The patented port drain with release valve gives you an access point to gently release pressure in the waste line, which controls messy blackwater spray and limits costly cleanup. Once the pressure is relieved, you can easily remove the Blackwater Alert device and snake the blockage in the waste line. This reduces the potential for messy, expensive cleanup and disinfection. Blackwater Alert sewer backflow preventer in Bridgewater Corners, VT is a device that allows the homeowner or plumber to gently release pressure in the waste line, which limits costly cleanup and messy blackwater spray. Once pressure is relieved, the plumber can remove the device and snake the blockage in the waste line. The Blackwater Alert device reduces the potential for messy, expensive cleanup and disinfection. It protects your property and your walls from damage by removing waste from sinks and toilets without damaging your walls. Blackwater Alert is a patented device that reduces the potential for messy, expensive cleanup when using a snake to unblock a waste line.