Connecting Conservation to Global and Local Sustainability : San Joaquin River Valley Pollution Solution

Water contamination is a larger issue in California than other states in the U.S. In the Central Valley region counties within the region, have been forced to face the reality that there is almost no clean water in towns that depend on well water. Farming communities within the valley created this issue over time by striving to meet the state’s agricultural demand. Farmers depend on pesticides to protect their crops from disease and insects. This need leads to mono-cropping, which is the use of one type of pesticide on all crops. But more importantly, the pesticides and fertilizers have had an adverse impact on our land and water.

Map of Central Valley California from smilingglobe.com

Water runoff from farms were previously not regulated or monitored. “Since 1982 central valley regional board waved agricultural discharge from California’s clean water law” (California for Pesticide Reforms). Water that soaks the crops that are covered in pesticide will run through the soil until it makes its way to ground water. The EPA found in a 2002 study that over 635 miles of rivers and streams in the central valley were so contaminated that it was unsafe to fish in, swim in and drink the water. These rivers and streams supply millions of Californians with their drinking water. While water can be treated and made safer, it is not commonly done and can result in chemicals like nitrate, arsenic, uranium, and DBCP being consumed.

Nitrate

Water will become contaminated with nitrate when it absorbs pesticides and fertilizers that are used to increase crop yield. The fertilizer increases the amount of nitrogen that is in the soil. Once that fertilizer reacts with oxygen they converge to make nitrate. Increased levels of nitrate in water can potentially be dangerous, especially for infants, this leads to limited oxygen that our red blood cells can’t carry. This is a disease known as methemoglobinemia, or more commonly known as Blue Baby Syndrome.

DBCP

DBCP, or Fumigant1, 2-dibromo-3 chloropropane is a chemical that was used as a soil fumigate to protect the soil from insects. While extremely effective as a pesticide, a resulting illness from the consumption and application of DBCP led to the chemicals being banned in 1977. 40 years after this ban, the groundwater in California still has traces of DBCP. Exposure to DBCP has the potential to infect someone with a wide range of illnesses based on the type of exposure received. “…Acute (short-term) exposure to DBCP in humans results in moderate depression of the central nervous system (CNS), and, pulmonary congestion from inhalation, and, gastrointestinal distress and pulmonary edema from oral exposure. Chronic (long-term) exposure to DBCP in humans causes male reproductive effects such as decreased sperm counts”(epa.gov). Since the ban of DBCP, cases of illness that are directly linked to the contaminants have dropped significantly; however, there are still traces in the California groundwater four decades later.

Natural Containments

It is not uncommon to have some arsenic in soil. It is an element that occurs naturally, but in a quantity that is not dangerous. Uranium also occurs naturally in soil, rocks and water. The levels of uranium are normally low enough to not cause concern, although in Madera County, the drinking water has the highest levels of uranium and is more than three times the state’s health standard. While these natural contaminants are inherent in the land, they are in even higher concentrations in the San Joaquin Valley groundwater. “In 2015, 60 percent of the state's public water systems reporting health violations for arsenic were in the Valley. Madera County drinking water has the highest levels of arsenic statewide (psmag).” This increase in low-risk contaminants has surpassed acceptable levels, this can lead to blindness, and has also been linked to certain cancers.

What can be done to help conserve the water?

Aside from banning pesticides like DBCP, conservation can be accomplished through different farming techniques. Since these contaminants are currently seeping into the water from farms, a simple solution for this could be to change the way that the farms in these locations operate. The way farmers water their crops can have a large effect on the soil and the water runoff. The standard sprinkling method of irrigation waters crops from above, soaking the plant and bringing any pesticides on the plant into the soil. Drip irrigation allows farmers to use half of the water required with the sprinkling method. It is inexpensive to install and allows farms to use land that would not normally be accessible like hills. Tubing is placed along the crop with holes placed at the root of the plant. According to the USGS Water Science School, in 2000, farmers in the United States used on average 137 million gallons of water every single day (Water.usg) . If farms refrained from using sprinkling methods to water their crops and instead relied on drip methods of watering, this number could be below 70 million gallons. Less water used would result in less runoff and less water seeping into the ground, preventing nitrates and other contaminates in pesticides from making their way into water underground.

Conservation tillage is the practice of placing crop from the previous growing season on top of new crops. The stalks slowly break down which is good for the soil. This method mixed with drip irrigation trap in moisture, keep the roots of the crops damp and prevent evaporation. This method is not practiced by many farmers because farmers tend to farm the same way generation after generation. If Conservation tillage was utilized by everyone in California it would protect crops, require less water meaning less runoff, and it would mean less contaminates absorbing into the soil and inevitably ground water.