Phase 2 - Private property testing

Phase two of the project has now been completed. Residents have been sent their property reports from Friday 8 June 2012.

Latest news

8 June 2012: Property reports sent to residents and property owners.

29 April 2012: Early data is back from the western part of the subdivision and will be sent to residents tomorrow. The raw data shows mainly elevated levels of arsenic and a few other heavy metals. The health advice remains unchanged and the project plan continues as published.

22 March 2012: Early data is back from the eastern part of the subdivision and will be sent to residents next week. The raw data shows mainly elevated levels of arsenic and lead. The health advice remains unchanged and the project plan continues as published. Find out more.

Most of the literature on lead we have found is based on lead paint contamination (we think most of the lead in the soil at Moanataiari is from natural sources), however some of the information below may be useful to get an understanding about this element.

Ministry of Health information

Please remember the current health advice in place at Moanataiari will also ensure you are kept safe from other possible contaminants.


Summary of results

  • 206 residential properties and 1 ECC
  • 6 residential properties not included in the investigation
  • 544 investigation locations – hand augers
  • Approx 30 sample locations per ha
  • 1668 soil samples
  • All samples analysed with the XRF
  • 409 samples (25%) analysed at the lab


Phase two involved

  • Testing nominated private properties
  • Installing monitoring wells to understand ground water implications
  • Background soil samples from the hills behind the suburb to understand the natural background levels of arsenic
  • Developing individual management/mitigation plans


20 parts per million arsenic - assumptions explained

At a recent community forum, the residential standard for arsenic was discussed (20 parts per million).

Members of the forum requested a plain-English explanation regarding some of the underlying assumptions that were made to formulate the national environmental standard.

The standard assumes:

  • That all of the arsenic is absorbed by the body if the soil is eaten (100% bioavailability)
  • A person's weight at 70kgs
  • That 10% of produce (fruit and veggies) consumed are grown at home
  • A life expectancy of 75 yrs
  • A person spends 350 days a year at the site (residential exposure frequency)