An investigation is under way after oil and other pollutants flowed into a rare chalk stream for several days. The Environment Agency is attempting to identify the source of the issue and is currently analysing samples taken from the Gaywood River in the Bawsey area in West Norfolk. Residents have said the problem continued throughout last week, and an absorbent boom has been placed downstream to contain the flow of the pollution. A spokesman for Gaywood River Revival, a group campaigning to protect the waterway, said: “This could have serious repercussions to the river’s ecosystem. “The pollu…