One of the common exclusions found in most property insurance policies is for water or sewage that backs up through sewers or drains or overflows from a sump pump or sump pump well.
The Fall/Winter 2014 issue of Elizabethtown Borough Bulletin sent to all residents of Elizabethtown Borough had advice about sewer backup. The article reminded residents that many factors can lead to a sewer backup. The Pennsylvania Governmental Immunity Statute also limits the legal responsibility of the Borough for sewer backups.
The article encouraged all property owners to contact their insurance agent to review their insurance policy. The Elizabethtown Borough recommends the purchase of sewer backup coverage!
I think that is good advice.