# Analytical Feasibility Support Document for the Six-Year Review of Existing National Primary Drinking Water Regulations (Reassessment of Feasibility for Chemical Contaminants)Printed on Recycled Paper 

# Office of Water Office of Ground Water and Drinking Water (4607M) EPA 815-R-03-003 www.epa.gov/safewater March 2003

## i EPA 815-R-03-003



# Analytical Feasibility Support Document for the Six-Year Review of Existing National Primary Drinking Water Regulations (Reassessment of Feasibility for Chemical Contaminants)

March 2003

United States Environmental Protection Agency Office of Water Office of Ground Water and Drinking Water

Standards and Risk Management Division Targeting and Analysis Branch 1200 Pennsylvania Avenue, NW (4607M) Washington, DC 20460

## ii Methods Support Document for Six-Year Review Final - March 2003 

# Acknowledgments The USEPA staff involved in the development and/or review of either all or portions of this document include Wynne Miller, Ed Glick, Pat Churilla, Jeanne Campbell, Richard Reding, Barry Lesnik, Terry Smith, Harry Allen, Judy Lebowich and Marc Parrotta. EPA staff assisted in one of several areas that included: (1) developing and/or reviewing the process used to assess whether the feasible limits have changed for a subset of the 68 chemical SDWA analytes under review; (2) review and comment on the preliminary results; (3) general QA/QC to verify that the approved analytical methods and the method detection limits listed for each contaminant was correct; and/or (4) writing and editorial review of portions of this document. Other USEPA staff (from EPA’s Office of Researchand Development) specifically involved in the internal peer review included Jody Shoemaker, Ted Martin and Jim Odell. ORD staff peer reviewed the draft document published in March of 2002 (EPA 815-D-02-002). This final version reflects their comments. EPA acknowledges the National Drinking Water Advisory Council (NDWAC) Drinking Water Committee for their recommendations on how EPA should review analytical feasibility. EPA also appreciates the technical support provided by The Cadmus Group, Inc, the prime contractor for this project. Dr. George Hallberg served as the Cadmus project manager and major contributions by Wendy Chou, Ashton Koo, Anne Isham and Susan Bj ork are gratefully acknowledged. Their support in the development of this document included documentation of approved analytical methods and their MDLs, the analyses of the Water Supply Data, the development of the graphs and tables, a large portion of the writing in the results section, and general QA/QC of the analyses and the document.

## iii Methods Support Document for Six-Year Review Final - March 2003 

# Executive Summary The Safe Drinking Water Act (SDWA), as amended in 1996, requires the Environmental Protection Agency (EPA) to review and revise, if appropriate, existing National Primary Drinking Water Regulations (NPDWRs). As part of the review, EPA developed a protocol document (entitled EPA Protocol for the Review of Existing National Primary Drinking Water Regulations) to describe the process and strategy for regulatory review that EPA used to meet its statutory requirement. EPA developed the protocol based on recommendations from the National Drinking Water Advisory Council (NDWAC), through internal Agency deliberations, and through discussions with the diverse stakeholders involved in drinking water and its protection. Based on the NDWAC recommendations, EPA's review included the consideration of five key elements, as appropriate: health effects, analytical and treatment feasibility, implementation-related issues, occurrence and exposure, and economic impacts . The purpose of the analytical methods feasibility analysis was to determine whether changes in the practical quantitation level (PQL) were possible in those instances where the Maximum Contaminant Level is limited, or might be limited, by analytical feasibility. This document, "Analytical Feasibility Support Document for the Six-Year Review of Existing National Primary Drinking Water Regulations: Reassessment of Feasibility for Chemical Contaminants ," describes the process recommended byNDWAC and used by EPA to address the analytical feasibility aspect of the current (1996-2002) SixYear Review. To be consistent with the accepted policy and procedures used by EPA to derive quantitation levels for drinking water contaminants, the Six-Year Reviewfocused on the process that has been used by the Office of Ground Water and Drinking Water for many years. Historically, EPA’s OGWDW used two main approaches to determine practical quantitation levels (PQLs) for SDWA analytes. One approach (and the preferred approach) used data from Water Supply (WS) Performance Evaluation (PE) studies. Although the primary use of the WS-PE data was for EPA’s laboratory certification, the data were also used as a secondary data source for many years to develop PQLs when the spike concentrations were in the appropriate concentration range. The derivation of the PQL using WS data involved determining the concentration of an analyte at which 75 percent of EPA Regional and State laboratories achieved results within a specified range around the spike value. In the absence of WS data, the other approach that EPA used was the MDL multiplier method. In this approach, the PQL was calculated by multiplying the EPAderived MDL by a factor of 5 or 10. The MDL multiplier method was mostly used in the early years of rule development for NPDWRs when insufficient WSdata were available. Once sufficient WS data became available, most of the PQLs developed using the MDL multiplier were validated using WS data. For the Six-Year analytical feasibility review, EPA focused on assessing whether the practical quantitation limit has changed since promulgation for a subset of the 68 chemical NPDWRs. EPA performed the analytical feasibility analysis for a total of 40 NPDWRs that fell into one of two categories:

< 

### First, for those contaminants where the MCL is currently limited by analytical feasibility (i.e., the MCL is set at the PQL) and the MCLG is still appropriate, EPA evaluated the currently approved methods for those contaminants and available WS data to determine whether it might be possible to lower the PQL and hence set an MCL that is closer to the MCLG.

