Winter 1995 (v7n1)
by Lyra Halprin, SAREP
[Editor's Note: This is the first part of a two-part article on the Oct. 20, 1994 conference "Animal Agriculture Impacts on Water Quality in California, which reported the results of a year-long study or the same name undertaken by the UC Davis Animal Agriculture Research Center and the UC Agricultural Issues Center (AIC). Proceedings Mil be available from AIC in January 1995.]
How does livestock affect California's water? The state's animal industry is large dairy, beef, poultry, sheep and hog operations brought in more than $5.25 billion in 1993, at least one-quarter of California's agriculture marketing receipts. State and federal agencies regulate the industry to protect water supplies, and yet there is a lack of research based, site-specific information on animals and water. These issues prompted the UC Davis Animal Agriculture Research Center and the UC Agricultural Issues Center to jointly sponsor a year-long research study on the relationship between animals and the state's water. More than 60 UC scientists from 16 departments and 14 Cooperative Extension offices, farmers and environmental groups as well as representatives from ten state and federal agencies contributed to the study, results of which were presented at the "Animal Agriculture Impacts on Water Quality in California" conference in Sacramento.
Keynote speaker Paul Johnson, chief of the USDA's Natural Resource Conservation Service (formerly the Soil Conservation Service), noted that because 75 percent of the land in the U.S. is private, water conservation must begin with those who live there. He said partnerships and coordinated research with state and federal agencies, the University of California, Cooperative Extension and the farm press will be necessary to protect water. A former farmer and a member of the Iowa House of Representatives, Johnson was instrumental in the passage of the Iowa Groundwater Protection Act of 1987, which emphasizes research, education and voluntary approaches to water quality.
Barbara Schneeman, dean of UCD's College of Agriculture and Environmental Sciences, noted that California's productive animal agriculture industry understandably generates a large quantity of by-products. "These aren't necessarily always negative, but they need to be dealt with," she said, referring to the 500 million tons of manure produced daily by the state's more than 300 million animals.
Where the Gaps Are
Schneeman said that researchers for the animal/water study were "charged to determine what information exists, how reliable it is, and identify where gaps in the information exist." She noted that livestock operations are larger and more concentrated here than in other states, there is less rain, more feed is imported and urban pressures are intense. Limited water has produced concern over its quality and quantity, "particularly in the midst of our eight-year drought," Schneeman said.
She pointed out that dramatic animal management changes have taken place in the state in the last 45 years. She said that the number and character of the state's dairy operations alone is very different, shifting from 20,000 small dairy operations in 1950 to only 2,400 in 1991, each averaging more than 500 head, with many much larger.
As she introduced the first of four research teams that worked on specific animal agriculture issues, she reiterated that accurate information was the primary goal of the study. "Everyone needs to be aware of what is really happening out there, and we need to tell others," she said.
Each team leader's report was followed by a panel response that included farmers and ranchers, water scientists, regulatory agency officials, and audience participation.
The first research team report was presented by James Oltjen, an animal management systems specialist in the UCD animal science department, who discussed potential sources of water contamination from grazing and confined animal operations. He noted that in California's varied climate zones and topography, site-specific factors are key. Potential pollutants of most concern are animal manure, production water, storm water runoff, dead animals, dust, silage, bedding, waste products, medicine, chemicals, sediment and soil disturbance. He said detailed information is needed to better understand animal agriculture's contribution to water pollution, and to look at the way manure can be a positive resource as it is recycled for fertilizer, energy production and feed.
Cattle, Poultry, Hogs and Fish
Oltjen said feedlots in California maintain 375,000 head of beef cattle. Each 1000 lb. animal produces approximately 58 pounds of total manure each day (8.5 lbs/solids). The approximately 1.22 million dairy cows in the state (average size 1300 lbs) each produce approximately 1.22 pounds of total manure daily (approximately 15/lb. solids). In the poultry industry, 233 million broilers produce 2.25 pounds each of dry manure during their short lifetimes, which totals 5 30 million pounds of manure dry matter per year The 26 million egg layers produce approximately 636 million pounds per year of manure dry matter, while the 23.6 million California turkeys produce 298 million pounds of manure dry matter annually.
Oltien also gave statistics for hogs and fish produced in the state. California hog growers raise 275,000 swine each year, less than one percent of the nation's pork. (The state's consumers eat more than 10 percent of all U.S. pork.) One thousand pounds of live-weight pig (several animals) produces 84 pounds of manure per day (11 lbs solids). (Not mentioned at the conference, but noted in the study, is information about horse manure. An average horse weighing one thousand pounds is expected to produce 5 1 pounds of manure per day, including 1 5 pounds of total solids. There are about one million horses in California.)
Aquaculture, an agriculture industry that contributes about $30 million per year to the state, has highly regulated discharge water "Low concentration of waste in aquaculture water makes it ideal for other applications such as agricultural irrigation," Oltjen said.
