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Subchapter 14. Petroleum Safety Orders--Drilling and Production
Article 14. Reservoirs and Stationary Tanks
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§6548. Drainage, Dikes and Walls for Aboveground Tanks.

(a) Drainage, diking and retaining walls for aboveground tanks shall be provided for employee protection as required by the provisions in the General Industry Safety Orders, Section 5595.

(b) (1) At least one means of safe access shall be provided over retaining walls to the ground level within the walled area.

(2) Where walls exceed three feet (3') in height, there shall be provided at least one emergency exit located as nearly opposite the means of access as practicable. The emergency exit shall be a stairway, walkway, fixed ladder or ramp.

(3) Walkways and ramps may be structures of metal or wood. For earthen retaining walls with sloping embankments, they may be suitably surfaced natural walkways or ramps on the embankment, in which case the slope of the walkway or ramp shall be no more than twenty degrees (20o ) from the horizontal.

(4) If the slope is greater than two inches (2") per foot, structural walkways or ramps shall have securely attached and uniformly spaced cleats not over sixteen inches (16") apart, or other protection against slipping.

(c) Stairways, walkways, and ramps over retaining or diversion walls more than thirty inches (30") high shall be provided with a stair railing or railings on the exposed sides, unless the stairways or ramps are laid upon sloping earth embankments. In that case, a railing or stair railing may be installed on one side only, if the vertical distance from the nose of the stairway tread or from the surface of the ramp to the earth below is no more than two feet (2').

(d) Roadway or walkway openings in diversion and retaining walls are prohibited, except temporarily during repairs.

(e) There shall be no openings or holes in diversion or retaining walls.

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Section (f) repealer filed 7-20-59; effective thirtieth day thereafter (Register 59, No. 12).

2. Amendment of section heading and section and new Note filed 5-8-95; operative 6-7-95 (Register 95, No. 19).

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