1 From: Palazzolo, Michael A. [Michael.Palazzolo@alcoa.com] Sent: Saturday, December 10, 2011 10:45 AM To: Boyd.Rochelle@epamail.epa.gov Cc: psohi@aluminum.org; Green, David A.; Kler.Denis@epamail.epa.gov Subject: FW: SAPU Calculations Attachments: RRR SAPU Calc Clarification.pdf



### Rochelle,
I reviewed the attached memo and agree with the stated approach except for the interpretation that production rates used during the performance test would be used to calculate the daily SAPU limit. The memo says that feed/charge rates used in the emission limit calculation “should be consistent with the feed/charge rate at which the facility operated during their performance test to demonstrate compliance.” This needs further clarification as discussed below.
The SAPU emission limit should be different each day, depending on what equipment is operated that day. As a simple example, consider an existing uncontrolled SAPU that has two Group 1 melting furnaces and one in-line fluxer. During normal operation (and for the compliance test), the emission limit would be calculated based on all three units:

For particulate matter, the Group 1 Melting furnaces have a limit of 0.4 lb PM/ton and the in-line fluxer has a limit of 0.01 lb PM/ton.

For this example, the Emission Limit is at a maximum for normal operations because two 

### of the three units have a high allowable emission rate (0.4 lb/ton) while one has a low allowable rate (0.01 lb/ton).
However, if one melting furnace is not operating (say on a weekend day), the limit for that day should be a lower value because the facility is averaging emissions between2 

### only one unit with a high allowable emission rate (0.4 lb/ton) and one unit with a low rate (0.01 lb/ton).

Defining a fixed SAPU limit based only on production rates during the stack test would make the MACT standard less stringent during periods when some equipment is not operating. I do not believe this was EPA’s intent when the SAPU averaging approach was developed.
Note that the throughput used to calculate the dailyEmission Limit should be the amount of feed or aluminum produced for each emission unit during the 24-hr period. The equations in Section 63.1505(k) create confusion in this regard. In Section 63.1505(k), Ti is defined as “the feed/charge rate for individual emission unit I”. This definition for Ti is not clear and incomplete.
For compliance testing, the SAPU limit must be calculatedbased on the throughput during the test. So, Ti would be defined in terms of “amount of feed or aluminum production during each stack test run”. (Average of three runs to demonstrate initial compliance.) However, for the daily SAPU calculation, Ti should be defined the same as it is in Section 63.1510(t): “the amount of feed or a luminum produced for each emission unit during the 24-hr period”. This would solve the confusion.
Please let me know if you would like a phone call to discuss this question further. I still owe you information on the New SAPU example we discussed during our meeting. I am traveling Monday and will try to get you something on Tuesday.
Regards,

Mike

Michael Palazzolo Alcoa, Inc. 201 Isabella Street Pittsburgh, PA 15212-5858 Ph: 412-553-4832

From:Boyd.Rochelle@epamail.epa.gov [mailto:Boyd.Rochelle@epamail.epa.gov] Sent:Tuesday, December 06, 2011 4:16 PM To:Paul Sohi Cc:Palazzolo, Michael A. Subject:SAPU Calculations3 Here is the interpretation memo for SAPU calculations. We will clarify in the preamble the correct way for SAPU calculations if we need to. Plants in Region IV are doing it this way. Please provide comments.

Also, by Friday if Mike could provide calculation examples for Existing SAPU with co-controlled and uncontrolled units, New SAPU calculations for co-controlled units, New SAPU for uncontrolled units in accordance with 1505, 1510 and 1513. Thanks.UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460



### 9 2007 

## MAR

OFFICE OF ENFORCEMENT AND COMPLIANCE ASSURANCE

MEMORANDUM

SUBJECT:· Clarification ofthe Calculations for**Se~ondary** Aluminum Processing Units in the Secondary Aluminum NESHAP

FROM:

TO: Michael S.Alushin, Director

# ~j.-**~** Compliance Assessment and Media Programs Division Office ofCompliance

Regional Air Division Directors

The purpose ofthis memorandum is to provide to the regions, states, and local agencies a ·clarification ofthe calculations for secondary aluminum processing units (SAPU) as required in the National Emission Standard for Hazardous Air Pollutants (NESHAP) for Secondary Aluminum Production, 40 CFR Part 63, Subpart RRR.

An SAPU is defined in 63.1503 as:

An existing SAPU.means all existing group 1 furnaces and all existing in-line fluxers within a secondary aluminum production facility. Each existing group 1 furnace or existing**in~line** fluxer is considered an emission unit within a secondary aluminum processing unit. A new SAPU means any combination of individual group 1 furnaces and in-line fluxers within a secondary aluminum processing facility which**~ither** were constructed or reconstructed after February 11, 1999, or have been permanently redesignated as new emission units pursuant to §63.1505(k)(6). Each ofthe group 1 furnaces or in-line fluxers within a new SAPU is considered an emission Unit within that secondary aluminum processing unit.

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Subpart RRR has three sets ofequations that are to be used for SAPU emissions calculations which are explained below. While the specific equations below are for calculating SAPU particulate matter**emis~ions,** this clarification applies to the equations for**hydrog~n** chloride and dioxinlfurans as well.

