Posts Tagged: water quality
Although there are many sources of water pollution, runoff from farms may contain contaminant levels that exceed water quality standards. Runoff from agricultural operations can pick up and carry natural and man-made pollutants, including fertilizers, salts, pesticides and sediments to lakes, rivers, wetlands and beaches, according to Loretta M. Bates, UC Cooperative Extension staff research associate, who leads the Agricultural Water Quality Research and Education Program in San Diego County.
Avocados and citrus are major tree crops in San Diego County, but “the app should be useful for growers of any tree crops,” says Bates.
The self-assessment questions fall into the following categories:
A. Property Management
B. Road Management & Erosion Control
C. Irrigation Practices
D. Leaching & Runoff
E. Nutrient Assessment & Fertilizer Management
F. Integrated Pest Management
“In the near future, we will have apps available for nursery and greenhouse growers and the apps will be available for use with devices other than iPads,” Bates says.
The tree crops app was developed by Ryan Krason, digital media specialist for UC Cooperative Extension in San Diego County, and Valerie Mellano, former UC Cooperative Extension advisor in San Diego County, with a third-party app developer. Krason and Bates are currently working on customizing the app for nursery and greenhouse operations.
The iPad app for tree crops is free and can be downloaded from the iTunes store. Search for "agricultural water quality."
For tree crop growers who don’t have iPads, the self-assessments can be printed off the Web at http://ucanr.org/sites/agwaterquality/files/121819.pdf and completed by hand. The Agricultural Water Quality Research and Education Program also offers printable self-assessments for greenhouse and nursery businesses and animal agriculture operations on the Web. While the iPad app will generate a report of suggestions, the print versions offer statements that address a group of questions.
For more information about the UC Cooperative Extension Agricultural Water Quality Research and Education Program, its iPad water-quality self-assessment app or other online assessment tools, visit http://ucanr.edu/sites/agwaterquality/Grower_Resources.
Cattle grazing and clean water can coexist on national forest lands, according to research by the University of California, Davis.
The study, published June 27 in the journal PLOS ONE, is the most comprehensive examination of water quality on National Forest public grazing lands to date.
“There’s been a lot of concern about public lands and water quality, especially with cattle grazing,” said lead author Leslie Roche, a postdoctoral scholar in the UC Davis Department of Plant Sciences. “We’re able to show that livestock grazing, public recreation and the provisioning of clean water can be compatible goals.”
Roughly 1.8 million livestock graze on national forest lands in the western United States each year, the study said. In California, 500 active grazing allotments support 97,000 livestock across 8 million acres on 17 national forests.
“With an annual recreating population of over 26 million, California’s national forests are at the crossroad of a growing debate about the compatibility of livestock grazing with other activities dependent upon clean, safe water,” the study’s authors write.
“We often hear that livestock production isn’t compatible with environmental goals,” said principal investigator Kenneth Tate, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis. “This helps to show that’s not absolutely true. There is no real evidence that we’re creating hot spots of human health risk with livestock grazing in these areas.”
The study was conducted in 2011, during the grazing and recreation season of June through November. Nearly 40 UC Davis researchers, ranchers, U.S. Department of Agriculture Forest Service staff and environmental stakeholders went out by foot and on horseback, hiking across meadows, along campsites, and down ravines to collect 743 water samples from 155 sites across five national forests in northern California.
These areas stretched from Klamath National Forest to Plumas, Tahoe, Stanislaus and Shasta-Trinity national forests. They included key cattle grazing areas, recreational lands and places where neither cattle nor humans tend to wander.
UC Davis researchers analyzed the water samples for microbial and nutrient pollution, including fecal indicator bacteria, fecal coliform, E. coli, nitrogen and phosphorous.
The scientists found that recreation sites were the cleanest, with the lowest levels of fecal indicator bacteria. They found no significant differences in fecal indicator bacteria between grazing lands and areas without recreation or grazing. Overall, 83 percent of all sample sites and 95 percent of all water samples collected were below U.S. Environmental Protection Agency benchmarks for human health.