< 

### The second circumstance under which EPA re-evaluated the PQL was for contaminants identified under the Six-Year health effects technical review as having potential changes to their MCLG. Because the information for the health effects review was not completely

## iv Methods Support Document for Six-Year Review Final - March 2003 

### available at the time the analytical methods analysis began, EPA took a broad-brush approach and included a number of contaminants that may not have needed a reassessment of their analytical feasibility. For each of these 40 chemical NPDWRs, the analytical feasibility reassessment included: (1) a methods comparisonstep to help identify whether the ability to detect (and therefore quantify) these contaminants at lower levels has increased; (2) a methods usage over timestep to identify the analytical methods that appear to be the most widely used for the analysis of particular contaminants. (3) a Water Supply data analysisstep to determine if a PQL can be recalculated (if sufficient WS information is available) or if there is anindication that a PQL may be lower using the available information. The results of these three steps aided in assessing whether a PQL might change for a specific contaminant and, if so, estimating what the new PQL might be. The results of Six-Year analytical feasibility reviewconcluded that the majority of the available WS data were insufficient to actually recalculate the PQL for many of the 40 contaminants of interest. The data were considered insufficient because either the true value of the spike concentrations used in the WS studies were above the concentration of interest and/or the percentages of labs passing exceeded the 75 percent criterion used to calculate a PQL. However,for many of the 40 contaminants, the available data were sufficient to indicate whether the PQL might changeor if the current PQL is still appropriate. Of the 40 NPDWRs evaluated, the available information indicates that the PQL for 25 might possibly be lower. The PQL for the remaining 15 appears to still be a ppropriate. For the 25 analytes where the WS data indicate that a lower PQL may exist, EPA used the information about method usage over time, the MDLs for these methods, and the 10 x MDL multiplier to estimate what the potentially lower PQL might be. This estimated value was used as a threshold value in the occurrence and exposure analyses to determine whether an improvement in public health protection might be possible if EPA were to consider gathering more definitive data to recalculate the PQL and possibly lower the MCL.

## v Methods Support Document for Six-Year Review Final - March 2003 

## Table of Contents Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

I. Introduction ..................................................................... 1 II. Background ..................................................................... 1 A. What is the Relationship Between SDWA Requirements and Analytical Methods? . . . 1 B. How Have PQLs Been Determined in the Past for SDWA Contaminants? . . . . . . . . . . 3 1. How Were Water Supply Studies Conducted? .......................... 3 2. What Criteria Are Used to Determine a PQL? . . . . . . . . . . . . . . . . . . . . . . . . . . 4 III. How Did EPA Identify Which Contaminants to Evaluate for a PQL Reassessment? . . . 5 IV. What Approaches Were Used to Reassess the PQLs of Contaminants Identified by the Six-Year Review Process? ................................................ 8 V. Results of the PQL Reassessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Alachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Conclusion for Alachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Benzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Conclusion for Benzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Benzo(a)pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Results of the WS Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Conclusion for Benzo(a)pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Beryllium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

## vi Methods Support Document for Six-Year Review Final - March 2003 

### Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Conclusion for Beryllium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Bis(2-ethylhexyl)phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Conclusion for Bis(2-ethylhexyl)phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Cadmium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Conclusion for Cadmium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Carbofuran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Conclusion for Carbofuran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Carbon Tetrachloride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Conclusion for Carbon Tetrachloride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Chlordane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Conclusion for Chlordane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Chromium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Conclusion for Chromium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

## vii Methods Support Document for Six-Year Review Final - March 2003 

### 1,2-Dibromo-3-chloropropane (DBCP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Conclusion for DBCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 1,4-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Conclusion for 1,4-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 1,2-Dichloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Conclusion for 1,2-Dichloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 1,1-Dichloroethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Conclusion for 1,1-Dichloroethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Dichloromethane (methylene chloride) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Conclusion for Dichloromethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 1,2-Dichloropropane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Conclusion for 1,2-Dichloropropane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 2,3,7,8-TCDD (Dioxin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

## viii Methods Support Document for Six-Year Review Final - March 2003 

### Diquat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Conclusion for Diquat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Ethylene Dibromide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Conclusion for Ethylene Dibromide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Fluoride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Conclusion for Fluoride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Conclusion for Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Heptachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Conclusion for Heptachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Heptachlor Epoxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Conclusion for Heptachlor Epoxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Hexachlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 b. Results of the PQL analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Conclusion for Hexachlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

## ix Methods Support Document for Six-Year Review Final - March 2003 

### Hexachlorocyclopentadiene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Conclusion for Hexachlorocyclopentadiene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Mercury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Conclusion for Mercury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Methoxychlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Conclusion for Methoxychlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Oxamyl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Conclusion for Oxamyl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

PCBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Conclusion for PCBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Pentachlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Conclusion for Pentachlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

## x Methods Support Document for Six-Year Review Final - March 2003 

### Picloram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Conclusion for Picloram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Tetrachloroethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Conclusion for Tetrachloroethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Thallium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Conclusion for Thallium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Toluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Conclusion for Toluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Toxaphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Conclusion for Toxaphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

