The Planning Commission on Tuesday gave the nod of approval to expand the regional landfill located in Suffolk, but no trash can be dumped in the new portion of the site until a transportation solution is found.

The 833-acre site between Route 58 and Nansemond Parkway is owned by the Southeastern Public Service Authority, which is counting on the landfill as a backup plan to dispose of trash starting in January if an outside company doesn’t come through with its promises.

Tuesday’s decision by the commission will send rezoning and conditional use permit requests to City Council in August for its consideration. Approval by City Council will allow the seventh cell of the landfill to be constructed.

But actually dumping trash there is a long way away, as a large transportation project has to take place prior to doing so.

In order to accommodate the large, slow trucks that constantly turn into and out of the landfill directly from a dangerous portion of Route 58 near the downtown exit, a flyover has been proposed that would allow eastbound traffic to cross the westbound lanes and enter the landfill without having to encounter the westbound traffic.

State transportation agencies have planned $5 million for preliminary engineering for the project in the VDOT Six-Year Improvement Program. As a result, construction funding is at least seven years out, city Director of Public Works Eric Nielsen said on Tuesday.

If the flyover is not constructed by the time Cell VII is ready for operations, an alternative plan could include a second entrance to the landfill from Nansemond Parkway.

The landfill could begin filling up more quickly in January, when SPSA is expected to switch its method of disposing of municipal waste from a Wheelabrator waste-to-energy facility located in Portsmouth to RePower South, a company that has proposed to build a Chesapeake facility to convert trash into energy pellets that would then be sold as an alternative energy source.

Some SPSA board members have been concerned in recent months about the timeline. The board has discussed in closed session terminating RePower’s contract but has not yet done so.

If RePower doesn’t come through, the authority is counting on the landfill as a backup method of disposal.