Televised ducts under slab floor. Ducts are PVC with metal elbows and connections. Most of the system has standing water in it. Plenum in heavily rusted and has water in it. Downspouts need to be extended away from the house. The property should be regarded to allow water to flow away from the house. Once the water issue is resolved the ducts should be spray lined with Duct Armor duct lining material.