The minister was 'satisfied' that safeguards under the Environmental Protection Act were 'adequate' and his approach was 'rational and in line with published government policy and precedent', said Mr Richards.
He was 'confident' the proposed incinerator would have no 'unacceptable impact' on the surrounding area and it was reasonable for him to leave detailed investigation of environmental issues to HM Pollution Inspectorate at a later stage when authorisation for the plant to begin operating is sought.
The inspectorate had power to stop the plant from opening if there were any risk of harm to 'any living organism', and the Secretary of State was convinced that all environmental issues would be 'satisfactorily addressed' by the inspectorate at the authorisation stage, said Mr Richards.
Gateshead Borough Council's case was that the Inspectorate might be 'constrained' to authorise the plant to begin operating even were there a risk of 'serious harm' to the environment.
That would be so if it were 'too expensive' to prevent harmful emissions from the plant, the Council alleges.
But Mr Richards told the court: 'We say it is clearly wrong on that point'.
HM Pollution Inspectorate 'could and would' withhold authorisation for the plant if there was any significant risk of harm to the environment, public health, or any living organism, he said.
The council is battling to overturn the Secretary of State's decision on May 24 this year to grant outline planning permission to Northumbrian Water Group Plc for construction of the plant on land off Follingsby Lane, Wardley.
It claims the minister 'irrationally' departed from the 'unequivocal and clear' recommendations of his own planning inspector that planning permission for the scheme be denied.
The proposed incinerator would have a 40 metre stack and would be used for disposal of some 8,000 tonnes of the Northern Regional Health Authority's clinical waste each year.
The court heard earlier of the council's fears for the environmental impact of the plant. They fear that emissions from the plant may 'find their way into the food chain', posing a long term problem for public health.
The hearing continues.