EESC 120 Laboratory Water Quality Analysis Laboratory Exercise
Background The impacts of nutrient pollution are found in all types of aquatic environments. These pollutants enter the upstream waters, like small streams and creeks, and then flow into larger bodies of water like lakes, rivers, and bays. Nutrient pollution stimulates the growth of algal blooms which negatively affect the aquatic ecosystem by decreasing dissolved oxygen levels in the water as bacteria aerobically break down all the dead algae. Excess nitrogen and phosphorus can travel thousands of miles to coastal areas where the effects of their pollution are found in the form of Dead Zones such as those found in the Gulf of Mexico and our Chesapeake Bay. Nitrogen can also percolate into the soil, down to the groundwater that is used by millions as their source for drinking water. Phosphate-Phosphorus Since phosphorus is the nutrient in short supply in most freshwater aquatic systems, even a slight increase in phosphorus can initiate a chain of undesirable events such as accelerated algal growth. There are many sources of phosphorus both natural and anthropogenic. These include soil and rocks, wastewater treatment plants, runoff from fertilizers from agricultural fields and lawns, failing septic systems, and runoff from animal feedlots among other sources. Pure “elemental “phosphorus (P) is rare. In nature phosphorus usually is found as part of a phosphate molecule (PO4). Phosphorus in aquatic systems occurs as organic phosphate (associated with carbon-based plant and animal material) and inorganic phosphate that is not associated with plant or animal material. Both organic and inorganic phosphorus can be dissolved in the water or suspended by being attached to particles in the water column. Refer back to the Phosphorus Cycle in your textbook. We will consider P levels > 0.1 ppm to be impaired and levels above 3 ppm call for remedial action. Nitrate-Nitrogen Nitrogen is found in different forms in terrestrial and aquatic ecosystems. These forms include ammonia (NH3), nitrates (NO3) and nitrites (NO2). Nitrates are essential plant nutrients but in excess amounts can cause water quality problems as discussed above. The natural level of ammonia and nitrate in surface water is usually less than 1mg/L but has been found in effluents from wastewater treatment plants as high as 30 ppm. Here, we will consider N levels > 1ppm to be impaired and require remediation. Note that WQA = water quality analysis Procedures Part 1 While studying at UMW, you become a research intern at the Frankel, Szulczewski, and Kisila Water Quality Analysis Laboratory. As part of ongoing environmental conservation efforts across the United States, this water quality lab has been collecting samples from surface waters and analyzing them for phosphate (PO4), ammonia, nitrite, and nitrate. As an intern, you have been tasked with describing the geographic landscape of a subset of these sites and identifying any potential sources of contamination using google maps. Instructions 1. Download, save, and open the WQA Report Worksheet and the WQA Data for Analysis document from Canvas. On this sheet you can view the date each sample was collected, the location in GPS coordinates, and the concentrations of ammonia, nitrite, nitrate, and PO4. For this exercise, you are tasked with examining Sites 3, 7, 9, 16, and 19. 2. Open google maps (https://www.google.com/maps ) in a web browser, input the GPS coordinates provided on the Excel sheet for Site 3, and hit search a. Hint: coordinates must be entered exactly as provided to work correctly! b. Once you have found the location, switch your view to “satellite mode” and begin to examine the site and the surrounding area by zooming in and out. c. Look for nearby water bodies, industrial sites, public utilities, and other environmental impacts. d. Use a search engine to find out more information about labeled sites nearby 3. On your worksheet, provide the following information: a. The county and state in which the site is located b. The name of the body of water the sample was collected from (if available, some sites are unmarked) c. A general description of the type and relative size of the body of water (lake, river, stream, etc.) d. A detailed description of the surrounding area (rural or urban, forested or unforested, etc.) of at least 3 sentences e. State whether levels of nitrogen, phosphorus, or both require remediation at the site. f. If water quality is poor, identify specific potential sources of contamination located near the site and provide a description of each. g. If water quality is good, provide an explanation as to why there is little to no contamination at that site. 4. Repeat this process for Sites 7, 9, 16, and 19. Part 2 During contaminant analysis, one of the technicians bumped into the cart while making a TikTok video causing three of the sample vials (#21, 22, and 23) to fall to the floor before they could be properly labelled with their locations. Perplexed, the technician analyzed each sample but is still not sure which site each came from. 1. Using the GPS locations and water quality data at the bottom of the data sheet, provide your best guess as to which sample belongs to which site and provide a detailed explanation for your guess. a. Hint: Different sources of pollutants typically can have higher levels of N or P. Do some background research on any suspicious buildings or geographic features. 2.
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