ANACONDA SMELTER NPL SITE ANACONDA REGIONAL WATER, WASTE & SOILS OPERABLE UNIT Final Spring 2013 Anaconda High Flow Stream Sampling Event - Addendum 1 to the Final Willow Creek Mass Loading Study Sampling and Analysis Plan (SAP) Atlantic Richfield Company May 23, 2013 ST, UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8, MONTANA OFFICE FEDERAL BUILDING, lOW. STREET, SUITE 3200 HELENA, MONTANA 59626 Ref: 8M0 May 17, 2013 Mr. Shannon Dunlap Atlantic Richfield Company 317 Anaconda Road Butte, Montana 59701 Dear Shannon: EPA, in consultation with DEQ, approves, with comment, Atlantic Richfield’s Draft Final Spring 2013 Anaconda High Flow Stream Sampling event — Addendum I to the Final Willow Creek Mass Loading Study Sampling and Analysis Plan (SAP), dated May 10, 2013. Atlantic Richfield may proceed with the sampling in accordance with the attached comments. Please notify EPA oversight personnel prior to initiating sampling activities, If you have any questions, please give me a call Charles Coleman Anaconda Project Manager cc: Andy Lensink, ENF-.L Joel Chavez, DEQ Jon Morgan, DEQ Joe Griffin, DEQ Katherine Haque-Hausrath, DEQ Gunnar Emilsson, CDM Ken Brockman, BOR Becky Guay, ADL AR; Roy Thun, AR John Davis, PRR Bill Duffy, DGS Don Booth, BC Kevin Bethke, TREC Tim Hilmo, RWFI Printed on Recycled Paper Coleman,_Charles From: Em ilsson, Gunnar [[email protected]] Sent: Thursday, May 16, 2013 8:54 AM Don Booth ([email protected]) ([email protected]) To: Joel Chavez Cc: [email protected]; Coleman, Charles; Joe Griffin ([email protected]); ([email protected]); Coover, Curt; [email protected] Subject: Agency Approval and Comments SW High Flow SAP Don: “Approved with Attached are the Agencies’ comments to the High Flow SAP. Tomorrow, Charlie will follow up with an Comment” letter (he is out of the office today). Please direct any questions and/or scheduling with Curt Coover and Joe Griffin. Thank you. Agency Comments on Creek Mass l.oading Study Spring 2013 Anaconda High Flow Stream Sampling Event — Addendum 1 to the Final Willow Sampling and Analysis Plan May 10, 2013 for Mill Creek. Sampling should be conducted in a synoptic fashion for each watershed. This is especially important moved upstream as needed to find flowing If there is no flow at ANT-i, the sampling location in Antelope Creek can be water. The background stations can be adjusted as needed based on access. data. CAL-9 should be sampled at the highway bridge to be consistent with previous Agency oversight should be present when selecting new sites. oversight prior to sampling Some of the historic locations shown on Figure 1 are inaccurate. Please consult with Agency to locate historic sites. reporting limits provided by The reporting limits listed in Table 2 are too high for copper, cadmium, and lead. Recent Pace Analytical are shown in the table below and should be sufficient. Please update Table 2. BPSOU Metals IDLs in Surface Water 2/2i/2012 Metal lDL,ig/L Cadmium 0.028 Copper 0.25 Lead O.0i8 Zinc 2.5 This plan does not address sediment sampling required in the SOW. Gunnar Emilsson, P.G., P.E., BCEE Project Manager CDM Smith 50 West 14th St., Suite 200, Helena, MT 59601 1 Response to Agency Comments to the Draft Final Spring 2013 Anaconda High Flow Stream Sampling Event-Addendum 1 to the Final Willow Creek Mass Loading Study Sampling and Analysis Plan (SAP) Prepared for Atlantic Richfield Company By Pioneer Technical Services, Inc. Dated: May 10, 2013 Date of Comments: May 17, 2013 General: The SAP Addendum was approved with comment. Comments and responses have been incorporated into the final document. Specific Comments: 1. Agency Comment: Sampling should be conducted in a synoptic fashion for each watershed. This is especially important for Mill Creek. Atlantic Richfield Response: Comment noted. The text in Section 2.1 states the following;” However, this sampling will include regular monthly sampling and storm flow sampling and will not necessarily target sustained high flows; therefore, the sample locations that NRD will sample have been included in the Mill Creek sampling required in this SAP Addendum such that a complete synoptic high flow data set is available on all locations within Mill Creek.” As discussed during the May 21, 2013 surface water technical meeting, the sampling goal is to collect Mill Creek within one day. Other drainages will be collected within one day, either prior to or after Mill Creek sampling depending on drainage specific flows. 