The study noted that several regional regulatory programs use different water quality standards for fecal bacteria. For instance, most of the study’s sample sites would exceed levels set by a more restrictive standard based on fecal coliform concentrations. However, the U.S. EPA states that E. coli are better indicators of fecal contamination and provide the most accurate assessment of water quality conditions and human health risks.
The study also found that all nutrient concentrations were at or below background levels, and no samples exceeded concentrations of ecological or human health concern.
The study was funded by the USDA Forest Service, Region 5.
Los Angeles Times.
That was just latest episode in a series of environmental woes for the lake that formed 150 miles southeast of Los Angeles in 1905 when the Colorado River flooded the Sonoran Desert. Now the Salton Sea is mainly fed by fresh water drainage from nearby farms and waste water from Mexicali, but becoming more salty as evaporation outpaces its replenishment. UC scientists are working on ways to improve the quality of the inland sea to make it more hospitable to wildlife.
Nitrogen and phosphorus are two main nutrients that spur algae growth and lower dissolved oxygen concentrations that cause massive fish kills in the Salton Sea.
Imperial Valley growers often fertilize their crops with nitrogen and phosphorus in irrigation water. Khaled Bali, UC Cooperative Extension advisor in Imperial County, gives growers “best management techniques” to ensure fertilizers are applied correctly so the nutrients end up the plants, not flowing into the Salton Sea.
“One of the irrigation management practices that we developed at the UC Desert Research and Extension Center is used in the valley to conserve water and improve water quality,” Bali said. “Implementation of this practice on commercial farms increases water use efficiency by more than 12 percent and reduces the load of sediment and soluble phosphorus in drainage water by more than 50 percent.”
A recent UC Berkeley study has demonstrated a cost-effective method for using manmade wetlands to clean contaminants out of the waters that flow into the sea, which is overly salty from evaporation and polluted with selenium, fertilizer nutrients and other chemicals from agricultural run-off.
The study was aimed at providing a wildlife habitat at the south end of the sea with low-salt, clean water, but the new wetland design also has the potential for broader environmental and agricultural applications, researchers say.
“No other published studies have shown any cost-effective system that approaches this level of efficient selenium removal,” said Norman Terry, professor in the Department of Plant and Microbial Biology at UC Berkeley, and principal investigator of the study. “The only other way to get water this clean is to use microbial bioreactors, which are prohibitively expensive and not feasible on the vast scale of the Salton Sea.”
In the proposed multi-step process, water from the Alamo or New River would be pumped into a sedimentation pond, and then allowed to flow through an algae pond and into a constructed wetland growing cattail plants before it finally enters into the species conservation habitat.
Terry’s next step is to obtain funding to build a pilot wetland to test the design in the field.
The study, published in the November 6 issue of Environmental Science and Technology, was funded as part of the California Department of Fish and Game's and Department of Water Resources’ efforts to develop pilot restoration projects that provide feeding habitat for migratory, fish-eating birds.
Drinking water is a commodity often taken for granted in the United States. When we turn on the tap, we assume the water streaming out is at least safe, if not always up to our individual taste. We expect that problems with our drinking water are isolated, temporary and newsworthy. Which may be one reason why a report released yesterday by UC Davis made headlines.
You can read “Addressing Nitrate in California’s Drinking Water” online in its entirety, or one of the shorter summary documents. This report was commissioned by the California State Water Resources Control Board in 2010 and is the first comprehensive scientific investigation of nitrate contamination in the Tulare Lake Basin and the Salinas Valley.
"The report defines the extent and costs of the problem, for the first time, and outlines how we can address it," said the report’s co-author Thomas Harter, UC Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis, in a UC Davis press release. "We hope it provides the foundation for informed policy discussions."
For the report, scientists examined data from wastewater treatment plants, septic systems, parks, lawns, golf courses and farms. The authors found that more than 90 percent of human-generated nitrate contamination in these regions’ groundwater is from agricultural activity—including applications of synthetic fertilizer and animal manures.
