I need a certified engineer with a PE in Somerville Massachusetts

WANTED: PE Engineer to supervise and approve an interesting project, a residential prototype grey water system, to be installed by its inventor, a construction contractor with Unrestricted License. This work is expected to lead to ongoing projects on a much larger scale, from major customers already lined up. The initial project will also include my own small airoponics bay, a simple small green roof (plastic lined milk crates full of Horticultural Perlite) with irrigation, as well as sundry electrical and plumbing. Need estimates. Pay negotiable. Requirements: Any applicable PE certification for Massachusetts.