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Nitrates and water contamination in San Joaquin Valley, CA
editIn 2015, California was the number one agricultural producing state.[1] The southern part of California’s Central Valley, San Joaquin Valley, is well known for its large agricultural production. In fact, in 2015 San Joaquin Valley’s 8 counties were among the top 10 counties in California that had the highest total value of production and leading commodities.[2] This has required heavy usage of fertilizer, specifically nitrogen fertilizer. As a result of intensive irrigation, over usage of nitrogen fertilizer, and livestock manure, groundwater contamination occurs.[3] About 95% of people in the San Joaquin Valley rely on groundwater for drinking.[4] The impact to people is the obstruction of the blood’s ability to carry oxygen particularly for pregnant women, infants less than 6 months, and children who drink formula with tap water.[5] These impacts disproportionately affect people of color.[4]
Large contributors of nitrates in agriculture
editFertilizer runoffs contributes roughly 90% of all nitrate inputs to the alluvial groundwater system. Within agriculture, the two major factors are High-Intensity Crop Production and Large Dairy Herds.[3]
High-intensity crop production
editWithin the past century, farmers have been increasing their production to meet the high demand that a developed country requires. To help increase output and efficiency, farmers have been increasing the amount of fertilizers used, which means increasing the level of nitrates being used. However, only a fraction of the nitrogen in fertilizers is efficiently used to help produce crops. This has led to a greater concentration of nitrates and phosphates in the waters, contaminating and causing eutrophication of possible drinking water.[6]
San Joaquin Valley more specifically has shifted its commodity production to more resource intensive commodities such as almonds, grapes, and milk, which are the top three commodities produced in the San Joaquin Valley.[7] Almonds and grapes are both water intensive crops that require constant irrigation with the ability to grow in shallow soils and high levels of clay.[8] Producing crops with shallow soil levels and a high percentage of clay, coupled with the fact that these crops require constant watering, means that the runoff levels are high since the water retention within the soil is low.
Large dairy herds
editRoaming dairy herds before the exponential demand of meat products and dairy has contributed an insignificant amount of nitrate pollution to the underlying groundwater systems. However, within the past few decades, the increasing amount of cattle has been one of the main contributors of nitrate contamination in the groundwater systems of California.[9] Roughly around 1960, cattle were openly grazing pastures, and because of the large amount of lands which they roamed manure was not intensively managed.[6] However, even though manure was not closely managed, "Nitrogen excretion and deposition in pastures likely did not exceed pasture buffering capacity and had no significant leaching to groundwater".[9] It was not until the mid 1970s when the transition to dry-lot and free stall-based dairy farming, coupled with irrigated forage crops, that dairy herds were a contributor to nitrogen contamination.
Milk is currently the second highest commodity produced within the San Joaquin Valley, since it holds almost 73% of California’s cows. Within the past fifty years, the amount of small dairy farms in the San Joaquin Valley has decreased, meaning that the existing farms have exponentially grown in size and also concentration of cows. The high concentration of cows causes waste management issues since it exceeds the soil absorption capabilities and can possibly contaminate the groundwater supplies for the citizens around the area.[10]
Possible solutions and alternatives
editThe large dairy herds create manure, which is used to create the fertilizers that is applied to the crop fields. Because of the exponential demand for crops, farmers have been looking to lower the costs of production. Using manure based fertilizers is cost effective since manure is a by-product of large dairy farms and herds. The alternative to manure, which contains a high level of nitrates, is composting. Composting however is relatively expensive compared to using manure as fertilizer, since it is not as effective and is more timely/costly to make because of the large amount of aeration needed.[11]
With regards to the soil contamination from large dairy herds, the San Joaquin Valley Unified Air Pollution Control District should gather more relevant information of the current manure storage situation, while also push for more distributed areas for cows so the concentration is not as high. This coupled with more regulation with regards to soil contamination would most likely reduce the amount of nitrates in the soil.[10]
San Joaquin has been producing high levels of crops, which require shallow soil levels with high amounts of clay. If the crops would be switched to those that do no require as much water and/or need deep soil to thrive, the amount of fertilizer runoff would be severely reduced. However the push for more extensive research and development with regards to making these crops have more water retention or give more yield while needing less water and fertilizer would promote the best solution.
