Mr Treadwell has been president of the Taihape A&P; Association and is now its patron. He has also been president of the Royal Agricultural Society. He is an honorary life member of both organisations and has also written a history of both.
As a board member and chairman of Ruanui Charitable Rest Home in Taihape, Mr Treadwell helped raise more than $1 million to leave the trust debt-free upon his retirement. Since retiring to Taupo he has also been a trustee of Lake Taupo Hospice Trust, helping raise tens of thousands of dollars for the organisation.