With all four of the town's election districts reported, De Palma leads by 29 votes. The results show that she has 921 (51 percent) to 892 (49 percent) for Dow.
Neither candidate could be reached for comment late Tuesday.
The two are vying for a seat that became subject to a special election when Dick Lyman resigned to become town supervisor. It is temporarily occupied by Deputy Supervisor Jon Powers.
Regardless of the election's outcome, the seat will be up for a regular election next year.
Both Dow and De Palma have expressed support for helping the Scotts Corners business district and in allowing for non-traditional septic, which have been notable town issues. The two also expressed deference to the review process for the Ridge 29 proposal, which calls for the construction of 44 housing units and alternative septic.
Click here to follow Daily Voice Pound Ridge and receive free news updates.