1,1,1-Trichloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Conclusion for 1,1,1-Trichloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

## xi Methods Support Document for Six-Year Review Final - March 2003 

### 1,1,2-Trichloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 b. Results of the PQL analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Conclusion for 1,1,2-Trichloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Trichloroethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Conclusion for Trichloroethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Vinyl Chloride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Conclusion for Vinyl Chloride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Xylenes (total) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Results of the Method Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Results of the Analysis of the WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 a. Method Usage Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 b. Results of the PQL Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Conclusion for Xylenes (total) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

VI. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

## xiii Methods Support Document for Six-Year Review Final - March 2003 

## List of Tables Table 1. SDWA Chemical Contaminants Undergoing Analytical Methods/PQL Reassessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 2. Results of the Analytical Methods Comparison for Alachlor . . . . . . . . . . . . . . . . . . 11 Table 3. Evaluation of Alachlor Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 4. Results of the Analytical Methods Comparison for Benzene . . . . . . . . . . . . . . . . . . 14 Table 5. Evaluation of Benzene Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 6. Results of the Analytical Methods Comparison for Benzo(a)pyrene . . . . . . . . . . . . 18 Table 7. Evaluation of PE Data for Benzo(a)pyrene from WS Studies . . . . . . . . . . . . . . . . . . 19 Table 8. Results of the Analytical Methods Comparison for Beryllium . . . . . . . . . . . . . . . . . 22 Table 9. Evaluation of Beryllium Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 10. Results of the Analytical Methods Comparison for Bis(2-ethylhexyl)phthalate . . . . 26 Table 11. Evaluation of Bis(2-ethylhexyl)phthalate Data from WS Studies . . . . . . . . . . . . . . . 27 Table 12. Results of the Analytical Methods Comparison for Cadmium . . . . . . . . . . . . . . . . . 30 Table 13. Evaluation of Cadmium Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Table 14. Results of the Analytical Methods Comparison for Carbofuran . . . . . . . . . . . . . . . . 33 Table 15. Evaluation of Carbofuran Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Table 16. Results of the Analytical Methods Comparison for Carbon Tetrachloride . . . . . . . . 36 Table 17. Evaluation of Carbon Tetrachloride Data from WS Studies . . . . . . . . . . . . . . . . . . . 38 Table 18. Results of the Analytical Methods Comparison for Chlordane . . . . . . . . . . . . . . . . . 39 Table 19. Evaluation of Chlordane Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Table 20. Results of the Analytical Methods Comparison for Chromium . . . . . . . . . . . . . . . . 42 Table 21. Evaluation of Chromium Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Table 22. Results of the Analytical Methods Comparison for DBCP . . . . . . . . . . . . . . . . . . . 46 Table 23. Evaluation of DBCP Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Table 24. Results of the Analytical Methods Comparison for 1,4-Dichlorobenzene . . . . . . . . 49 Table 25. Evaluation of 1,4-Dichlorobenzene Data from WS Studies . . . . . . . . . . . . . . . . . . . 51 Table 26. Results of the Analytical Methods Comparison for 1,2-Dichloroethane . . . . . . . . . . 52 Table 27. Evaluation of 1,2-Dichloroethane Data from WS Studies . . . . . . . . . . . . . . . . . . . . . 54 Table 28. Results of the Analytical Methods Comparison for 1,1-Dichloroethylene . . . . . . . . 55 Table 29. Evaluation of 1,1-Dichloroethylene Data from WS Studies . . . . . . . . . . . . . . . . . . . 57 Table 30. Results of the Analytical Methods Comparison for Dichloromethane . . . . . . . . . . . 58 Table 31. Evaluation of Dichloromethane Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . 60 Table 32. Results of the Analytical Methods Comparison for 1,2-Dichloropropane . . . . . . . . 61 Table 33. Evaluation of 1,2-Dichloropropane Data from WS Studies . . . . . . . . . . . . . . . . . . . . 63 Table 34. Results of the Analytical Methods Comparison for 2,3,7,8-TCDD . . . . . . . . . . . . . . 64 Table 35. Results of the Analytical Methods Comparison for Diquat . . . . . . . . . . . . . . . . . . . . 65 Table 36. Evaluation of Diquat Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Table 37. Results of the Analytical Methods Comparison for Ethylene Dibromide . . . . . . . . . 69 Table 38. Evaluation of Ethylene Dibromide Data from WS Studies . . . . . . . . . . . . . . . . . . . . 71 Table 39. Results of the Analytical Methods Comparison for Fluoride . . . . . . . . . . . . . . . . . . 72 Table 40. Evaluation of Fluoride Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Table 41. Results of the Analytical Methods Comparison for Glyphosate . . . . . . . . . . . . . . . . 77 Table 42. Evaluation of Glyphosate Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Table 43. Results of the Analytical Methods Comparison for Heptachlor . . . . . . . . . . . . . . . . 80 Table 44. Evaluation of Heptachlor Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Table 45. Results of the Analytical Methods Comparison for Heptachlor Epoxide . . . . . . . . . 83 Table 46. Evaluation of Heptachlor Epoxide Data from WS Studies . . . . . . . . . . . . . . . . . . . . 86

