Response to Public Comments

The Shelby County Health Department-Pollution Control Section (SCHD-PCS) prepared a draft 

Redesignation Request and Maintenance Plan (Plan) for public review and comment prior to 

submission for approval to the Tennessee Air Pollution Control Board for subsequent 

submission to the United States Environmental Protection Agency (EPA) for their consideration. 

The required 30-day public comment period was formally opened on November 10, 2015 with a 

notice published in the Memphis Daily News. In accordance with the SCHD-PCS public notice 

protocol, electronic notice was sent to a list of interested individuals and local elected bodies. In 

addition, electronic notice was sent to local members of the Metropolitan Planning Organization 

(MPO).

A public hearing was scheduled and held at the Shelby County Health Department auditorium

on Tuesday, December 15 at 5:30 PM. 

During the comment period, the SCHD-PCS received comments from three sources. A 

description of those comments and the SCHD-PCS response in italics follows.

Commenters

1. U.S. Environmental Protection Agency, Region 4 comments dated: December 15, 2015

2. State of Tennessee Department of Environment and Conservation (TDEC), comments dated 

December 15, 2015

3. Shelby County Health Department - Pollution Control Section (SCHD-PCS)

Summary of Comments Received and DepartmentResponses

Commenter 1 - EPA

EPA Region 4 submitted a letter electronically and later by US mail postmarked December 15. 

The letter contained 1 specific comment.

EPA 1.

In Section E of the maintenance plan, Shelby County notes that “all existing stationary source 

controls will remain in force.” Pursuant to Section 175A(d) of the Clean Air Act, please include 

this requirement in the contingency provisions portion of the maintenance plan and expand it to 

require Shelby County to implement all measures with respect to the control of the air pollutant 

concerned (i.e., ozone) which were contained in the state implementation plan for the 

nonattainment area before redesignation to attainment.

Shelby County Response to EPA1.

We have added a statement in Phase 2 of the contingency measures.
Commenter 2 - TDEC

The Tennessee Department of Environmental Conservation submitted a letter electronically on

December 15. The letter contained 10 specific comments.

TDEC 1.

We recommend Table 1 be revised for clarity as there are a number of rows that indicate a single 

year as well as a 3 year design value. We recommend the table be simplified and broken into 

two tables. Additionally, we recommend explanatory text be included in the document 

explaining the tables in a way that is understandable for a member of the public who is not 

familiar with ozone air quality data or ozone design values. This is a critical section as it 

encompasses air quality data.

Shelby County Response to TDEC1.

For clarity, rather than split the table, we simplified it to only reflect design values at each area 

monitor over the subject years.

TDEC 2

We recommend including a map showing the locations of the ozone monitors depicted in figure 

2.

Shelby County Response to TDEC2

A map depicting the ozone monitors has been incorporated into the document.

TDEC 3

Werecommend a thorough review to ensure appropriate labeling of tables. It appears that tables 

II through IV are missing, or the tables are not numbered correctly. It also appears there are two 

tables labeled VI.

Shelby County Response to TDEC3

A thorough review of the document was preformed and the table labels have been corrected.

TDEC 4

We recommend a footnote be added to the bottom of Table V to correspond with the “Effective 

Model Year2” in the table header.

Shelby County Response to TDEC4

A footnote has been added to the bottom of what is now Table II to correspond with the 

“Effective Model Year2” in the table header.
TDEC 5

Table VI indicates a drop in VOC emissions between 2017 and 2020 for Area sources, but it is 

not clear what accounts for this drop. It seems to differ from the general trend. We recommend 

adding an explanation that discusses the drop.

Shelby County Response to TDEC5

An error was found in applying growth factors to area sources between the analysis years of 

2017 to 2020. This has been corrected and it now shows some increase in emissions between 

these two years in what is now Table IV

TDEC 6

On page 14; in section 1 of the Section 182(a) discussion, it is mentioned that resources were 

redirected to preparing an “attainment demonstration.” We recommendthe text be modified to 

state a “redesignation request and maintenance plan” instead.

Shelby County Response to TDEC6

The text was modified to state “redesignation request and maintenance plan” instead of 

“attainment demonstration”.

TDEC 7

We recommend the discussion on the bottom of page 19 regarding motor vehicle emissions 

budgets be revised to clarify what is not “not necessary” as stated in the sentence beginning 

“This is not necessary...”.

Shelby County Response to TDEC7

Changes have been made which should better describe what is being done and why.

TDEC 8

Table VII no longer has MVEBs set for the base year, 2012. Did the MPO request MVEBs be 

set for 2012 as discussed and agreed to at the August 5th MATS meeting (we note that a base 

year MVEB is optional)?

Shelby County Response to TDEC8

This has been done so that it is now clear the MVEB stays the same across the 10 years of the 

maintenance plan
TDEC 9

Caution should be exercised if the Fuels Wizard was used in MOVES2014; EPA has issued a 

notice that the Fuels Wizard does not work properly in MOVES2014 and should not be used. 

