The Scienceware® Churn Sample Splitter provides a convenient and efficient method for preparing subsamples of collected water-sediment mixtures from stream flows for water quality analysis. Water sediment samples are customarily collected in 473mL (1 pint) or 946mL (1 quart) bottles using suspended sediment samplers. The samples are composited into one representative cross section sample of the stream flow and divided into the required four to sixteen representative subsamples using the Churn Sample Splitter. The rugged polyethylene sample splitter is molded with thick walls to survive hard use in the field and fitted with a swing handle suitable for carrying a filled vessel. A specially designed hole pattern in the churn maximizes mixing and a locating notch maintains churn orientation for assured repeatable results. The easy to clean spigot has a built-in lever stop at the full open position to accurately drain subsamples into bottles for delivery to the water quality laboratory. Lid, spigot and churn are replaceable.