Award Date

5-15-2026

Degree Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Civil and Environmental Engineering and Construction

First Committee Member

Erica Marti

Second Committee Member

Ariel Atkinson

Third Committee Member

Jacimaria Batista

Fourth Committee Member

Zhange Feng

Number of Pages

200

Abstract

The American Water Works Association (AWWA) revised their Underground Service Lines and Fittings standard (C800-21) stating that brass fittings should contain ≤16% zinc. The Las Vegas Valley Water District (LVVWD) currently uses corrosion-resistant alloy C89833 (2–6% zinc) in the distribution network. This alloy will soon be obsolete due to a shift in manufacturing to EcoBrass alloy C87850 (17–20% zinc). The aim of this research is to compare the dezincification of the two alloys when exposed to LVVWD finished water under varying flow/stagnation scenarios during a 9–12-month period. The corrosion pilot consists of six trains fed by finished drinking water. Two trains operated under continuous flow (2.5 gpm) and the other four trains were operated with varying ratios of flow and stagnation to simulate average household use, extended stagnation (e.g., due to seasonal use/vacations), and stagnation requirements for Lead and Copper Rule (LCR) compliance sampling. Influent and effluent water samples were analyzed for zinc, copper, free and total chlorine, dissolved oxygen. Between alloys, for both aqueous zinc and copper concentrations, there was no significant difference during nearly all conditions tested; the only exception was for zinc concentrations during the 7-day stagnation period for the first 1.6 simulated years; however, all values remained below the maximum contaminant level (MCL) of 5 mg/L. 7-day stagnation showed copper leaching above the MCL of 1.3 mg/L, which violates the Lead and Copper Rule. There was no downward trend in aqueous copper concentrations, as there was with the zinc concentrations during this condition. Microbial growth of organisms occurred on the fittings, which can be associated with corrosion such as dezincification. The elemental composition of the fittings before and after pilot testing did change significantly. Future testing will involve pit depth analysis of cut fittings to give information on the extent of dezincification (or other corrosion experienced), soil batch testing to determine if moisture and extreme corrosivity affect outer corrosion, tensile strength testing to inform how the flow and stagnation conditions affected the strength of the fittings, and water batch testing to determine if smaller-scale testing can predict or inform initial pilot corrosion results. The data from this project will provide insight into the propensity of brass alloy C89833 (2–6% Zn) vs C87850 (17–20% Zn) for dezincification with LVVWD finished water. Results will inform acceptance and use of the higher zinc alloy within the LVVWD distribution network.

Keywords

Dezincification; Drinking water distribution network; flow and stagnation; underground brass alloy water fittings

Disciplines

Environmental Engineering | Urban, Community and Regional Planning | Urban Studies | Urban Studies and Planning

File Format

PDF

File Size

4500 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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Available for download on Tuesday, May 15, 2029


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