Masters Theses

Abstract

“Early-era polyvinyl chloride (PVC) pipe made prior to 1977 was often manufactured using excess vinyl chloride monomer. When used in potable water distribution systems, this excess vinyl chloride monomer can leach from the PVC pipe into the water and cause vinyl chloride concentrations to exceed the maximum contaminant level (2 μg/L). Fortunately, vinyl chloride concentrations can be controlled through a properly designed flushing protocol specific to each distribution system. This research examined the leaching rates of vinyl chloride from early-era PVC pipe in eight water districts in Missouri, some of which were known to regularly exceed permissible levels. A Fickian diffusion model modeled the leaching rates and resulted in vinyl chloride concentrations as a function of time, temperature, water usage rates, pipe schedule (diameter and wall thickness), and pipe age. This work resulted in a useful series of graphs to allow an operator to determine the appropriate flush volume and frequency to control the vinyl chloride concentration to any desired level within their system. The results show considerable variability in the amount of vinyl chloride monomer present in early-era PVC pipe and not all early-era PVC pipe are subject to vinyl chloride leaching. Futhermore, only dead-end lines are subject to vinyl chloride excedences because of the regular flushing that occurs in non-dead-end lines. Finally, vinyl chloride contamination via leaching from PVC pipe is shown to be a limited (though serious) problem that can be addressed through either a properly designed and implemented flush program, or through pipe replacement”—Abstract, page iv.

Advisor(s)

Adams, C. D. (Craig D.)

Committee Member(s)

Fitch, Mark W.
Ybarra, Robert M.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Environmental Engineering

Comments

The authors thank the Missouri Department of Natural Resources (MDNR) for sponsoring this research.

Publisher

University of Missouri--Rolla

Publication Date

Fall 2000

Pagination

xiii, 74 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2000 Michael Kenneth Beardsley, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Thesis Number

T 7841

Print OCLC #

45902239

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