Another water contamination source is surface run-off. Severely compacted and hydric, meaning waterlogged, soils are more prone to surface run-off because the potential for infiltration has been drastically reduced. As heavy rains fall, the rate of infiltration is slower than the rate of rainfall and the result is surface run-off. Once a soil has reached its water-holding capacity, infiltration ceases and all falling water reverts to surface run-off. Instead of dissolved chemicals moving through the soil and into the groundwater, soluble chemicals are moved away over the surface and may be carried directly into natural water sources like rivers and lakes.
New research on surface run-off by Jan Vymazal and Tereza Březinová (2015) shows promise in how cultivators might prevent and limit water run-off while using plants to clean contaminated surface run-off water.
Attempts to prevent run-off from farms using vegetated ditches and fabricated wetlands alongside fields have been more popularized due to the increasing knowledge and awareness of the hazards of contamination. Wetland vegetation had been used sporadically in the past to remove excess fertilizers, but has only become more accepted in the last ten years or so for removing pesticides. Because surface run-off almost immediately enters waterways, the risk of pesticide contamination is much higher than the slower, albeit irreversible, contamination through a soil profile once it meets the groundwater.
Methods involving permanently installed vegetation have been successful in removing pesticides from water. Ditches surrounding fields filled with riparian vegetation act as a buffer between the field and natural water sources. These constructed wetlands act as water treatment systems, engineered and built to engage the natural processes of wetland vegetation, soils, and their associated microbial populations. These fabricated wetlands assist in treating contaminated surface run-off through physical, chemical and biological mechanisms. Results of this research indicate that pesticide removal is variable for singular pesticides, but that they can be categorized according to their chemical composition. Although some types of pesticides are better removed than others, future research opportunities comparing the various constructed wetlands in a single location offer promise for determining the most effective systems for treating different pesticide types.
Greater awareness of the types and characteristics of chemicals, soil and water sources used when cultivating Cannabis, and any other crop for that matter, will help prevent further contamination of the waterways we all share. Water can be tested for pesticides to ensure against secondary contamination of Cannabis through pesticide tainted water.
Understanding varying pesticide solubility and degradation rates will help growers better understand how to apply such chemicals without adding the unnecessary stress of contamination to local water sources. Integrating manufactured wetlands and other bioremediation tools in the cultivation area can also help enhance the quality of our water. Utilizing integrated pest management plans can help reduce the need for chemical interventions during cultivation, thus limiting future water contamination.
Limiting or eradicating the usage of pesticides in agriculture may have adverse results on crop yield, but on the other end of the spectrum, increasing pesticide use to further increase yield may present disastrous consequences for our environment. The balance lies in arming oneself with the knowledge about these compounds and how they affect other systems to allow for the use of such products in a responsible manner.
Soil and water are not endless resources, and ancient civilizations that have destroyed the soil and water sources in which they relied upon should serve as a reminder that no amount of technology can resolve the issue of using a resource quicker than it can be replenished or purified
Brady NC, Weil RR (2010) “Soil and the Hydrologic Cycle.” Elements of the Nature and Properties of Soils. Third ed. Upper Saddle River, NJ: Pearson Prentice Hall. Print.
Grube A, Donaldson D, Kiely T, Wu L (2011) Pesticides industry sales and usage: 2006 and 2007 market estimates. EPA 733-R-11-001. U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention.
Hwang JI, Lee SE, Kim JE (2015) Plant uptake and distribution of endosulfan and its sulfate metabolite persisted in soil. PLoS ONE 10(11): e0141728. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0141728#pone.0141728.ref010
Toccalino PL, Giolliom RJ, Lindsey BD, Rupert MG (2014) Pesticides in groundwater of the United States: decadal-scale changes, 1993-2011. Groundwater 52(1): 112-125 http://dx.doi.org.libproxy.uoregon.edu/10.1111/gwat.12176
Vymazal J, Březinová T (2015) The use of constructed wetlands for removal of pesticides from agricultural runoff and drainage: A review. Environment International 75: 11-20 www.sciencedirect.com/science/article/pii/S0160412014003201
Ms. Marquez began working as a Cannabis testing laboratory technician for Oregon Analytical Services in 2014. In 2016 she became responsible for the management of back-office operations of the laboratory, including quality assurance, compliance, and procurement. She also provides microbiological testing services for the lab.
Prior to joining OAS and the EVIO Labs group, she worked with Dr. Alan Shanks at The Shanks Lab at the Oregon Institute of Marine Biology on a variety of research projects. She also worked as a Naturalist where she provided educational tours elucidating the ecology of the Pacific Northwest through Whale Research EcoExursions. She was selected to work as intern in the highly competitive Centers for Ocean Sciences Education Experience (COSEE) where she stayed on as a lab technician. Her work included deployment of oceanographic instruments and microscopy work at sea.
Ms. Marquez has prior experience working for a financial investment firm where she worked as assistant to the President performing documentation and staffing tasks. A member of the Phi Theta Kappa Honor Society, Kaylynne Marquez is currently completing her degree in Biology at the University of Oregon.