1

To: Petroleum Refineries Docket EPA-HQ-OAR-2010-0682 

From: Chris Sarsony, EPA/OAQPS/ATAG 

Re: Environmental Screening Results for Petroleum Refineries Source Category 

Date: October 22, 2014 

This memo to the docket provides additional information regarding an interim calculation that is 

part of the environmental screening assessment for the Petroleum Refinery source category. The 

information in this memo does not alter the environmental risk screening assessment in any way, 

nor does it alter the conclusions. The information is provided per a request from a commenter. 

As part of the risk assessment for the petroleum refineries source category, we conducted a 

screening-level evaluation of the potential adverse environmental risks associated with emissions 

of the following environmental HAP: lead, mercury, cadmium, PAHs, dioxins, hydrogen 

chloride and hydrogen fluoride. The results of the environmental screening analysis are 

summarized in Table 1 (this table also appears as Table 3.2-6 in Section 3.2 of the May 2014 

“Draft Residual Risk Assessment for the Petroleum Refining Source Sector” hereafter referred to 

as the “draft risk report”). 

In the Tier I screening analysis modeled concentrations for four facilities exceeded sediment 

benchmarks for PAH and one facility exceeded a soil benchmark for HgCl2. After completion of 

the draft risk report, we determined that HgCl2 was not emitted from the facility (NEI 46556), 

and therefore, the HgCl2 emissions were included in the environmental screening analysis in 

error. We have corrected this error which resulted in no exceedances of the soil benchmark for 

HgCl2 in the Tier I screen. Table 1 below reflects this correction. It is important to note that this 

correction does not alter the conclusions of the Tier II environmental screening assessment as 

presented in the draft risk report. For the facilities that exceeded the Tier I benchmarks, we 

conducted a Tier II assessment. In the Tier II screening analysis for PB-HAP none of the 

individual modeled concentrations for any facility in the source category exceeded any of the 

ecological benchmarks (either the LOAEL or NOAEL). As explained in section III.A.5 of the 
2

preamble to the proposed rule, our screening analysis for lead examined whether there were any 

estimated exceedances of the secondary lead NAAQS and we determined that there were none. 

The facility specific environmental risk screening results for PB-HAP based on actual emissions 

are shown in Table 2. As noted in Section 3.2 of the draft risk report, there were no exceedances 

of the acid gas benchmarks. 

Table 1. Summary of Environmental Risk Screen Results for the Petroleum Refineries 

Source Category 

Environmental 

HAP 

Number of Facilities In Category 

Exceeding 

Percent of Modeled 

Area in Category 

Exceeding2

Tier I Screen Tier II Screen1

NOAEL LOAEL NOAEL LOAEL NOAEL LOAEL

PBHAP 

Pb None None None None 0% 0% 

HgCl2 NA None3 None None 0% 0% 

Cd None None None None 0% 0% 

PAH 4 None None None 0% 0% 

Dioxin None None None None 0% 0% 

Acid 

Gases 

HF4 NA None - - NA 0% 

HCL5 NA None - - NA 0% 

NA – Not Applicable. 

1- Tier II screen is performed for PB-HAP when there are exceedances of the Tier I screen. The acid gas 

screen is a one tier screen. 

2 - A value of 0% indicates that none of the modeled data points exceeded the benchmark or the area 

exceeded is less than 0.5 percent. For PB-HAP the percent area is based on the Tier II results, if a Tier II 

analysis is performed. Otherwise, the percent area is based on the Tier I results. 

3 – After completion of the draft risk report, it was noted that HgCl2 emissions from facility NEI 46556 

were included in environmental screening analysis in error. As a result of this correction, there were no 

Tier I exceedances for HgCl2. 

4 – For HF, we evaluated two benchmarks, one from Canada and the other from the State of Washington. 

Although, they are both considered to be LOELs - the level between a NOAEL and a LOAEL, we have 

listed the results under the LOAEL column. 

5 – For HCL, we evaluated one benchmark at the LOAEL level. 
3

Table 2 – Environmental Screening Results for Facilities with Tier I Exceedances for PB-H

(Based on Actual Emissions) 

a – The number of times the media concentration exceeds the benchmark. 

Facility NEI ID Environmental HAP Assessment Endpoint Benchmark Effects Level T

NEI6087 - Marathon Petroleum Company LP 

Garyville, LA PAH Sediment Community No-effect Level 

NEI12988 - Phillips 66 

Ponca City, OK PAH Sediment Community No-effect Level 

NEI34050 - Northern Tier Energy LLC 

St. Paul Park, MN PAH Sediment Community No-effect Level 

NEI41591 - Valero Refining Company - 

Tennessee, L.L.C., a Delaware limited liability 

company 

Memphis, TN 

PAH Sediment Community No-effect Level