The Water and Sewer Commission this week helped a 454-unit proposed senior housing development clear its first major hurdle. Members on Tuesday voted 6-1 to allocate a majority of the sewer capacity Pelletier-Niantic LLC estimates it needs for 160 condominiums, 144 apartments, and a 150-bed assisted living section, as well as urgent care and radiology facilities that would be open to the public. The company’s principal is listed as New York-based architect Eric J. Pelletier. The developer could begin filing permit applications with the land use department “maybe in a couple months,” according to Pfanner. Multiple public hearings will be required as the project moves through the regulatory process. Of the 1.5 million gallons per day allotted for sewer lines in East Lyme, 1.02 million gallons are for municipal use while the rest are reserved for the state at sites including York Correctional Institution and Camp Nett. The town averaged about 708,000 gallons per day in each of the past five years, according to North.