Our insured has a water backup or sump pump overflow endorsement on his homeowners policy, which states the insurer covers direct physical loss caused by "water or sewage, which backs up from outside the residence premises plumbing system through sewers or drains." A heavy rainstorm occurred, and water entered the residence through the drain in the basement floor.

Because the insured has a radon remediation system installed in the drain, the engineer sent by the insurer reported that the water must "have come into the drain system via the perforated pipe and the drain could not handle the flow. Thus the water backed up onto the basement floor." The insurer then denied the claim, citing the exclusion for water below the surface of the ground, and then adding that the surface water below the ground entered into the perforated radon remediation system.

We think this is a covered loss and would like your thoughts.