The facility at Winsford, Cheshire, will be the first of its type in the UK and will store waste in a secure, concrete underground facility.
In giving his judgment, Mr Justice Harrison rejected a statutory challenge to the Office of the Deputy Prime Ministers decision in December last year to grant planning permission for the facility.
Minosus managing director Roger Shaw said: We are pleased with todays outcome because it means we are now able to put the necessary construction work in hand to have our operation at Winsford in business by June next year.
The timing is important because in July 2005, legislation on Waste Acceptance Criteria comes into force, meaning that an underground facility like ours becomes even more important for the safe disposal of certain hazardous wastes.
Minosus is a joint venture between Compass Minerals UK and waste management specialist Onyx.