What: a break in an 18-inch gravity sewer under Mill Creek near the concrete spillway across from Old Elizabeth Lake that let creek water into the sewer.
Where it stands: after a heavy rain the system took in more than 9 million gallons a day, about 3 to 4 million gallons a day above normal, risking limits in the plant permit. A bypass pumping operation is in place over a temporary bridge.
Next: plug the leak, lay a new line under the creek to a new manhole, fill and abandon the old line in place, timed for dry weather. The repair will likely be costly.
Details
Staff said the plans date from before the 1980s, and the pipe under the creek is encased in concrete that may have cracked with settlement.
The City is working with the state on the permit exceedance risk.
Repair will need sheet piling and bypass pumping of the creek, a blue line stream, in a residential area.