Modesto Dumping Partially Treated Wastewater Into San Joaquin River

MODESTO (CBS13) — The white bubbles in a holding pond at the Modesto Waste Water Treatment Plant on Jennings Road, marks the exact spot where millions of gallons of partially treated wastewater are being dumped into the San Joaquin River on Thursday afternoon. It is not what the city of Modesto wants to do. They say it is what they have to do.

"You have to do what you have to do to protect your infrastructure," explained Larry Parlin, director of utilities for the City of Modesto.

The force from the excess rain water in the Tuolumne River broke a main sewer line last week, which inundated the treatment facility. Millions of gallons were pushed into the treatment facility from the hole in the sewer line. It has since been repaired, the extra water filled up the holding ponds, putting pressure on the site's infrastructure and the ponds' levees. The only option the city had was to release water.

"We are at capacity now, so we had no choice but to dispose of the water or jeopardize our pond levees and our storage levees, and flood our existing facility," said Parlin.

Treated sewage water is stored in these ponds and is released for irrigation in the summer. By the city's own admission, releasing the untreated water is classified as a health hazard. The water has been treated, but not disinfected.

"The water in these storage ponds has been through the treatment process," assured Monte Hamilton, the Jennings Road maintenance supervisor.

But without being disinfected, drinking or swimming in the water can make people sick. But the city points out that much of flood is already heavily contaminated.

"Flood water already has a lot of nasty stuff in it. It has all kinds of animal waste, septic waste. Who knows what gets into flood water. Maybe runoff from compounds people are storing," said Parlin.

The goal is to release water to bring pond levels down and to protect the facility and the systems that are in place. But the city knows, despite this fix, there may be more problems to come.

"We are still concerned. Here, it is only March 2. There is still 200 percent of snowpack up there. The reservoirs are full. So, we are concerned and we are preparing for additional flooding this spring," said Parlin.

It is not just Modesto. Cities across California are facing the same problem at their water storage sites with excess water from rain and floods.

City officials will continue to monitor the river levels and report back to state regulators.