(Beyond Pesticides, March 14, 2012) Yet another report documents hazards of chemical-intensive agriculture that could be avoided by switching to organic practices. Nitrate contamination in groundwater from fertilizer and animal manure is severe and getting worse for hundreds of thousands of residents in California’s farming communities, according to a study released by researchers at University of California Davis. The report states the problem is likely to worsen, threatening ground water wells and eventually drinking water.
According to the report, Addressing Nitrate in California’s Drinking Water, nitrate runoff from agricultural regions is one of the state’s most widespread groundwater contaminants. Nearly 10 percent of the 2.6 million people living in the Tulare Lake Basin and Salinas Valley might be drinking nitrate-contaminated water, the report found. If nothing is done to stem the problem, the report warns, those at risk for health and financial problems may number nearly 80 percent by 2050.
The report is the most comprehensive assessment so far of nitrate contamination in California’s agricultural areas. The study area includes four of the nation’s five counties with the largest agricultural production. It represents about 40% of California’s irrigated cropland (including 80 different crops) and over half of California’s dairy herd. Many communities in the area are among the poorest in California and have limited economic means or technical capacity to maintain safe drinking water, given threats from nitrate and other contaminants. California’s governments, communities, and agricultural industry have struggled over nitrate contamination for decades. High nitrate levels in drinking water are known to cause skin rashes, hair loss, birth defects, and “blue baby syndrome,” a potentially fatal blood disorder in infants. A recent National Institutes of Health study links increased risk of thyroid cancer with high nitrate levels in public water supplies.
Nitrate-contaminated water is well-documented in many of California’s farming communities. The agricultural industry, however, has maintained that it is not solely responsible because nitrates come from many sources. According to the UC Davis report, 96 percent of nitrate contamination comes from agriculture, while only 4 percent can be traced to water treatment plants, septic systems, food processing, landscaping, and other sources. In order to reduce this pollution, the report recommends managing nitrogen fertilizer and manure to increase crop nitrogen use efficiency, managing crop plants to capture more nitrogen and decrease deep percolation, as well as improving the storage and handling of fertilizers and manure to decrease off-target discharge.
Similarly, pesticide use in California rose in 2010 after declining for four consecutive years, according to data from the Department of Pesticide Regulation. More than 173 million pounds of pesticides were reported applied statewide, an increase of nearly 15 million pounds — or 9.5 percent — from 2009. Overall, most of the growth in pesticide use was in production agriculture, where applications increased by 12 million pounds. Fertilizer and pesticides use therefore contribute to the growing environmental contamination of California’s surface and ground waters, as well as other environmental components.
Nitrates are odorless, tasteless compounds that form when nitrogen from ammonia and other sources mix with water. While nitrogen and nitrates occur naturally, the advent of synthetic fertilizer has coincided with a dramatic increase in nitrates in drinking water. Rural residents are at greater risk because they depend on private wells, which are often shallower and not monitored to the same degree as public water sources. Current contamination likely came from nitrates introduced into the soil decades ago. That means even if nitrates were dramatically reduced today, groundwater would still suffer for decades to come.
At the other side of the country, in Maryland, state law requires cities and farms to keep a close eye on nutrient runoff in the Chesapeake Bay. Pollution in the Chesapeake Bay, which supports over 3,600 species of plants, fish, and other animals, increases when nitrates and phosphorous from fertilizer wash into its waters from snow and rainfall. Reports studying the Bay have also found that nitrogen and phosphorus loads, along with pesticide pollution from farm fields and households, contribute to the Chesapeake Bay’s decline. Last year, the Maryland House of Delegates passed the Fertilizer Use Act of 2011 (HB 573) to limit fertilizer use on lawns.
Take Action: Want to do your own part to help reduce the release of dangerous and damaging chemicals in our homes, farms, and environment? Support organic agriculture and institutional IPM programs at schools and hospitals! You can even go organic in your own home, lawn, and garden. There are alternatives to toxic pesticides available for a wide range of pests whether in agriculture, or throughout the urban environment including structural and landscape pest problems.
To learn even more, attend our Healthy Communities Conference, March 30-31 in New Haven, CT. Join researchers, authors, organic business leaders, elected officials, activists, and others to discuss the latest pesticide science, policy solutions, and grassroots action. For more information, including a full speaker list and schedule of events, please see the Forum webpage.
Source: California Watch