Delta Thermo hoped to get final approval at the planning commission’s Dec. 11 meeting, but planners did not act because they had not yet received a review letter about the project from the Lehigh Valley Planning Commission.

In the spring of 2012, Allentown City Council approved a 35-year-contract with Delta Thermo to build the plant, after public meetings and much debate.

No residents spoke to oppose the project before the planning commission.

The 48,000-square-foot plant will be built on 3.07 acres of land leased from the city, between Union Street and Allentown’s sewage treatment plant. It will burn Allentown’s municipal solid waste and sewage sludge to produce electricity.

Construction of the waste-to-energy plant will begin in March or April, according to Rob Van Naarden, president and CEO of Delta Thermo.  He hopes it will be operational by August 2014.

It will be built off Union Street, along the roadway that services the sewage plant.

Tuesday’s final approval included two waivers involving street frontage and lot grading along a frontage road. “Because there is no frontage road, it’s a non-issue,” said Hefele.