Temporal and Spatial Patterns of Water Isotope Ratios (Delta2H and Delta18O) in Municipal Tap Water as Measured by TCEA-IRMS

Abstract

An understanding of fine resolution variability in water stable isotope ratios is needed to ascertain the utility of water stable isotope ratios for observational purposes and sensor applications. While others have demonstrated that intra-annual ranges of tap water isotope ratios are relatively small (~10% difference) and large geographic distances yield large variation in tap water isotope ratios (Bowen et al. 2007; Kennedy et al. 2011) further assessment of short term variability and fine geographic resolution is required. Here we present a laboratory assessment of the spatial and temporal variability in water stable isotope ratios (Delta2H and Delta18O) Samples were collected from 12 locations within a single office building over the course of three months to determine patterns in daily, long-term and spatial variation. Samples were analyzed by quantitative high temperature conversion elemental analysis (TC/EA), chromatographic separation and stable isotope ratio analysis. The study revealed minimal daily variation and covariance in (Delta2H and Delta18O) Covariance in (Delta2H and Delta18O) has been demonstrated by others (Bowen et al. 2007). Evidence of seasonal variation was observed and was expected based on previous reports (Kennedy et al. 2011). Specifically, both (Delta2H and Delta18O) demonstrated an observable shift towards isotopic enrichment as the sampling period transitioned from spring to summer. This investigation reveals that with consideration of predictable seasonal patterns in 2H and 18O these analyses, and relative to global geospatial variations (Povinec et al., 2011), the methods used here provide a robust indicator of water sources.

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Document Details

Document Type
Technical Report
Publication Date
Apr 19, 2012
Accession Number
ADA560516

Entities

People

  • Leila J. Hamdam
  • Rebecca E. Plummer
  • Richard B. Coffin

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Chemical Kinetics
  • Chemistry
  • Covariance
  • Digestive System Processes
  • Drinking Water
  • Geospatial Intelligence
  • High Temperature
  • Isotopes
  • Mass Spectrometers
  • Military Research
  • Office Buildings
  • Planetary Sciences
  • Potomac River
  • Rivers
  • Seasonal Variations
  • United States
  • Water

Fields of Study

  • Environmental science

Readers

  • Coastal Oceanography
  • Environmental Engineering
  • Space/Atmospheric Physics.