Yusuf Jameel PhD Candidate University of Utah Understanding urban water transmission pattern using stable isotopes of water a.k.a where is the water in my tap coming from? Yusuf Jameel PhD Candidate University of Utah

Where is my water coming from? Local runoffs Recycled water Inter-basin transport Groundwater well

Water isotopes for tracking transmission pattern Differences in isotope ratios of the different sources In general, stable isotopes of water, strontium isotopes, major ion concentration can be used to track urban water supply pattern

Test region: Salt Lake Valley metropolitan region Collaboration with Jordan Valley water conservancy district (JVWCD) Continuous sampling from April 2015 to October 2015 More than 80 source and supply samples from each month

Hierarchical Bayesian mixing model Distance from source Weighted contribution from each source

EXAMPLE JUNE 2015 68 sites 7 sources δ18O and δ2H isotopes

Fractional contribution of the different sources

Robustness of the results

Source contribution during May – October 2015

Summary May – October 2015

Conclusions Proof of concept - Water isotopes provide a novel way to interrogate urban water supply system Accuracy and robustness of the results could be improved by integrating multiple geochemical tracers Could be extremely useful in solving water right issues and contamination cases