How were the future year fuels with the RVP of 9.0 and 10.0 selected or developed? We 

recommend adding text to describethis in the document for the MPO’s use in conformity 

determinations. Details on how future year onroad emissions were developed should also be 

included in the document.

Shelby County Response to TDEC9

The future year fuels were selected by exporting the default fuel specifications for Shelby 

County, Tennessee from the MOVES2014 fuel input screen panel, making the appropriate RVP 

adjustments, and then consulting with the MOVES Team via EPA Region 4 to determine if the 

fuels selected and adjustments performed were appropriate. During this process, the MOVES 

TEAM advised SCHD-PCS that the MOVES2014 Fuels Wizard was not working properly. 

However, considering the scope of the onroad emission analysis to be performed, which 

included adjusting the summertime RVP, it was imperative to have the refinery analysis 

performed. At the request of SCHD-PCS, the MOVES TEAM performed the refinery analysis 

and subsequently conveyed the results to SCHD-PCS via email. Using this data, the summertime 

RVP and the corresponding parameters associated with the Fuel Supply, Fuel Formulation, and 

Fuel Usage specifications in the MOVES2014 Fuels input were adjusted for analysis years 2017, 

2020, and 2027. 

Finally, text was added to the document to describe the future year fuelswith RVP of 9.0 and 

10.0 were selected or developed

TDEC 10

We recommend including a list of frequently used acronyms at the beginning of the document.

Shelby County Response to TDEC10

A list of frequently used acronyms has been added to the document.
Commenter 3 - SCHD-PCS

SCHD-PCS

During the comment period, SCHD-PCS staff continued to review the data used to develop the 

redesignation request and maintenance plan.This internal review identified the following:

oversights:

The 2012 Area source VOC emissions estimate of 44.04 tons/day, which was correctly 

stated in the emissions inventory table, was incorrectly stated in the MVEB table as 

43.99 tons/day

The 2027 Area source NOx emissions estimate of 4.34 tons/day, which was correctly 

stated in the MVEB table, was in incorrectly stated in the emissions inventory table as 

4.24 tons/day.

Some of the Area source emissions estimates for 2020 and 2027 were projectedwith 

negative growth values which caused a slight decrease in the resulting grand totals

The 2017, 2020, and 2027 MOVES2014 runs were inadvertently run with the default 

Ramp Fraction input value.

The fuels input and the refueling spillage and vapor loss input for the 2012, 2017, 2020, 

and 2027 Nonroad Equipment runs were corrected and rerun with MOVES2014.

While these oversights were relatively inconsequential and did not affect the MVEBs, they were

corrected. The following tables illustrate the earlier and the revised calculations for the 

emissions inventory.

Summer Season Tons Per Day

Shelby County Volatile Organic Compounds Emission Inventory

Type Year Area Non-Road On-Road Point Total

Base Year 2012 44.04 28.31 19.01 9.30 100.61

Interim Projection 2017 45.33 21.13 11.58 6.64 84.63

Interim Projection 2020 43.16 19.55 9.10 6.22 80.34

Maintenance Year 2027 46.30 19.09 5.79 6.24 77.42

Shelby County Nitrogen Oxides Emission Inventory

Base Year 2012 4.11 35.88 61.56 13.87 115.42

Interim Projection 2017 4.18 32.05 31.51 13.45 81.19

Interim Projection 2020 4.23 30.53 22.46 8.34 65.57

Maintenance Year 2027 4.33 29.94 12.41 8.43 55.11
Summer Season Tons Per Day

Revised Shelby County Volatile Organic Compounds Emission Inventory

Type Year Area Non-Road On-Road Point Total

Base Year 2012 44.04 28.44 19.01 9.30 100.79

Interim Projection 2017 45.33 21.32 11.22 6.64 84.51

Interim Projection 2020 45.53 19.76 8.75 6.22 80.26

Maintenance Year 2027 46.30 19.33 5.81 6.24 77.69

Shelby County Nitrogen Oxides Emission Inventory

Base Year 2012 4.11 35.93 61.56 13.87 115.47

Interim Projection 2017 4.18 32.09 31.30 13.45 81.01

Interim Projection 2020 4.24 30.57 22.42 8.34 65.56

Maintenance Year 2027 4.34 29.77 12.51 8.43 55.05

Likewise, the following tables illustrate the earlier and the revised calculations for the onroad 

emissions budgets. 

