About the former Tauhara Timber site
The former Tauhara Timber site (which is believed to have closed down in 1960s) was located over a large area of land at the corner of Tauhara and Spa roads, Taupō.
Waikato Regional Council became aware the site existed in this area, which is largely now used for commercial/industrial purposes. However, with the increased availability of historic aerial images, it become clear that the original footprint of the timber treatment area was actually larger than originally thought.
Some of the land previously occupied by the timber company is now used for 38 residential sections and a school. These properties were developed in the early 1970s which was prior to any legislation requiring land or soil testing of potentially contaminated sites prior to redevelopment.
Soil has been tested at the school and results show that samples meet the soil guideline level for recreational use. Soil has also been tested in the residential area and results distributed (see below for further details).
Mountview School soil test results
Tonkin and Taylor, on behalf of Waikato Regional Council, carried out preliminary sampling at the Mountview School in November 2016 as part of the investigation into the historic Tauhara Sawmill and Timber Treatment site.
- Permission to sample the school was provided to Waikato Regional Council by the Ministry of Education.
- Ten locations from across the school grounds were sampled which provides us with a good indication of soil quality on the school site.
- Some of the 10 locations were sampled at different soil depths with 16 samples taken altogether.
- The samples were tested for arsenic, copper, chromium, boron and pentachlorophenol (PCP). These were tested in response to the Preliminary Site Investigation which suggested these substances were used, or wood treated with them was stored on this part of the site.
- The results have been assessed against the National Environmental Standard for Contaminants in Soil which contains guideline contaminant levels that are designed to protect human health.
- All samples were found to be below the soil guideline level for recreational use which is the level that schools are primarily assessed against.
- Copper, chromium, boron and PCP were below the level for residential use for all samples (PCP was not detected).
- Two samples were found to be above the arsenic guideline level for residential use but below the guideline level for recreational use. These two samples were taken from grassed areas that are not part of the school field or playground and are at a depth of 30cm and are covered with soil that meets the residential guideline.
We have now completed sampling of the school grounds and the results from this area are reassuring.
You can download a copy of the full results and sampling map for Mountview School
Residential area test results
Tonkin and Taylor, on behalf of Waikato Regional Council, carried out sampling across the residential area from November 2016-March 2017. Landowners and residents received results relevant to their properties soon after they were received. The results have been included in an overall report which is available to download here [PDF, 22 MB].
Sampling information for individual properties will also be held on at the Taupō District Council, and is likely to be included on any LIM issued for the land. If you have any questions about the LIM process, please contact the Taupō District Council on 07 376 0899.
If you have any health related enquiries, please visit your doctor or medical centre for advice, or phone Healthline on 0800 611 116. Potential health effects, although unlikely, can be managed by following health advice prepared by Dr Jim Miller, Medical Officer of Health, which you can download here [PDF, 220 KB]; or you can visit the Toi Te Ora Public Health Service webpage for more information here.
The below FAQs were made available to residents and landowners prior to testing taking place.
Why is it important to know that the timber industry used to occupy this land?
Some parts of this area were used to store and treat timber. We know that such activities have the potential to affect soil quality.
Why are we telling residents now?
Waikato Regional Council has always known that Tauhara Timber occupied an area of land at the corner of Tauhara and Spa roads in Taupō.
However, increasing access to historic aerial imagery has shown that the original footprint of the timber yard was larger than initially thought. We now know that the former timber storage and treatment yard once occupied what is now a residential area and school.
Waikato Regional Council is offering to undertake soil testing on residences in the Tauhara subdivision to assess soil quality. This can only occur with landowner and occupier permission – at no cost and at a time convenient to them.
How likely is it that the land could be affected?
Without testing samples collected from your property it’s impossible to know if the soil is affected by historic timber treatment chemicals. However, through our investigations we understand the timber company, which is believed to have closed in the 1960s, used containment measures to reduce spills which could have affected soil.
It is also likely that cut-and-fill (soil movement) occurred, and that fresh topsoil was brought in when the development was formed on the former yard surface.
