A slough next to the Sacramento River contains an illegal dumping site. It's largely invisible to the naked eye.
Two abandoned cranes and a half-submerged boat hint at the waste in an area traveled by dozens of boats docked at a nearby marina.
Under the water, as shown on a radar screen, at least five other boats are sunk in a stretch running less than 300 yards.
The Sacramento County Sheriff's Department considers the abandoned boats an environmental and safety hazard. The department, with the help of a state agency, has been leading an effort to remove abandoned boats and other debris from the Sacramento-San Joaquin Delta.
Todd Thalhamer, a waste management engineer for CalRecycle, said the agency has spent almost $3 million cleaning the Delta since 2009. He estimates $20 million more is needed to finish the work.
State and county officials say the work is important considering the Delta provides drinking water for two-thirds of California. Recovered boats have been found with drums of hazardous material, gas, oil, batteries, asbestos and other pollutants.
Abandoned boats also create a safety hazard in waterways frequented by recreational and commercial boats.
The sheriff's Marine Enforcement Detail has cataloged abandoned boats in Sacramento County's portion of the Delta, which runs across six counties in all.
"It's not a popular topic," said Sgt. Scott Maberry, head of the Marine Enforcement Detail. "People don't want to take ownership of the problem because it's expensive."
People often abandon boats for financial reasons, such as not being able to pay for storage. Marinas typically charge $10 a foot per month to store a boat, and send eviction notices when they're not paid, said Deputy Marc Warren of the marine detail.
Sacramento County has received financial and technical assistance from CalRecycle, which uses fees collected from garbage haulers to clean up illegal dumpsites. The agency spends about $3 million each year for waterway cleanups across California.
About $1 million has gone in the past year to removal efforts in Sacramento County. In March, the state and the county removed more than 20 boats and other debris from the Delta.
Removing the boats takes a lot of work, starting with the legal responsibility of trying to find the owner through registrations and filing public notices if an owner can't be found.
Once a boat is selected for removal, many participants get involved. The U.S. Coast Guard, CalRecycle, the Sheriff's Department, the Sacramento city fire and parks departments and several contractors played roles in this year's cleanup.
To get boats on riverbanks, an excavator is loaded onto a landing craft. The craft brings the excavator to the boats, and the excavator picks them up and drops them in the water.
Tugboats then bring the abandoned boats to a staging area. The boats are pulled from the water by a crane and placed on the ground.
Workers identify and remove hazardous waste before stripping the boats of metal (to be recycled) and removing other materials to go to landfills.
The cost of the work varies widely. CalRecycle spent $420,000 removing more than 20 boats from the Delta, but spent more than that removing just one boat a large ferry that once was based in San Diego.
In some cases, officials say they can recover some of the costs by selling stripped metal the San Diego ferry brought in more than $100,000 or by negotiating with boat owners or taking legal action against them.
Abandoning a boat is illegal and the Sheriff's Department has pursued cases in Superior Court.
But more often than not, the owners don't have money to pay or can't be found, officials say.
Officials at the Sheriff's Department clearly feel good about their efforts. Yet they also realize they've only just begun an effort that will take years and may never end.
"There's so much work to do in the Delta," said David Guthrie of the Sheriff's Department. "It's a daunting task."
On a recent tour of the Sacramento River, Warren shook his head as he looked at a large waste site on Mayberry Slough.
Two triple-wide trailers sat on large concrete piles. Two boats were moored to the encampment. A large crane hovered over it all.
The owner lives in Idaho, and state and county officials haven't been able to reach an agreement with him about how to clean up the site, Warren said.
A couple of miles upstream, Warren pointed to the area where most of the county's March cleanup took place. Two more boats have since been abandoned there.
"I think there's a perception out there: 'If I leave it here, the state will pick it up,' " Warren said.