relax.txt
relax.txt
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Texas Natural Resource Conservation Commission
Austin Texas
Memorandum
To: Permit Engineers
From: Lawrence Pewitt, P.E., Permits Program Director
Date: August 9, 1990, Updated September 27, 1994
Subject: Prevention of Significant Deterioration (PSD) and
Nonattainment Review Implications for Relaxation of
Permit conditions
This is to alert you to some obscure situations in which EPA
may require PSD and nonattainment review. See 40 CFR 52.21
(r)(4), 52.21(b)(2)(iii)(e) and (f) in the PSD rules and 40
CFR 51.165 (a)(5)(ii) and 51.165 (a)(1)(v)(C)(5) and (6) in
the nonattainment rules. Generally the issue in these rules
is if the facility has the capability to be major, there was
a "federally enforceable state permit condition" which
resulted in the source being minor and then "relaxation of the
standard" (e.g., when removed or changed during a state
permit/amendment review) results in the source becoming major
then the permit unit is reviewed as if it were originally
built major. The areas where the rules are focused are raw
material and fuel changes and increases in throughputs or
operating hours such as adding an additional shift.
For example,
1. A company proposes to build a 10 million standard cubic
feet per day (MMSCFD) gas sweetening unit which will emit
220 tons per year (TPY) sulfur dioxide (SO2). The TACB
issues a state permit limiting them to 220 TPY SO2. One
year later the company wants to process a slightly higher
throughput, no construction is required and emissions will
increase by 35 TPY to 255 TPY SO2. EPA would consider
this a relaxation of a permit limit which if it had not
been there the company would have had to get a PSD permit
to start the process. So a PSD permit is now required as
if the plant was being built as a grassroots plant unless
the company limits their increase so that the total plant
emission rate is less than 250 TPY after the relaxation.
2. Similarly, the same gas sweetening plant which did not
have a throughput increase but had a hydrogen sulfide
(H2S) concentration increase (an alternative raw material)
resulting in the same increase in emissions would be
subject to PSD review.
3. The same thing would be true for nonattainment review.
If the company built a plant and represented 20 TPY of VOC
in a nonattainment county and then came in with no
construction and requested an increase of 10 TPY of VOC
emissions, this would be considered as all one project.
Nonattainment review and offsets for the entire 30 TPY
would be required. This assumes the permit was received
and issued after the November 15, 1992 deadline for the
new ozone nonattainment requirements of the 1990 Federal
Clean Air Act Amendments.
4. An existing major source modifies a plant and increases
throughput (with or without construction), which results
in an increase of 35 TPY. The TACB issues a state permit
or amendment which limits the emissions. Then later the
company discovers that they can operate at a slightly
higher throughput with no construction and requests a
permit amendment to increase emissions another 6 TPY.
This will require a PSD permit as a major modification
since the total increase would have been 41 TPY if the
company had come in for the total allowable at the
beginning. This is also the case for nonattainment
review in a nonattainment county.
5. If any of these cases required the addition of significant
equipment then it would not be an increase solely as a
result of a relaxation of a federal permit condition.
However, EPA may consider it phased construction and PSD
review may be required. We need to proceed very
cautiously in these cases. This separate, but related
concern arises from construction of related units over a
short period of time in separate projects where it may be
suspected that a company is trying to circumvent the
PSD/nonattainment regulations by keeping each individual
project below major. It is difficult to prove
circumvention, so it is best to remind permit applicants
that phased construction projects have to be evaluated as
a single project when determining PSD/nonattainment
applicability.
Key issues in making these applicability decisions are:
1. Is the only thing that is holding the facility below major
a permit condition? In other words is the already
permitted equipment capable of emitting at a "major rate"
with no physical modifications?
2. Is the proposed change resulting in increased emissions at
the previously permitted facility the result of the use of
alternate fuel or raw material, increased operating hours,
or increased throughput?
3. Does the proposed change not require any significant
construction? Changing out a little pipe and a few pumps
would not be considered significant construction.
4. After the proposed change will the total permitted
facility emissions be increased to above major?
If the answers to all of these are yes, then PSD or
nonattainment review is probably required for the original and
proposed project due to relaxation of a permit condition.
There is no official guidance from EPA on a time frame over
which the relaxation of a permit condition causes the total
increases for all the projects to be added together to
determine major status. However, after discussion with Merrit
Nicewander and staff at EPA Region 6 on August 1, 1990, we
came to the conclusion that clearly we need to be especially
alert to any relaxations within two to three years after start
of operation of the facilities. But even changes that may
occur outside that two to three year boundary may very well be
considered a relaxation when looking at all the facts. The
final decision on all these situations should be made on a
case-by-case basis with your Division Director or myself.
cc: Steve Spaw, P.E., Executive Director
Bill Campbell, Deputy Executive Director
James C. Myers, P.E., Deputy Director, Regulatory
Operations
Regional Directors