With the recent rain has come a very unwelcome visitor: sewage spills. And now authorities are beginning to suspect foul play.
Last week, hundreds of thousands gallons of sewage poured out of manholes near Ross Valley, and only a small fraction was able to be cleaned up. The rest made its way into storm drains that empty into the bay.
Overflows aren't unheard of in the area, where some sewer pipes date back many decades. The Ross Valley Sanitary District is over a century old. But during the cleanup, officials discovered an unexpected cause: a backup of construction debris in the pipes. That included whole chunks of roadway, wire, and even hard hats. Laws clearly forbid disposing of construction debris in such a way that it could wind up in the sewers.
The culprit appears to be a contractor who was working on the Woodland-College-Goodhill improvement project. It's unclear whether the dumping was done out of negligence or as a malicious act.
The extent of the damage is still unknown. Some estimates peg the leak at around a million gallons of raw sewage, the contents of which are anyone's guess.
A recent sewage spill in Morro Bay near San Luis Obispo led to authorities prohibiting the collection of shellfish. That incident had a more mundane cause: a tree fell onto a sewage line, releasing 50,000 disgusting gallons.
San Francisco is unique in that its stormwater is treated before it is released. That means that anything flushed down the drain or down an on-street sewer grate will be processed and cleaned. But it also means that during heavy rain, the system can back up, and occasionally overflow.
In other words, if you see water gushing out of the sewer, move away and call 311 to report it right away. And when there are heavy rains, you might not want to take a dip in the bay.