terrain, high water tables,
and extreme cold weather areas. Other possible constraints were: areas where
soil conditions resulted in septic system bans or gravity sewers could not be
physically, or economically, reached. Those constraints resulted in new demands
for alternative home sewage systems. Those demands resulted in the development
of pressurized sewer systems to handle wastewater for communities, single
residences or in light commercial applications. Many of these pressure pump systems
were serviced with grinder pumps.
Grinder Pumps are used to pressurize small diameter plastic lines in
areas where large gravity lines are impractical or uneconomical. Discharge
points may be existing gravity sewer mains, large pump lift stations or
direct to central treatment systems. All that’s needed in this type of
system is a grinder pump or pumps, a pump station to collect residential
sewage, a control panel to turn the pump on and off, some small diameter
plastic pipe and a small trencher. Grinder pumps can actually reduce
infrastructure costs. Since these pumps cut large solids into smaller
particles and pump at higher pressures, residential sewage can be pumped
through smaller diameter pipes to greater elevations and longer distances.
