A development company preparing to build homes on a previously undisturbed parcel of oceanfront land in Cumberland violated the terms of a conservation agreement in effect there when it destroyed about an acre of town-owned meadowland and scrub forest, using the area as a construction yard for tree-clearing. The intrusion onto a town-owned portion of the former Payson property first raised eyebrows May 8, when town officials learned that contractors working for Bateman Partners of Portland at the site had used town land to store the cut timber, in the process destroying an acre of meadow, said William Shane, Cumberland’s town manager. Shane said that where deep fescue grass and wildflowers once grew, felled trees lay in stacks, a tall mound of topsoil waited to be spread, and several pieces of other heavy equipment stood nearby. “I met with the contractor on site, and basically I was kind of in shock,” Shane said.