How to Finish a Basement Bathroom: Install the sewage ejector pump in the sewage basin and connect the PVC plumbing to the main sewer line.

This project is continued from How to Finish a Basement Bathroom – Part 8.

Basement Bathroom: Liberty Sewage Pump

I bought a new Liberty Pumps Model LE71A2 3/4 HP sewage on eBay.com for just $299.00 – compare this price to $975.00 for the same item at Grainger. I could have gotten by with 1/2 HP pump but chose the 3/4 HP model for added reliability because I don’t want to open the sewage basin and pull the pump – that would be dirty job. Consult the Liberty Pump Engineering Specifications to size a pump for your particular needs.

In the following photo the pump is shown with the gray mechanical float switch and white 2-inch threaded PVC pipe adapter on the discharge outlet. As the water level rises, the metal ball in the float switch rolls and closes the on/off switch contact to turn on the pump.

The water level should never rise more than half-way up the side of pump housing before the pump activates to empty the sewage basin. This pump is rated at 60 gallons per minute at 20 feet of head for my situation. “Head” is the vertical number of feet, including friction losses for plumbing elbows, that the pump must lift the sewage. Given that I only have a shower that uses ~7 gallons per minute, 1.6 gallon per flush toilet and a normal size sink faucet it will be impossible for the inflow volume to exceed more than 10 to 15 gallons per minute worst case.

The intake opening is shown here on the bottom of the pump. A cast iron impeller rotates at 1725 RPM inside the housing. It runs vibration free but does make a noticeable “Rrrrrrr” noise when it pumps out the sewage basin. The pump empties the basin in 3 seconds or so.

Basement Bathroom Sewage Basin

I cleaned the dirt and cement splatters off the sewage basin 2-part metal cover which revealed several rust blisters under the original paint. The rust spots were sanded down with a wire brush drill attachment and treated with Naval Jelly rust killer then painted with four coats of Rust-Oleum black enamel spray:

The sewage basin metal cover is secured to the perimeter of the basin by mirror mount nuts and bolts. The old ones were rusted (left side of photo) and replaced with six new assemblies. Mirror mount nuts splay out in star pattern when the bolt is tightened to secure the nut to the plastic rim of the sewage basin.

I also trimmed sewage basin discharge outlet with a Roto-Zip tool to clean up the sloppy cutout made by the home builder which would’ve interfered with the sewage flow. The round black plastic ring I cut from the discharge outlet is lying on the bottom of the basin:

Install the Basement Bathroom Sewage Pump

The sewage pump installation diagram will be helpful to understand the following installation steps:

The basement bathroom sewage ejector pump is lowered into the sewage basin and turned so the discharge outlet is aligned with the plumbing holes in the black metal cover. The rubber grommets for the soil stack (sewage discharge pipe), vent pipe and electrical connections are laying to the left. Also notice the new mirror mounts nuts are installed in the rim of the sewage basin:

The combination check and ball valve is dry fitted to a 36 inch length of 2 inch PVC pipe to begin the sewage line connections. I purchased mine from Grainger, part #4RG93, the item in the Grainger catalog looks a little different than the one here. The purpose of the check valve is to prevent backflow when the pump is idle. The blue handle on the ball valve allows me to close the valve for pump maintenance. It’s also required by the Building Code.

If I ever need to disconnect and pull the sewage pump, the check/ball valve has a slip union threaded joint to disconnect the pipe:

The PVC stem pipe and ball/check valve is set into the threaded PVC discharge outlet adapter screwed into the cast iron pump. I’m still dry-fitting the PVC sewage plumbing and haven’t glued any connections:

Update: Check Valve Water Hammer Problem

I didn’t realize it at the time but the combo check/ball valve unit I originally installed is NOT a “silent” or “quiet” type sewage check valve. The check valve suffered from a severe water hammer problem when the sewage ejector pump shutoff and the 12 foot column of sewage water reversed direction and slammed the check valve closed. The water hammer caused a loud thud and rattled the PVC pipes. After 3 years of operation the rattle and vibration caused by the water hammer eventually cracked the PVC solvent weld joint inside the Union fitting causing a small sewage leak.

The original check/ball valve shown above was replaced with an A.Y. McDonald 2068S/2067S Silent Check Valve that solved the water hammer problem. See the How to Replace a Sewage Pump Check Valve project for details.

My strong recommendation is to install a silent sewage check valve to prevent water hammering.

Now back to the original program…

Closeup of the 2 inch PVC sewer pipe connection and pump inside the basin.

Connect the Basement Bathroom to the Main Sewer Line

I wasn’t looking forward to sawing open the PVC main sewer line to install the Tee-fitting for basement bathroom sewer hookup. It turned out to be a pleasant “dirty job”.

A section of the 3 inch PVC main sewer line that runs below the floor joists must be cut to install the Fernco QT-300 Tee connector for the sewage pump line. The installed Tee in the main sewer line:

Sanitize the Sewer Line

The 3 inch PVC sewer line in the photo above serves the master bathroom. In anticipation of cutting the sewer line, I poured 1/2 gallon of bleach down the toilet in the master bath and flushed several times to disinfect the PVC sewer pipe. The master bathroom was off-limits for 24 hours to allow the sewer line to fully drain because I didn’t want to get dripped on when I sawed open the sewer line.

Install the Flexible Tee Fitting in the Main Sewer Line

The section to be sawn out of the 3 inch PVC sewer line is marked as shown using the Fernco QT-300 Tee as a reference. I removed one of the steel bands from the Tee and tightened it around the PVC sewer pipe to mark a perfect circle.

The section of the main sewer pipe to be cut out to splice in the basement bathroom plumbing:

I was concerned over what might spill out of the PVC sewer pipe when I sawed it open. I didn’t know if it would be dripping, filled with sludge or something worse. I suspended a plastic bin from the floor joist with wires under the section of the sewer pipe to catch the saw dust and drips:

I used a Milwaukee Sawzall to make the saw out section marked on the PVC sewer line:

The Sawzall cut the PVC pipe like butter. The plastic bin caught the PVC shavings and the section of pipe as it dropped free. To my surprise, the sewer line was bone dry and odor free! I deburred the PVC sewer pipe ends by smoothing off the shavings with my gloved fingers. The burrs can also be removed by scraping utility knife blade along the pipe edges.

The Fernco flexible Tee fitting is installed in the main sewer line in the following photo. I had to partially fold the rubber Tee to squeeze between the sewer pipe ends, which is what it’s designed to do. I had considered using a rigid PVC Tee fitting and was happy I didn’t because there was almost no wiggle or ability to widen the gap between the 3 inch PVC pipe ends to install a rigid fitting.

Another view of the rubber Tee spliced into the main sewer line:

Working from the ground up, I installed the rubber grommet in the sewage basin cover and completed the 2 inch PVC sewer pipe connections and cemented the joints together. Lubricate the rubber grommet with liquid soap to slide through the 2 inch PVC sewer pipe. Remember the bottom of the check/ball valve is slip union connection for a quick disconnect in case I ever need to pull the sewage pump:

2 inch PVC riser pipe is installed to carry the waste water up from the sewage pump up to the main sewer line. The sewage flows upward from the pump and basin to the main sewage line as indicated by the red arrows:

The sewage pump discharge lines must empty into the main line from above to avoid backflow, hence the 45 degree elbows to clear the existing feeder sewer line and floor joist. Red arrows indicate the direction of sewage flow. Metal hanger straps to support the PVC sewer pipe are noted by the blue arrows:

The sewage basin PVC vent pipe and high water alarm are installed in How to Finish a Basement Bathroom – Part 10.

Hope this helps,

Bob Jackson