(a) Applicability: Subsection (c) applies to
all VOC liquid storage vessels equipped with external floating roofs, having
capacities greater than 150,000 liters (39,000 gallons) except as indicated in
subsection (c) and paragraph (c)(H);
(b) Exemptions: Subsection (c) does not apply
to petroleum liquid storage vessels which:
(A) Are used to store waxy, heavy pour crude
oil;
(B) Have capacities less than
1,600,000 liters (420,000 gallons) and are used to store produced crude oil and
condensate prior to lease custody transfer;
(C) Contain a VOC liquid with a true vapor
pressure of less than 10.5 kPa (1.5 psia) where the vapor pressure is measured
at the storage temperature;
(D)
Contain a VOC liquid with a true vapor pressure less than 27.6 kPa (4.0 psia);
that
(i) Are of welded construction; and
(ii) Presently possess a
metallic-type shoe seal, a liquid-mounted foam seal, a liquid-mounted liquid
filled type seal, or other closure device of demonstrated equivalence approved
by DEQ; or
(E) Are of
welded construction, equipped with a metallic-type shoe primary seal and has a
secondary seal from the top of the shoe seal to the tank wall (shoemounted
secondary seal).
(c) No
owner of a VOC liquid storage vessel subject to this rule may store VOC liquid
in that vessel unless:
(A) The vessel has
been fitted with:
(i) A continuous secondary
seal extending from the floating roof to the tank wall (rim-mounted secondary
seal); or
(ii) A closure or other
device which controls VOC emissions with an effectiveness equal to or greater
than a seal required under subparagraph (A)(i) as approved in writing by DEQ.
(B) All seal closure
devices meet the following requirements:
(i)
There are no visible holes, tears, or other openings in the seals or seal
fabric;
(ii) The seals are intact
and uniformly in place around the circumference of the floating roof between
the floating roof and the tank wall; and
(iii) For vapor mounted seals, the
accumulated area of gaps exceeding 0.32 cm (1/8 inch) in width between the
secondary seal and the tank wall are determined by the method in subsection (d)
and must not exceed 21.2 cm2 per meter of tank diameter (1.0 in2 per foot of
tank diameter).
(C) All
openings in the external floating roof, except for automatic bleeder vents, rim
space vents, and leg sleeves, are:
(i)
Equipped with covers, seals, or lids in the closed position except when the
openings are in actual use; and
(ii) Equipped with projections into the tank
which remain below the liquid surface at all times.
(D) Automatic bleeder vents are closed at all
times except when the roof is floated off or landed on the roof leg supports;
(E) Rim vents are set to open only
when the roof is being floated off the leg supports or at the manufacturer's
recommended setting;
(F) Emergency
roof drains are provided with slotted membrane fabric covers or equivalent
covers which cover at least 90 percent of the area of the opening; and
(G) The owner or operator of a VOC
liquid storage vessel with an external floating roof subject to subsection (c)
must:
(i) Perform routine inspections
semi-annually in order to ensure compliance with paragraphs (A) through (F) and
the inspections must include a visual inspection of the secondary seal gap;
(ii) Measure the secondary seal
gap annually in accordance with subsection (d) when the floating roof is
equipped with a vapor-mounted primary seal; and
(iii) Maintain records of the types of VOC
liquids stored, the maximum true vapor pressure of the liquid as stored, and
the results of the inspections performed in subparagraphs (G)(i) and (ii).
(H) The owner or
operator of a VOC liquid storage vessel having a capacity equal to or less than
150,000 liters (39,000 gallons) with an external floating roof, but containing
a VOC liquid with a true vapor pressure greater than 7.00 kPa (1.0 psi), must
maintain records of the average monthly storage temperature, the type of
liquid, and the maximum true vapor pressure for all VOC liquids with a true
vapor pressure greater than 7.0 kPa;
(I) The owner or operator of a VOC liquid
storage vessel subject to this rule, must submit to DEQ, as a minimum, annual
reports summarizing the inspections;
(J) Copies of all records and reports under
paragraphs (G) (H), and (I) must be retained by the owner or operator for a
minimum of five years after the date on which the record was made or the report
submitted;
(K) Copies of all
records and reports under this section must immediately be made available to
DEQ, upon verbal or written request, at any reasonable time;
(L) DEQ may, upon written notice, require
more frequent reports or modify the monitoring and recordkeeping requirements,
when necessary to accomplish the purposes of this rule.
(d) Secondary Seal Compliance Determination:
(A) The owner or operator of any VOC source
required to comply with section (4) must demonstrate compliance by the methods
of this section or an alternative method;
(B) A person proposing to conduct a VOC
emissions test must notify DEQ of the intent to test not less than 30 days
before the proposed initiation of the tests so DEQ may observe the test. The
notification must contain the information required by, and be in a format
approved by DEQ;
(C) Compliance
with subparagraph (4)(c)(B)(iii) is determined by:
(i) Physically measuring the length and width
of all gaps around the entire circumference of the secondary seal in each place
where a 0.32 cm (1/8 inch) uniform diameter probe passes freely (without
forcing or binding against the seal) between the seal and tank wall; and
(ii) Summing the area of the
individual gaps.
NOTE: This rule is included in the State of Oregon
Clean Air Act Implementation Plan that EQC adopted under OAR
340-200-0040.