The project will add 13,000 square feet to the facility, doubling its size, according to a news release.
Between 20 and 30 jobs likely will be added to the hospital after the expansion, the hospital said.
When the department was built in 1986 it served about 16,000 patients each year. In 2012, the hospital expects to see more than 32,000 patients it its emergency department, the release stated.
About 60 percent of the patients admitted to Ephrata Community come through the emergency area, President and CEO John M. Porter Jr. said in a statement.
The expansion originally was planned to begin three years ago, but was delayed because of the "challenging economic environment," the hospital said.
The construction is scheduled to be completed by the end of 2013, the hospital said.
Ephrata Community's emergency area then will feature 26 treatment areas, 10 more than it has right now, and dedicated areas for behavior health, stroke patients and less urgent health needs.
Both privacy and security will be increased as part of the new design, according to the release.
Funding for the project is through Lancaster-based Fulton Bank and a capital campaign. The campaign has raised $3.12 million with the goal of reaching $5 million, Ephrata Community said.
The hospital also plans to upgrade its heating, ventilation and air conditioning system throughout its facilities for $2.2 million, according to the release.
General contractor for the project is Benchmark Construction Co. Inc., based in West Earl Township, Lancaster County. Lancaster-based Richard F. Mulá Architects designed the expansion, and subcontractors include Frey Lutz Corp., based in West Hempfield Township, Lancaster County, and Guardian Electrical Contractors, based in Manheim Township, Lancaster County.