<prompt> A good trap should have effective seal of2.5 cm5 cm7.5 cm10 cm  <response>: The trap: Is a bent pipe in sanitary latrine, about 7.5 cms in diameter and connected with the panTrap is a Water seal: it holds water; prevents access by flies and suppresses the nuisance from smellDepth of water seal in RCA sanitary latrine: 2 cms 34 inchWater seal in sanitary latrine is an example of Sanitation barrier. 