Arsenic levels far exceeding national safety levels have been found in the soil underneath a suburb in Thames on the Coromandel Peninsula.

Moanataiari, which is built on land reclaimed using mining tailings, has been found to have arsenic levels 235 times over the National Soil Contaminant Standard in preliminary tests undertaken in the past month.

Thames Coromandel District Mayor Glenn Leach has called a public meeting in Thames tonight, with district council, Waikato Regional Council and Waikato District Health Board experts present to advise concerned residents.

Twenty-eight soil samples across the suburb were tested for antimony, arsenic, cadmium, and chromium.


The National Soil Contaminant Standard for arsenic - 20 mg/kg for residential soils - was exceeded in all locations tested, apart from the Moanataiari School playing field, with the level ranging from "marginal" to "substantial".

The top surface sample was 350 mg/kg, while at a depth of 1 metre the two highest readings were 1020 mg/kg and 4700 mg/kg.

The arsenic is believed to have come from the mining tailings dumped at the site in the mid 20th Century, although is not an introduced chemical in the mining process but rather a naturally occurring trace element often found in higher concentrations around elements such as gold.

Petroleum hydrocarbons were also found at one site, however not at concerning levels.

"Our primary concern right now is the health and well-being of our community and I urge everyone to read the advice issued by the Ministry of Health; we are confident that if people follow the health advice, they can remain safe while we get on with the next steps," Mr Leach said.

"I also want to reassure our Moanataiari community that they have the full commitment of this council and the other agencies involved to sort this out; however in the short term it will take time to work through the issues and more patience will be required."

The councils are to apply for funding from the Ministry for the Environment to conduct further soil tests on private land to ascertain the full scope of contamination.

The council has recommended people refrain from digging on their properties and advised residents to avoid coming into contact with soil and dust in the suburb.


However last month when the testing operation began, both the regional and district councils said it was highly unlikely anything posing a threat to human health would be discovered, the Hauraki Herald reported on October 21.

Moanataiari School principal David Brock yesterday told he would not be talking to the media until he had discussed the matter with staff and board of trustees.
Council contractors yesterday began remediation work at the school yesterday, removing a large pile of top soil from the grounds.

"We are also working with the pre-school on the primary school grounds and the Early Learning Centre to get some measures in place very quickly to ensure parents can have confidence in these vital community assets," Mr Leach said.

"These schools are the heartbeat of the Moanataiari community and we are outworking plans rights now with them to ensure they can operate business as usual, while we undertake further testing as soon as possible."

The Ministry of Health advises Moanataiari residents to:
- Take care with personal hygiene (i.e. hand washing after handling soil);
- Make sure children don't eat or play in soil;
- Remove footwear before going indoors to avoid carrying soil dust indoors - particularly for households with very young children;
- Cover soil (e.g. grassing, paving, gravel) to reduce dust and direct access by young children;
- Not to eat home grown fruit and vegetables, especially young children, until further quantification of the contamination is available and the risk can be assessed, unless it is known that the garden soil is clean fill. If you choose to eat home grown fruit and vegetables, then thoroughly wash produce that may be contaminated with soil, and peel the skin off root vegetables;
- Don't be concerned about the drinking water supply, it is separate (and safe);
- As always, if unwell for any reason, see your doctor.