Abstract: The invention relates to an apparatus for water sampling. The invention relates to such a water sampling apparatus that permits intake of so-called composite samples as well as individual samples from different depths of water. The apparatus comprises a sampler (2) driven by an electric motor (3) and placed into connection with a buoyant container (10). The sampler is preferably a centrifugal pump (2) placed into connection with the container (10). The suction side of the pump (2) communicates with the sampling point and the pressure side communicates with a sample receiver. The sampler (2) is arranged to operate under control of a control unit (8) for taking samples of specific volume at specific intervals. The control unit (8) is placed inside said container (10). The electric motor (3) is powered by an accumulator (7) placed preferably inside the container (10).

Abstract: A wastewater tank intended for use in a small sewage treatment plant. A spiral pipe is coiled around the exterior casing of the tank and is structurally secured to that casing, so that the pipe imparts structural stiffness to the tank. For example, the casing and pipe may be of a thermoplastic material and are thermoplastically welded together so that the pipe is structurally attached to the casing. Wastewater passes in turn through the multiple treatment spaces in the tank, to undergo pre-sedimentation, flocculation, and clarification.