Factors driving freshwater salinization syndrome (FSS) influence the severity of impacts and chances for recovery. We hypothesize that spread of FSS across ecosystems is a function of interactions among five state factors: human activities, geology, flowpaths, climate, and time. (1) Human activities drive pulsed or chronic inputs of salt ions and mobilization of chemical contaminants. (2) Geology drives rates of erosion, weathering, ion exchange, and acidification-alkalinization. (3) Flowpaths drive salinization and contaminant mobilization along hydrologic cycles. (4) Climate drives rising water temperatures, salt stress, and evaporative concentration of ions and saltwater intrusion. (5) Time influences consequences, thresholds, and potentials for ecosystem recovery. We hypothesize that state factors advance FSS in distinct stages, which eventually contribute to failures in systems-level functions (supporting drinking water, crops, biodiversity, infrastructure, etc.). We present future research directions for protecting freshwaters at risk based on five state factors and stages from diagnosis to prognosis to cure.

The Colorado Department of Public Health and Environment developed a standardized protocol for corrosion testing procedures that is available as a resource for utilities. Immersion testing can be used to evaluate corrosion mechanisms, determine optimal corrosion control treatment, and examine the impacts of source water or treatment changes, while greatly reducing the cost and complexity compared with pipe loop testing. Exploring various resources, such as academic research, first-hand utility experience, and water industry guidelines, can help a utility select the corrosion testing approach that best suits its needs and circumstances.

A redesign, construction, and replacement of the filters used for water reuse at a 11 million gallon per day Florida municipal water reclamation facility provided a prime opportunity to evaluate the impact of the filtration technologies on water quality, trace organic contaminant (TOrC) removal, and removal of pathogens. This study was designed to capture operational data, pathogen removal (Cryptosporidium and Giardia), and TOrC removal before the replacement of the filters using the existing synthetic media filters (SMF) and traveling bridge filters (TBF) followed by an evaluation of the deep bed filters (DBF) after construction and commissioning. The new DBF units provided substantially improved control of turbidity and total suspended solids while also significantly improving the removal of Giardia cysts (increase of >2 log removal) as compared to removal across the older SMF and TBF units and minor improvements to Cryptosporidium oocyst removal. TOrC removal was not significantly changed when comparing removal across the SMF, TBF, and DBF units nor post chlorination (chloramination).

Key TakeawaysRecovering from nitrification can be difficult for a chloraminated drinking water system, so prevention, early detection, and swift mitigation are key.The City of Corpus Christi (Tex.) changed its complex yet flexible nitrification action plan to make it more stringent and action‐oriented.Using a mobile application in the field has enabled a near‐immediate response to water quality issues, including rechecking samples, flushing the sample station, or flushing nearby hydrants.

Key Takeaways A 2019 US corrosion control survey benchmarks recent utility perspectives before the release of the proposed LCR revisions, providing insight on regulatory impacts. Rates of orthophosphate use continue to increase, and the results add to evidence that orthophosphate is effective for controlling lead release. The primary challenge facing utilities is coordinating compliance sample collection, and the greatest priority is ensuring optimal corrosion control treatment.

Disinfection byproduct (DBP) precursors originate in large reservoirs from at least three types of sources: (1) watershed or allochthonous, (2) algal or autochthonous, and (3) bottom sediments or benthic. The properties of the bulk natural organic matter (NOM) and the DBP precursor content of that NOM are unique to each source. Knowledge about the relative importance of these three sources would be valuable in understanding the natural variability in DBP precursor occurrence and in managing source waters for the purpose of minimizing DBP precursors. In this study, we used temporal and spatial water quality data from a drinking water reservoir to shed light on autochthonous and benthic sources of NOM and DBP precursors. The Cannonsville Reservoir (New York) was chosen for this work because of its well‐documented water quality. To assist in the data analysis, we developed a series of two‐dimensional contour plots that bring clarity to benthic and near‐surface (algal) processes on water quality. Combining conventional water quality parameters with DBP precursor analysis can facilitate a more comprehensive understanding of limnological factors that define DBP precursor levels. These data were compared with known properties of NOM and related natural biochemical parameters. From this analysis, we conclude that algal‐dominated NOM contributes disproportionately to dihaloacetonitrile formation, whereas watershed‐dominated NOM is especially rich in trihaloacetic acid and trihalomethane precursors as well as ultraviolet‐absorbing substances. The sediment‐dominated precursor behaved like a mix of the other two but most resembled the watershed NOM.

Utilities can recover from wildfires and extreme weather events with resiliency plans and operation designs that address subsequent water quality challenges.

Direct potable reuse (DPR) increases water supplies, but possible DPR‐blending scenarios and water quality must be evaluated at blending locations.

New York City's unfiltered Catskill System of reservoirs provides high‐quality water to help meet demands for more than 9 million people. Following extreme storms, however, these reservoirs periodically experience high levels of turbidity that may require alum addition before the water enters the city's distribution system. A study was conducted to evaluate measures to control turbidity and reduce the need for alum treatment. The study involved development and application of a linked water supply–water quality modeling platform to simulate performance of structural and nonstructural turbidity control alternatives under realistic operations and over a broad array of hydrologic conditions. Results indicated that modest improvements to the existing infrastructure and modified system operations could control turbidity and reduce the need for costly capital improvements. This study provides a useful framework for other utilities to follow in developing analytical tools to help them meet both current and future water supply challenges.

Natural organic matter (NOM) is present in all raw water supplies and is the major precursor to chlorinated disinfection by-products (DBPs). Given water quality considerations and budget realities, reduction in the amount of NOM entering treatment plants and a better understanding of NOM character are essential for optimizing treatment. A study of the unfiltered New York City (NYC) water supply system evaluated the extent to which alternative raw water selection strategies could reduce finished water DBP concentrations. A two-year monitoring program was conducted to establish spatial and temporal patterns of DBP precursors in NYC's upstate reservoirs. An operations model was driven with long-term time series of reservoir dissolved organic carbon concentrations to evaluate alternative operating rules to minimize precursor transport to terminal reservoirs. Results indicated that DBP precursors varied among reservoirs and over time but that modified reservoir operations could be effective at substantially reducing finished water DBP concentrations.

Treatment options for meeting LT2ESWTR's more stringent turbidity limits range from expensive to less costly. Optimizing filter performance offers an economical solution.

in telephone conversations that this report be submitted to them on an annual basis. The Annual Document Log section of this report meets the requirements of 40 CFR 761.180(a)(2), as applicable, while the Annual Records section meets the requirement of 40 CFR 761.180(a)(1).

submit an inventory of radioactive-contaminated PCB waste in storage at the Idaho National Laboratory (INL) for the previous calendar year. The annual inventory is separated into two parts, INL without Advanced Mixed Waste Treatment Project (AMWTP) (this includes Battelle Energy Alliance, LLC, CH2M-WG Idaho, LLC, and the Naval Reactors Facility), and AMWTP.

This article, part of a series developed by the Coagulation and Filtration Committee, discusses backwashing basics for optimum filter operation. Topics covered include: three parameters for determining when to backwash a filter; backwash flow rate; filter media selection; temperature factor; granular activated carbon; air scour; and, surface wash.