Run-off contamination mitigation measures seemed to have worked at the Plan B highway realignment project during Friday's heavy rain, P.E.I. transportation officials say.

Crews were working hard to ensure there would be minimal run-off into the West River near the Bonshaw construction site.

"I mean, we still had some discoloured water at some of the structures, but again, with all the hydro-seeding and rock dams and other areas that we had mitigation measures in, we were quite pleased," said Steve Yeo, the province's chief engineer.

Crews continue to work on environmental controls at the project, said Yeo.