There are also defunct gold and silver mines within the same Puhipuhi location, and a discarded roading metal quarry. The quarry was abandoned when it was discovered roading metal from it contained mercury which was found later to poison the waterways beside the roads where it was used.
Recent NRC water and sediment testing at the location was found to have surface water within this catchment above Anzecc (Australian and New Zealand water quality guidelines) trigger limits for chromium, copper and zinc.
The survey indicated sediments within the Puhipuhi catchment contain mercury above the Anzecc levels, with the site below the mine dam having the highest levels. However, the community groups are concerned the council merely received the report, with no further action planned.
Ms Kirk said the mining remnants have never been properly assessed for dangerous after-effects; nor does the group think the mine tailings have been monitored for leakage, stability, contamination or potential collapse. The NRC was approached for comment, and said it would investigate the group's concerns.