On Tuesday, councilmembers agreed to pay thousands of dollars in fines they owe for violations at the plant.
Officials recently learned that groundwater near the plant may have been contaminated when workers sprayed too much sludge on nearby fields. City officials said they are concerned about the quality of the groundwater.
Workers are digging for rat poison believed to buried on the grounds. They are also removing soil that may be contaminated with herbicides and other toxins.
Councilmembers also approved renovations so the plant can hold more waste.
Councilmembers are hiring a consultant to study the long-term solutions.