The Dalles City Council will hold a worksession on Monday to discuss the wastewater treatment plant upgrade project. Phase 1A of the project, which involved a number of required upgrades to meet new federal regulations, is being wrapped up. But two more phases remain, and Mayor Steve Lawrence says the Council wants to review what aspects of those actually need to be done. City staff will give Councilors summaries of four different alternative concepts at the worksession. It will begin at 1 p.m. Monday in City Hall.