Summer Season Tons Per Day

Volatile Organic Compounds On-Road Emission Budget 

Year Area NonRoad

OnRoad Point Total Safety 

Margin

On-Road 

Safety 

Margin 

Allocation

On-Road 

Budget Remaining Safety Margin 

2012 43.99 28.31 19.01 9.30 100.61 N/A N/A N/A N/A

2027 46.24 19.09 5.79 6.24 77.37 23.24 13.22 19.01 10.03

Nitrogen Oxides On-Road Emission Budget

2012 4.11 35.88 61.56 13.87 115.42 N/A N/A N/A N/A

2027 4.34 29.94 12.41 8.43 55.11 60.32 49.15 61.56 11.17

Summer Season Tons Per Day

Revised Volatile Organic Compounds On-Road Emission Budget 

Year Area NonRoad

OnRoad Point Total Safety 

Margin

On-Road 

Safety 

Margin 

Allocation

On-Road 

Budget Remaining Safety Margin 

2012 44.04 28.44 19.01 9.30 100.79 N/A N/A 19.01 N/A

2027 46.30 19.33 5.81 6.24 77.69 23.10 13.19 19.01 9.91

Nitrogen Oxides On-Road Emission Budget

2012 4.11 35.93 61.56 13.87 115.47 N/A N/A 61.56 N/A

2027 4.34 29.77 12.51 8.43 55.05 60.42 49.04 61.56 11.38
In summary, the revisions to the emissions inventory table are as follows:

VOC revisions –

For 2012 –the Nonroad source VOC emissions estimate was revised from 28.31 to 28.44 

tons/day and the Total VOC emissions estimate was revised from 100.61 to 100.79

tons/day.

For 2017 – the Nonroad source VOC emissions estimate was revised from 21.13 to 21.32

tons/day, the Onroad source VOC emissions estimate was revised from 11.58 to 11.22

tons/day, and the Total VOC emissions estimate was revised from 84.63 to 84.51 tons/day.

For 2020 – the Area source VOC emissions estimate was revised from 43.16 to 45.53 

tons/day, the Nonroad source VOC emissions estimate was revised from 19.55 to 19.76

tons/day, the Onroad VOC emissions estimate was revised from 9.10 to 8.75 tons/day, 

and the Total VOC emissions estimate was revised from 80.34 to 80.26 tons/day.

For 2027 - the Nonroad source VOC emissions estimate was revised from 19.09 to 19.33

tons/day, the Onroad source VOC emissions estimate was revised from 5.79 to 5.81 

tons/day, and the Total VOC emissions estimate was revised from 77.42 to 77.69

tons/day

NOx revisions –

For 2012 - the Nonroad source NOx emissions estimate was revised from 35.88 to 35.93

tons/day and the Total NOx emissions estimate was revised from 115.42 to 115.47

tons/day.

For 2017 – the Nonroad source NOx emissions estimate was revised from 32.05 to 32.09

tons/day, the Onroad source NOx emissions estimate was revised from 31.51 to 31.30

tons/day, and the Total NOx emissions estimate was revised from 81.19 to 81.01 tons/day.

For 2020 – the Area source NOxemissions estimate was revised from 4.23 to 4.24

tons/day, the Nonroad source NOx emissions estimate was revised from 30.53 to 30.57

tons/day, the Onroad NOx emissions estimate was revised from 22.46 to 22.42tons/day, 

and the Total NOx emissions estimate was revised from 65.57 to 65.56 tons/day.

For 2027 - the Area source NOx emissions estimate was revised from 4.33 to 4.34 

tons/day, the Nonroad source NOx emissions estimate was revised from 29.94 to 29.77 

tons/day, the Onroad source NOx emissions estimate was revised from 12.41 to 12.51 

tons/day, and the Total NOx emissions estimate was revised from 55.11 to 55.05

tons/day.

Similarly, the revisions to the emissions budget table are as follows:

VOC revisions –

For 2012–the Area source VOC emissions estimate was revised from 43.99 to 44.04

tons/day, the Nonroad source VOC emissions estimate was revised from 28.31 to 28.44 
tons/day, and the Total VOC emissions estimate was revised from 100.61 to 100.79

tons/day.

For 2027 – the Area source VOC emissions estimate was revised from 46.24 to 46.30 

tons/day, the Nonroad source VOC emissions estimate was revised from 19.09 to 19.33 

tons/day, the Onroad source VOC emissions estimate was revised from 5.79 to 5.81 

tons/day, the Total VOC emissions estimate was revised from 77.37 to 77.69 tons/day, 

and the Safety Margin was revised from 23.24 to 23.10 tons/day.

NOx revisions –

For 2012–the Nonroad source NOx emissions estimate was revised from 35.88 to 35.93

tons/day and the Total NOx emissions estimate was revised from 115.42 to 115.47

tons/day

For 2027 - the Nonroad source NOx emissions estimate was revised from 29.94 to 29.77

tons/day, the Onroad source NOx emissions estimate was revised from 12.41 to 12.51 

tons/day, the Total NOx emissions estimate was revised from 55.11 to 55.05 tons/day, 

and the Safety Margin was revised from 60.32 to 60.42 tons/day.