A project to re-engineer the eroding shoreline at Squibnocket Beach has hit a new potential roadblock with a group of Chilmark residents appealing to the state for further review.

Building an elevated causeway, removing a revetment along the Atlantic-facing shoreline and relocating a town parking lot are the key components of two plans that comprise the Squibnocket project, which went through two years of exhaustive debate and study before winning approval in 2015 and 2016 by town voters, the Martha’s Vineyard Commission and the conservation commission.

The two projects together have been billed as managed shoreline retreat, although some residents have questioned the need to install solid structures near the eroding shoreline. Concerns have focused mostly on the steel-and-concrete causeway, which would stand about 11 feet high and provide access to the homes at Squibnocket Farm, an isolated promontory.

The conservation commission unanimously approved both projects on May 25, following four public hearings.

A June 13 petition signed by 20 Chilmark residents asks the state Department of Environmental Protection to overrule the conservation commission by issuing a superseding order of conditions for the causeway.

Led by Blacksmith Valley resident Doug Liman, the appeal claims the town violated local zoning laws and the Wetlands Protection Act in permitting the causeway project. It calls for additional approval by the town zoning board of appeals and argues that a notice of intent understates the potential harm to wetlands and the barrier beach.

“I take issue with the construction of something of this magnitude without all alternatives being explored and without the true impact on such a sensitive resource area being demonstrated,” the petition reads in part. “I take issue with the project not conforming to local zoning bylaws. And I take issue with the project being mislabeled as the moving of an existing causeway.”

The Chilmark selectmen announced the appeal at their meeting last week. The Squibnocket Farm Homeowners Association, which is funding the causeway portion of the project, has filed a request for dismissal. Town counsel Ronald Rappaport has written in support of the dismissal, the selectmen said.

The town has twice received a major Coastal Zone Management grant for its portion of the project, but both times the deadline came and went as public debate continued. The town reapplied this year, and with all the permits in place, had hoped to begin construction in September. It is unclear whether the appeal will hold up both projects, or if the town portion could move forward on its own.

Selectmen said the town had not received a response from the DEP.

The petition is signed by the following: Robert S. Dietz, Matthew Dix, Chris Fischer, Paul S. Hornblower, Rosalie Hornblower, Andrew Kaufman, Doug Liman, Sophie McNally, Rebecca Miller, Willits Sawyer, Abigail Soloman, Jason Teuscher, Kate Treitman, Elisabeth A. VanVeen, Carina Wallance, Daniel Wallance, Gregory J. Wallance, Lisanna Wallance, Luke Weinstock and Lynne Williams.