Document rp31RMmvzV1jnKje7DyxYwLBJ

Addendum to the Evraz ESI Report January 13, 2024 The EPA conducted a National Pollutant Discharge Elimination System (NPDES) Evaluation Sampling Inspection (ESI) at the Colorado Fuel and Iron (CF&I) Steel, L.P. dba Evraz Rocky Mountain Steel facility (Evraz) located at 2100 South Freeway, Pueblo, CO 81004 on the following five sampling dates: September 1, 2022; September 6, 2022; November 1, 2022; November 2, 2022; and February 1, 2023. The ESI report was transmitted by the EPA to Evraz on July 25, 2023. The objective of the ESI was to gather information, independent of Evraz's self-monitoring under its NPDES permit, to determine any impact of wastewater discharges and stormwater runoff from the Evraz site on the water quality of Salt Creek. The EPA conducted sampling events at various locations along Salt Creek identified in Tables 1 and 2 of the ESI report for the pollutants of concern identified in Table 3 of the ESI report. The EPA submitted its field samples for analysis by the EPA Region 8, EPA Region 7 and Colorado Department of Public Health and Environment (CDPHE) laboratories, as identified in Table 3. The CDPHE laboratory provided analyses for total chromium and hexavalent chromium for sampling events conducted on September 1, 2022, September 6, 2022, and February 1, 2023. As part of its analytical package, the CDPHE laboratory provided quality assurance records with its results for total chromium and hexavalent chromium, which were included in the ESI Report: Section 5. Based on the EPA's evaluation of the laboratory analytical records and quality assurance documents provided by the CDPHE in 2023, the total chromium and hexavalent chromium data met quality assurance/quality control criteria. The EPA was subsequently notified by the CDPHE in a series of emails, beginning on September 18, 2024, that the laboratory analytical reports for a subset of these sampling events are recalled due to mischaracterized quality control information and data integrity issues. The EPA is also uncertain of the quality of the data sent to the CDPHE laboratory that was not recalled by CDPHE. Without reliable laboratory results, the EPA is removing all total chromium and hexavalent chromium data from evaluation in the original ESI report transmitted to Evraz on July 25, 2023. All other field samples analyzed by non-CDPHE laboratories remain unaffected, and the resulting data presented in the ESI report are considered reliable with respect to quality control and quality assurance. EVRAZ and Salt Creek Compliance Sampling Inspection CO-0000621 September 1, 2022 through February 1, 2023 Addendum - January 13, 2025