No abstract

Droughts, which are difficult to predict, are a natural feature of the hydrology in most regions.Climate change, however, has the potential to increase the frequency and magnitude of future droughts. While the lack of water availability during droughts is widely publicized, there are equally severe water quality impacts that occur during and after droughts as well. Recent droughts have led to water quality implications for drinking water supplies including turbidity, taste and odor, pathogen concerns, and challenges in managing disinfection byproducts (DBPs). This paper presents the results from a series of case studies prepared for a Water Research Foundation study on the effects of extreme weather on drinking water quality in order to help utilities prepare for vulnerabilities under future climate change. A key finding from the case studies is that droughts can fundamentally alter nutrient cycling and biota within both watersheds and reservoirs that influence water quality for months or years after the event. A few of the critical management actions for responding to degraded water quality related to droughts include awareness of potential impacts, increased monitoring during and after the event, and capacity to quickly adjust treatment processes.

CyanoTOX is a spreadsheet tool developed to estimate the removal of extracellular cyanotoxins and help utilities address the complexities of the oxidation of cyanotoxins.

No abstract

Many water utilities have recently initiated or are considering initiating monitoring programs to establish baseline contaminant concentrations of endocrine‐disrupting compounds (EDCs) and pharmaceuticals/personal care products (PPCPs) in their water supply. Unfortunately, monitoring sites and sampling frequency have often been conducted without regard to end use of the data, loading dynamics, and environmental behavior of trace contaminants. This article provides an a posteriori analysis of more than eight years of monitoring data from Lake Mead, Nev., including more than 80 EDCs/PPCPs to ascertain what effects sample location, sample frequency, and analyte reporting limits have on interpretation of the baseline dataset. The results of this study indicate that, for the Lake Mead dataset, the same general conclusions regarding the mean, median, maximum, and minimum concentrations can be drawn from the complete monthly sample dataset as can be drawn from a two‐year snapshot and/or even quarterly or bimonthly data alone. This finding points to the possible reduction of sampling, campaign frequency, and duration for utilities, although this type of analysis needs to be conducted in other watersheds to determine portability of results.