Crews will be back Tuesday for day five of the clean up of thousands of gallons of diesel that spilled into the San Diego River.
"This is bad news,” said Jim Peugh of the San Diego Audobon Society.
At first sight, Peugh doesn't like what he sees as he surveys the damage along the San Diego River.
"Oh God. There's diesel coming up off the bottom or some kind of oil coming off the bottom,” he said.
Thousands of gallons of diesel came from a tanker that overturned Friday on the Morena Boulevard off-ramp and landed on its side.
Peugh worries for the wildlife that take refuge in this part of the river which runs through the Mission Valley Preserve.
"There's a lot of ducks that like this fresh water kind of environment. One good news is this isn't the time of year that huge number of ducks are in San Diego,” said Peugh.
But he's concerned about a nearby bird sanctuary, home to two endangered birds. The California Least Tern is just moving into San Diego for nesting season.
"They actually dive in the water and catch really small fish,” said Peugh.
The Ridgway Rail is also endangered. Peugh says at this point, it appears the diesel isn't reaching its habitat in the salt marsh part of the river which is closer to I-5.
"You can see up the river, they've blocked it off, so the diesel doesn't get passed that point. You see there are two white lines across the river,” added Peugh.
Peugh said that's a good sign. Those two white booms are keeping the diesel from spreading down into the ocean.
Peugh became more reassured after seeing the clean up crews out in boats picking up pads or diapers, as they call them, which they set out to soak up as much of the diesel as they can. Others are cutting down any trees affected and digging up any diesel-soaked soil. They're putting everything in hazardous containers and hauling everything off.
“It looks like they're doing a really good job of getting the soil out,” said Peugh. "It’s disappointing to see there's still so much diesel on the surface of the water."
Friars Road in the west end of Mission Valley remains closed until the clean up is complete. The clean up could take at least a couple more weeks to a month.
The county's Hazmat team says some of the fuel may have seeped into parts of Friars Road and Morena Boulevard. That means crews may have to dig up parts of those roads.