Six Flags Discovery Kingdom is responding to more concerns over debris and litter left at Vallejo's Lake Chabot and its nearby creek.
The amusement park, which operates on the lake's shoreline, previously had structures in the water that were used in the amusement park's water ski shows. Through the years, the structures deteriorated, and storms carried them down stream.
Last year, Discovery Kingdom told NBC Bay Area it was working to clean up the area after concerns were raised by Doug Darling, a Vallejo environmentalist looking to preserve Lake Chabot.
Darling spent seven years chronicling the mess left by the amusement park.
Last July, he showed NBC Bay Area the mess along the shoreline as well as pieces of floating platforms, foam and other debris in the creek the lake feeds into.
"Back then they said they'd take care of it. The last three presidents said they'd take care of it," Darling said on Thursday. "Again, it's not been taken care of."
Darling, who was posting videos of the debris and mess on YouTube, has brought his camera out again to document the remaining debris.
Discovery Kingdom's spokesperson said they removed all the debris identified to them last year.
"We were apprised this week of the debris that remained, which is not visible from the lake surface or our property and was not aware it was there," Discovery Kingdom said in a statement.
The amusement park said "the debris in question was being removed [Thursday]."
Darling would like to see Discovery Kingdom keep its portion of the lake clean.
"We deserve a corporation on the other side of the lake that respects our property," he said. "It's not their lake. It's our lake. We live here too."
Discovery Kingdom says, by the end of the day Thursday, the mess was all cleaned up. Park officials say some of the mess belonged to them and some did not.
Darling promises to keep pressure on the park.