Elevated concentrations of brominated disinfection by‐products (DBPs) have been reported recently by some drinking water utilities. Some of these occurrences have been correlated with upstream discharges of bromide‐containing wastes from coal‐fired power utilities, discharges of hydraulic fracturing wastewater, and other industrial sources. This article discusses this problem in terms of the chemistry of DBP formation when bromide is present, regulatory changes that have resulted in the increased use of bromide by industries, and the number of water utilities potentially affected by these discharges. The authors investigated this problem through a review of published and unpublished sources and through interviews with utility personnel and state regulators.

Three strategies are commonly used to optimize corrosion control: adjusting pH and alkalinity, developing Pb(iv) scale by maintaining free chlorine residuals throughout the distribution system, and applying orthophosphate‐based corrosion inhibitors at appropriate dosages and pH ranges.

Disinfection byproducts (DBPs) formed during potable water treatment can be affected by bromide (Br)containing discharges into receiving streams from coal-fired power plants as well as other sources that increase the bromide content of the source water. This research focused on two aspects related to bromide increases in receiving streams. First, a bromide river transport model was adapted to track bromide concentrations in the river following a point discharge. In this work, the point discharges modeled were coalfired power plants. The model tracked the bromide concentrations at river segments after the point of discharge daily and, therefore, at water intakes as a function of time. In this article, the application of the model is illustrated for two rivers: the Ohio River along the Indiana and Kentucky borders and the Dan River in Virginia and North Carolina. Second, models to predict DBP formation due to increased bromide in source waters were developed. The source waters used in the DBP models were obtained from 13 states across the United States. Good model fits were found for predicting trihalomethane as bromide varies, as well as for predicting the unregulated sum of four haloacetic acids (HAA4). A method was also developed to predict the sum of nine HAAs (HAA9) based on measured sum of five HAAs (HAA5; the currently regulated HAAs) and modeled HAA4. The DBP formation models developed using the specific criteria evaluated in this research would have applications beyond only bromide discharges from coal-fired power plants and would apply to any cause of a bromide increase in the source water.

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Particle counting can be a sensitive tool for monitoring filter performance and improving the quality of finished water. Minor changes (1–2 mg/L) in the primary coagulant dosage can significantly affect particle counts in filtered water. Jar tests were inconclusive in selecting a coagulant dosage for source water of low turbidity (<5 ntu). Measurements of turbidity in filtered water were also not definitively altered by small changes in coagulant dosage. On‐line particle counting was successfully used in a 0.5 × 106–m3/d (135‐mgd) conventional water treatment plant to distinguish the effects on water quality of small changes in coagulant dosage and filter flow. Measurable changes in particle counts in filtered water were detected when the aluminum sulfate dosage ranged from 5 to 10 mg/L at filter loading rates of 4–9.5 m/h (1.7–4.0 gpm/sq ft). Particle count percentile plots and statistics (10th, 50th, 90th, 95th, and 98th percentiles) were valuable indicators of the performance of both individual filters and the overall plant.