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. This is an update providing a more complete desc ription of the tiering methodology provided in Docket Item EPA-HQ-2010-0682-0485. The informa tion in this memo does not alter the

conclusions of the environmenta l risk screening assessment. 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 th e potential for adverse environm ental risks associated with emissions of the following environmental HAP: lead, mercury, cadmium, PAHs, dioxins, hydrogen chloride and hydrogen fluoride. The scr eening-level evaluation for mercury, cadmium, PAHs, and dioxins includes two tiers, and if modeled concentrations do not exceed available benchmarks in Tier I, we consider the emissions from the facility to be below the level that might

cause an adverse environmental effect. If modeled concentrations exceed benchmarks in Tier I,

we conduct a Tier II screen that includes less-conservative, site -specific data for several key parameters. For refineries, we iden tified four facilities that exceed ed a benchmark in Tier I, and

we therefore conducted a Tier II screen. The resu lts of the environmental screening 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 concentrations for four facilities exceeded sediment benchmarks for PAH and one facility exceeded a soil benchmark for HgCl 2 . For the facilities that exceeded the Tier I benchmarks, we conducted a Tier II assessment. In the Tier II screening2 analysis for PB-HAP none of the individual modele d concentrations for any facility in the source category exceeded any of the ecological benc hmarks (either the LOAEL or NOAEL). As explained in section III.A.5 of the preamble to the proposed rule, our screening analysis for lead examined whether there were any estimated ex ceedances of the secondary lead NAAQS and we determined that there were none. The facility sp ecific environmental risk screening results for

PB-HAP based on actual emissions are shown in Ta ble 2. As noted in Section 3.2 of the draft risk report, there were no exceedances of the acid gas benchmarks.

After completion of the draft risk report, we determined that HgCl 2 was not emitted from the facility that had the modeled exceedance of the soil benchmar k (NEI 46556), and therefore, HgCl 2 emissions were included in the environm ental screening analysis for that facility in error. Correcting this error to exclude emissions of HgCl 2 for this facility results in no predicted exceedance of the soil benchmark for HgCl 2 under the Tier 1 analysis. Table 1 below differs from Table 1 in the draft risk report in that it reflects this correction. This correction does not

alter the conclusions of the envi ronmental screening assessment as presented in the draft risk report; rather, with the correction this facility scr eens out at the Tier I level instead of the Tier II level as is presented in the draft risk report.

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.3 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 determined that the facility that exceeded the soil benchmark as part of the Tier I analysis (NEI 46556) did not emit HgCl 2 . Correcting our analysis to exclude modeled HgCl 2 emissions for this facility results in 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.4Table 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