|(a) A guard rail with an opening that is designed
to provide access must have a removable chain across the opening when
the opening is not in use.
(b) An open valve box, pit, tank, or basin with walls
that extend less than 4.0 feet above ground must have a railing that
extends from the top of the walls to at least 4.0 feet above ground
level. The railing must be capable of preventing an individual from
falling into the open valve box, pit, tank, or basin.
(c) Equipment and work areas that are more than 4.0
feet above or below ground level must be designed with a permanent
stairway for access unless the work area is a manhole or a similar
(d) A ladder must have flat safety tread rungs and
must extend at least 3.5 feet out of a vault.
(e) A walkway above an open tank must have a toe board
at least four inches tall that is designed to prevent a person from
slipping off the walkway. Owners and engineers should refer to 29
Code of Federal Regulations, Part 1910, Subpart D, for additional
guidance on walking and working surfaces.
(f) Walkways, steps, landings, and ladder rungs must
have a non-slip finish. The vertical rise between adjacent steps on
a stairway must not exceed 9.5 inches. Stairways must be designed
with no horizontal gap between the tread run of adjacent steps.
(g) An overhead pipe or other overhead obstruction
must have at least a 7.0-foot clearance, unless the pipe or obstruction
is padded to prevent head injury and has a warning sign.
(h) Basins with vertical walls terminating more than
4.0 feet above or below ground level must be designed with a stairway
(i) Guard rails on walkways shall have adequate clearance
space for maintenance operations.
(j) Clarifiers must have grating across the discharge
pipe in the launder or stop bars across the launder before the discharge
pipe to prevent an individual from entering the discharge pipe from
(k) All guard rails, railings, ladders, walkways,
and associated appurtenances must be designed and constructed to ensure
the safety of individuals at the wastewater treatment facility.