A plan to subdivide 70 acres fronting Katama Bay on Chappaquiddick into 11 lots is now before the Martha’s Vineyard Commission for review as a development of regional impact (DRI).

The property is owned by Richard and Laura Chasin, who want to subdivide the land as a Form A, a provision under the state subdivision control law that allows simple divisions of land fronting a road that the town planning board determines adequate for access. The Chasin land planned for subdivision fronts Quammox and Jeremiah Roads on Chappy. Review by the MVC was triggered because the subdivision is 10 or more lots and because the property is more than 30 acres.

The subdivision is for estate planning purposes. The property is 69.3 acres divided into six lots with four existing houses; the plan calls for redividing the land into 11 lots with a prohibition on any future subdivision. Lot sizes range from just over three to just over 10 acres. One house and a guest house would be permitted on each lot. Building envelopes and view channels are drawn on the plan. Landowners have agreed to maintain an important wildlife corridor of pitch pines which exists on the property.

At a public hearing last Thursday commission DRI coordinator Paul Foley said the plan meets the spirit of the commission’s open space policy, although he said the commission would like to see additional conservation restrictions along the habitat corridor which supports the imperial moth, a rare moth that occurs on the Island.

“The fact that they’re preserving 86 per cent of [the property] as habitat in general will serve very well,” said commission executive director Mark London. “Normally [the Mass Division of Fish and Wildlife’s Natural Heritage and Endangered Species Program] doesn’t ask for that much.” The land falls in the Natural Heritage priority habitat. In December 2008 the Chasins sold 22 acres along Quammox Road to the Martha’s Vineyard Land Bank.

Edgartown planning board member Mike McCourt said his board strongly backs the plan, noting that the property could have potentially been subdivided into 23 lots.

“We all thought the subdivision was well planned out,” he said, adding: “We liked the thought of the affordable housing lot being taken out of the parcel.”

The planning board has not yet determined that all the lots in the plan have adequate road access.

A commission staff report recommends limiting the allowed areas for managed, fertilized turf and using an effluent drip wastewater disposal system for new houses. But one member of the commission questioned if it was enough, given the proximity of the property to nitrogen-sensitive Katama Bay.

“This is potentially 42 extra bedrooms,” said commissioner Katherine Newman. “I’m taking that to the extreme, I know that’s maxed out, and it might not happen, but can a nitrogen drip irrigation system handle that?”

MVC water quality planner William Wilcox has found the plan falls well below guidelines for nitrogen discharge.

The commission voted to continue the public hearing on Dec. 2.