Health impacts of nitrates
editNitrates are of concern because it interferes with the blood's ability to carry oxygen, and can have severe health effects on pregnant women, infants under 6 months, and children who drink formula with tap water.[12] Because nitrates interfere with blood's capacity to carry oxygen, infants are at high risk of death from blue-baby syndrome, which can occur when there are high nitrate levels in the blood that are untreated.[12]
Wells contaminated with nitrates
editCalifornia's Water Board has an interactive map showing areas that are or have been out-of-compliance, which are the red stars in the map. They also show places that have no violations of the primary drinking water, which are the blue stars in the map. In addition to showing areas that have been out-of-compliance, there are violation details allowing people to understand what type of violation that specific area has or had.[13]
Incidents
editSan Joaquin Valley, within the Central Valley of California, is made up of eight counties that are well known for agriculture.[9] Overuse of nitrogen fertilizers and irrigated agriculture is common, and according to Thomas Harter, the Chair for Water Resources Management and Policy at UC Davis, “more than 80 pounds of nitrogen per acre per year may leach into groundwater beneath irrigated lands, usually as nitrates”.[14] Between the 1950s and 1980s, when nitrogen fertilizer use grew sixfold, nitrate concentrations in groundwater increased 2.5 times.[15] Because these communities are cut off from larger water distribution, they are dependent on wells,[16] making groundwater a source of drinking water for 90-95% of San Joaquin Valley's residents.[5]
Tulare County
editNitrates have found their way into the aquifers around the San Joaquin Valley, affecting over 250,000 people in communities that are poor and rural.[16] In 2006, the State Water Resources Board took samples from domestic wells in Tulare County. The results indicated that 40% of 181 domestic wells had nitrate levels above the 10 mg/L legal limit.[9] Though locals have typically used filters for their water, the filters need to be installed correctly and replaced frequently, which may not be economically feasible for the residents in Orosi.[17] Table 2 on page 20 from Pacific Institute's "The Human Costs of Nitrate-contaminated Drinking Water in the San Joaquin Valley" indicates the water systems that were contaminated with nitrates over the legal limit, the percentage of the population affected that are non-white and that are below or near poverty-level, and the year since the violations began.[9]
Turlock Water Basin
editThe Turlock water basin is a sub-basin of the San Joaquin Valley groundwater basin found within Stanislaus County and Merced County in the Central Valley[18]. In California's Groundwater Bulletin 118, a chart, linked below, illustrates the number of non-compliant public supply wells with nitrates over the maximum contaminant level (MCL). According to this chart, there were eight wells which had nitrate levels above the 10 mg/L MCL, out of 90 sampled for nitrates in 2006[18].
Addressing nitrates in groundwater
editGroundwater contaminated by nitrates can be treated with reverse osmosis, resin-based processes, or blended with higher quality water before being placed in water supply distribution systems.[19] New technological innovations have also allowed for more effective treatments, such as biological treatment in the form of fixed beds, fluidized bed, and membrane bioreactors.[20] However, costs can impede groundwater remediation, as groundwater treatment or replacing or improving deteriorating water infrastructure is expensive, and can take years, decades or longer to remediate contaminated groundwater sites.[20]
High fixed costs of remediation disproportionately affect small community water systems (CWS), such as those found within San Joaquin Valley, as they usually lack the infrastructure and economies of scale of larger systems, and oftentimes cannot afford to treat or find alternative supplies for a contaminated drinking water source.[20] The small, rural and disadvantaged, are most affected by the high fixed costs, making the unaffordability of water treatment a focus of environmental justice concerns. Even if the disadvantaged communities (DACs) manage to acquire the funding to improve their drinking water systems, they often cannot afford the operation and maintenance (O&M) costs necessary for providing safe drinking water.[20] This is especially due to the fact that small rural communities face higher per capita O&M costs and capital costs that result in higher water rates.[21]
Recommendations for addressing nitrate in groundwater
editIn a 2013 report to the Legislature on recommendations for addressing nitrate in groundwater, the State Water Resources Control Board (State Water Board) made 15 recommendations to address the issues associated with nitrate contaminated groundwater.[21] These recommendations reflect a comprehensive strategy focused on the following four categories:
- Providing safe drinking water
- Monitoring, assessment and notification
- Nitrogen tracking and reporting
- Protecting groundwater [21]
Although recommendations in this report specifically address groundwater nitrate contamination in the Tulare Lake Basin and Salinas Valley pilot project study areas, they may also be implemented in other parts of the San Joaquin Valley or statewide in other areas with nitrate-contaminated groundwater.[21]
Providing safe drinking water
editOne of the biggest impediments to providing safe drinking water to DACs impacted by nitrate contamination is the absence of a stable, long-term source of funding. The State Water Board makes five recommendations regarding the provision of safe drinking water, with the goal to create a stable funding source integrated with institutional changes, in order to provide long-term safe drinking water infrastructure and alternative solutions for the small DACs impacted by nitrate contamination.[21]
