Moanataiari Subdivision and project history

History

1800s - The reclamation formed progressively over 100 years through the use of mine tailings, rocks and dredging from the port.

1960s  - There was reportedly a clean cap of clay and weathered rock on top of the reclamation from the hills surrounding the site. This capping was completed "under controlled conditions in the mid to late 1960s.

1970s -   Although reclamation began much earlier, most was undertaken in the 1950s and 1960s, the work was completed by the late 1960s to the early 1970s. Homes were progressively built on the reclaimed land from the 1960s, with the largest developments occurring from the early 1970s after the reclamation had been completed.

More recent developments

2006  - While undertaking research into potential contamination of sediments in the Firth of Thames near  Moanataiari, a Waikato Regional Council scientist became aware of a 2001 Ministry for the Environment report on Coastal Protection that identified that the Moanataiari reclamation contained   mine tailings. The scientist considered a potential source of sediment contamination may be the soils within the subdivision.

2007 - Limited testing of soil at the Moanataiari school showed no contamination issues. The regional council's assessment was that, due to the clean cap of fill reportedly used in the development of the  subdivision, the presence of healthy plants and the 2007 test result from the school playing field, it was unlikely contaminants in the tailings posed an immediate health risk to residents. However, the area was identified among a handful of high priority sites for further investigation as regional council resources permitted. Subsequently, some limited information about Moanataiari has been on the regional council's website since 2007. Further testing was planned at Moanataiari. The regional council investigates one high priority site a year. Since 2007 other high priority sites investigated have been the Tui Mine, Rotowaro carbonisation plant and the Cambridge gasworks.

2009 - Moanataiari included as "unverified potential contaminated site" on the regional council's publically available Selected Land Use Register.

2010 - In April, the Thames-Coromandel District Council (TCDC) was advised of Moanataiari being on the regional council's register. From May, regular monthly updates on properties on the register are sent to local councils. A new study for the regional council confirmed Moanataiari was reclaimed using mine tailings. TCDC provided some information for this study into the history of the subdivision.

2011 - In January 2011, the Ministry for the Environment (MfE) commissioned consultants to develop a contaminated sites prioritisation tool. MfE then asked all regional councils to provide them with their priority contaminated/potentially contaminated sites to develop a National Priority List of contaminated sites. The purpose of this list is to inform the allocation of the Contaminated Sites Remediation Fund. As a result of Waikato Regional Council's sediment investigation, the subdivision was considered a priority site and provided to MfE as a site that required future investigations.

In March, Moanataiari's status on the register was updated to "verified potential contaminated site- not sampled". This change was communicated to TCDC and the Land Information Memoranda (LIMs) were updated shortly after to reflect the new status of the subdivision on the register.

In April, TCDC was notified by the regional council about the MfE's National Priority List of contaminated sites and the need to investigate Moanataiari.

In October, soil testing was carried out at sites at Moanataiari. These latest results have shown that  relative to other parts of Moanataiari, surface soils of the primary school playing field are unusually clean. In its history, the school playing field was built up a further metre above other areas, and this additional capping layer appears to have made the difference on the playing field.