Marin board approves 5-15 MGD desalination plant

The board of the Marin Municipal Water District (MMWD) in California, USA, approved on 19 August 2009 a 5 MGD (19,000 m³/d) desalination plant expandable to 15 MGD (57,000 m³/d) as one of its potential future water supply sources.

On 11 February 2009, the board adopted several other water supply options, including operational improvements to the reservoir system, an expansion of MMWD’s recycled water distribution system, investigation into ways to improve the reliability of the district’s Russian River water supply, and further investment in MMWD’s aggressive water conservation program.

In calling for the vote on desalination, MMWD board vice president David Behar said, “Based on the evidence, it seems clear that conservation alone will not solve all our problems, and therefore we need to keep all options on the table. Moving to the next stage of desalination analysis is one way to do that.

“There are 44 desalination plants in one stage or another of development in California today. This isn’t an option unique to MMWD – it’s part of managing water in the west today, where drought and increasing demand are challenges that can’t be ignored,” he concluded.

The board directed MMWD staff to file a Notice of Determination under the California Environmental Quality Act, which the district has done. Completion of these steps was necessary before MMWD can proceed with any other future activity on desalination.

In 2005, MMWD successfully operated a temporary desalination pilot plant that showed that bay water could be purified to levels that exceed state drinking-water quality standards. The project is not expected to produce water before 2014.