Department of Water Resources
A daily compilation for DWR personnel of significant news articles and comment
April 23, 2009
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Panel: Wastewater ammonia 'likely' alters Delta
The
Renewed drought conditions fan
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Panel: Wastewater ammonia 'likely' alters Delta
The
By Matt Weiser
A panel of independent scientists has affirmed in a new report that ammonia from urban wastewater is a "likely" contributor to environmental shifts in the Sacramento-San Joaquin Delta.
But the panel, assembled by the CalFed Bay Delta Authority, says more research is needed to determine where ammonia fits among numerous threats to the estuary.
The Bee reported last year on emerging research suggesting that ammonia from treated urban sewage, discharged continuously into
But the research has been hotly disputed by the sanitation district and others. So CalFed agreed to host an independent review of existing science.
That review, released last week, raises more questions than it answers. But significantly, the four scientists on the panel conclude the subject merits further study as a potentially significant factor in the degradation of Delta.
Increased ammonia "likely has led to major modification" of the estuary to favor foods less nutritious to fish as well as toxic algae blooms, the panelists state.
Numerous Delta fish species have been in a death spiral since about 2001. Leading the pack are the Delta smelt, longfin smelt, threadfin shad and striped bass. A more charismatic victim is the
Declines in the smelt species triggered new rules that cut water exports from the Delta, aggravating drought conditions in some parts of the state. Those exports are one suspect in the Delta's decline, along with water pollution and foreign species.
State and federal agencies have spent millions of dollars researching the problem but have not found a smoking gun. They believe many factors are at work, and it now seems they must add ammonia to that list.
The chief concern is not whether ammonia kills fish. Instead, the volume of ammonia may have grown so large from urbanization that it is upsetting the natural food chain.
"We now have better reason to believe that it (ammonia) is perhaps an important suspect, but we still don't know exactly its role among the huge number of suspects we have here," said Anke Mueller-Solger, a CalFed lead scientist investigating the species' declines.
Ammonia is a natural byproduct of human urine and feces. In the sewage treatment process, it typically gets converted into an ionized form called ammonium. But this isn't removed by so-called "secondary" sewage treatment systems like
Many other sewage treatment entities have upgraded to more advanced "tertiary" systems that do remove ammonium. But the
The district manages the sewage of about 1.4 million people in the capital metro area and discharges treated wastewater into the Sacramento River near
"Overall, they're saying it's a possibility that ammonia has played a role in the shift in the ecosystem over time," said Stan Dean, district chief of policy and planning. "But they don't go so far as to specify any shifts, how they work their way up or down the food chain, whether they're good or they're bad."
The panel does not point a finger at any ammonia source. Instead, it says many sources should be investigated, including ammonia that may come from farms and wetlands.
The agency has an expansion plan pending before the Central Valley Regional Water Quality Control Board to handle population growth. Board officials have been keenly interested in the ammonia problem as a factor to consider in reviewing the expansion. #
http://www.sacbee.com/topstories/story/1802637.html?mi_rss=Top%20Stories
| Renewed drought conditions fan By Oren Dorell California is bracing for another year of bad wildfires as a thin mountain snowpack, parched vegetation and an early heat wave signal a third consecutive year of drought. Recent surveys by the state of Record high temperatures from 93 in "It's very concerning to have dry conditions this early," Berlant says. "That's why we're making the public aware and also ramping up our fire operation." Conditions early this month resembled late-April and early May conditions in 2007 and 2008, which later produced the worst Fire officials have activated fire stations a month early in Several fires have already cropped up this spring. Lygia Chappellet, a rancher in "It was terrifying that it was an explosive type of fire in the coyote brush, poison oak, bay trees and even into the redwoods," Chappellet said. "It was flaring up as if it was August." Elissa Lynn, senior meteorologist for the California Department of Water Resources, said more rain and snow fell this year than in 2007 or 2008, but it was still 80% of normal. January, usually the state's biggest snow month, was the eighth-driest on record since 1930, "For three years we're missing almost a whole season's worth of precipitation," she said. "If you have really dry conditions for several years, you need an above normal year to get out of the drought." Drought conditions are hitting Water supplies are so low that 30,000 agricultural jobs are expected to be lost in the The dry conditions have led to 600,000 acres taken out of production and unemployment of 25% in Orange Cove, "Our cities are hurting," Lopez said. Dan Errotabere, president of the Fresno County Farm Bureau, says he took about a quarter of his 5,500 acres out of production and cut his workforce from 40 to 25 because of the water shortage. Now he irrigates with groundwater, which has a high salt content that hurts the plants. Todd Bradley, co-owner of Walter Todd Salon in San Diego, expects a recent citywide 20% hike in water rates — and a proposal to raise rates for businesses that use a lot of water — to boost his usual $300 bi-monthly water bill by up to 40%. "We're probably going to have to raise our prices," Bradley says.# http://www.usatoday.com/weather/drought/2009-04-22-drought-california_N.htm |
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