Septic tank
A septic tank is an underground chamber made of concrete, fiberglass or plastic through which domestic wastewater (sewage) flows for basic treatment. Settling and anaerobic processes reduce solids and organics, but the treatment efficiency is only moderate (referred to as "primary treatment"). Septic tank systems are a type of simple onsite sewage facility (OSSF). They can be used in areas that are not connected to a sewerage system, such as rural areas. The treated liquid effluent is commonly disposed in a septic drain field which provides further treatment. However, groundwater pollution may occur and can be a problem.
South Hook LNG terminal
The terminal is built to store and re-gasify liquefied natural gas imported from the Qatargas 2 LNG plant in Qatar. in the five storage tanks located onsite. The large tanks are each 94 metres in diameter and 31 metres high, rising another 12 metres to the top. This makes a tank's volume roughly equivalent to that of Albert Hall.
The regasified natural gas is to be fed through the South Wales Gas Pipeline to the national gas network at Tirley, Gloucestershire.