The use of 1080 has been given approval from the Environmental Protection Authority.
The poison is used to control animal pests such as possums, rabbits, stoats and rats, and is spread annually over 400,000 to 500,000 hectares of land.
The use of 1080 often comes under fierce attack from critics who say it is cruel and can contaminate the natural environment.
In a five-yearly review, the authority says there are fewer breaches of established procedures now than there used to be and the total amount of the poison used has fallen in that time.
The report says data from more than 500 samples showed 1080 in only two of them - and even then it was at safe levels.
It says the poison was not found in drinking water catchments at all.