2. Agency Comment: If there is no flow at ANT-1, the sampling location in Antelope Creek can be moved upstream as needed to find flowing water. Atlantic Richfield Response: Comment noted. Table 1 has been modified to reflect that if there is no flow at the proposed location, the sample location will be moved upstream as needed to find water flow. The location of the Antelope station will be discussed with oversight during the field work. 3. Agency Comment: The background stations can be adjusted as needed based on access. Atlantic Richfield Response: Comment noted. The location of the background stations will be discussed with oversight during the field work. Response to Agency Comments for the Page 1 of 3 Draft Final Spring 2013 Anaconda High Flow Stream Sampling Event- Addendum 1 to the Final Willow Creek Mass Loading Study SAP 4. Agency Comment: CAL-9 should be sampled at the highway bridge to be consistent with previous data. Atlantic Richfield Response: Comment noted. The Figure 1 and Table 1 have been modified to reflect the change in CAL-9. 5. Agency Comment: Agency oversight should be present when selecting new sites. Atlantic Richfield Response: Comment noted. The sampling schedule will be coordinated with the Agencies and it is anticipate the Agencies will be present during the work. 6. Agency Comment: Some of the historic locations shown on Figure 1 are inaccurate. Please consult with Agency oversight prior to sampling to locate historic sites. Atlantic Richfield Response: Comment noted. Atlantic Richfield has visited the sample sites to determine and identify the location, to as close as possible, that historic samples were collected. The historic sample location will be utilized to the extent possible for all samples. 7. Agency Comment: The reporting limits listed in Table 2 are too high for copper, cadmium, and lead. Recent reporting limits provided by Pace Analytical are shown in the table below and should be sufficient. Please update Table 2. BPSOU Metals IDLs in Surface Water 2/21/2012 Metal IDL µg/L Cadmium 0.028 Copper 0.25 Lead 0.018 Zinc 2.5 Response to Agency Comments for the Page 2 of 3 Draft Final Spring 2013 Anaconda High Flow Stream Sampling Event- Addendum 1 to the Final Willow Creek Mass Loading Study SAP Atlantic Richfield Response: Comment noted. Table 2 has been modified to reflect the following reporting limits obtained from Pace Analytical Metal IDL µg/L Cadmium 0.032 Copper 0.174 Lead 0.046 Zinc 0.98 8. Agency Comment: This plan does not address sediment sampling required in the SOW. Atlantic Richfield Response: Comment noted. Sediment sampling will be addressed in the forthcoming 2013 storm water sampling SAP Addendum anticipated to be submitted in late May, 2013. Response to Agency Comments for the Page 3 of 3 Draft Final Spring 2013 Anaconda High Flow Stream Sampling Event- Addendum 1 to the Final Willow Creek Mass Loading Study SAP ANACONDA SMELTER NPL SITE ANACONDA REGIONAL WATER, WASTE & SOILS OPERABLE UNIT Final Spring 2013 Anaconda High Flow Stream Sampling Event - Addendum 1 to the Final Willow Creek Mass Loading Study Sampling and Analysis Plan (SAP) Prepared for: Atlantic Richfield Company 317 Anaconda Road Butte, Montana 59701 Prepared by: Pioneer Technical Services, Inc. P. O. Box 3445 Butte, Montana 59702 May 23, 2013 TABLE OF CONTENTS Page 1.0 INTRODUCTION .............................................................................................................. 1 2.0 HIGH FLOW STREAM WATER MONITORING PROGRAM ...................................... 1 2.1 High Flow Sampling Locations .............................................................................. 1 2.2 Sample Location Access ......................................................................................... 2 2.3 Time and Duration of Sampling ............................................................................. 2 2.4 Sampling Methods and Procedures ......................................................................... 3 2.4.1 Sample Collection Method ......................................................................... 3 2.4.2 Flow Measurement Method ........................................................................ 3 2.5 Sampling Analysis and Procedures ......................................................................... 4 2.6 Safety ...................................................................................................................... 4 3.0 DATA MANAGEMENT/ DATA VALIDATION ............................................................ 4 4.0 REPORTING ...................................................................................................................... 4 5.0 REFERENCES ................................................................................................................... 5 Final Spring 2013 Anaconda High Flow Stream Sampling Event - Addendum 1 Page i of ii to the Final Willow Creek Mass Loading Study SAP Rev. 2 LIST OF FIGURES Figure 1 ARWW&S Sitewide Surface Monitoring High Flow Sampling Locations LIST