At that point, the water is tested to see if it needs more treatment before the pH level is adjusted back down and the water is sent to a set of four 950,000-gallon holding tanks that resemble oversize above-ground swimming pools.

The water must then pass another test before it can be pumped into the river at up to 1,500 gallons a minute, a stream dwarfed by the overall flow of the river there. Independent scientists have a lab on the premises where they will test the water when it is in the tanks as well as when it is flowing into the river. It will take about 24 hours for any water that enters the system to make its way to the river if it passes every test along the way. All test results will be posted online.

Dominion Virginia Power’s plans for Bremo and the other three sites in Virginia that contain ash ponds have drawn protests from environmental activists and challenges in court. A group of student activists is planning a protest today with a symbolic funeral for the James River near the Bremo Power Station.

The James River Association dropped its lawsuit in March after reaching a settlement with Dominion Virginia Power that required the utility to clean the water to levels more stringent than state standards and to test fish tissue from the river.