As long as the pesticide containing material is used as a pesticide, it will not be waste. If the rinsewater contains pesticides regulated as hazardous waste, it should not be stored for more than ninety days. RCRA requires notification and permitting of storage of hazardous waste for more than ninety days. It is preferable to avoid this potential by using all collected rinsewater as soon as possible. Never store pesticide rinsewater in a sump.
Sumps are essentially underground storage tanks, and the possibility of a leak always exists.
Ideally, sumps should be pumped dry every day. Storage or abandonment of rinsewater in a sump could trigger RCRA requirements for registration and permitting of underground storage of hazardous wastes. It is possible to treat pesticide rinsewater or other pesticide containing materials that cannot be used as a pesticide. However, until RCRA regulations are changed, it is impractical for pesticide mixing and loading facilities to attempt to use treatment systems for pesticides regulated as hazardous waste due to the cost of obtaining the necessary permits, and designers should avoid including such systems in facilities. The facility operator must know what pesticides these solid or semi-solid materials contain.