Preventative Maintenance is a priority as the weather starts to turn cold.

Adjust the Biomass. Because every 10 degree (F) drop in temperature results in a drastic change of bacterial metabolic rates, it is necessary to adjust your biomass to make up for the slower metabolic rates.
Increase grease/solid removal. Remove grease/solids more often. Increased flow of fall and winter rains or snow will result in more grit and grease in your aeration basin, negatively altering the bacterial makeup.
Clear walkways and bridges. Make sure all walkways and chained bridges are de-iced and cleared off.
Keep channels free of ice. Keep ice cleared throughout channels and piping in the plant, it can quickly build up and cause blockages.
Test the heat exchangers. If your plant has digesters that capture gas, make sure your heat exchangers are working to eliminate any temperature drops that could result in bacterial changes.
Drain all fixtures with standing water to prevent damage from freezing.
Ensure heaters are working throughout the plant.

Perspectives

Checklist: Preparing your Wastewater Treatment Plant for Winter