Section 63: 1505(k)

Section 63 .1505(k) provides the following equation that is to be used to calculate an average**e~ission** limit for SAPUs.

n 

## (Eq. ]} 

# I (Tti <.I 

### i 

### I

Iri the equation above, Tti equals the feed/charge rate for an individual emission unit. Some regulatory agencies have requested clarification as to what feed/charge rate should be used in this SAPU calculation. The feed/charge rate utilized in the equation should be consistent with the feed/charge rate at which the facility operated during their performance test to demonstrate compliance. The performance testing requirements in Sections 63.1511(b)(1), (2), and (3) specify that:



## (1) rhe owner or operator must conduct each test while the affected source or

.. emission unit is operating at the**h~ghest** production level with charge materials representative ofthe range ofmaterials processed by the unit and, ifapplicable, at 'the highest reactive fluxing rate.

(2) Each performance testfor a continuous process must consist of 3 separate rlins; pollutant sampling for each run mustbe conducted for the time period specified in the applicable method or, in the absence ofa specific time period in the test method, for a minimum of 3 hours.

(3) Each performance test for a batch process must consist ofthree separate runs; \ pollutant**sampli~g** for each run must be conducted over the entire process operating cycle.3

The performance testing requirements state that the performance tests must be conducted
at the highest production level and consist ofthree separate runs. Therefore, the feed/charge rate utilized in calculating the SAPU emission limit should be the average feed/charge rate from the three separate runs conducted during the performance test.

.

Also in the equation**above~** Lti is the individual emission unit emission limit from Sections 63 .l,505(i) and 

### 0), which is for group 1 furnaces and in-line fluxers, respectively. The SAPU emission limit is a fixed emission limit until the emission units in the SAPU are retested.

Section 63.1513(e)

Once**th~** performance test has been validated by the appropriate agency, the SAPU emission limit can be calculated for each pollutant. Section 63.1513(e) provides the equations to determine the SAPU's compliance status with the particular pollutant's calculated SAPU emission limit. '

n

## ~'(E 

## . L 1,,- t Ipl'vl 

## E CPM**i;~,** 

## r '

n 

## (Eq. l); 

# I{Tti ) j: 

### I

In the equation abo.ve, Eti is the measured emissions for the individual emission unit during the performance test and Tti is the average feed/charge rate for the individual emission unit during the performance test. Section 63.1513(e)(1) states that the SAPU is in compliance if the mass-weighted emissions for the SAPU using the equations in Section 63 .1513(e) are less than or equa1 tothe SAPU emission limit that was calculated using the equations in Section 63.1505(k).

Section 63.1510(0

Once the SAPU has demonstrated compliance with the SAPU emission limit for the particular pollutant, Section 63.1510(t) requires that 3-day, 24-hour rolling average emissions be

. calculated on a daily basis.4

11 

# L.{Ti xER j ') 

## E day · i ).

n 

## (f.

..**~** 

## I 4\ \.

...t..

. , 

# L.Ti

i" l

In the equation above, Tj is the total feed/charge rate for

### ea~h emission unit for the 24-hour period, and ER is the measured emission rate ofthe particular pollutant from the performance test. The rule describes how to calculate the 3-day, 24-hour rolling average emissions as follows:

(1) Calculate and record the total weight ofmaterial charged to each emission unit in the secondary aluminum processing unit for each 24-hour day ofoperation using the

. feed/charge weight information required in paragraph (e) ofthis section. 

### Ifthe owner or operator chooses to. comply on the basis ofweight ofaluminum produced by the emission unit, rather than weight of material charged to the emission unit, all performance test emissions results and all calculations must be conducted on the aluminum production weight basis.

(2) Multiply the total feed/charge weight to the emission unit, or the weight ofaluminum produced by the emission unit, for each emission unit for the 24-hour period by the emission rate (in lb/ton offeed/charge) for that emission unit (as determined during the performance test) to provide emissions for each emission unitfor the 24-hour period, in pounds.

.
(3) Divide the total ,emissions for each SAPU for the 24-hourperiod by the total material charged to the SAPU, or the weight ofaluminum produced by the SAPU over the '24-hour period to provide the daily emission !ate for the SAPU.

Therefore, the feed/charge weights will be measured and recordea for each operating cycle or time period used during the performance test, then a 24-hour feed/charge weight for each emission unit will be**calculated~** The 3-day, 24-hour rolling average emissions calculated from the three most recent days will be used to compare to the SAPU emission limit which is calculated using Section 63.1505(k). The SAPU is in compliance ifthe 3-day, 24-hourrolling average emissions do not exceed the SAPU emission limit that is calculated using the equation in Section 63.1505(k), per Section 63.1505(k)(1).i. •

5

Sections 63 .1506(d)(3) and 63.151 O(t)(1) allow aluminum produced to be used instead of feed/charge provided that certain conditions are met Ifthe facility decides to use aluminum produced, then Section 63.151

## o (t)(1 ) requires that all performance test emission results and all calculations must be conducted on the aluminum production weight basis when complying with the SAPU emission limit.

.

Notethat Subpart RRR allows facilities with emission units within an SAPU to demonstrate compliance with either the SAPU emission limit which is calculated, or each individual emission unit may demonstrate cOf!1pliance with the individual emission limit through·

a performance test.

cc: Ifyou have any questions,**pl~ase** contact Scott Throwe ofmy**sta~f** at (202) 564-7013.

Regional Air Enforcement Branch Chiefs Todq Russo, Region 4 JeffOahris, Region 5 Tanya Boomer, Region 5 Richard Tripp, Region 7 Joshua'Rickard, Region 8 Stanley Tong, Region 9 John Brock, Region 9 Donnalee Jones, OAQPS Mamie R. Miller, CAMPD Michael S. Alushin, CAMPD Scott Throwe, CAMPD

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