Water customers in some of Los Angeles County's foothills are being asked to tighten taps further and refrain from watering lawns for as long as 10 days starting Feb. 29 while the Metropolitan Water District of Southern California temporarily closes a La Verne treatment plant for infrastructure upgrades.
During the work period, homes and businesses served by Foothill Municipal Water District's retail agencies — including Crescenta Valley Water and La Cañada Irrigation districts and the Mesa Crest and Valley Water companies — will not receive imported water from the MWD.
The MWD is switching its F.E. Weymouth Filtration Plant from a chloramine-based treatment method to ozonation, in which ozone injected into raw water creates bubbles that carry away pathogens and contaminants, spokesman Bob Muir said.
To do that, all five of the treatment plants the district maintains must be retrofitted to accommodate newly built ozone facilities.
"It's a more effective way of treating water. It's just an overall better disinfectant for our supplies," Muir said of the switch, part of a $270-million project to fully introduce ozonation in 2017.
For Altadena residents, the temporary shut-off will begin even earlier, Feb. 23, because of additional work being planned for area supply lines, Muir said. The work should be completed by March 10.
With MWD supplies temporarily dried up, retail water agencies must rely on local water and stored supplies to meet demand. Officials are asking customers to help make ends meet during the planned outage by not watering their lawns and reducing indoor use.
As a reminder to save resources while the work is being done, Foothill Municipal Water District will increase the area's conservation status from "orange," indicating a rationing to two irrigation periods a week, to the more critical "red," under which outdoor watering is not allowed.
"We have very limited storage, so we need to be careful," said the Foothill district's general manager, Nina Jazmadarian. "As soon as we feel more comfortable with the supply, we'll change it back to orange."
Muir said he is confident that if people pitch in during the shut-off, there will be no interruptions to local water supplies. Jazmadarian asks customers for their continued patience.
"I know that people are tired of the drought, and we really appreciate everything everyone's done — we've had some great numbers," she said. "This is just a little step more for the 10 days. And then, once we're out of it, back to drought mode."
For more information, call Foothill Municipal Water District at (818) 790-4036, or visit bewaterwise.com for conservation tips.