Sanctuary sewage pathway: schematic sketches (Background Report)

WHAT IS THE ROLE of the sewage pit and its vestigial plumbing? I’m glad you asked! Until this past month, I had only the vaguest idea. But now I can clue you in.

The covered sewage ejection pit

Below the jump are three schematic diagrams, along with brief annotations, that quickly explain the basics of our sanctuary building’s sewage system. Finally, it shows a detail from a revealing City diagram—as interpreted by the late Phil Raider (z"l) some 20 years ago—that provides a key clue.

These are elevation diagrams—meaning that in each one, the items shown at the top are in real life physically at a higher elevation than items shown at the bottom. Red arrows show the direction of the effluent’s flow. (As usual, click/tap on an image to enlarge it.)

1.  Way back in 1941 when the sanctuary basement was constructed, it was below the level of the City sewer main. Consequently, the effluent from its toilets and sinks needed to be collected and pumped up to reach the main line, for disposal.…

2.  Some years later, the City put in a larger and deeper sewer main. At that point, our effluent was rerouted to create a gravity-feed discharge to the main line, which naturally bypasses the sewage pit. (Such a reconfiguration would have been required by code.) Our synagogue’s pump was then removed, while the pit has remained as a vestige of the original system.…

3.  Recently, however, when tree roots clogged the lateral drain line, the effluent backed up into the sewage pit, because it had nowhere else to go.…

 

In effect, the pit served as a buffer to delay the overflow of sewage into our basement rooms.

A Revealing City Diagram

The following image is a detail from the City’s as-built drawing and plan for the “Mayor’s Priority Program — Smart Crosswalk, Main St & Navy St. Nov–Dec 2001.” It was created in preparation for the installation of the pedestrian-actuated yellow flashing beacons at the crosswalk in front of our sanctuary building. In this case, I’m more interested in what it shows as buried underground than what is overhead.

It shows that in the center of Main Street is a 30" (diameter) sewer pipe that at some point was abandoned in favor of a 36" pipe. Presumably the new pipe was placed lower down. This would account for why Mishkon abandoned its sewage ejection system and removed its pump.

That was the insight of Phil Raider, as a member of the B&G Committee circa 2006, when he came across this City drawing while we were wondering about the pit and its purpose and history.