Former Tauhara Timber site

Some parts of this area were used to store and treat timber. We know that such activities have the potential to affect soil quality.

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.

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.

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.

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.

No. The cost of collecting the samples and analysing them will be covered by the Waikato Regional Council, with contribution from Taupō District Council.

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.

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.

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).

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.

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)

If contaminants are found to be above guideline levels, further advice will be sought from Toi Te Ora Public Health Service.

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.

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.

Please visit your doctor or medical centre for advice, or phone the Healthline on 0800 611 116.

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.

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.