Ca 2+ in your water Naomi Bryner David Millard

Why experiment?  Does bottled water have an advantage to tap water?  Is the water company keeping up to their standards?  Has pollution ruined the ecosystem of our local waterways?  What are you putting into your body?

Method  Prepared EDTA solution to titrate with (re- standardized daily), prepared CaCO 3 solution to standardize with.  Ammonia buffer was treated to pH 10 daily.  Water samples (10) had pH and temperature recorded on day of testing.  Spike added to show titration method was valid.

Data Day 2  EDTA Concentration 1.017*10-3M  Water Fountain  [Ca 2+ ]: 8.069*10 -4 M, Hardness: 32.34ppm  Brockie (untreated)  [Ca 2+ ]: 8.402*10 -4 M, Hardness: 33.67ppm

Data (Continued) Day 3  EDTA Concentration 1.055*10 -7 M  Acadia bottled water  [Ca 2+ ]: 2.181*10 -8 M, Hardness: 8.739*10 -4 ppm  Aquafina bottled water  [Ca 2+ ]: 1.674*10 -9 M, Hardness: 6.709*10 -5 ppm

Data (Continued) Day 4  EDTA Concentration: 1.182*10 -6 M  Fiji bottled water  [Ca 2+ ]: 1.254*10 -6 M, Hardness: 5.276*10 -2 ppm  Dasani bottled water  [Ca 2+ ]:1.620*10 -7 M, Hardness: 6.493*10 -3 ppm

Data (continued) Day 4 (continued)  Tyler Run Creek  [Ca 2+ ]: 1.767*10 -6 M, Hardness: 7.080*10 -2 ppm  Brockie (treated)  [Ca 2+ ]: 3.854*10 -7 M, Hardness: 1.544*10 -2 ppm

Data (Continued) Day 5  EDTA Concentration: 1.359*10 -3 M  Well water (treated)  [Ca 2+ ]: 1.324*10 -3 M, Hardness: ppm  Well water (untreated)  [Ca 2+ ]:1.495*10 -3 M, Hardness: ppm

SampleSourceExperimental mean Reported value t calc significance95% CIRelationship to reported value 1 Well water untreated ns[60.332, ] Lower 2 Well water treated ns[52.880, ] Lower 3 Brockie Commons water untreated ns[37.674, ] Lower 4 Brockie Commons water treated ns[0.147, ] Higher 5 Tyler Run water *[0.555, ] Within 6 Dasani bottled water *[0.384, ] Within 7 Figi bottled water ns[0.750, ] Higher 8 Aquafina bottled water *[0.419, ] Within 9 Campbell Hall fountain water ns[32.753, ] Lower 10 Acadia bottled water ns[0.536, ] Higher

Discussion  Tyler Run, Dasani, and Aquafina had significantly different concentrations.  Difficulties finding known, reliable values.  Values were inferred, calculated, or previously reported.  Trace amounts were harder to detect and report.  A spike of 24ppm Ca 2+ was added to verify method.

Discussion (continued)  Endpoint of titration, sometimes questionable.  Instrumentation could have helped proven data.  Possible contamination.

Summary  Majority of reported values were close to stated values.  Difficulties gathering information on water samples.  Bottled water did have less Ca 2+.  Treatments for well water and Brockie water did lower Ca 2+ concentration.  Thanks to Dr. Foresman for supplying well water.

References  Fiji  A_Water_Quality_Report_June11.pdf  York Water Company  water.com/  Well water  pubs.usgs.gov/of/2012/1045/pdf/ofr _Reddy_508.pdf

References (continued)  Acadia  tled-Water-Quality-Investigation  Susquehanna River  pa.water.usgs.gov/reports/ofr pdf  Pepsi and Coke  Customer service was called.