“Nitrate discharges to groundwater and the degradation of underground water supplies are a chronic problem. Do the economic benefits of groundwater degradation outweigh the negative effects of degraded groundwater? Will it be cheaper, and better for all, to pay for the treatment of small water systems and preserve agricultural jobs? Would such an approach threaten long-term groundwater salinization from some of the same sources? Who will bear these costs of source reduction?”
While yesterday’s report looked directly at drinking water contamination, another—the California Nitrogen Assessment, currently under way—will evaluate existing information to gain a comprehensive view of nitrogen flows in the state, with a particular focus on the roles agriculture can play. The Agricultural Sustainability Institute's Tom Tomich gave an update to CDFA earlier this month about the progress of the California Nitrogen Assessment, which has brought stakeholders (including farmers) together to evaluate potential future scenarios in relation to nitrogen management and California agriculture.
These two reports apply science to define problems, evaluate costs and benefits, suggest solutions, compare options and otherwise serve to help guide decision makers throughout the state.
UC Cooperative Extension researchers have been working with growers on ways to improve fertilizer management, irrigation efficiency and other farming practices that can—according to the UC Davis report—significantly affect drinking water sources.
Here are some highlights of current UC ANR projects that aim to help reduce fertilizer contamination of groundwater:
- Nitrogen management in vegetable crops: With trials in lettuce fields, UCCE advisors in Monterey County have demonstrated effective ways to reduce nitrogen inputs, save money and provide water quality benefits while maintaining equivalent yields, using a combination of weekly nitrate testing and scheduled irrigation management.
- Nutrient analysis via leaf sampling for nut trees: Though leaf sampling currently provides tree-crop growers with a threshold "critical value" of nutrient analysis, this team of researchers is working to establish more robust and useful leaf sampling protocols that could point to specific timing of applications, fertilizer rates or other "nutrient budget" details for nut trees, particularly almond and pistachio.
- Tools for dairies to manage nitrogen and water discharge: UCCE specialists at UC Davis and UC Riverside have developed comprehensive resources to help dairy operators comply with regional water discharge requirements, including step-by-step instructions for sampling supply wells and subsurface drainage systems, solid manure, liquid manure and soil.
Find out more about how UC is working to ensure all Californians have access to healthy crops and safe water including details of projects like these, peer-reviewed publications and experts, by visiting http://ucanr.edu/hcsw.
A new wireless data collection system deployed at Duncan Peak, located near the town of Foresthill on the Middle Fork of the American River basin, is part of a new water information system for California. This extensively distributed sensor network will allow for better characterization on the amount of water stored in the snow and the soil throughout the watershed.
This wireless system is part of the research being conducted by University of California researchers as part of the Sierra Nevada Adaptive Management Project (SNAMP) to investigate the impacts of fuels treatment projects on water quality and quantity and how water is routed through catchments. Information collected from these wireless systems includes measurements of snow depth, temperature, relative humidity, soil moisture, and solar radiation. The data will also be integrated into models which will extend the results to areas where no measurements are being made.
UC Professor Roger Bales and a meteorological station data collector.
Using one base station to log all the measurements and broadcast out over the landscape, it connects wirelessly to sensors up to 350 feet away, a distance that can be extended multiple times by placing “hoppers,” or signal relays, between the sensors and base station. This ‘mesh network’ insures multiple readings so no data is lost during transmission. Twenty more base stations are planned for instillation in the American River Basin.
The wireless system is made possible by the development of ultra-low power radios that can run on two AA batteries for up to two years and which can transmit data over long distances using the same technology as a home internet wireless network. This mesh radio network comes from DUST Networks. Researchers Steve Glaser and Branko Kerkez from UC Berkeley, working with Prof. Roger Bales at UC Merced, have also installed a sensor network at their Critical Zone Observatory research site near Shaver Lake to monitor the same hydrologic variables as in the SNAMP sites. If the wireless system drops out due to extreme conditions, such as a snow storm or other malfunction, no problem! Each sensor also logs to a USB stick, from which the data can also be easily retrieved.
Low power computer components used in the snow depth wireless sensor network.
More precise estimates on water storage within a basin will lead to increasingly accurate predictions of water availability for use in hydropower, irrigation, habitat and household consumption.
Duncan Peak meteorological station.