Outfall Sediment Total Maximum Daily Loads (TMDLs) Glossary Glossary and Key Word List Definition: The point where water flows from a conduit, stream, or drain. Outfall Terms of Environment Glossary and Key Word List Definition: The place where effluent is discharged into receiving waters. Outfall RCRA Glossary of Terms Glossary and Key Word List Definition: The place where effluent is discharged into receiving waters.