Documentation for 2002-2018 SO2 Inventories

The 2002-2018 SO2 Inventories are three (four?) distinct inventories
representing snapshots of Maine DEP’s point source inventory and
projected emissions based on anticipated controls of sulfur in residual
(and distillate?) fuel oil.  Process unit specific records can be found
on the accompanying spreadsheet, 2002-2018_SO2_Point_Inventory.xls.
Sections of that spreadsheet are referenced below.

1.  2002 MANE-VU Point Source Inventory

As its baseline, Maine DEP is using the MANE-VU 2002 Emissions
Inventory, version 3, which can be found at   HYPERLINK
"http://www.marama.org/visibility/Inventory%20Summary/2002EmissionsInven
tory.htm" 
http://www.marama.org/visibility/Inventory%20Summary/2002EmissionsInvent
ory.htm .  Maine DEP participated through NESCAUM in the development of
this inventory, designed specifically for regional haze modeling.  All
annual, point source records for SO2 were extracted and can be found in
Section 2:  2002 MANE-VU (Ver. 3) SO2 Inventory (Columns D-J).

Total SO2 Emissions: 23,711 tons

2.  2018 SO2 Inventory based on 2008 Maine DEP Point Source Inventory

The second inventory presented is the first of two project 2018
inventories based on Maine’s 2008 Point Source Inventory.  Records
were matched at the process unit level to the 2002 MANE-VU Inventory. 
The following additional additions, deletions and assumptions were made:

Maine DEP has removed SO2 emissions for all facilities which ceased
operation and/or surrendered their air emissions license from 2001
through 2009.  In all, emissions from 25 facilities were deleted from
the inventory.  

Thirty-two (32) facilities included in the 2002 MANE-VU Inventory have
undergone air emission license renewals or amendments and are no longer
subject to point source emissions inventory reporting under 06-096 CMR
Chapter 137.  In theory, SO2 emissions from these facilities would be
counted from this point forward in the aggregate nonpoint emissions
inventory, however, as we have chosen not to revise the nonpoint
inventory for this project, these emissions are being retained in the
point source inventory and carried forward to 2008 (and 2018) using a
conservative growth factor of 1.  

Two other facilities which had temporarily ceased operation in 2008 had
their emissions carried forward from the 2002 MANE-VU Inventory as well,
using a growth factor of 1.

For all reported point source emissions in 2008, 2018 emissions are
assumed using a growth factor of 1.

See Section 3:  2008 MEDEP Point Source Inventory, projected to 2018,
using GF=1, minus facility closures, 2001-2009 for facility-specific
details.

Total SO2 Emissions: 13,194 tons

3.  2018 SO2 Inventory, assuming 0.5% Sulfur in Residual Oil

The third inventory presented builds upon the second, with the
additional assumption that the State of Maine adopts a 0.5% sulfur limit
for residual oil/Bunker C.  Residual oil use was identified at the
process level by Source Classification Code (see spreadsheet tab, SCCs).
 The following steps were used to calculate this inventory:

Based upon the total emissions, annual throughput, percent sulfur,
emission factor and control efficiency reported in 2008, a side
calculation was done to determine that the following emissions
calculation formula was used.

[Total Emissions] = [Annual Throughput] * [Percent Sulfur] * [Emissions
Factor] *

                                (1-[Control Efficiency%]) / 2000

If a facility did not report an emissions factor or did not follow the
formula above, such as emissions reported from a CEMS device or some
other manual calculation, an emissions factor was derived using the
above equation, based upon the actual reported sulfur content of the
fuel.

The percent sulfur was then changed from its actual reported value to
the assumed value of 0.5% and emissions were re-calculated using the
formula in Step a.

Records marked in red on the accompanying spreadsheet under Section 4: 
2008 MEDEP Point Source Inventory, projected to 2018, using GF=1, minus
facility closures, 2001-2009, assuming 0.5% sulfur for all residual oil
burned, depict those calculations.

Total SO2 Emissions: 8,445 tons

