UNION COLLEGE TESTS FOR HEAVY METAL CONTAMINANTS IN DRINKING WATER (Invited Presentation)

In response to the Flint, MI water crisis, New York State legislature required all public schools to test their drinking water for Pb contamination. This mandate is a step in the right direction, but currently, all colleges and the community at large are not covered by the NYS legislation. Thus, the Union College (NY) Geology Department is bridging this gap for their campus and the local community by testing for Pb, Cu, Zn, Sr, Rb, Ba, and U. Metals such as Pb and Cu can have major health risks, which prompted the USEPA to set requirements stating that the 90^th percentile for lead and copper must be under 15 ppb and 1300 ppb, respectively. For those receiving their water from the Schenectady city water, like Union College, the 2015 reports show that the 90^th percentile from 30 samples yield 2 ppb Pb and 78 ppb Cu, signifying safe drinking water. Pb and Cu levels higher than the source likely result from local plumbing contamination, but this is unlikely to be the source of the other metals, besides scale dissolution and fragmentation. Nearly 400 samples have been analyzed from Union College so far with the average levels of Pb and Cu being 1.4 ppb and 452 ppb, respectively. However, of these, 1 from the Union campus yielded Pb and Cu levels of 20 ppb and 1376 ppb, respectively. The college was notified, this fountain was shut off, and an additional sample was sent out to a certified laboratory, which confirmed our results. Additionally, because Sr, Rb, Ba, and U are relatively conservative elements in oxidizing fresh waters, they are useful in distinguishing different water sources. For Schenectady, this source is the Great Flats aquifer, underlying the Mohawk River Channel. Many samples we receive from the community come from outside that water system. Keeping track of different sources can be aided by Sr, Rb, Ba, and U, as their ratios are relatively constant. For example, the Great Flats aquifer water has a Sr/Ba ratio of about 12. Other samples have quite different ratios, related to the specific water source. The abundances of these elements can also help identify waters treated with filters, which tend to reduce some element concentrations to near-zero. The plan is to extend this project indefinitely, to raise public awareness of drinking water quality, and to identify contaminated drinking water locations so appropriate response can be made.