Developing a New Zealand source of phosphate could minimise the
health risks associated with cadmium, according to Widespread Energy
Ltd.
Widespread is evaluating the economic potential of developing a
reserve of 30 to 100 million tonnes of rock phosphate, which has tested
low levels of cadmium. The reserve is located on the seabed in shallow
waters of New Zealand’s Chatham Rise.
The Ministry of Agriculture and Forestry announced on Friday it is
planning to manage the gradual build up of cadmium in New Zealand soils
through the cadmium contained in imported phosphate.
Tests of samples of the Chatham Rise rock phosphate by the local industry shows it has minimal cadmium levels.
“While those tests are not conclusive, they are encouraging,” Chris Castle, Widespread managing director said.
“We have been aware of the cadmium issue and we see our potentially
low cadmium levels as one of the environmental benefits of developing a
local phosphate resource.
Widespread is currently planning an international initial public
offering to finance the development of the resource. A local resource
will also reduce New Zealand’s carbon footprint through lower transport
costs, and benefit the country’s balance of payments and foreign
exchange exposure.
A key part of extracting the resource will focus on environmental
impacts by minimising seafloor disturbance and extracting the resource
from less than 1/1000th of the Chatham Rise.
“This project potentially offers major environmental and economic
benefits for New Zealand, especially because rock phosphate can be
applied directly as a slow release fertiliser, with none of the nitrogen
run-off problems caused by super phosphate,” Mr. Castle said.
The MAF cadmium control programme follows research that shows cadmium
levels have gradually increased over decades. The strategy recommends
farmers and growers work closely with their fertiliser representatives
to determine the most cost effective, efficient and appropriate
fertiliser application and land management options.
An NZPA report says the main concerns raised by cadmium are that
chronic exposure can lead to kidney damage, bone disease and may be a
risk factor in breast cancer. The build-up of cadmium levels in sheep
made MAF ban the export of some offal from animals older than 2-1/2
years.
Testing showed up to 28 percent of sheep kidneys and 20 percent of
cattle kidneys sampled between 1989 and 1991 exceeded the maximum
residue levels allowed in New Zealand meat of 1 mg per kg. Health
guidelines for soil contamination at the time had a maximum level of
3mg/kg of soil.
The natural average level of cadmium in NZ soils is 0.16mg/kg, but
when farmland is taken into account, the average is more than double
that, 0.35mg/kg, and soils on farms which have had a lot of super
phosphate, such as dairy farms, can have as much as 2.52mg/kg.
Dairying
areas with high fertiliser use tend to have the highest average
contamination, including Taranaki (0.66mgkg), Waikato (0.60mg/kg) and
the Bay of Plenty (0.52mg/kg).
Chatham Rise Project Background
On 25 February 2010, a consortium comprising Widespread Energy and
associated company Widespread Portfolios Limited, (“the Joint Venture or
JV”) was granted an offshore prospecting permit by the Crown Resources
division of the Ministry of Economic Development covering an area of
4,726 km2 on the central Chatham Rise. The permit area, which is in New
Zealand territorial waters, is located 450 km east of Christchurch and
includes significant shallow seabed deposits of rock phosphate and other
potentially valuable minerals.
The initial term of the permit is two years with further priority
rights to either extend the prospecting permit or apply for a mining
licence.
An independent valuation of the project by Rockpoint Corporate
Finance in May 2010 found the project had a realistic possibility of
being commercially viable. It found that, based on conservative
modelling, the project could earn net profit before tax of $40 million a
year. Widespread’s own models put that figure as high as $80 to $100
million a year.
In addition to its financial potential, the project offers a number of benefits to New Zealand including:
- Reduced exposure to currency and commodity risk and reduced import burden
- Known, fixed costs
- Reduced carbon footprint from lower transport costs
- Possible export earnings.
The project is also New Zealand owned and controlled.
The challenges identified of extracting the resource include its
sporadic distribution (it averages 66 kg/m but there is great
variability). Also extracting phosphate at 400m depth has not been
achieved, though other minerals have been extracted at greater depths.
The phosphate, in nodules of 2mm to 150mm, is located in a 1m layer of
sandy silt above a chalky clay sediment basement.
Environmental considerations are an important part of the work being
done and the company has an ongoing wide-ranging programme of
consultation with fishing, conservation, Maori and other interest
groups.
For further information please call Chris Castle on 021 55 81 85 or email chris@widespread.co.nz