Current through Register Vol. 54, No. 38, September 21, 2024
(a)
General. The area surrounding a tank or a group of tanks shall
be provided with drainage or shall be diked to prevent accidental discharge of
liquid from endangering adjoining property or reaching waterways, except that
in particular installations these provisions may be waived or altered at the
discretion of the fire marshal when the tanks under consideration do not
constitute a hazard to adjoining property.
(b)
Drainage. If protection
of adjoining property or waterways is by means of a natural or manmade drainage
system, such systems shall comply with the following:
(1) A slope of not less than 1.0% away from
the tank toward the drainage system shall be provided.
(2) The drainage system shall terminate in
vacant land or in an impounding basin having a capacity not smaller than that
of the largest tank served. This termination area and the route of the drainage
system shall be located so that if the flammable or combustible liquids in the
drainage system are ignited, the fire will not expose tanks or adjoining
property.
(3) The drainage system,
including automatic drainage pumps, shall not discharge to adjoining property,
natural water courses, public sewers, or public drains, nor discharge in any
manner that would constitute a hazard.
(c)
Diked areas. If
protection of adjoining property or waterways is accomplished by retaining the
liquid around the tank by means of a diked area, such diked area shall comply
with the following requirements:
(1) Except as
set forth in paragraph (2), the diked area shall be designed to contain the
volume of liquid that can be released from the largest tank.
(2) For tanks with fixed roofs containing
crude petroleum with boilover characteristics, the diked area shall be designed
to contain the volume of liquid that can be released from all tanks served by
the enclosure.
(3) Walls of a diked
area shall be of earth, steel, concrete, or solid masonry designed to be liquid
tight and to withstand a full hydrostatic head. Earthen walls 3 feet or more in
height shall have a flat section at the top not less than 2 feet wide. The
slope of an earthen wall shall be consistent with the angle of repose of the
material of which the wall is constructed. Dike walls shall be restricted to a
maximum height of 6 feet above interior grade. The use of building walls as
part of dike walls is prohibited.
(4) Provision shall be made for draining
water from diked areas. Drainage shall have a uniform slope of not less than
1.0% away from tanks toward a sump, drainbox, or other safe means of disposal
located at the greatest practicable distance from the tank, and shall be
accessible to control under fire conditions. Such drains shall be kept closed
except when in use and shall be designed so that they do not permit flammable
or combustible liquids to enter natural water courses, sewers, or drains if
their presence would constitute a hazard. Pumps or other means used in
providing drainage from diked areas shall be manually controlled
only.
(5) No loose combustible
material, drum, or barrel shall be permitted within the diked area.
(6) In densely populated areas a fence which
will enclose the tank or equipment may be required where public access to the
tank is not otherwise restricted.
(d)
Particular installations.
These provisions may be altered in particular installations at the
discretion of the fire marshal after consideration of special features such as
topographical conditions, nature of occupancy and proximity to buildings,
height and character of construction of such buildings, capacity and
construction of proposed tanks and character of liquids to be stored, degree of
private fire protection to be provided, and facilities of fire departments to
cope with flammable or combustible liquid fires.
This section cited in 34 Pa. Code §
14a.8 (relating to vents); 34 Pa.
Code §
14a.111 (relating to storage and
handling); 34 Pa. Code §
14a.141 (relating to scope and
application); 34 Pa. Code §
14a.151 (relating to scope and
application); and 34 Pa. Code §
14a.161 (relating to general
provisions).