## xiv Methods Support Document for Six-Year Review Final - March 2003 

## Table 47. Results of the Analytical Methods Comparison for Hexachlorobenzene . . . . . . . . . 88 Table 48. Evaluation of Hexachlorobenzene Data from WS Studies . . . . . . . . . . . . . . . . . . . . 90 Table 49. Results of the Analytical Methods Comparison for Hexachlorocyclopentadiene . . . 91 Table 50. Evaluation of Hexachlorocyclopentadiene Data from WS Studies . . . . . . . . . . . . . . 93 Table 51. Results of the Analytical Methods Comparison for Mercury . . . . . . . . . . . . . . . . . . 95 Table 52. Evaluation of Mercury Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Table 53. Results of the Analytical Methods Comparison for Methoxychlor . . . . . . . . . . . . . . 99 Table 54. Evaluation of Methoxychlor Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . 100 Table 55. Results of the Analytical Methods Comparison for Oxamyl . . . . . . . . . . . . . . . . . . 102 Table 56. Evaluation of Oxamyl Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Table 57. Regression Results for Oxamyl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Table 58. Results of the Analytical Methods Comparison for PCBs . . . . . . . . . . . . . . . . . . . . 108 Table 59. Evaluation of PCBs Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Table 60. Results of the Analytical Methods Comparison for Pentachlorophenol . . . . . . . . . 110 Table 61. Evaluation of Pentachlorophenol Data from WS Studies . . . . . . . . . . . . . . . . . . . . 112 Table 62. Results of the Analytical Methods Comparison for Picloram . . . . . . . . . . . . . . . . . 114 Table 63. Evaluation of Picloram Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Table 64. Results of the Analytical Methods Comparison for Tetrachloroethylene . . . . . . . . 117 Table 65. Evaluation of Tetrachloroethylene Data from WS Studies . . . . . . . . . . . . . . . . . . . 120 Table 66. Results of the Analytical Methods Comparison for Thallium . . . . . . . . . . . . . . . . . 121 Table 67. Evaluation of Thallium Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Table 68. Analytical Methods Comparison for Toluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Table 69. Evaluation of Toluene Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Table 70. Results of the Analytical Methods Comparison for Toxaphene . . . . . . . . . . . . . . . 127 Table 71. Evaluation of Toxaphene Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 Table 72. Results of the Analytical Methods Comparison for 1,1,1-Trichloroethane . . . . . . . 131 Table 73. Evaluation of 1,1,1-Trichloroethane Data from WS Studies . . . . . . . . . . . . . . . . . . 134 Table 74. Results of the Analytical Methods Comparison for 1,1,2-Trichloroethane . . . . . . . 135 Table 75. Evaluation of 1,1,2-Trichloroethane Data from WS Studies . . . . . . . . . . . . . . . . . . 138 Table 76. Results of the Analytical Methods Comparison for Trichloroethylene . . . . . . . . . . 139 Table 77. Evaluation of Trichloroethylene Data from WS Studies . . . . . . . . . . . . . . . . . . . . . 141 Table 78. Results of the Analytical Methods Comparison for Vinyl Chloride . . . . . . . . . . . . 142 Table 79. Evaluation of Vinyl Chloride Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . 145 Table 80. Analytical Methods Comparison for Xylenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Table 81. Evaluation of Xylenes (total) Data from WS Studies . . . . . . . . . . . . . . . . . . . . . . . 148 Table 82. Summary of Results from the Methods Comparison and WS Analysis . . . . . . . . . 150 Table 83. Estimated PQLs Based on Method Usage and 10 x MDL Multiplier . . . . . . . . . . A-2

