Last week’s speaker for the final installment of the Van Tuyl lecture series, Dr. Graham E. Fogg of UC Davis, presented about groundwater sustainability.
Fogg started by talking about the importance of California farmland. He said, “California Produces 50% of the nation’s fruits and vegetables with irrigation.” Regarding water, its sustainability, and the reason for his research into the subject, he added, “It’s going to take centuries for this to play out and for me, the call to arms was: Well we better figure this out. Is an entire resource going to be lost? Shouldn’t we know about it and warn somebody and rethink our regulations and whether they are effective and working?”
According to Fogg the groundwater in most systems is hundreds to thousands of years old yet the pollutants that humans are adding to the water are only fifty to sixty years old. The ages of waters are “Generally highly mix and molecular ages typically range greatly within a single sample.” As a result, in many systems the quality of the groundwater is likely to decline in the near future. Fogg went on to ask “what is the evidence that the water quality is getting worse?” Historically, data from city wells is often limited because after the detection of high levels of contaminates, the city will shut down that well and discontinue testing the well for contaminates. Recently though, cities are gathering data from these shut down wells and from non urban areas where most non-point sources exist. Fogg also said, “The question is, ‘How long is it going to take the contaminated water to move down and to gradually contaminate more and more ground water?'”
Fogg believes the answer to this question depends on the contamination sources. The main sources that Fogg outlined were farmland runoff and cattle manure runoff. The fertilizer used on crops contains many contaminants that adversely affect the groundwater. Fogg believes that if farmers drill shallow wells they could reuse the contaminated groundwater to water the crops. The nutrients in the contaminated groundwater would supplement the fertilizer and allow farmers to use fertilizer in more sustainable amounts without decreasing their crop yield.
Fogg ended his lecture by informing the audience what needed to be done to sway public opinion. He said, “We need to be able to answer the question, If we reduce nitrogen loading by fifty percent is that going to amount to a profit or not? If you can’t tell people when positive effects will occur then you’re not going to get anybody to change their practices.” Unfortunately, Fogg also said that models that can accurately predict how groundwater interacts and moves in order to determine requirements for keeping contaminants at a steady state, “have not even come close to being produced.” Solving this problem, like many modern public health issues is going to be no easy task and requires lengthy research before public interest is swayed.