Farmer Response
Responders included dairy farmer Richard Michel, who discussed the importance of manure-handling use plans for producers that extend from one to five years.
"No one is more concerned about water quality than the dairy farmer," Michel said. "He or she drinks the water, the employees drink the water, the animals drink the water Poor quality water means poor crops, sick animals, and soon to-be-out-of-business. "
Michel said producers know it isn't possible to pile manure up forever in one place and not expect a consequence. He said, however, that dairy farmers generally see manure not as a potential problem, but as an asset. "We seem to be moving toward sustainable and organic farming practices," he said. "This manure is a great asset. We use it (on our own fields) to help offset the cost and use of commercial fertilizer."
"Let's keep in mind the potential contamination of water from animal operations," Michel said. "We have to acknowledge that the possible contamination also comes from other sources." He noted that when water is tested, it is not possible to determine which nitrates or metals come from animals, and which come from vineyards or orchards and commercial fertilizers.
Michel said further studies of potential contamination problems "could be justified by the university working with dairy associations in specific areas of the state to make long-term analysis."
"We want long-term studies," he said. "The university can work with Extension service people and farm advisors, who already have a relationship with farmers. University researchers can provide information gathering and testing. Above all, let's avoid an additional bureaucracy that would entail extensive and frequent reports and new fees from the farmer."
Lonnie Wass, a senior water resources control engineer in the Central Valley Regional Water Quality Control Board in Fresno noted that he has seen permit requests for large dairy operations increase, including one now under consideration for a three-phased dairy farm of more than 10,000 cows. "That's the size of a city in terms of waste production," he said. "We need to be careful in evaluating the permits to make sure we're not impairing the beneficial uses of surface or ground water in the region."
Sherman Swanson, a riparian scientist at the University of Nevada, Reno said that understanding cattle grazing behavior can help researchers figure out what to do to maintain stream environments.
Human Health Impacts
Kenneth Tanji, UCD professor of hydrologic science in the land, air and water resources department, reported on his team's research on the impacts on human health and agriculture and natural systems. He said that nitrate maps of California water wells only show deeper wells, and do not include the many shallow, private wells throughout the state. Tanji stressed that the impacts of animal wastes may be felt on-site as well as off-site; there is not enough research now to know exactly where animal wastes go. He said nitrogen from manure and urine can be converted to nitrate, the most mobile nitrogen form. Water and land management practices contribute to the possibility of nitrates migrating. He said it may take "decades of travel time" for the nitrate to migrate to aquifers. The Chino Basin area of Southern California, which started increasing its animal population in the 1930s, began showing signs of high nitrates in well water in the 1960s, he said. The area has frequently been used as an example of concentrated animal waste and groundwater contamination. Tanji noted the need for increased environmental monitoring and the use of models to improve waste management practices. "We need to better define the problem to evaluate the effectiveness of management alternatives," he said.
Ralph Jurgens, of New Era Farm Services, responded to Tanji's report and talked about how he uses manure to produce composted fertilizer. He said there are 600 dairies within 20 miles of his Tulare County office. He stressed the systems approach to composting what comes out of dairy farms, and using the products on other farms. "Manure, if handled properly, is not a waste product and does have a value," Jurgens said. "We compost this material and sell it as a composted soil amendment and as a fertilizer." Jurgens' operation serves more than 500 growers throughout the state, representing 490,000 acres.
Bruce Macler, regional toxicologist for the U.S. EPA office in San Francisco, said his work has showed him the truth in the sayings "everything is connected to everything; everything has to go somewhere; and there is no such thing as a free lunch." He pointed out that sedimentation released into streams by grazing animals is like sandpaper, and takes the stream bed with it. Animal wastes released into streams encourage the growth of algae, and toxic ammonia becomes part of the water stream. Growing alfalfa for animal feed brings the problems of subsidized water use and pesticides into the picture. He noted that human health concerns include contaminated wells, the problems of recreational exposure by people using rivers and lakes, and airborne dust contaminated with pathogens. He pointed out that pollution by microbials like giardia contribute to human health problems. "The identified outbreaks that occur from waterborne disease in the U.S. are small relative to the estimated 3 to 5 million endemic waterborne illnesses that occur each year," he said. In terms of animal wastes, Macler said that EPA is concerned with bacteria and protozoa contaminating streams and groundwater.
Brett Matzke, the Sierra Nevada manager of California Trout, Inc. presented one environmental organization's view of the water problems related to animals. He noted that 39 subspecies of salmon and 40 species of other fish "are in trouble." Sport fishing brings in $1.7 billion to California coffers each year, Matzke said, not including fishing license fees which contribute an additional $40 million per year. He expressed concern about the 39 million acres of California land that is grazed, calling grazing the "number one culprit in damaging trout species. " He agreed that partnerships are "an excellent way to get rid of stereotypes' among the groups affected by regulation.
[ Back | Search | Feedback ]