Overlooked Pond Could Become San Leandro’s Secret Weapon in Water Pollution Control

This is part of our ongoing series about where taxpayer funds from 2016's Measure AA to restore the San Francisco Bay are going. Find all the stories here.

The parking lot outside of San Leandro’s Water Pollution Control Plant has a lingering stench. Its odor partly comes from the average 5 million gallons of wastewater it processes a day and from its neighbor, a trash dump.

A short walk away from the lot the smell subsides a little at a small patch of wetland. That's where I met up with plant manager Justin Jenson. He's showing me another project getting tax money from Measure AA, the "Clean and Healthy Bay" measure passed two years ago. To me, the area just looks like a neglected pond.

“This used to be a polishing pond,” says Jenson. “That means we used to actually send our treatment plant effluent out here and process it further.”

Effluent is the treated water that comes out of wastewater facilities. Jenson says, now, this 4.3 acre pond is basically just used as temporary water storage. But it has the potential to be so much more.

The more than $500,000 granted to this project will go toward the design and permitting for the restoration of the pond and to create a treatment wetland.

“It changes this from what you see right here which is an ugly, old, unused pond into something that's actually used to produce very, very clean water,” says Jenson.

The flora in a treatment wetland make the water very, very clean by filtering out additional nutrients, like nitrogen and phosphorous, coming out of the wastewater plant. According to the U.S. Geological Survey, too much of these nutrients in a body of water can actually begin to pollute it and cause harmful algae blooms.

Jenson says, the state water board has strict regulations regarding cleaned wastewater discharge into the San Francisco Bay and he expects water quality rules to become even tighter in the years to come. He says water treatment alternatives like this project will help the San Leandro plant stay ahead of the curve while also keeping the Bay’s water cleaner and healthier.

“With more people moving to the Bay Area, there’s more potential for pollution and nutrient build-up in bay,” says Jenson. “We want to make sure that we're able to meet the water regulations. This pond could be something that helps us weather them.”

Jenson hopes this project will become part of a growing network of water treatment wetlands across the Bay Area. Both the Discovery Bay and Oro Loma wastewater treatment plants have already piloted their own treatment wetland program.