Final Internship Report: Palouse Falls Water Pollution
Miranda Marti and I were given the opportunity to do an internship involving the research of the water pollution sources at Palouse Falls. We started by meeting with Amy Molitor and then we contacted Sandra Cannon, who gave us clear objectives for this internship. Basically, she wanted us to find where the pollutant point and non-point sources were along the Palouse River, concentrating mostly upstream of the falls. Two students before us had tested the water for nitrates, nitrites and phosphates, but had not done a very thorough testing due to lack of time and funding.
I started researching by surfing the websites of the U.S. Geological Survey and the Washington State Department of Ecology. The U.S. Geological Survey had a lot of information, but the last sampling period was in 1994. They do assessments of water quality once a decade, which isnít very often. They found that the nitrate concentrations exceeded the drinking water standard in twenty-percent of all wells sampled. The highest exceedence rates occurred where fertilizer use and irrigation were the greatest. This wasnít surprising, since farmers supplement nitrates to their wheat by the placement of fertilizer. Also, the Palouse subunit is comprised of mostly wheat agriculture. The primary source of excess nitrates was the agricultural fertilizers, but other sources included cattle feedlots, food processing plants, septic tanks, and wastewater discharges. This is bad because it can cause eutrophication, death of fish and other organisms by lack of oxygen. They also detected pesticides in ground water and volatile organic compounds from the high application of fumigants on potatoes. Both were greater than the national median. Another interesting fact is that they found Radon in the dry land wheat area that exceeded the national median. Of course, it is bad to breath due to the high-energy alpha particles that can damage lung tissue, but they also found that there is an increased health risk from drinking water contaminated with Radon. The sampling also detected a surplus of PCBís, organochlorine compounds that are toxic and persistent in the environment. The loss of the riparian vegetation combined with other land use practices has resulted in streams having an average of seventy-percent bank erosion, increasing the potential for nitrates and pesticides to travel into the water.
After browsing through all this information, I sent an email to Luis Fuste at the U.S. Geological Survey who sent me a packet of information concerning the Palouse subunit. Mostly, it confirmed what the website said and gave more detail on how much of each pesticide was detected. The study area was in the Palouse River Basin. They studied the water in the Palouse River and the South Fork Palouse River. According to the Survey and the Washington State Department of Ecology, the South Fork Palouse River has the worst water quality in the state. This is mostly due to high inorganic and organic nitrogen. Between 1994 and 1995, they sampled 6 sites on the Palouse River above the confluence with the South Fork Palouse River, 6 sites on the South Fork system, 4 sites on the Palouse River below the confluence with the South Fork, and 3 sites on other major tributaries of the Palouse River. They analyzed for 84 pesticides in the wells and surface-water sites. Ground water was also analyzed for 60 volatile organic compounds. Out of the commonly used pesticides in the subunit, they found 10 in the surface water and none in the ground water. However, they detected 5 VOCís in the ground water. (VOCís are associated with industrial activities but are also used as inert ingredients in pesticides and as fumigants).
According to the Survey, the pesticides can be transported to the water from agricultural fields to surface water due to rainfall and erosion. They can dissolve into the water or bind to soil particles. Dissolved pesticides can also leach into the ground water and be further transported. The amount and timing of pesticide application are also important environmental factors. If excessive amounts of pesticides are applied, there is more available for transport to the water. Also, if a pesticide is applied right before a storm where there is excess irrigation and erosion, it is likely that it will be transported to the water as well. Some agricultural practices increase the likelihood of erosion and therefore create an easy transport of pesticides. In some parts of the subunit, fields have been plowed down to the very edge of roads and through streambeds. Run off from fields can be limited by contour plowing or strip cropping. Also, riparian buffer zones can also reduce erosion.
Reasons why VOCís and pesticides are transported to ground water are poor well construction and open-hole basalt well construction, preferential pathways into the surficial loess aquifer and the deeper basalt aquifers, river leakage, and bank storage.
From the Washington State Department of Ecology website, I found that they tested the water quality of the Palouse River every month at Palouse, Hooper and the South Fork Palouse River at Pullman. They tested for fecal bacteria, temperature, oxygen and pH. In July 2001, the temperature, pH, and the fecal coliform bacteria were all above the standard. In August 2001, the statistics were still above the standard, but less severe. For example, in July, the pH was 9, exceeding a standard of 8.5. In August, the pH was 8.57. I also sent an email to them and have received an answer back, pointing to the website that I had already looked at, i.e. not very helpful.
Miranda and I also learned how to use a hatch kit with Professor Drabek. We can now test for nitrates, nitrites, phosphates, pH and turbidity. We had planned to go out to the field and collect our own samples as soon as we could get out with Sandra, but busy schedules and loss of weekends prevented us from doing so. We talked to Amy Molitor about it and she told us that it would take a full day out in the field. We basically ran out of weekends, with other class fieldtrips and multitudes of homework, we were not able to go out. We thought that maybe we could go out the weekend after Thanksgiving break, but we found that we had to get the poster and report done by the following week, as well as deal with the end of the semester crunch. It seemed like we were doing well at the beginning of the semester and then we just ran out of time for the internship. If we had had more time, I think Miranda and I would have loved to go out and see Palouse Falls and do our own testing. We are both science people and it would have been fun to analyze the water quality ourselves. We just had so much to do in so little time. I personally feel like we have found a lot of useful information and the next step would be to talk with and educate the farmers, as well as make sure that the wastewater from different chemical plants, such as the McGregor, donít end up spilling into the river. Creating riparian buffer zones and using contour plowing or strip cropping will help to reduce the erosion that transports the pesticides into the water. Also, cattle grazing must be fenced in and riparian buffer zones must be implemented nearby the water so that we donít get fecal bacteria transport and erosion. We need to make sure that the water is clean for people to drink from, for recreation, and so that fish and other organisms donít die of chemical overdose. I really enjoyed this internship, as it gave me a hands-on experience of chemistry and environmental studies. I am really glad that we could find point sources. Now we can work on trying to stop the pollution of the water. Overall, it has been a very interesting internship and I wish that I could have worked on it longer.
Sources to look at for the next intern
Greene, Munn and Ebbert, U.S. Geological Survey Water Resources Investigations Report 96-4078, ď Nutrients, Benthic Algae, and Stream Quality During Low Streamflow in the Palouse River Basin, Washington and Idaho.Ē Tacoma, Washington 1997.
Ebbert (from USGS) and Roe (from USDA), ďSoil Erosion in the Palouse River Basin: Indications of Improvement.Ē U.S. Geological Survey Fact Sheet 069-98, July 1998.
Wagner and Roberts, U.S. Geological Survey Water-Resources Investigations Report 97-4285, ďPesticides and Volatile Organic Compounds in Surface and Ground Water of the Palouse Subunit, Central Columbia Plateau, Washington and Idaho, 1993-95.Ē
U.S. Geological Survey website.
Washington State Department of Ecology website.