Hawke's Bay Regional Council has released a list of about 1500 potentially contaminated sites, some in residential areas.
Councils around the country are releasing similar lists following the ruling by Ombudsman David McGee that such information should be made widely available to the public.
Hawke's Bay Regional Council chair Alan Dick says most of the sites should not be of any real concern.
However a residential area with about 100 homes built over a former landfill site near Onikawa Park in Napier will be investigated further, he says.
Sample drilling will be carried out to make sure the cap over the 1930s landfill site is adequate.