Monitoring, assessment and notification
editCritical to effectively managing groundwater quality is the presence of a groundwater monitoring and assessment program. The recommendations that focus on monitoring, assessment and notification require the development and management of data needed to identify and manage nitrate-contaminated groundwater.[21] These recommendations particularly focus on the following:
- defining nitrate high-risk areas in order to prioritize regulatory oversight and assistance
- notifying groundwater users in nitrate high-risk areas
- requiring property owners to sample their well as a part of a property title transfer or purchase[21]
Nitrogen tracking and reporting
editDue to the fact that nitrogen fertilizing material application is a primary source of nitrate contamination, the State Water Board recommends the development and implementation of a system that can track and report the nitrogen mass balance, in order to manage the application of nitrogen fertilizing materials.[21]
Protecting groundwater
editThe State Water Board recommends the development of an effective system for minimizing discharges of nitrates to groundwater in order to maintain a safe drinking water supply by preventing the need for costly groundwater treatment or new well constructions. The development of an effective system would require the following:
- the establishment of a nitrogen management training and certification program recognizing the importance of water quality protection
- the continuation and improvement of agricultural nitrate education and research programs
- the convening of a panel of experts to recommend improvements in agricultural nitrate control programs, and implementing the recommendations
- the evaluation of the effectiveness of existing permits to address nitrate contamination in high-risk areas in order to improve permitting activities[21]
Funding for addressing nitrates in groundwater
editThe California Department of Public Health (CDPH), through its Drinking Water Program, oversees multiple funding programs to assist California public water systems in order to achieve and maintain compliance with safe drinking water standards .[20] The four main funding programs for California public water systems that the CDPH administers are SDWSRF, Proposition 50, Proposition 84, and the American Recovery and Reinvestment Act of 2009 (ARRA). Although these programs have provided a total of $1.87 billion combined to 441 public water systems in order to solve health risk problems and Safe Drinking Water Act violations,[20] this has not been enough to address the ongoing issue of nitrate contamination in the water systems of the Central Valley.
Unlike mainstream water systems that only require the expansion and augmentation of existing funding sources for implementing the recommendations for addressing nitrates in groundwater, the small community water systems of disadvantaged communities (DACs) within the San Joaquin Valley require new funding sources altogether. The four main existing funding programs for California public water systems only provide initial funding for improving water infrastructure.[20] New sources are required altogether in order to fund new operation and maintenance costs that come with new and improved treatment plants. The funding available to DACs has proven to be insufficient in providing safe drinking water and meeting the stricter water quality regulations. DACs thus require new long-term funding sources that can be used in combination with existing funding sources in order to create, operate, and maintain safe drinking water systems for DACs.[21]
Environmental Justice
editFive of San Joaquin Valley’s eight counties have some of the highest rates of water contamination per person in California and the number of nitrate-contaminated wells in California is only increasing.[22][23] A study done in the Central Valley showed that smaller community water systems with larger number of Latinos and renters are exposed to higher nitrate levels in their drinking water in comparison to communities with higher levels of white residents and homeownership.[23] Small community water systems service the people of color, the rural, and the disadvantaged, but the cost to provide safe drinking water for these smaller systems is significantly greater on a per-capita basis than that of larger public water systems.[20] Per household costs for compliance with existing regulations for small water systems can be more than four times greater than those for medium-to-large water systems.[20] The high costs impede the disadvantaged who are most affected by the nitrate contamination from seeking improved water infrastructure.
The inadequacy of small community water systems in providing safe drinking water requires residents of the San Joaquin Valley who rely on these smaller systems to take alternative measures in order to avoid nitrate-contaminated water.[9] However, alternative measures, such as bottled or vended water, or point-of-use filters, also increase the total cost spent on safe drinking water.[9] The increased cost added from accessing water from alternative sources, coupled with the low earnings of households most affected by the nitrate-contamination suggests that low-income families disproportionately shoulder the burden of nitrate-contaminated water.[9]
Currently the laws that address water contamination are the Clean Water Act (CWA) and the Safe Drinking Water Act (SDWA). Trump’s proposed Environmental Protection Agency (EPA) cuts[24] may impact the ability to address nitrate water contamination thus allowing the continual exposure of nitrates for people of color.