## xv Methods Support Document for Six-Year Review Final - March 2003 

## List of Figures Figure 1. Overview of the Protocol for the Revise/Not Revise Decision with a Focus on Where Analytical Feasibility was Re-evaluated. .............................................. 6 Figure 2. Distribution of Analytical Techniques by WS Study: Alachlor . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 3. Distribution of Analytical Techniques by WS Study: Benzene . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 4. Two-part Distribution of Benzene WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 5. Distribution of Analytical Techniques by WS Study: Benzo(a)pyrene . . . . . . . . . . . . . . . . . 19 Figure 6. PQL Evaluation from PE WS Data: Benzo(a)pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 7. Distribution of Analytical Techniques by WS Study: Beryllium . . . . . . . . . . . . . . . . . . . . . . 23 Figure 8. Two-part Distribution of Beryllium WS Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 9. Distribution of Analytical Techniques by WS Study: Bis(2-ethylhexyl)phthalate . . . . . . . . 27 Figure 10. Two-part Distribution of Bis(2-ethylhexyl)phthalate WS Data . . . . . . . . . . . . . . . . . . . . . . 29 Figure 11. Distribution of Analytical Techniques by WS Study: Cadmium . . . . . . . . . . . . . . . . . . . . . 31 Figure 12. Distribution of Analytical Techniques by WS Study: Carbofuran . . . . . . . . . . . . . . . . . . . . 34 Figure 13. Distribution of Analytical Techniques by WS Study: Carbon Tetrachloride . . . . . . . . . . . . 37 Figure 14. Distribution of Analytical Techniques by WS Study: Chlordane . . . . . . . . . . . . . . . . . . . . . 40 Figure 15. Distribution of Analytical Techniques by WS Study: Chromium . . . . . . . . . . . . . . . . . . . . . 44 Figure 16. Distribution of Analytical Techniques by WS Study: DBCP . . . . . . . . . . . . . . . . . . . . . . . . 47 Figure 17. Distribution of Analytical Techniques by WS Study: 1,4-Dichlorobenzene . . . . . . . . . . . . . 50 Figure 18. Distribution of Analytical Techniques by WS Study: 1,2-Dichloroethane . . . . . . . . . . . . . . 53 Figure 19. Distribution of Analytical Techniques by WS Study: 1,1-Dichloroethylene . . . . . . . . . . . . 56 Figure 20. Distribution of Analytical Techniques by WS Study: Dichloromethane . . . . . . . . . . . . . . . 59 Figure 21. Distribution of Analytical Techniques by WS Study: 1,2-Dichloropropane . . . . . . . . . . . . . 62 Figure 22. Distribution of Analytical Techniques by WS Study: Diquat . . . . . . . . . . . . . . . . . . . . . . . . 67 Figure 23. Distribution of Analytical Techniques by WS Study: Ethylene Dibromide . . . . . . . . . . . . . 70 Figure 24. Distribution of Analytical Techniques by WS Study: Fluoride . . . . . . . . . . . . . . . . . . . . . . . 74 Figure 25. Distribution of Analytical Techniques by WS Study: Glyphosate . . . . . . . . . . . . . . . . . . . . 78 Figure 26. Distribution of Analytical Techniques by WS Study: Heptachlor . . . . . . . . . . . . . . . . . . . . 81 Figure 27. Distribution of Analytical Techniques by WS Study: Heptachlor Epoxide . . . . . . . . . . . . . 85 Figure 28. Distribution of Analytical Techniques by WS Study: Hexachlorobenzene . . . . . . . . . . . . . 89 Figure 29. Distribution of Analytical Techniques by WS Study: Hexachlorocyclopentadiene . . . . . . . 92 Figure 30. Distribution of Analytical Techniques by WS Study: Mercury . . . . . . . . . . . . . . . . . . . . . . 96 Figure 31. Distribution of Analytical Techniques by WS Study: Methoxychlor . . . . . . . . . . . . . . . . . 100 Figure 32. Distribution of Analytical Techniques by WS Study: Oxamyl . . . . . . . . . . . . . . . . . . . . . . 103 Figure 33. PQL Evaluation of PE WS Data: Oxamyl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Figure 34. Two-part Distribution of Oxamyl WS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Figure 35. Distribution of Analytical Techniques by WS Study: Pentachlorophenol . . . . . . . . . . . . . 111 Figure 36. Evaluation of PE WS Data: Pentachlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Figure 37. Distribution of Analytical Techniques by WS Study: Picloram . . . . . . . . . . . . . . . . . . . . . 115 Figure 38. Distribution of Analytical Techniques by WS Study: Tetrachloroethylene . . . . . . . . . . . . 119 Figure 39. Distribution of Analytical Techniques by WS Study: Thallium . . . . . . . . . . . . . . . . . . . . 122 Figure 40. Distribution of Analytical Techniques by WS Study: Toluene . . . . . . . . . . . . . . . . . . . . . . 125 Figure 41. Distribution of Analytical Techniques by WS Study: Toxaphene . . . . . . . . . . . . . . . . . . . 129 Figure 42. Distribution of Analytical Techniques by WS Study: 1,1,1-Trichloroethane . . . . . . . . . . . 133 Figure 43. Distribution of Analytical Techniques by WS Study: 1,1,2-Trichloroethane . . . . . . . . . . . 137 Figure 44. Distribution of Analytical Techniques by WS Study: Trichloroethylene . . . . . . . . . . . . . . 140 Figure 45. Distribution of Analytical Techniques by WS Study: Vinyl Chloride . . . . . . . . . . . . . . . . 144

