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David Hess

Publications and source records attributed to David Hess.

2 recordsLinked to original sources

Measuring urban water conservation policies: Toward a comprehensive index

This article (1) discusses existing efforts to measure water conservation policies (WCPs) in the United States (U.S.); (2) suggests general methodological guidelines for creating robust water conservation indices (WCIs); (3) presents a comprehensive template for coding WCPs; (4) introduces a summary index, the Vanderbilt Water Conservation Index (VWCI), which is derived from 79 WCP observations for 197 cities for the year 2015; and (5) compares the VWCI to WCP data extracted from the 2010 American Water Works Association (AWWA) Water and Wastewater Rates survey. Existing approaches to measuring urban WCPs in U.S. cities are limited because they consider only a portion of WCPs or they are restricted geographically. The VWCI consists of a more comprehensive set of 79 observations classified as residential, commercial/industrial, billing structure, drought plan, or general. Our comparison of the VWCI and AWWA survey responses indicate reasonable agreement ( ρ = 0.76) between the two WCIs for 98 cities where the data overlap. The correlation suggests the AWWA survey responses can provide fairly robust longitudinal WCP information, but we argue the measurement of WCPs is still in its infancy, and our approach suggests strategies for improving existing methods.

Journal of the American Water Resources Associatio

Isotopic composition and distribution of lead, uranium, and thorium in a Precambrian granite

The isotopic compositions and concentrations of lead and uranium have been determined in some separated minerals and the composite of a granite from Monmouth township, Haliburton County, Ontario. The chemical and mass spectrometric methods that were used are described. The age of the zircon from the granite is 1050 million years. Much of the lead, uranium, and thorium exists in chemically unstable and presumably interstitial phases of the granite. A comparison of the observed amounts of uranium, thorium, and lead in the various minerals with those amounts that should have been present, had these three elements existed within the minerals as closed systems, shows a non-balance of these elements in every case. It appears that the granite as a whole has closely approximated a closed system since it was formed with respect to uranium and its decay products, but has been an open system with respect to thorium and its decay products. Interpretations concerning the relationship of these data to lead ores are discussed.

GSA Bulletin