Filtering socks: If the source of the pollution is known, the filter sock can be placed at or around the point source. If the point ... The second level of a treatment train would be drain filters.

Oilfield filter socks, used to filter wastewater at drilling sites, have turned up in some odd corners of North Dakota, including a roadside, an Indian Reservation, a city garbage can, and tucked ...

Kwinana Mayor Carol Adams said more than 25 million people had since interacted with a single picture of the drain sock in action that the council posted on social media.

RP Services, based in Riverton, Wyo., is under investigation for improper storage, handling and transportation of the filter socks.

He said drain sock was developed in the early 1990s by a fisherman based in New South Wales before it was acquired by the company. "Why all the interest now?