Fines

Portion of a soil finer than a No. 200 (75 mm) US standard sieve.

Fit-For-Use Criteria

Criteria used to determine if sewer structures are in a condition that justifies continued operation for its designated service.

Fixture Unit

See Drainage Fixture UnitA drainage fixture unit, often referred to as a fixture unit or FU, is a unit of measure of the waste water flow generated by an appliance, such as a sink or toilet. For example, the typical full bath has a value of 9 FUs. See availability fee for cost..

Flare or Flaring

The bending out of the front end of the lead joint to give clearance. Depending on ground conditions, the flares may have all cracks, or cuts fully welded, or a complete flare not welded, or a segmented flare where only portions of the joint are flared.

Flash Point

Temperature at which a material begins to vaporize.