Oxygen levels, necessary for fish, are up and dangerous phosphorus levels are down in the historically polluted waterway. But a new report points to climate change as a possible wildcard.
"It goes without saying that pouring concrete down the drains into our sewers isn't going to do any good," said a London water provider.
Made up of cooking fat, wet wipes and other sanitary products, the mass is said to weigh as much as 11 double-decker buses. A water company official compared removing it to breaking up "concrete."