For these reasons, it is unlikely that the original ground surface still remains, and so the risk of soil being affected at the land surface is low.
Things to consider before we test the soil
There is no evidence yet to suggest that the land in this area has been affected by timber treatment chemicals. For this reason we do not recommend any changes to the way residents currently use their property, which includes playing outside, gardening and growing vegetables etc.
Do residents have to get the soil on their property tested?
Because we do not believe that there is a significant risk, soil sampling is a precautionary approach. Waikato Regional Council is offering to undertake soil testing at no cost. It is their decision whether you would like to accept this offer.
Will they have to pay for soil testing?
No. The cost of collecting the samples and analysing them will be covered by the Waikato Regional Council, with contribution from Taupō District Council.
Will soil sampling damage properties?
No. Only a very small amount of soil is required (about half a cup), and samples are collected using a 50mm diameter tube pushed into the ground by hand. If a piece of turf larger than this needs to be removed for sampling, it will be replaced. Residents may not even notice where the sample has been collected from.
Do they need to be home when the soil testing takes place?
No. Our soil testers are experienced in collecting soil samples, and so long as they have permission, can work quickly provided they have access (i.e. no locked gates or dogs). However, if residents would like to be present when samples are collected, we can arrange for this. The soil testers will need to be on the property for about half an hour; in most cases less.
How long will results take?
It will take approximately three weeks for the soil samples to be tested and the results to be received and reported. Waikato Regional Council scientists will be able to help explain the results. If soil is found to be contaminated, we will provide advice to minimise health risks (if any).
What is contaminated land?
Contaminated land is where at some point in the past, chemicals have made their way into the soil and are present in high enough concentrations that they may affect health. Contaminated land is defined under the Resource Management Act as land with hazardous substances in or on it that are reasonably likely to have significant adverse effects on the environment (including human health).
The threshold for classifying land as contaminated depends on its current land use. For example, what might be considered contaminated for a residential land use may not be considered contaminated for an industrial / commercial use or even a recreational (parks and reserves) use because the way people interact with the land and soil. There is contaminated land all over the country, often the result of historic land use. There are also naturally occurring contaminants in soil.
What substances could remain from the timber industry?
Through our investigations of the timber industry, there is the potential for soil to contain:
- Boron, copper, chromium and arsenic (associated with timber treatment and storage).
- Pentachlorophenol (associated with timber treatment and storage).
- Dioxins (a minor component of the PCP mixture).
- Polycyclic aromatic hydrocarbons (associated with diesel storage and burning of waste)
What might change if the land is found to have contaminants above recommended levels?
If contaminants are found to be above guideline levels, further advice will be sought from Toi Te Ora Public Health Service.
What is pentachlorophenol (pcp)?
Pentachlorophenol (PCP) was used by the timber industry until its voluntary withdrawal in 1988. Technical grade PCP typically contained dioxin impurities.
PCP was used either as a permanent timber preservative or as a temporary antisapstain treatment to prevent fungal attack on the timber while it was being dried before further processing.
What are dioxins?
Dioxins refer to a particular group of chemicals that can harm human health under certain conditions. Dioxins are an unwanted by-product from the production of other chemicals, in this case pentachlorophenol (PCP), which was used historically as a wood preservative. There are also naturally occurring sources of dioxins such as volcanic eruptions and forest fires.
All dioxins are very stable and unlike most other chemicals do not quickly decompose or break down in the environment. Some of them have demonstrated adverse health effects in animals at very low levels.
More information can be found on the Ministry for the Environment website or the Ministry of Health website.
Who can I contact if I’m worried about my own health?
Please visit your doctor or medical centre for advice, or phone the Healthline on 0800 611 116.
Would it be recorded on Land Information Memorandum (LIM) that properties are on contaminated land?
Results from the testing will be recorded on property files as it is a legal requirement for any known information to be published in LIMs.
Would this prevent any additional building on my properties?
It would depend on the results from the soil sampling. It would be highly likely normal building work can proceed but it may require some additional management of soil during the construction process. Advice may be sought from Tonkin + Taylor to enable development to occur based on best practice guidelines and to minimise cost to property owners.