## xvi Methods Support Document for Six-Year Review Final - March 2003 

### Figure 46. Distribution of Analytical Techniques by WS Study: Xylenes (total) . . . . . . . . . . . . . . . . 147

## 1 Methods Support Document for Six-Year Review Final - March 2003 

## Analytical Feasibility Support Document for the Six-Year Review of Existing NationalPrimary Drinking Water Regulations (Reassessment of Feasibility for Chemical Contaminants)
I. Introduction The Safe Drinking Water Act (SDWA), as amended in 1996, requires the Environmental Protection Agency (EPA) to review and revise, if appropriate, existing National Primary Drinking Water Regulations (NPDWRs). As part of the review, EPA developed a protocol document (EPA Protocol for the Review of Existing National Primary Drinking Water Regulations)that describes the process and strategy EPA used to review existing NPDWRs in order to meet its statutory requirement. EPA developed the protocol document based on recommendations from the National Drinking Water Advisory Council (NDWAC), through internal Agency deliberations, and through discussions with the diverse stakeholders involved in drinking water and its protection. To more efficiently utilize limited resources, EPA performed a series of analyses that were intended to target those NPDWRs that are the most appropriate candidates for revision. As part of the review, and where appropriate, EPA reviewed the following key technical elements to make decisions regarding regulatory changes: health risks assessments; technology assessments (analytical feasibility and treatment technology); other regulatory revisions (e.g., monitoring and reporting); occurrence and exposure analyses; and available economic information. This document discusses the analytical feasibility aspect of the current (1996-2002) Six-Year Review. The 1999-2002 Six-Year Review includes the review of 68 chemical NPDWRs promulgated prior to the 1996 SDWA Amendments. Because the analytical measurement feasibility may have been the limiting factor in setting the Maximum Contaminant Level (MCL) for some of the existing NPDWRs or because the health effects reviews may indicate a potential change in the MCLG, this report examines the reassessment of analytical methods capabilities including a reassessment of whether the Practical Quantitation Levels (PQLs) may have changed since promulgation. The PQL is generally defined as "the lowest level that can be reliably achieved within specified limits of precision and accuracyduring routine laboratory operating conditions" (50 FR 46906, November 13, 1985). The purpose of this support document is to: • provide background information on the relationship between SDWA requirements and the analytical methods feasibility; • describe how PQLs have historically been determined; • and describe the process used to identify which of the 68 chemical NPDWRs under the 1996-2002 review are subject to a further assessment with regards to analytical methods capabilities and a reassessment of the PQL.

II. Background A. What is the Relationship Between SDWA Requirements and Analytical Methods? The SDWA [§1401(1)(C)(i); 42 U.S.C. § 300f(1)(C)(i)] states that an MCL for a national primary drinking water regulation is set "if, in the judgment of the Administrator, it is economically and technologically feasible to ascertain the level of such contaminant in water in public water systems." According to SDWA, NPDWRs include "criteria and procedures to

## 2 Methods Support Document for Six-Year Review Final - March 2003 

## assure a supply of drinking water which dependably complies with such maximum contaminant levels; including accepted methods of quality control and testing procedures to insure compliance with such levels" [§1401(1)(D); 42 U.S.C. § 300f(1)(D)]. Except in certain circumstances, EPA is to set the MCL as close to the Maximum Contaminant Level Goal (MCLG) as is feasible with the best available technologies (Section 1412 (b)(4)(B)). The MCLs for several SDWA contaminants were set due to the limits of the analytical feasibility at that time. Since the promulgation of pre-1996 SDWA NPDWRs, newer analytical methods and updated methods for measuring SDWA contaminants have been approved. The approval of newer analytical techniques may have provided laboratories with the analytical capability to measure some contaminants at lower levels. In addition, some laboratories may have improved in their ability to measure at lower levels using the same methods that were originally promulgated. In considering analytical methods for use in compliance monitoring, EPA evaluates the overall sensitivity of the techniques. In previous regulations, EPA used two measures of analytical capability, the Method Detection Limit (MDL) and the Practical Quantitation Level (PQL).

< 

## The MDL is a measure of method sensitivity. The MDL is defined at 40 CFR Part 136 Appendix B as "the minimum concentration of a substance that can be reported with 99% confidence that the analyte concentration is greater than zero." MDLs can be operator, method, laboratory, and matrix-specific. Due to normal day-to-day and run-to-run analytical variability, MDLs may not be reproducible within a laboratory or between laboratories. The regulatory significance of the MDL is that EPA uses the MDL to determine when a contaminant is deemed to be detected and it can be used to calculate a PQL for that contaminant.

< 

## In the preamble to a November 13, 1985 rulemaking (50 FR 46906), the PQL was defined as "the lowest concentration of an analyte that can be reliably measured within specified limits of precision and accuracy during routine laboratory operating conditions." The Agency has used the PQL to estimate or evaluate the minimum concentration at which most laboratories can be expected to reliably measure a specific chemical contaminant during day-to-day analyses of drinking water samples. The PQL is a means of integrating information on the performance of the approved analytical methods into the development of a drinking water regulation (52 FR 25699, July 8, 1987). The PQL incorporates the following (50 FR 46880, November 13, 1985; 52 FR 25690, July 8, 1987; 54 FR 22062, May 22, 1989):

C 

## quantitation,

C 

## precision and bias,

C 

## normal operations of a laboratory, and

C 

## the fundamental need to have a sufficient number of laboratories available to conduct compliance monitoring analyses.

C 

## In some cases, the quantitation limit for a particular analyte may have been the limiting factor in the determination of the MCL for that analyte. This could be especially true for contaminants with MCLGs of zero. Also, there are several SDWA contaminants with non-zero MCLGs that have their MCL set at the PQL.

