Draft Phase 1A SAP Attachment 14C-2 Section D: Sampling and Analysis Revision 0 US Magnesium NPL Site August 2013

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Document Tracking Number: 14C-2-25

RECORD OF UFPQAPP-SAP MODIFICATION

INSTRUCTIONS: This form is required anytime a modification is being made to any worksheets or sections for any portion of the Phase 1A SAP, including attachments, tables, figures, and/or SOPs.

Requestor: Kevin Lundmark Title: ERM RI Field Lead Name of Site/Field Event: US Magnesium Phase 1A RI SAP, Revision 0 Date of Proposed Modification: Revised 8 May 2015 Modified SAP Section(s): 1) Worksheet 15, Attachment 15 A, Aqueous-8270 Worksheet 2) Worksheet 11, Section 11.3.2, Step 7, Sampling and Analysis Methods

Attachment 17A, SOP USM-08, Surface Water Sampling Standard Operating Procedure • Section 6.1 Equipment, • Section 6.2 Surface Water Sampling Procedure, Step 6, and • Attachment 1, Equipment List.

3) Worksheet 19, Perchlorate analysis for aqueous matrix Attachment 17A, SOP USM-08, Surface Water Sampling Standard Operating Procedure Describe the Modification:

1) Attachment 15A. Add pentachlorobenzene, CAS RN 608-93-5, to the Aqueous-8270 worksheet:

Target Quantitation Limit = 0.32 µg/L, Tap Water RSL Laboratory Detection Limit =0.46 µg/L Laboratory Quantitation Limit =10 µg/L

Also add a footnote (5) for pentachlorobenzene, stating: “Pentachlorobenzene was added as a SVOC analyte in May 2015, after many Phase 1A site-wide water samples had been analyzed without this SVOC. Consequently, pentachlorobenzene will not be included in the data adequacy evaluation for surface water and groundwater (WS#11 and WS#37).”

2) Worksheet 11, Section 11.3.2, Step 7, Sampling and Analysis Methods. Revise to eliminate the requirement to use a splitter sampling method when a split sample is required by USEPA:

A dipper sampling method can be used where filtering is not required. A splitter sampling method is required when split sampling is required by the EPA, taking care to minimize disturbance of sediment as per WS#17 and Attachment 17A.

Attachment 17A, SOP USM-08, Surface Water Sampling Standard Operating Procedure. • Section 6.1, Equipment:

o Omit the section describing the Sample Splitter.

Draft Phase 1A SAP Attachment 14C-2 Section D: Sampling and Analysis Revision 0 US Magnesium NPL Site August 2013

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• Section 6.2, Surface Water Sampling Procedure: o Delete Step 6 o Add the following sentences to Step 7:

“If split samples are required at the sample location, fill USEPA split sample QC bottles concurrently with ERM sample bottles to the extent possible. ERM and USEPA sample bottles corresponding to the same analyses should be filled concurrently, alternating between ERM and USEPA bottles. For example, fill the first ERM bottle for PCB analysis, then fill first EPA split bottle for PCB analysis, then fill second ERM bottle for PCB analysis, then fill second USEPA split sample for PCB analysis, and so on.”

• Attachment 1, Equipment List:

o Omit Sample Splitter and Bubble Level from list.

3) Worksheet 19, Perchlorate analysis for aqueous matrix:

• Eliminate 0.2 µm filtration for perchlorate analysis. Revise preservation requirements to “Field-filtered through 0.45 µm filter, 1/3 volume headspace, cool to 4 ±2 °C.”

Attachment 17A, SOP USM-08, Surface Water Sampling Standard Operating Procedure:

• Revise Step 11 to read: “After rinsing the 0.45 μm filter, samples for dissolved metals, perchlorate, or other analyses requiring field-filtration can be collected from the outlet of the filter. Sample bottles for perchlorate analyses must be left with 1/3 bottle of headspace to help prevent anaerobic degradation of the sample.”

• Delete Step 12. • Section 8.0: Eliminate discussion of 0.2 µm syringe disk filters from procedures for collecting filter

blank QC samples for perchlorate analysis.

Justification or Reason for the Modification:

Modification 1):

Pentachlorobenzene has been added as a SVOC analyte, as requested by USEPA’s contractor during the March 2015 Phase 1B RI Scoping meetings. Because 30 groundwater and 16 surface water Phase 1A RI samples have already been analyzed without pentachlorobenzene, there will not be a sufficient number of water samples with pentachlorobenzene results to evaluate data adequacy per Phase 1A SAP Worksheets 11 and 37.

Modification 2):

The use of a sample splitter when collecting oversight split surface water samples during the Phase 1A RI was found to be difficult and at times ineffective due to the following reasons:

• The splitter could not be filled quickly enough to provide uniform flow through all sample ports, resulting in uneven filling of sample containers. It is not practical to increase the sampling rate sufficiently for the splitter to work properly due to pump limitations, health and safety concerns, and limitations on filtration rates.

• USEPA split sample bottles for some analyses were of different sizes (volumes) than the ERM bottles

• Use of the splitter resulted in significant splashing which creates a health and safety risk to field personnel, especially when sampling acidic water.

These observations are consistent with the limitations identified in the Technical Memorandum for Oversight of the Phase 1A Remedial Investigation in PRI Areas 2 and 8 through 17 (PWT3 2014).

Draft Phase 1A SAP Attachment 14C-2 Section D: Sampling and Analysis Revision 0 US Magnesium NPL Site August 2013

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The request to use a splitter was based on differences between VOC and SVOC results between ERM and EPA split QC water samples collected (without a splitter) during the Phase 1A DMA, as described in SAP Attachment 11F: EPA Oversight Soil, Sediment, Solid Waste, and Water DMA Results Reports (field and analytical). However, these differences were limited to situations where either one or both results were below the quantitation limit and are therefore likely to be more an effect of different analytical methods (with different QLs) rather than sample heterogeneity. This is corroborated by the results for Phase 1A RI field duplicate surface water and groundwater QC samples, which were collected without the use of a splitter and showed excellent agreement.

Modification 3): During Phase 1A water sampling activities completed November 2013 – April 2014, field filtering through the 0.45 µm filter was possible; however, the 0.2 µm filter was found to clog quickly and sufficient volume could not be collected for analysis. Aqueous perchlorate samples for Phase 1A were field-filtered using a 0.45 µm in-line cartridge filter only. EPA Review/Approval: ________________________________________Date: ________________

(RPM or designee)

Each approved UFPQAPP-SAP Modification Form will become part of Attachment 17B in the Phase 1A Final SAP and also incorporated into the appropriate RI Results Report. A copy is to be provided to all recipients identified on SAP Worksheet #3.