A state of emergency has been declared in Los Angeles over an underground leak of methane gas which has reportedly emitted pollution equivalent to the amount released by 4.5 million cars every day since it started in October.
More than 2,000 families have reportedly moved from their homes, with many feeling unwell, due to the leak which started at a well in the Porter Ranch neighbourhood, on the outskirts of Los Angeles, on 23 October.
Measures are underway to repair a damaged pipe line and stop the leak, but these have not yet been successful.
Officials from Southern California Gas, which operates the well, have said the company expects to stop the leak in February to late March.
Nearby residents have complained of headaches, nausea and respiratory irritation from mercaptan - the odorant added to natural gas - although Los Angeles County health officials have said past studies had found no long-term health effects from mercaptans.
The methane entering the atmosphere from the leak reportedly now accounts for about a quarter of the state’s total emissions of the strong greenhouse gas.
Tim O’Connor, a lawyer with the Environmental Defense Fund, told the BBC: “Let’s call it an environmental and public health catastrophe.
“In terms of timelines this is going to surpass the gulf oil problem by a mile.
"What we do know is that that climate equivalent of this leak is like burning thus far almost 700 million gallons of gasoline or it’s the same amount of pollution as 4.5 million cars put out every day, it’s tragic.”
The utility company has provided temporary accommodation or funds for residents who have had to move as a result of the leak while repairs continue.
Dennis Arriola, president and chief executive of Southern California Gas, said: “As we have since this incident began, SoCalGas stands willing and ready to cooperate with the governor’s office, all state and local officials and regulatory agencies.”
