He cited two concerns. In the 19th Century, silver mining operations occurred in the San Gabriel Canyon and the residues from that, he said, could be toxic.
And for decades the Navy conducted torpedo testing in Morris Reservoir and that, he said, could likewise have embedded heavy metals and hazardous material in the sediment on the reservoir's bottom.
These factors, he said, made getting estimates difficult. He has asked contractors to include bids that would incorporate filters to screen heavy metals.
Regardless, he said, it is pointless to make repairs until the county tests for toxics in the reservoir bottom.
"They haven't done adequate testing," Covell said, echoing environmental concerns that Azusa officials cited in an unsuccessful federal suit filed in 1991 against the sluicing project.
As his evidence, Covell displayed gruesome photos. "Here's the autopsies we took on our foal that died."
He attributed half a dozen miscarriages, difficult births or deaths of prematurely born baby horses to their mothers' drinking water fouled by the sluicing. He said, "I'm not a rocket scientist but I figure the county is responsible."
Wolfe said there is absolutely no evidence these problems are connected to the sluicing.
"We have no knowledge that there is a problem with the sediment," he said.
In 1991, Wolfe said, tests for heavy metals in the mud, rock and debris were undertaken during the sluicing and "didn't turn up any hazardous materials."
Since then, however, possible contamination of the reservoir bottom has lingered as an issue. The Army Corps of Engineers, critical of the county's environmental studies on the effects of the sluicing, had requested further testing of the reservoir sediment.
Officials from both the county and the corps say they have been discussing the issue and that testing will take place.
"I'm thankful they have helped us," Covell said of the county. "But I'm mad they had to help us at all."
On Monday, the fight escalated to a war of words and a game of chicken.
County officials had told Covell they were coming that day to take out the water tank the county had set up to supply water to the ranch.
In response, a friend of Covell had driven his big rig on the narrow bridge over the San Gabriel River leading to the ranch. There, with the hood raised, the truck had strangely "broken down."
Seeing this, the county backed off from removing the tank but delivered no water.
Enter Robert W. Bowcock, the city of Azusa's water superintendent who is trying to function as a peacemaker.
"They've been arguing for two years," said Bowcock, who drove to the ranch early Monday to forestall a showdown. "And it's time for it to come to an end."
By Tuesday morning Bowcock had arranged for a truce. He also guaranteed that the city of Azusa would supply the water for 60 days under an arrangement that would allow Covell to be billed. In turn, Covell could submit that bill to the county.
Bowcock has set up peace talks in Azusa City Hall for Oct. 20. "I'm hoping to have a signed agreement between all parties within 60 days,' he said. "I want to make sure Covell gets everything he's entitled to and that the county gets a fair shake too."