# Presentation: 205161

## Overview of RIA Analysis for Pb NAAQS Proposal

- Briefing for Interagency Group
- January 16, 2008

## Briefing Outline

- Background
- Monitoring
- Emissions Inventory
- RIA Methodology

## Background

- NAAQS proposal package is due to OMB end of February, 2008.
- RIA Reminders/Caveats:
- Cost & economic impact cannot legally be considered in decisions to re-affirm or revise (upward or downward) a NAAQS.
- RIAs can inform the public.  However, data availabilities, uncertainties, and time limit the extent of the economic analysis relative to recent RIAs (O3 and PM NAAQS).

## Monitor Placement and Data

## TSP-Pb Monitoring Sites, 2003-05

## Where is the monitoring network located?

- Source-oriented Pb-TSP sites will contribute to the majority of Pb nonattainment depending on the level at which NAAQS is set.
- Non Source-oriented sites:
- 0.058 ug/m3 Mean Max Monthly Mean
- 0.03 ug/m3 Median Max Monthly Mean

**Doe Run NOT Included**
**Max (2.09)  2****nd**** Max (1.23)**

## Level of the NAAQS Will Dictate Importance of Pb of Uncertain Origin

**   ****Re-entrained miscellaneous dust could become significant depending on the stringency of the NAAQS level selected.**

**Level of the NAAQS Will Dictate Importance of Pb of Uncertain Origin**

## Air Quality Monitors

- 191 monitors representing 84 counties
- 27 counties with source-oriented sites
- 57 counties with non-source-oriented sites
- About 40 counties with monitors exceeding 0.05

|  | 0.05 μg/m3  | 0.10 μg/m3  | 0.20 μg/m3  | 0.50 μg/m3  | 1.54 μg/m3  |
| --- | --- | --- | --- | --- | --- |
| Max month over 3 years  | 
   40
 | 
   31 | 
   21 | 
   11 | 
    6 |

## Emissions Inventory

## Emission Sources

- Industrial activities
- Point sources (stack)
- Area sources (defined, for the purpose of this briefing, as smaller common facilities such as gas stations and auto shops)
- Re-entrained dust at industrial sites
- Miscellaneous re-entrained dust
- Uncertain origin (possibly from old Pb in gas, building demolition, construction, etc.)
- Emissions from aviation fuel

## What portion of overall emissions is captured in the emissions inventory?

**Monitored Pb ambient concentrations appear to exceed modeled concentrations by about a factor of 3.**
- We looked at estimates from 36 km grid model for PM10 and PM2.5 (Pb portion).
- Possible explanations:
- Significant data gap in model inputs
- 36km grid may have spread emissions too broadly
- ANPR acknowledges a study suggesting miscellaneous re-entrained dust as a significant source of emissions, and notes that it may be a significant contributor depending on the stringency of the NAAQS level selected.
- Miscellaneous re-entrained dust is not accounted for in the emissions inventory.

## RIA Methodology

## Four Parts to Analysis

- Determine target NAAQS levels to analyze
- Tease out emissions / air quality relationships
- Cost out control options for each target NAAQS level
- Assess benefits of control options

## Recommended Target NAAQS Levels* to Analyze

- Current standard = 1.5 μg/m3 (quarterly max)
- Range:  0.05 μg/m3  to 0.5 μg/m3 (monthly max)
- Mid-range:  0.1 μg/m3  to 0.2 μg/m3 (monthly max)
- * EPA is only at the ANPR stage and has yet to identify proposal alternatives.

## Developing Emissions / Air Quality Relationships

## Spreadsheet Analysis

- This is a general spreadsheet analysis of just those monitors expected to exceed a range of potential target NAAQS levels.
- Potential sources of ambient Pb:
- Background concentration
- Re-entrained miscellaneous lead containing dust
- Point source emissions
- Re-entrained soil containing lead from industrial facilities
- Leaded aviation gasoline
- Area source emissions
**Concentration = Background + Miscellaneous Re-entrained Dust + Industrial Point + Industrial Fugitive + Av Fuel + Area Sources**

## Background Concentration

- As indicated in previous analyses, background is not relevant to RIA, because RIA is an incremental analysis.
- In addition, background in this case is so small (0.0005 ug/m3) as to be irrelevant to any calculations.
- Therefore given the resolution of the monitoring devices & precision of the analysis, background is assumed to have no contribution to violations at the design value monitor

## Re-entrained Miscellaneous Dust

- Estimate based on ambient monitoring data:
- Basis for assessment
- Select monitors with no NEI emission sources within 1 mile
- Develop central tendency ambient impact estimate to represent miscellaneous dust in spreadsheet; use one national estimate.

