(WSB photo from Sunday)

Seattle Public Utilities has figured out part of what went wrong before a sewer overflow flooded Orchard just north of Delridge on Sunday (here’s our original report). From SPU’s Andy Ryan:

Crews were in the vicinity again today investigating the cause of the sewer discharge in the right of way near Delridge Way SW and SW Orchard Street. They determined that the overflow was caused by two maintenance-hole covers that were not watertight. We are exploring ways of sealing the holes to prevent future overflows at the location.

Crews also found that the new Delridge combined-sewer-overflow (CSO) project construction is working as designed.

By Sunday evening (11/15), crews responded to and contained the sewage overflow. They removed warning signs once the area had been cleared, and the road was reopened to traffic. We will let you know when we have figured out how, and when, we seal the maintenance holes that caused the overflow.