This coming Friday is usually the busiest day of the year — not just for retailers, but also for plumbers, the result of what happens in many homes on Thanksgiving day. Plumbers refer to this as “Brown Friday”, because so many people report backed-up sewage lines at home. The main culprit: hot fats, oil and grease poured down drains which then congeal somewhere in the pipes below, and the result isn’t pretty, as WFIR’s Evan Jones reports.