Water and wastewater sampling is discussed within the context of a water quality monitoring program. The general characteristics of the source flows are described, and the mechanics of polydisperse systems as they affect sample gathering are discussed. It is pointed out that the collection of a sample that is representative of the source in all respects is a frequently underrated task, especially insofar as suspended solids are concerned. The various types of samples are defined, compared, and their use indicated. Other practical considerations addressed include frequency of sampling, site selection, and sample quantity, preservation, and handling. Recommendations on when to use manual versus automatic sampling are given. Each of the elements of an automatic sampler is discussed from the viewpoint of design considerations in order to help the reader assess the ability of a particular unit to meet his needs. Commercially available samplers and some custom designed equipment are reviewed. Recommended field procedures for sampling are given, and a review of automatic sampler performance is provided. An appendix provides, in a common format, 102 descriptions covering over 250 models of commercially available automatic samplers and 16 descriptions of custom built devices.

EPA-600/4-77-039. NTIS PB-272 664.