The Edgartown board of health this week took enforcement action against a Chappaquiddick homeowner who has advertised his Sampson’s Hill properties as luxury vacation rentals, saying the homes may exceed their allowed septic capacity.

In a June 12 letter, health agent Matthew Poole told Stephen Olsson that the board of health is concerned that his Chapel avenue and Chappaquiddick avenue homes are being marketed “for rental occupancy significantly in excess of the permitted septic system design capacities.”

The board has denied a disposal system construction permit for a two-bedroom pool house and cabana on the Chappaquiddick avenue property, requesting more information.

Mr. Poole told the Gazette this week that Mr. Olsson will be required to show the board of health that he is in compliance with permitted septic capacity, and if he fails to do so, the board will take further action. “This is the beginning of a process,” the health agent said. Mr. Olsson declined to comment for this story.

Mr. Olsson, a New Hampshire resident, has caused a small uproar among neighbors by advertising the two homes as luxury rentals sleeping more than 30 people combined. The neighbors say the hotel-like development violates residential zoning rules on rural Chappaquiddick.

The home at 7 Chapel avenue, which has a permitted septic system and a deed restriction for two bedrooms, was advertised as a five-bedroom house sleeping 14 people, Mr. Poole wrote in the letter.

The 72 Chappaquiddick avenue home is permitted for 12 occupants, but was advertised as accommodating 20, the letter said.

This week, rental advertisements for the homes on weneedavacation.com were amended, with the Chapel avenue home now listed as sleeping 10, and the Chappaquiddick avenue home listed as sleeping 12.

In the letter Mr. Poole described a telephone conversation with Mr. Olsson in May, where he offered to come to the Chapel avenue house to witness the conditions, and if the dwelling was in compliance with septic system design he would immediately process all pending permits. Mr. Olsson denied the requested access.

“It is clear that the abutting properties located at 72 Chappaquiddick avenue and 7 Chapel avenue are being operated under your single control,” Mr. Poole wrote, adding that the board of health denied a disposal system construction permit for the guesthouse and cabana “until you provide assurances to the board that the facilities . . . are being used in such a way that a larger system is not required.”