References
edit- ^ "Farm Income and Wealth Statistics". United States Department of Agriculture. February 2017.
- ^ "Agriculture Statistical Review" (PDF). USDA’s Economic Research Service. 2008–2009. Retrieved April 21, 2017.
- ^ a b AFP. "Nitrates poison water in California's Central Valley". DailyMail. Associated Newspapers Ltd. Retrieved 23 March 2017.
- ^ a b Balazs, Carolina; et al. (2011). "Social disparities in nitrate-contaminated drinking water in California's San Joaquin Valley". Environmental Health Perspectives. 119 (9): 1272–1278. doi:10.1289/ehp.1002878. PMC 3230390. PMID 21642046.
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(help) - ^ a b Community Water Center (Dec 2013). "Water & Health in the Valley: Nitrate Contamination of Drinking Water and the Health of San Joaquin Valley Residents" (PDF). Community Water Center.
- ^ a b Burow, Karen. "Assessment of regional change in nitrate concentrations in groundwater in the Central Valley, California, USA, 1950s–2000s" (PDF). Ca Water Usgs. 3. Retrieved 23 March 2017.
- ^ Administrator. "Top 10 Commodities". www.sjfb.org. Retrieved 2017-04-24.
- ^ "Almond - Netafim". www.netafim.com. Retrieved 2017-04-24.
- ^ a b c d e f g h Moore, Eli. "Human Costs of Nitrate-contaminated Drinking Water in the San Joaquin Valley" (PDF). Pacific Institute. Pacific Institute. Retrieved 17 April 2017.
- ^ a b MacMullan, Chelsea. "Dairy CAFOs In California's San Joaquin Valley" (PDF). http://www.humanesociety.org/assets/pdfs/farm/macmullan_apa-2007_final.pdf.
{{cite web}}
: External link in
(help)|website=
- ^ Gamroth, Mike. "Composting: An Alternative for Livestock Manure Management and Disposal of Dead Animals" (PDF). Oregon State University. Retrieved 18 April 2017.
- ^ a b "Guides and Fact Sheets: Nitrates". Community Water Center. 2016.
- ^ "Exceedance/Compliance Status of Public Water Systems". California's Water Board. Retrieved March 1, 2017.
- ^ Harter, Thomas (2009). "Agricultural Impacts on Groundwater Nitrate" (PDF). Southwest Hydrology. 8: 22–23.
- ^ "Groundwater Shock: The Polluting of the World's Major Freshwater Stores | Worldwatch Institute". www.worldwatch.org (in cust-en). Retrieved 2017-03-05.
{{cite web}}
: CS1 maint: unrecognized language (link) - ^ a b AFP (September 19, 2016). "Nitrates Poison Water in California's Central Valley". Community Water Center.
- ^ Carroll, Gerald (Nov 14, 2006). "Tulare County Private Wells Test High for Nitrates" (PDF). Visalia Times-Delta.
- ^ a b water.ca.gov (April 11, 2017). "California's Groundwater Bulletin 118" (PDF).
- ^ "Groundwater/Aquifer Remediation" (PDF). California Department of Water Resources. July 29, 2016. Retrieved March 6, 2017.
- ^ a b c d e f g h i "Drinking Water Treatment and Distribution" (PDF). California Department of Water Resources. July 29, 2016. Retrieved March 6, 2017.
- ^ a b c d e f g h i j "Recommendations Addressing Nitrate in Groundwater" (PDF). California Department of Water Resources. 20 February 2013. Retrieved 6 March 2017.
- ^ Ramos, P. (2003). "Promoting Quality, Equity, and Latino Leadership in California Water Policy". San Francisco: Latino Issues Forum.
- ^ a b Balazs, C. (2010). "Trends in Nitrate Violations: Maximum Contamination Level (MCL) Violations Over Time in California and the San Joaquin Valley". California Department of Public Health, Permits, Inspections, Compliance, Monitoring and Evaluation (PICME).
- ^ Kim Soffen, and Denise Lu (March 16, 2017). "What Trump cut in his budget". The Washington Post. Retrieved April 21, 2017.