There is provided in the present invention a small bore sewer system comprising a clarifier tank for receiving sewage, separating liquid and solid sewage and retaining the solid sewage; and a collection device connected to the clarifier tank for receiving the liquid sewage and carrying it to a sewage...http://www.google.es/patents/US5895569?utm_source=gb-gplus-sharePatente US5895569 - Small bore sewer system
