Our great union has been here in Columbus, Ohio for over 125 years. Local Union 189 is a proud organization whose purpose is to serve those who toil in the plumbing and mechanical piping industry. We take great pride in our Apprentice and Journeyman training to provide the best craftsmanship money can buy. Along with our MCACO Mechanical Contractors we have forged a partnership to build a strong and viable Plumbing and Piping Industry in Central Ohio.