Sludge & Sediment Sampling

ERE carries the samplers used to collect bottom sediment, sludge and settled solids for environmental assessments and wastewater operations. Grab samplers take the surface layer of the bottom: the all-stainless Ekman dredge for soft sediment in calm water, the 15 and 25 lb bottom dredges and the sand/silt dredge for coarser material, and the pole-mounted Snapper. Core samplers keep the layers: the AMS sludge sampler with valved tips, the multi-stage sludge/sediment kit that works through up to 12 ft of water, and the sand/sludge/sediment probe. For tanks, clarifiers and sewers, the Sludge Nabber and Swing Sampler sample from a pole, and the Sludge Judge® measures the sludge blanket.

Sludge and sediment sampling FAQ

Grab sampler or core sampler for sediment?

A grab sampler, such as a dredge or the Snapper, collects the surface layer of the bottom in one drop, which suits surveys of surface sediment quality. A core sampler collects a column, so you can see and sample the layers at depth. Our grab sampler guide covers the options.

Ekman dredge or bottom dredge?

The Ekman dredge is built for soft mud, silt and organic ooze in calm lakes, ponds and lagoons; its jaws close when a messenger weight is sent down the line. On sand or compacted silt, choose the 15 or 25 lb bottom dredge or the sand/silt dredge; in flowing water, the Snapper or a pole sampler. See Ekman dredge vs Snapper vs Swing Sampler.

How do I measure the sludge blanket in a tank or lagoon?

Use a Sludge Judge®: lower the clear, graduated tube slowly so the valve seats, pull it up and read the depth of settled solids against the 1 ft markings. The Sludge Judge II and Sludge Judge Ultra assemble from three 5 ft sections to 15 ft and are made for settleable solids of 5% or less. Take readings at several points, since a blanket is rarely level; see our Sludge Judge protocol.

How do I sample sludge from a tank, clarifier or sewer?

Use a pole sampler from the edge. The Sludge Nabber holds a 250 to 1,000 mL bottle on an aluminum pole that extends from 4 to 6.5 ft, and the Swing Sampler pivots up to 90° on a 6 to 12 ft fiberglass pole to sample horizontal flows in sewers and channels. For a core of settled sludge, the AMS sludge samplers have valved tips that keep non-cohesive sludge in the tube.

Can I sample sediment under water?

Yes. Dredges are lowered on a line: the Ekman dredge ships with 100 ft of nylon rope and a messenger. For cores below water, the multi-stage sludge/sediment sampler kit assembles to 12 to 48 in. sample lengths and reaches through up to 12 ft of water with its 4 ft extensions.