With so many other sources of water drying up, the city of Ukiah is finding its recycled water in high demand. In such high demand, in fact, that it will soon be like those other sources of water: tapped out.
“We distributed 13 million gallons of recycled water, literally four times as much recycled water as surface water, in one week,” Sean White, the city’s director of water and sewer resources, told the Ukiah City Council at its last meeting July 7. “That amount of water is not sustainable, and we’re definitely minding our storage pretty heavily at the recycled water facility.”
Water treated at the Ukiah Valley Wastewater Treatment Plant began being delivered through the city’s Purple Pipe system about two years ago for mostly agricultural uses such as vineyard irrigation, but has become particularly valuable this year as historic drought conditions are drying out the entire state of California and beyond.
“We knew we were going to run out this year, but I think we’re a little bit ahead of that curve, and we want to make sure that everybody makes it through,” White told the City Council of the discussions being had about how to best allocate the water to everyone who needs it. “I think we can do it, (but) it’s gonna take a little informal water mastering and goodwill amongst neighbors.”
White said the city is also looking at ways to increase its supply of recycled water, which he said has been reduced not only by people showering and flushing their toilets a bit less often, but more significantly by recent major improvements to the city’s underground sewer system.
While 1.24 million gallons flowed into the Treatment Plant on a recent day this summer, White said “on a normal summer day, it would be very typical to have 2.5, maybe 2.8 million gallons (flowing in). And that would be a low day. Historically, we’d be hovering right around 3 million gallons.”
White further explained that a lot of the reduction in the amount of “used” water available for the Purple Pipe system is because of recent improvements to the collection system below streets such as Luce, Washington and Observatory avenues, as well as under both North and South State Street.
“With all of those big chunks of main replacement and our new policy of really doing the innerties to the laterals correctly, our French Drain system ain’t what it used to be,” White said. “We’re going to see sustained lower flows … in what shows up at the plant, which is good news for the amount of water we need to treat and get rid of, but it is not great news for making recycled water in a year like this. Which is why we’re going to deplete our storage ahead of schedule.”
“So it seems that one of the tasks before us is to figure out how do we get more water into the system when there is more than abundant water,” said City Council member Doug Crane, to which White responded that city staff have “talked about that previously, and I think it may be time to step that up if we need to.”
When City Council member Mari Rodin asked what the options were for increasing the flow into the treatment plant, such as “annexation or using more water,” White said annexation was not an option, as the city already “treats the wastewater from all of the areas outside of the city, which is how we are able to produce as much water as we do.” Instead, White said the city could look into adding stormwater and “blending inflows.”
“We can’t expand our footprint, because our footprint is already as big as it can be, but we can look at other sources of water, such as stormwater or other things, or blend it after treatment to increase the volume,” he said.
As for providing potable water to its residents, White said the city has “really shifted our operations from surface water to groundwater to the best of our ability at the moment. Right now we’re using 97 percent less surface water than we did in June of 2020, which is a pretty stark reduction. Normally this time of year our split is about 55 percent surface water, 45 percent groundwater, and right now we’re running about 85 percent groundwater and 15 percent surface water.”