Earth Week 2026: How BART helps keep the Bay clean

Juncus patens, a perennial herb native to California, is pictured in the bioretention area at North Berkeley Station.

California brown pelicans, salt marsh harvest mice, leopard sharks, flounder; a range of endangered species call the San Francisco Bay home. And like all of us, they depend on a habitat that is safe, clean, and resilient.

But the waterways these species rely on are increasingly at risk from climate change, development, and pollution, much of it originating from human activity.

At BART, sustainability is a core priority. Our stations aren't just transit hubs; they are part of a larger ecosystem with the potential to improve environmental health across the Bay Area for people and wildlife alike.

One area of focus is stormwater. When rain falls on parking lots, roads, and plazas, it picks up pollutants like oil, trash, metals, and sediment, carrying them into local creeks and ultimately the Bay. This runoff can degrade water quality and trigger ripple effects throughout the ecosystem.

To help address this regional issue, BART has been installing bioretention areas, often called "rain gardens," at stations across the system. You'll find them at Richmond, Warm Springs, Lafayette, El Cerrito del Norte, Concord, Millbrae, Balboa Park, San Bruno, and Antioch, among others.

A bioretention planter at Antioch Station.

These landscaped areas are designed to slow, capture, and naturally filter stormwater before it enters waterways. Using layers of soil and climate-adapted plants, bioretention areas remove pollutants like harmful hydrocarbons, heavy metals, and debris.

They also deliver measurable benefits: bioretention systems can absorb significantly more stormwater than traditional landscaping and remove a large share of pollutants from runoff. By reducing the volume of water entering storm drains, they also help prevent flooding.

"Bioretention planters utilize natural processes to clean stormwater runoff. The plants work together with beneficial microorganisms in the soil to remove pollutants," explained Cynthia Greenberg, BART Principal Landscape Architect.

These systems also help manage excess nutrients like phosphorus and nitrogen, which can fuel harmful algal blooms that deplete oxygen in the water and harm fish and other creatures.

A bioretention planter at North Berkeley Station.

Most recently, new bioretention planters were added at North Berkeley Station as part of a broader effort to improve bicycle and pedestrian access. Runoff from the parking lot and nearby bike path is now directed into these planters, where it is filtered before flowing into Schoolhouse Creek and eventually the Bay near the Berkeley Marina.

The planters also support native plant species that enhance the station environment. Riders might spot California gray rush, a hard worker when it comes to filtering stormwater, as well as showy milkweed that attracts Monarch butterflies, and Douglas iris that supports pollinators like bees.

Beyond their environmental function, these green spaces create more welcoming, attractive station areas for riders and the surrounding community.

Next time you pass through one of these stations, take a moment to stop and smell the flowers and appreciate these landscapes that quietly help keep our beloved bay blue and beautiful.

What's in the North Berkeley planters?

What riders can do

• Put litter in its place: Dispose of trash into garbage and recycling receptacles provided by BART in our stations and parking lots.
• Use reusables: You can prevent litter by using reusable containers like travel mugs.
• Decline the printed receipt at BART ticket and parking machines if you can.
• Car maintenance: You may not be polluting but your car may be. If you drive to BART, please ensure your car isn't leaking. Regular tune ups and leak inspections can prevent leaks or fix them if you have one.
• Car wash: The grime on your car that includes residue from gasoline, motor oil, and other chemicals can get washed off during a rainstorm if your car is parked in one of our outdoor lots. Help prevent this runoff by taking your car to a commercial or coin operated self-service car wash where all wash water is recycled and properly disposed of.

What BART is doing

• BART has installed storm drain markers to inform the public that what goes down that drain flows to the bay.
• BART cleans parking lots and plazas and landscape to remove trash and pollutants.
• BART has moved towards low-impact development (LID) as a standard practice, which is an approach to land development that works with nature to manage storm water as close to the source as possible.

Rain drips from a strawberry tree at Lafayette Station during a storm.