Spill containment is where spills of chemicals, oils, sewage etc are contained within a barrier or drainage system rather than being absorbed at the surface. One method is to use an inflatable stopper which is inserted into the outflow of a drainage system to create a containment vessel. In the event of a spill the stopper bladder is inflated to block the drain/s and to prevent the spilt agent from entering the ground water, stream or river. Spill containment is considered by some to be a more eco-friendly solution than using absorbent spill kits that have very small capacity, require disposal after use and do not permit re-cycling of the spilt agent. Chemical handling and oil transfer companies all over the world are now deploying spill containment bladders and valves that can be retro-fitted to existing drainage systems in just a few hours. Remote control of the inflation process is also available eliminating risk to operatives in the event of hazardous chemical spills. Normally controls are pneumatic eliminating the need to run electrical cables down into the drainage system. Drains of all sizes can be fitted with systems available with extension brackets that cater for drain depths from 500 mm to over 2.5m deep. There are also pneumatically controllable flap valves which can be fitted to existing soil waste systems. Again containment is controlled by application of pneumatic pressure in the event of a spill. Triggering of systems can be by manual panic button or by the introduction of sensors in the flow such as level, ph, turbidity and conductivity.