Specific problems encountered during water treatment are known to be a function of the type of macromolecules present. The pyrolysis–GC–MS analytical technique described in this article shows the inadequacy of existing models to accurately reflect the complex mixture that comprises the organic matrix of natural waters. In fact, the highly condensed aromatic cores described by most of these models were determined by the research reported here to be minor constituents.

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The advantages of organic polymers, or polyelectrolytes, in water treatment are many. But what is the fate of a polymer subjected to typical treatment processes? What by‐products are formed by ozonation and chlorination? Are there manufacturing impurities accompanying the polymers? What are the toxic and mutagenic effects of these impurities and by‐products? An anionic organic polymer commonly used in France was analyzed by several methods. It was found to be generally acceptable for drinking water standards in the United States and France. But the by‐products and impurities that were detected require more research to determine their potential health effects and demonstrate the need for adequate quality controls during manufacture of the polymer.

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As part of a project on the use of ultrafiltration (UF) for particle removal, studies were performed to evaluate the use of low‐pressure hollow‐fiber UF as an alternative for complying with Surface Water Treatment Rule (SWTR) requirements for microbial removal and/or inactivation. Pilot studies were conducted on four different untreated source waters, two from northern California and two from Boise, Idaho. Process efficacy was assessed by conducting MS2 virus, total coliform bacteria, and Giardia muris seeding studies, as well as monitoring for naturally occurring bacteria. The study showed that UF was capable of meeting SWTR requirements for alternative filtration technologies without the use of chemical disinfection. Four or more logs of Giardia and more than 6.5 logs of virus were removed from each of the untreated source waters. Differences in water quality or changes in operating parameters did not appear to affect removal capabilities of the process. Maintenance of membrane integrity was critical to assuring process efficacy. When module integrity was compromised, as in fiber breakage, both MS2 virus and G. muris were detected in the permeate. Changes in membrane integrity were not necessarily reflected by changes in permeate turbidity; however, particle counting was an effective method for detecting a compromised membrane module.