A rusting drum possibly containing agricultural poison has been found buried in a New Plymouth park, although Taranaki Regional Council says the site was clear in tests seven years ago.
District council workers digging wastewater pipe trenches on Friday uncovered the drum and the corroded remains of another in Marfell Park.
A decade ago, the former landfill was suggested as a possible dumpsite for the then-Ivon Watkins Dow chemical factory.
IWD made herbicides contaminated with dioxin, but the regional council's resource management director Fred McLay says no contaminants were found during tests in 2001 and 2002.
Mr McLay says vigilance is needed and the drums - along with 80 cubic metres of soil also smelling of chemicals - have been removed.
He says work continues nearby but the landfill site will be left until test results come back next week.