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THE USEFULNESS OF SCALE ANALYSIS: EXAMPLES FROM EASTERN MASSACHUSETTS
Citation:
Schock*, M R., T. Tran, AND M. Taylor. THE USEFULNESS OF SCALE ANALYSIS: EXAMPLES FROM EASTERN MASSACHUSETTS. Presented at New England Water Works Assoc. Spring Conference & Exhibition, Worcester, MA, 03/30-04/2/2004.
Description:
Many water system managers and operators are curious about the value of analyzing the scales of drinking water pipes. Approximately 20 sections of lead service lines were removed in 2002 from various locations throughout the greater Boston distribution system, and were sent to USEPA for analysis. This represents the largest known collection of lead service line specimens collected from a single water distribution network, and therefore presents a rare opportunity to look for spatial differences in scale characteristics that represents both water quality history and a basis to determine the impact of current treatment practice when coupled with tap and system water monitoring program results. Several additional lead service line specimens were obtained from other communities, some of whom were having lead control treatment problems. All samples were analyzed for crystalline compounds by X-ray diffraction and 40 elements by multi-acid digestion with ICP/MS. Depending on the volume of scale available, additional analyses were conducted for such parameters as total and inorganic carbon, water, hydroxide, silicon and sulfur.
This presentation will give an overview of what kinds of scale analysis techniques would be generally available to water systems and their consultants, and what the relative merits and costs would be in terms of the types of practical information gained from each approach. Examples of useful information that can aid in diagnosing treatment problems, interpreting and optimizing corrosion control, understanding system history, and anticipating both positive and negative impacts of other kinds of treatment changes (such as blending, ion exchange, DBP control, etc.) will be given using the data collected in this study.