Thursday, January 31, 2013
De-salting seawater is one of the most expensive ways to supply the Monterey Peninsula. According to California American Water estimates, its proposed regional desal plant would produce water at more than $5,000 per acre-foot. The more Cal Am can supplement desal with cheaper means, the less ratepayers will see their water bills spike.
A key component: aquifer storage and recovery (ASR), which takes extra water from Carmel River wells during high winter flows and injects it into the Seaside Basin for use in the dry season. The resulting water, produced by a partnership between Monterey Peninsula Water Management District and Cal Am, costs about $1,700 per acre-foot, by the district’s estimate. (Cal Am puts the number $500 to $1,600 higher.)
But a series of glitches – mechanical, operational and weather-related – have reduced this year’s ASR output to 45 percent of what it would be if all three completed wells were running the way they should.
This season’s ASR began Dec. 3 and paused Jan. 16, when Carmel River flows dropped too low to continue. In those six weeks, almost 195 acre-feet were injected into the Seaside Basin.
But an update presented to the district water board Jan. 30 finds that if the three ASR wells had been maximized, Cal Am could have injected 660 acre-feet in that time frame. (A fourth ASR well was recently built but is not yet connected to electrical and water lines.)
Why is the program falling short? One ASR well, according to the report, is out of service while Cal Am repairs broken shaft bearings. An equipment glitch at a river source well couldn’t be fixed due to wet conditions. Cal Am system demand spiked at times, reducing the amount of water that could be diverted to ASR. And several upper-river source wells stopped working when temperatures dropped below freezing earlier this month. Cal Am also missed several days of ASR production at the beginning of the season because its production wells were not ready, according to District General Manager David Stoldt.
Some factors, like demand spikes and an offline well, are beyond Cal Am’s control. But water board director Kristi Markey blames Cal Am for others – like failing to insulate its pipes before the temperatures dropped, and not being ready for the December rain.
“I’m disappointed with Cal Am falling down on the job here,” she says. “We can’t afford to lose the opportunity to add to our water supply.”
Cal Am spokeswoman Catherine Bowie maintains the company isn’t at fault. Cal Am was ready for the agreed-upon Dec. 3 start date, she writes by email, and even precautionary actions couldn’t prevent the cold-weather impacts. The pump failure that took the largest ASR well offline was unplanned, she adds, but it’s being repaired on schedule.
“In our water system, as in any water system, there will be mechanical failures and main breaks that occur,” she writes.
Stoldt says Cal Am is honoring the terms of its ASR agreement with the district, which puts the water company in charge of day-to-day operations. The district owns the original ASR facility, monitors the river and oversees the program.
“This has been a very good learning season,” Stoldt says. “You can’t just let water flow down that river that could be sequestered in the Seaside Basin. We’ve got to get better at it, and that goes for both parties.”
Paradiso Trattoria
Monterey
Comments
Antony says...
"Over the last thirteen years, the amount of unused water treated at the RTP and discharged out of the ocean outfall has averaged over **10,600** Acre-Feet per Year (AFY). " (p 3 - 4) *OPENING BRIEF OF THE MONTEREY REGIONAL WATER POLLUTION CONTROL AGENCY REGARDING WATER RIGHTS FOR A GROUNDWATER REPLENISHMENT PROJECT*
The shortfall to be addressed by Desal and GWR is **9700** AFY.
Seems the Desal plant can be a lot smaller.
[RTP = Regional Treatment Plant]
Posted 4 February 2013, 1:43 p.m. Suggest removal
CaliforniaAmericanWater says...
Thanks to the MC Weekly for keeping up on water issues and giving attention to the ASR program, which is a key part of our water supply portfolio. As proposed, however, ASR costs no less than current water supply, and will cost less than future desalinated water supply.
Also, any water that we pump into the ASR system is subtracted from the annual Carmel River pumping limits to which we are held under the Cease and Desist Order - in other words, ASR does not provide extra water that would help us stay within the CDO limits. Once the CDO is satisfied, ASR will be considered additional water, but again, that is not the case today.
Readers should also understand that when a well goes out in Carmel Valley, our priority is to serve our customers - not pump as much as possible into ASR at the expense of meeting customer demand. When the desal plant is online, we will be relying much less on Carmel Valley wells to meet daily demand and will be able to use those wells to maximize ASR. Right now, the major benefit of ASR is to the river - it allows us to keep MORE water in the Carmel River in the Summer.
Rather than "falling down on the job" our operators dealt professionally with mechanical failures, that will occur from time to time, and made their priority what it should be - making sure our customers stay in water... as always, our number one job, and we salute them.
Posted 8 February 2013, 4:13 p.m. Suggest removal
Log in to comment