Move the container to a secure, sheltered outdoor area away from spark sources or flames, children and pets. Open the lid and allow liquid to dry. Discard hardened residue at household hazardous waste collection or in trash if permissible by transfer station or landfill. Solvents flushed in a community waste water treatment system or a home septic system may interfere with the normal biodegradation process. Toxic solvents can pass through the system unchanged to be discharged directly into the drainfield soil and might move back into well water.
Septic systems can only partially treat chemical wastes.
Technically, most household waste is exempt under RCRA hazardous waste regulations. However, householders should manage potentially hazardous household waste responsibly. The McGraw-Hill recycling handbook. Disposal Do it Right . Household Products Disposal Council.