Document Type

Thesis - University Access Only

Award Date

2006

Degree Name

Master of Science (MS)

Department / School

Civil and Environmental Engineering

Abstract

The Stage 2 Disinfectants/Disinfection Byproduct Rule (D/DBP) Rule was published January 4, 2006 to further protect public health. It applies to all public water systems that use a chemical disinfectant or deliver chemically disinfected water. Following the Stage 1 D/DBP Rule, the Stage 2 D/DBP Rule further regulates the exposure to Disinfection Byproducts (DBPs), specifically total trihalomethanes (TTHM) and five haloacetic acids (HAAS) by changing the DBP compliance for water distribution systems from system-wide running annual averages (RAA) to locational running annual averages (LRAA) and requiring water distribution systems to complete an initial distribution system evaluation (IDSE). This research was aimed at providing municipal water distribution systems in South Dakota and the Great Plains region with guidance in determining locations of DBP peaks in their water distribution systems as municipalities begin the Stage 2 D/DBP IDSE. Although there are many factors that influence D/DBP behavior, the focus of this thesis was to identify the main factors that contribute to DBP variability and/or the factors that could be more easily used to assess locations where peak DBP concentrations may exist. By identifying these factors and forming correlations between the characteristics of disinfectants, water age, temperature, and DBP production along with the other factors that could play a role in DBP formation, it was anticipated that a greater understanding of the behavior of disinfectants and disinfection byproducts in distribution systems in South Dakota and the upper Great Plains region could be attained. The objectives were accomplished by soliciting historical data from two South Dakota municipal distribution systems. The municipal systems that participated in this study were Sioux Falls, South Dakota and Watertown, South Dakota. They were chosen as they represented typical South Dakota systems that could be affected by the promulgation of the Stage 2 Disinfection/Disinfection Byproducts Rule (D/DBP Rule). Sioux Falls and Watertown represent municipal systems that utilize surface water, ground water, or a blend of surface water and ground water. Sioux Falls presently uses chloramine as a secondary disinfectant; however, the water system used free chlorine prior to 2001. Watertown utilizes free chlorine and has two water treatment plants. The systems volunteered historical data on parameters that include: disinfectant use (type, concentration), source water characteristics, disinfectant residual sampling data, TTHM/HAAS data, temperature data, flow data, and any additional information that was available. After extensive analysis of the historical data provided by Sioux Falls and Watertown, it was determined that the main factors influencing DBP formation in these systems included residual disinfectant type, seasonal variations and temperature, water age, and NOM variations. It will be important for water distribution systems to analyze these factors in order to accurately develop their IDSE.

Library of Congress Subject Headings

Water -- Purification -- Disinfection -- South Dakota

Water -- Purification -- Disinfection -- South Dakota -- By-products

Water quality management -- South Dakota

Format

application/pdf

Number of Pages

215

Publisher

South Dakota State University

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