John, I've had to replace my septic tank system, and in the process was considering hooking to the county sewage. I was told by my county prior to this there was no plans to run sewage down my street & there would be no sewage on my street to hook up to, but a builder changed all that, so the lines are now in front of my house. However, in the research process, I was told that because of the distance out the street, I would need a grinder pump in the system. Grinder pumps are not cheap, about $1000-$2000 for residential sizes, depending on the pump.
Here is what I found that explains what that pump does:
What does a Grinder Pump do?
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.
It turned out the county wanted $10,000 for the permits to hook up, not including the actual work being done by a master plumber, so I declined & just stick with my own septic. That cost me less than $4000, which I was able to finance thru a local bank with a special program the county had and I'll likely be long gone from this Earth before it ever needs to be replaced again!