Progress report on greenway--Nov. 10, 2010

  • As of Tuesday afternoon, tree removal had been completed. One large tree outside the orange fence lower north side) had to be cut, to accommodate a lateral.
  • Work was beginning on the sewage pipes...   They were digging a hole at the west end, to place the first junction for a lateral--a large, circular precast concrete structure.  The lateral to Marsha Siik's house had apparently been completed here.
  • A huge metal bin was being brought down to the hole. It was intended to be a "hopper" for gravel--a convenient place to store materials needed for construction.
The old, main sewage line is cut

Starting work on the main sewage line at the west end of the Greenway.

Don't flush your toilet today...

Raw sewage accumulating in  bottom of hole, coming from the main upstream pipe on the right, covered with a clot of earth.  The downstream pipe is more readily visible on the left.
About 2:00 pm today, as I watched from just outside the orange fence, as a power shovel was breaking into the existing main sewage line. Not a lateral--the main line. You could clearly see two stub ends of the pipe, at the upstream and downstream sides of the hole.

Fluid was leaking out of the upstream broken pipe end.
I asked the worker, is that the main sewage line? "Yes."
Is that the sewage coming out? "Yes."
Where is it going?
"Into the bottom of the hole."

Apparently, it isn't against rules to let sewage leak into the hole--but work must be stopped and the spill dealt with if spilled sewage moves beyond the trench.* And, the sewage within the trench is supposed to be fed back into the sewage system.

The amount of sewage flow wasn't large--about the amount from a garden hose. But few people were at home.

The crew worked until well into the dusk, leaving a bit past 5:00 pm.   By the time they had left, the first junction--a small concrete silo with a manhole on top--had been installed.  They left the power shovel's scoop on top of the hole, so no children could climb inside.

Several residents were watching the work and talking to the men.  They called across to a resident on the other side, to compare notes.  They remarked about how skilled and careful the workers were, and how quickly they worked.  I was amazed that all this could be done with a small crew of only about 4-5 workers.

A tree expert from Stephenson Tree Care had been onsite most of the day, working to protect the trees.

During the day, a water-cooled saw was used to cut a hole in one of the large concrete junction silos.  The toxic slurry was discarded onto Owen Drive, where it ran down the gutter, and across the entrance to a driveway where several small children live.  More on wastewater.

This wastewater causes burns similar to those of a strong acid. Source.

See a slide show of all today's photos here.
#     #     #

* Here are the detailed rules, from the Standard Specs, which contractors must follow:

503.3(g) Wastewater Control (refers to raw sewage released during construction)

Wastewater Control shall include all equipment, labor... and incidentals required to control or divert, to the Engineer’s satisfaction, sanitary sewer flows during reconstruction of the sanitary sewer. This shall include pumps with adequate capacity of 100 g.p.m. and all associated equipment required to maintain a functioning sanitary sewer system during construction. At no time shall the normal flow of wastewater in sanitary sewer service laterals be disrupted without prior approval from the Engineer. This condition shall also hold at the time of connection of an existing lateral to the new sewer main.

If the Contractor elects to use bypass pumping as a means of wastewater control, the methods, equipment, type of hose, etc. shall be subject to approval by the Engineer. Hoses crossing streets, driveways, parking areas, etc., are to be ramped over to prevent damage to hoses. Spillage of wastewater is to be contained within the trenches and disposed of downstream to previously installed sewer piping. No spillage of wastewater to adjacent streets, lawns, etc. shall be tolerated. If any such spillage should occur, all construction operations shall cease. Cleanup shall commence immediately and be completed to the satisfaction of the Engineer prior to the resumption of any construction operations.

No comments:

Post a Comment

Please feel free to comment on the article above, or on other watershed issues.