## Point Source Emissions

- Distance weighted ambient impacts of emissions within 10 km of the design value monitor
- Proposed methodology:
- List out all point sources within this predetermined distance from design value monitors
- Sort by source type
- Estimate % contribution to monitor violation

## Point Source Categories likely to be important for the analysis

- Tentative findings based on the 2002 NEI:
- Of the 20 highest emitting stationary source categories within 10 km of a monitor exceeding 0.05 ug/m3, 14 of those are source categories also in the NEI nationwide top 20.
- The top 10 highest emitting categories within 10 Km of such a monitor are:
- Primary Pb Smelting, Secondary Pb Smelting, Integrated Iron & Steel Manufacturing, Primary Nonferrous Metals, Utility Boilers, Primary Copper Smelting, Municipal Waste Combustors (small), Iron & Steel Foundries, Sewage Sludge Incineration, Industrial Machinery & Equipment Finishing, and Primary Metal Products Manufacturing.

## Confidence in Lead Point Source Emission Estimates

**Confidence: Generally Medium (or better) if subject to MACT/GACT/Section 129**
**About 80% of point source Pb emissions are (or will be) subject to MACT, GACT, or Section 129 standards.**
- State/Local/Tribal – 90% subject to MACT/GACT/Sect.129
- Toxics Release Inventory – 50% subject to MACT/GACT/Sect.129
- MACT / GACT industry data used in reg. development –100% subj. to MACT/GACT/Sect.129
- CAMD fuel throughputs very good, emission factors of variable quality

## Re-entrained Dust from Industrial Facilities

- Identified monitors in areas where industrial sites are now closed.  Netted out impact of other sources at those sites [NEI sources (including airports) + miscellaneous re-entrained dust];
- Derived an adjustment factor to account for impact of re-entrained lead dust at an industrial site.

## Aviation Gasoline Emissions

- Identify airports within 10 km of a monitor exceeding an alternative ambient Pb  target
- There are 25 of the >5,000 public airports nationwide that are being evaluated in this analysis (i.e., are within 10 km of a monitor)
- Develop emissions to air quality relationship for airports
- EPA is developing an approach to estimate Pb emissions at airports for landing/take-off operations
- EPA is working on an approach to allocate Pb emissions outside the LTO cycle.
- EPA is estimating Pb emitted at airports missing from the current NEI

## Area Source Emissions

- Apportion through the county or counties of interest.
- The % of emissions that are within 10km of the design value monitor are emissions of interest for this assessment
- Distance weight area sources by distributing them evenly – i.e. assume same % of overall stationary source emissions within 10km as within the entire county.
- Develop an empirical estimate to account for area source contributions to design monitor.

## Analysis of Costs and Benefits

## Cost Analysis

- Basic methodology is tried and true:
- Cost out possible reductions needed from each source type to get monitors to NAAQS levels
- Rank order source categories by doable emission reductions, from least to greatest $/ton.
- Given emissions / air quality relationships, sort by $ / ug/m3.
- For point sources, the range of controls would include fabric filters, ESPs, wet suppression of dust or ash, covering coal or dust piles, etc.
- We are likely to have the same residual non-attainment with known controls dilemma here that we have faced in the PM & O3 NAAQS

## Benefits Assessment

- Goal: Estimate the human health benefits of alternate Pb standards
- Scoping analysis completed
- Relationship between ambient Pb and blood Pb
- Risk assessment identified best techniques
- Health endpoints
- Children: IQ decrements avoided (ages 0-6); infant mortality
- Adults: cases of hypertension avoided; cases of coronary heart disease avoided; strokes avoided; adult mortality avoided
- Valuation functions
- Two principle studies available to value IQ decrements
- Premature mortality valued using standard VSL techniques (consistent with BenMAP)
- Cardio endpoints valued using cost of illness studies (consistent with BenMAP)

## Benefits Assessment

- Analytical plan
- Apply reduced form spreadsheet model
- A screening-level tool that allows quick benefits assessments of monitor rollbacks to alternate standards
- Uses reduced form relationships between ambient lead, inhalation exposure and blood lead
- Can be refined with improved air quality data as needed
- Limitations
- More tenuous link between emission controls and air quality improvements
- Inherently less refined than traditional BenMAP assessment

## Timing and Bottom Line

- Bottom Line:  given the recommended scope of alternative standards & projected reduction in Pb emissions for counties with violating monitors, and a February delivery date of the draft RIA to OMB, a ***limited*** quantitative analysis is possible.
- The Pb NAAQS draft & final RIAs will contain many more caveats, assumptions and guesstimates than the usual NAAQS RIA
- We expect to provide RIA analyses to OMB by the end of February