City and County officials said after their third meeting with Chargers officials, a consensus may be near.
At a press conference following their meeting, Mayor Kevin Faulconer, County Supervisor Ron Roberts and City Attorney Jan Goldsmith and other members of the negotiating team spoke.
The nearly two hour meeting with the Chargers representatives was a "productive exchange, back and forth," Faulconer said.
"I think we're very very close now to a consensus," Ron Roberts said, adding that the meeting today would lead to a second stage of negotiations.
City leaders say they are "optimistic" they can get their environmental agreement approved in time to have the stadium project put to a vote of the people by the end of this year.
The Chargers have said in the past they do not believe Mission Valley will work because of the environmental approval issues.
City leaders will not say what type of enironmental obstacles the Mission Valley location faces, but traffic and dealing with building around the San Diego River have been cited by experts in the past.
Goldsmith says they hve got an easier path to meet a law known as CEQA, or California's Environmental Quality Act because they would be replacing an existing stadium with a smaller one.
"There will always be some thought if there is an environmental issue here or there, the truck traffic, things like that - there are exemptions in CEQA," Goldsmith said. "There's also different options how you have alternative ways to comply. "
Faulconer said in the meeting, they also discussed timing and resources for the stadium and, Faulconer said, they wanted to work on a solution by the end of the year.
"This has been a united effort from the very beginning," Faulconer said. "Really, the County and City coming and working together on an uprecedented level."
The goal they were working toward, Faulconer said, is keeping the Chargers in San Diego.
The next step, officials said, is to meet with NFL staff to talk about proposals.
NBC 7 has reached out to Chargers Special Counsel Mark Fabiani for comment but has not heard back.