Plans to create a 4-acre solar array in Portland are forcing city officials to address longstanding issues at its closed landfill off Ocean Avenue.

The city is looking to install more than 2,800 solar panels on the closed landfill by the end of the year so it can take advantage of higher rates paid for electricity from solar projects. Changes to so-called net metering rules will begin ratcheting down rates for solar energy beginning next year.

But before it can install the solar panels, the city must fix the landfill cover, which has settled over the years and been compromised by recreational use, lack of maintenance and erosion. The city must also install vents to address methane gas that is collecting underneath the landfill cover.