... hygiene(such as garbage landfill site, treatment of sewage, containment of poisonous or harmful wastes, hazardous warehouse, industry ... 3. municipal engineering(expressway, subway, underground engineering of building; and liner of roof pool, roofgarden's waterproofing, sewage channel ... control for sea cucumber circle's slope protection, liner of fish pool & shrimp pond)10. seepage, corrosion, leaks ...