## 3 Methods Support Document for Six-Year Review Final - March 2003 

## B. How Have PQLs Been Determined in the Past for SDWA Contaminants? Historically, EPA’s OGWDW used two main approaches to determine a PQL for SDWA analytes. One approach (and the preferred approach) used data from Water Supply (WS) Performance Evaluation (PE) studies. Although the primary use of the WS-PE data was for EPA’s laboratory certification, the data were also used as a secondary data source for many years to develop PQLs when the spike concentrations were in the appropriate concentration range. The derivation of the PQL using WS data involved determining the concentration of an analyte at which 75 percent of EPA Regional and State laboratories achieved results within a specified range around the spike value. In the absence of WS data, the other approach that EPA used wasthe MDL multiplier method. In this approach, the PQL was calculated by multiplying the EPAderived MDL by a factor of 5 or 10. The 5 or 10 multiplier was used to account for the variability and uncertainty that can occur at the MDL. The MDL multiplier method was mostly used in the early years of rule development for NPDWRs when insufficient WS data were available. Once sufficient WS data became available, most of the PQLs that were developed using the MDL multiplier were validated using WS data. 1. How Were Water Supply Studies Conducted? Water Supply Performance Evaluation (WS PE) studies were an integral part of EPA's certification program for drinking water laboratories for over 20 years. Historically, WS studies were conducted semi-annually by EPA for all current and proposed drinking water contaminants. Although the WS studies were conducted semi-annually, for certification purposes, laboratories were only required to demonstrate acceptable performance once a year (141.23(k)(3) and 141.24(f)(17)). WS study samples (spike samples) were sent to all laboratories that conduct drinking water analyses, including utility laboratories, commercial laboratories, and State and EPA Regional laboratories. Each WS study included samples or sample concentrates that were analyzed both for all SDWA analytes and for analytes that were being considered for regulation under the SDWA. During these WS studies, EPA’s National Exposure Research Laboratory (NERL) in Cincinnati, Ohio, sent participating laboratories a set of stable sample concentrates in sealed glass ampules, a data reporting form, and appropriate instructions. Each laboratory produced the study samples by diluting a measured quantity of the specific concentrates to volume with reagent water. The laboratory then analyzed the samples using the specified procedures. The completed reporting form was sent to EPA for evaluation, the data were carefully reviewed (QA/QC’ed), entered into a database, and a fully detailed report was then returned to each laboratory. The responsible State or EPA office contacted those laboratories that demonstrated potential problems. At this point in time, the WS Performance Evaluation studies are no longer performed by EPA. On July 18, 1996 (61 FR 37464), EPA proposed options for the externalization of the PE studies program (now referred to as the Proficiency Testing or PT program). After evaluating public comment, in the June 12, 1997 final notice EPA stated that the Agency has decided (62 FR 32112):

## 4 Methods Support Document for Six-Year Review Final - March 2003 

## ...on a program where EPA would issue standards for the operation of the program, the National Institute of Standards and Technology (NIST) would develop standards for private sector PE (PT) suppliers and would evaluate and accredit PE suppliers, and the private sector would develop and manufacture PE (PT) materials and conduct PE (PT) studies. In addition, as part of the program, the PE (PT) providers would report the results of the studies to the study participants and to those organizations that have responsibility for administering programs supported by the studies. Since the last WS PE studies performed by EPA were done in the Fall of 1999, the externalization of the PE program should not effect the data needed for this Six-Year Review process. However, at this time the Agency has not determined how to gather data to reassess PQLs for subsequent reviews of NPDWRs. 2. What Criteria Are Used to Determine a PQL? The derivation of the PQL involves determining the concentration of an analyte at which a set percentage of the laboratories achieve results within a specified range of the spiked value. Historically, the percentage of laboratories has been set at 75 percent, while a range of acceptance limits around the spiked value has been used. In many cases, EPA derived PQLs only from the data submitted by the EPA Regional and State laboratories that participate in the WS studies. A PQL derived from WS data in such a manner is considered a stringent target for routine laboratory performance because:

C 

## WS samples are prepared in reagent water and therefore do not contain the matrix interferences that may occur in field samples.

C 

## Laboratories analyze only a small number of samples for the study and are aware that the samples are for the purposes of performance evaluation (i.e., they are not "blind" samples). In deriving a PQL from WS study data, the Agency typically sets a fixed percentage or 2 sigma (2 standard deviation) acceptance window around the known concentration (or spike value) of the WS samples. Then the percentage of laboratories achieving results within the specified acceptance window (y-axis) is plotted against the known spike concentration of the Water Supply study samples (x-axis). While the acceptance limits for inorganics typically range from 15 to 30 percent (40 CFR §141.23(k)(3)(ii)), the acceptance limits for organics generally range from 20 to 50 percent (141.24(f)(17)(i) and 40 CFR §141.24(h)(19)(i)). Several SDWA analytes have acceptance limits of 2 sigma (2 standard deviation). Linear regression or graphical analysis is performed on the WS data to determine the concentration at which 75 percent of EPA Regional and State laboratories achieve acceptable results.

## 5 Methods Support Document for Six-Year Review Final - March 2003 

## III. How Did EPA Identify Which Contaminants to Evaluate for a PQL Reassessment? For the Six-Year analytical feasibility review, EPA focused on assessing whether the practical quantitation level (or PQL) has changed since promulgation for a subset of the 68 chemical NPDWRs. Figure 1 illustrates the overall Six-Year protocol and the basic process used to identify the subset of contaminants for which a PQL reassessment should be appropriate. Using the protocol, EPA identified and performed the analytical feasibility analysis for a total of 40 NPDWRs (Table 1), which fell into one of two categories:

< 

## First, for those contaminants where the MCL is currently limited by analytical feasibility (i.e., the MCL is set at the PQL) and the MCLG is still appropriate, EPA evaluated the currently approved methods for those contaminants and available WS data to determine whether it might be possible to lower the PQL and hence set an MCL that is closer to the MCLG.

