4.1 This practice is intended for use in the sampling of surface waters and other liquids.

4.2 Dipper equipment is uncomplicated in construction, simple to use, and relatively easy to decontaminate; however, this practice will not provide accurate results with multiphase liquids.

4.3 This practice is to be used by personnel acquiring samples.

4.4 The dipper is best used to take a surface sample of liquid. No attempt should be made to take subsurface samples with a dipper because mixing and dilution will occur as the dipper is brought to the surface. Subsurface layers must be sampled using a device that can be closed prior to bringing it to the surface (for example, a COLIWASA, tube sampler, or bottle sampler).

4.5 The dipper is not appropriate for sampling multiphase liquids if quantitative characterization is needed.

4.6 When volatile organic analysis (VOA) will be performed, samples obtained with a dipper should be poured into an appropriate container (VOA vial) with minimal air contact and agitation.

4.7 This practice should be used in conjunction with Guide D4687, which covers sampling plans, safety, quality assurance (QA), preservation, decontamination, labeling, and chain-of-custody procedures; also Practice D5088, which covers decontamination of field equipment used at waste sites. Other documents pertinent to this practice are EPA-600/2-80-018 and EPA-600/4-84-076.