A water chemical model involving the complexation and solubility equilibria of calcium, magnesium, zinc, iron, manganese, silica, chloride, orthophosphate, and carbonate has been developed and applied to laboratory pipe‐loop‐coupon and field data on asbestos–cement pipe. Calculation of the saturation states of the relevant solids enables graphic guides to be prepared for the prediction of dosage levels for in‐situ pipe coating by zinc compounds as well as protection afforded by coatings formed by natural inhibitory constituents of the water.

Asbestos‐cement pipe has had a reputation for resisting attack by aggressive waters that cause corrosion of metal pipe materials. The results of this study suggest that asbestos–cement pipe behaves much like other piping materials, except PVC, that are commonly used for potable water distribution.

Increasingly, organics in water are receiving attention. According to the authors of this article, there has been no apparatus that combines the features of low cost, reliability, portability, and ease of use until now.Here is a first installment, detailing the apparatus and describing, gen erally, the ramifications of testing. In March, the JOURNAL will publish complete test procedures.*Because the concentration of CCE may vary, depending upon the method of collection and extraction, additional lower-case letters are pro posed to identify the method used to obtain the data.

Water quality analyses are very sensitive, and it is critical that the pH be measured as accurately as possible. This technique was developed after the authors observed that many water utility and research laboratory personnel follow poor techniques for determining pH.

Chlorine residual, an indication of adequate chlorination of a water supply, has a definite relationship with the bacteriological quality of the supply. This paper discusses how much, what kind of, and the proper surveillance of, chlorine residual.