The city council of San Diego, US, has speeded up plans to introduce a water reuse scheme known as Pure Water, the San Diego Union-Tribune reports.

The council approved plans to recycle 30 million gallons a day of wastewater into drinking water by 2021, covering $52 million of projects, and backed a proposal to use methane to power water purification. This brings forward the original plan for 15 million gallons a day by 2023, and 30 million gallons a day by 2027.

Additionally, the revised scheme allows for wastewater to be treated wholly at a purification plant in Miramar, rather than half at Miramar and half in Otay Mesa, as originally planned; and recycled water will flow into Lake Miramar reservoir, eight miles away, and not travel 18 miles to San Vicente Reservoir — a move which it is estimated could save $50 million.

The overall $3 billion programme will be paid for through water rates.

The city must now get approval for the scheme from California State, including permission to store recycled water above ground, unlike in other parts of the state where it’s stored underground.

San Diego City Council additionally outlined a second phase for Pure Water, which aims to increase the amount of recycled water to 83 million gallons a day, or a third of the city’s water supply.