sludge

Campaigners have previously complained that dredged sediment fills nearby rock pools with a "black, thick, slimy, petrochemically smelling sludge", which is toxic to people and the environment.

The scale of 374Water's current technology is small: it can handle just a fraction of the tonnes of wet sludge the facility produces daily.

Rescue operations are progressing at a slow pace as there is a large amount of sludge and debris covering the area.

These are chemicals used in construction to bind soil and prevent erosion, but if they escape into the water system, they can create sludge.

County Sanitation Districts operate the Tulare Lake Compost facility, which processes sewage sludge and agricultural waste to produce high-grade compost.