Water We Putting in the Mohawk? Kimberly A. O’Reilly, ‘20 and Elizabeth V. Whitney, ’20 Department of Chemistry, Union College BACKGROUND RESULTS AND DISCUSSION RESULTS AND DISCUSSION significantly The Hudson River t-test data t t 6 Mohawk R. 30 Figure 1. Graph of chloride calc table different? Watershed consists of 11 analysis for each body of 25 CBL 10.36 4.303 yes major sub-watersheds, one water. Light blue bars show of which is the Mohawk 20 data from external calibration, SCH 36.3 4.303 yes 1 dark blue bars show data from MKR 0.77 2.776 no River (MKR). The 15 IC. Chloride ions from CBL and Schoharie Creek (SCH) Table I. Table of t-test values comparing AAS to IC at 95% confidence 10 SCH get carried to MKR, which contributes 1,650 of the for calcium concentration in each water sample. CBL and SCH values are 5 has additional sources of Concentration (ppm) Hudson R. statistically significantly different. Because these values all trend 4,086 river miles to the chloride. The most likely together, there is greater confidence that both methods are probably Mohawk River watershed, 0 source of chloride in water is SCH MKR CBL accurate. making it the largest road salt. Sample NO - PO 3- SO 2- External Calibration IC 3 4 4 contributor to the Mohawk. CBL 0.3 ± 0.1 0.06 ± 0.02 2 ± 0 2,3 The Cobleskill Creek Figure 2. Graph of calcium ion https://en.wikipedia.org/wiki/Schoharie_Creek SCH 0.1 ± 0.1 0.02 ± 0.02 2.3 ± 0.6 (CBL), located in https://www.waterqualitydata.us/provider/BIODATA/ concentration in each body of USGS-NY/USGS-01349150/ 50 MKR 0.53 ± 0.06 0.08 ± 0.02 6 ± 0 Schoharie County, flows in the east-northeast direction to 45 water as analyzed by AAS and Table II. Table of Hach kit test values in ppm for NO -, PO 3-, and SO 2- 4 40 IC. CBL has the highest 3 4 4 Schoharie Creek. The map shows how the bodies of water ions in each water sample. These ions were below the lowest standards flow together to create a large watershed that provides active 35 concentration of calcium ions. 30 This gets diluted in the other measured for IC, so data using this method is unavailable. For reference, - sites for recreational activities, such as fishing and swimming, 25 rivers. The most likely source the maximum level of NO3 in drinking water recommended by the EPA 20 2- 7 3- across New York State. Since the Cobleskill Creek flows to the of calcium is the dissociation of is 10 ppm and SO4 is 250 ppm . For PO4 in streams and rivers, it 15 8 Schoharie Creek, which flows in to the Mohawk, the goal of the underlying bedrock.5 See should be less than 0.1 ppm. While it is not recommended that people 10 drink from these waters, the samples all fall under the recommended this project is to assess common substances found in each of Concentration (ppm) 5 Table I for t-test calculations limits. these rivers. The samples were analyzed to see whether or 0 between AAS and IC. not these elements and compounds get carried from one body SCH MKR CBL CONCLUSIONS of water to the next due to their interconnected nature. AAS IC v Calcium ions and alkaline sources in CBL get diluted before they Figure 3. Graph of alkalinity in reach SCH, which indicates that MKR has sources of calcium and MATERIALS AND METHODS ppm CaCO in each river. alkalinity that do not come from SCH and CBL. 140 3 Hach Kit Tests Alkalinity is determined by v Chloride ions accumulate from CBL and SCH in MKR, which partially ) 120 many basic ions in water. The attributes to MKR’s higher chloride concentration in the water Water samples were measured in the lab using the Hach DR/890 3 high alkalinity of CBL is likely Datalogging Colorimeter with the PhosVer 3, SulfaVer 4, and 100 samples that were analyzed. NitraVer 5 methods. due to chemicals spread on the v There is a correlation between measured alkalinity and measured pH 80 Atomic Absorption Spectrophotometry (AAS) farm fields and road that are in the three water samples, implying that higher pH corresponds to Standards were used to create an external calibration curve, which 60 near the trail from where the higher alkalinity. 5 2+ sample was taken. Because v AAS and IC are not significantly different in determining calcium was used to calculate the concentration of Ca ions in the water 40 samples. SCH has a lower alkalinity concentration for MKR, but are significantly different in determining 20 Ion Chromatography (IC) Alkalinity (ppm of CaCO compared to CBL, MKR likely calcium concentration for CBL and SCH, which prompts further has other sources that Samples were filtered and sent in triplicate to the Union College 0 investigation into more accurate detection of these ion contribute to its alkalinity. Geology Department to test for various anions and cations using the SCH MKR CBL concentrations. - - Dionex DX-500 Ion Chromatograph. v Interferents in Cl solution using ISE could be mistaken for Cl , but in IC the ions get separated out from one another, so there are no InductiVely Coupled Plasma Mass Spectrometry (ICP-MS) Figure 4. Graph of pH for each Three samples of each water source were run on the PerkinElmer interferents in that data. This accounts for the slightly higher values body of water. The higher pH for Cl- using external calibration as compared to IC. Elan 6100 DRC ICP-MS to quantify various metals in the water. 8.4 of CBL corresponds to its Alkalinity Tests 8.2 relatively high alkalinity as REFERENCES A titration with 0.02 N sulfuric acid was conducted on the water 8 compared to the other 1. Hudson River Watershed Alliance http://www.hudsonwatershed.org/hudson-riverwatershed.html Accessed May 18, 2018. samples using methyl orange indicator. 2. Mohawk River Watershed https://www.dec.ny.gov/lands/48041.html Accessed May 18, 2018. 7.8 samples. It is likely that the 3. Finelli, B. Water quality report on Mohawk River a mixed bag https://dailygazette.com/article/2017/03/17/water-quality-report- Chloride Analysis by Ion SelectiVe Electrode (ISE) alkaline substances of CBL get on-mohawk-river-a-mixed-bag Accessed May 18, 2018. 7.6 4. Cobleskill Creek (in Schoharie County, NY) https://newyork.hometownlocator.com/maps/feature-map,ftc,1,fid,946982,n,cobleskill Standards of 10-, 50-, and 100-ppm Cl- were used to create an diluted before the water creek.cfm Accessed May 21, 2018. 5. Johnson, R. L.; Redding, K.; Holmquist, D. D. Water quality with vernier: water quality tests using vernier sensors; Vernier Software & - 7.4 external calibration curve to test for Cl in the water samples. The Measured pH reaches the point where the Technology: Beaverton, OR., 2007 Accessed May 21, 2018. 6. Harris, D. C. Quantitative Chemical Analysis, 9th ed.; W. H. Freeman: New York, 2016. standards and water samples were measured using the Accumet 7.2 SCH sample was taken, as the 7. National Primary Drinking Water Regulations https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking- water-regulations Accessed May 30, 2018. Chloride Half-Cell Ion Selective Electrode with a silver-silver 7 pH of SCH is lower (see Figure 8. http://osse.ssec.wisc.edu/curriculum/earth/Minifact2_Phosphorus.pdf Accessed May 30, 2018. chloride probe. 3). MKR might also have other 6.8 ACKNOWLEDGEMENTS pH Tests SCH MKR CBL sources contributing to its pH, The pH of each water sample was tested in the lab using the Fisher as it is slightly higher than that Professors Lou and MacManus-Spencer Schoharie River Center Union College Chemistry Department Schoharie County Trail Association Scientific Accumet Basic pH probe. of SCH. Union College Geology Department CHM 240 Lab Students .