Mr Burkhardt, who is also chairman of the Ngati Kuri Trust Board, was appointed to provide iwi leadership for the predominantly Maori schools.
The most recent ERO reports, released last month, recommended a review of the effectiveness of the current intervention.
"ERO has had little information from, or involvement with, the commissioner about his plans for and work within the school since his appointment," the report found.
Mr Burkhardt said he declined to work with ERO because it did not tell them anything they did not already know.
"I've been on record saying that ERO doesn't add value when it comes to these schools ... we know what's wrong," he said.
It will take time to turn around the schools, he added.
"It's just the result of dealing with an organisation that has been dysfunctional for a number of years."
ERO found accelerating student achievement was matter of urgency. "At this stage, most students are not achieving the National Standards in reading, writing and mathematics," the report said.
Improving the outcomes of students was the main priority, Mr Burkhardt said.
The ERO report said the Minister of Education had directed Mr Burkhardt to appoint a combined board of trustees in July 2014, but that had not happened.
Mr Burkhardt said he did not think the school was ready yet. "I'm not comfortable handing it over until it's stable."
A new, experienced principal was appointed by Mr Burkhardt in July 2014 with a dual leadership role over both schools.
Ms Casey said the ministry regularly reviewed statutory interventions with the next review due in September. ERO would visit again in one-two years.