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 inform ation 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 envi ronmental 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 petr oleum refineries source category, we conducted a screening-level evaluation of the potential adverse envir onmental risks associated with emissions of the following environmental HAP: lead, mercury, cadmium, PAHs, dioxins, hydrogen chloride and hydrogen fluoride. The results of the environmental sc reening analysis are summarized in Table 1 (this tabl e also appears as Table 3.2-6 in Section 3.2 of the May 2014
“Draft Residual Risk Assessment for the Petrol eum Refining Source Sector ” hereafter referred to as the “draft risk report”).

In the Tier I screening analysis modeled concen trations for four facilities exceeded sediment benchmarks for PAH and one facility exceeded a soil benchmark for HgCl 2 . After completion of the draft risk report, we determined that HgCl 2 was not emitted from the facility (NEI 46556), and therefore, the HgCl 2 emissions were included in the environmental screening analysis in
error. We have corrected this error which resu lted in no exceedances of the soil benchmark for HgCl 2 in the Tier I screen. Table 1 below reflects this correction. It is importa nt to note that this
correction does not alter the c onclusions of the Tier II environmental screening assessment as presented in the draft risk report. For the fac ilities 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 NOA EL). As explained in section III.A.5 of the2 preamble to the proposed rule, our screening analys is for lead examined whether there were any
estimated exceedances of the sec ondary lead NAAQS and we determined that there were none. The facility specific environmental risk screen ing 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 Sc reen Results for the Petroleum Refineries Source Category

Environmental HAP Number of Facilities In Category Exceeding Percent of Modeled Area in Category Exceeding 2 Tier I Screen Tier II Screen 1 NOAEL LOAEL NOAEL LOAEL NOAEL LOAEL

PBHAP Pb None None None None 0% 0% HgCl 2 NA None 3 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 HF 4 NA None - - NA 0% HCL 5 NA None - - NA 0%

NA – Not Applicable. 1- Tier II screen is performed fo r 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 mode led data points exceeded the benchmark or the area exceeded is less than 0.5 percent. For PB-HAP the perc ent area is based on the Tier II results, if a Tier II analysis is performed. Otherwise, the perc ent area is based on the Tier I results. 3 – After completion of the draft risk report, it was noted that HgCl 2 emissions from facility NEI 46556 were included in environmental screen ing analysis in error. As a result of this correction, there were no Tier I exceedances for HgCl 2
. 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.3Table 2 – Environmental Screening Results for Facilities with Tier I Exceedances for PB-HAP(Based on Actual Emissions)a – The number of times the media concentration exceeds the benchmark.Facility NEI IDEnvironmentalHAPAssessmentEndpointBenchmark EffectsLevelTier 1aTier 2aNEI6087 - Marathon Petroleum Company LPGaryville, LAPAHSedimentCommunityNo-effect Level 6Below Tier 2ThresholdNEI12988 - Phillips 66Ponca City, OKPAHSedimentCommunityNo-effect Level 2Below Tier 2ThresholdNEI34050 - Northern Tier Energy LLCSt. Paul Park, MNPAHSedimentCommunityNo-effect Level 3Below Tier 2ThresholdNEI41591 - Valero Refining Company -Tennessee, L.L.C., a Delaware limited liabilitycompanyMemphis, TNPAHSedimentCommunityNo-effect Level 2Below Tier 2Threshold