< 

## The second circumstance under which EPA re-evaluated the PQL was for contaminants identified under the Six-Year health effects technical review as having potential changes to their MCLG. Because the information for the health effects review was not completely available at the time the analytical methods analysis began, EPA took a broad-brush approach and included a number of contaminants that may not have needed a reassessment of their analytical feasibility.

## 6 Methods Support Document for Six-Year Review Final - March 2003 Yes

No Does the review suggest possible changes in MCLG/MCL/TT and or other regulatory revisions?

Is a significant gain in public health protection or significant cost savings likely to occur? No Revision at this time

Candidate for Revision Are the data sufficient to support regulatory revision ? NPDWR remains appropriate after data/information review

Negligible gain in public health protection

and/or cost savings

Data gaps - determine research needs Yes No Pending health risk assessment Is a health risk assessment in process/planned?

Yes No Yes

No In-depth Technical Analysis New risk assessment, methods feasibility, treatment effectiveness, occurrence and exposure and economic implications. For methods - focussed on determining if analytical feasibility an issue for NPDWRs with potential changes in MCLG.

1. Publish FRnotice with preliminary revise/not revise decisions

. 2. Review Public Comments and consider revising decisions in context of new information. 3. Publish FRnotice with final list of NPDWRs to be revised and planned rulemaking schedule(s). NPDWRs under review

Initial Technical Review Health Effects, methods and treatment feasibility, and other regulatory revisions.

For methods - focused on MCLs that are currently limited by PQL. 

## Figure 1. Overview of the Protocol for the Revise/Not Revise Decision with a Focus on Where Analytical Feasibility was Re-evaluated.

## 7 Methods Support Document for Six-Year Review Final - March 2003 

## Table 1. SDWA Chemical Contaminants Undergoing Analytical Methods/PQL Reassessment

SDWA Chemical Contaminant MCLG 1 (mg/L) MCL 2 (mg/L) Current PQL 3 (mg/L) Acceptance Limit4

1 Alachlor zero 0.002 0.002 ± 45 %

2 Benzene zero 0.005 0.005 ± 20 % or 40 % 3 Benzo(a)pyrene zero 0.0002 0.0002 2 Std Dev. 4 Beryllium 0.004 0.004 0.001 ± 15 % 5 Bis(2-ethylhexyl)phthalate zero 0.006 0.006 2 Std Dev 6 Cadmium 0.005 0.005 0.002 ± 20 % 7 Carbofuran 0.04 0.04 0007 ± 45 % 8 Carbon tetrachloride zero 0.005 0.005 ± 20 % or 40 % 9 Chlordane zero 0.002 0.002 ± 45 10 Chromium (Cr III and VI) 0.1 0.1 0.01 ± 15 % 11 1,2-Dibromo-3-chloropropane (DBCP) zero 0.0002 0.0002 ± 40 % 12 1,4-Dichlorobenzene (para) 0.075 0.075 0.005 ± 20 % or 40 % 13 1,2-Dichloroethane zero 0.005 0.005 ± 20 % or 40 % 14 1,1-Dichloroethylene 0.007 0.007 0.005 ± 20 % or 40 % 15 Dichloromethane (methylene chloride) zero 0.005 0.005 ± 20 % or 40 % 16 1,2- Dichloropropane zero 0.005 0.005 ± 20 % or 40 % 17 Dioxin (2,3,7,8-TCDD) zero 3 x 10-8 3 x 10-8 2 Std Dev 18 Diquat 0.02 0.02 0.004 2 Std Dev 19 Ethylene dibromide zero 0.00005 0.00005 ± 40 % 20 Fluoride 4.0 4.0 0.5 ± 10 % 21 Glyphosate 0.7 0.7 0.06 2 Std Dev 22 Heptachlor zero 0.0004 0.0004 ± 45 % 23 Heptachlor epoxide zero 0.0002 0.0002 ± 45 % 24 Hexachlorobenzene zero 0.001 0.001 2 Std Dev 25 Hexachlorocyclopentadiene 0.05 0.05 0.001 2 Std Dev 26 Mercury 0.002 0.002 0.0005 ± 30 % 27 Methoxychlor 0.04 0.04 0.01 ± 45 % 28 Oxamyl (Vydate) 0.2 0.2 0.02 2 Std Dev 29 PCBs - Polychlorinated biphenyls (as decachlorobiphenyl) zero 0.0005 0.0005 ± 100 %
30 Pentachlorophenol zero 0.001 0.001 ± 50 % 31 Picloram 0.5 0.5 0.001 2 Std DevSDWA Chemical Contaminant MCLG 1 (mg/L) MCL 2 (mg/L) Current PQL 3 (mg/L) Acceptance Limit4



## 8 Methods Support Document for Six-Year Review Final - March 2003 32 Tetrachloroethylene zero 0.005 0.005 ± 20 % or 40 % 33 Thallium 0.0005 0.002 0.002 ± 30 % 34 Toluene 1 1 0.005 ± 20 % or 40 % 35 Toxaphene zero 0.003 0.003 ± 45 % 36 1,1,1-Trichloroethane 0.2 0.2 0.005 ± 20 % or 40 % 37 1,1,2-Trichloroethane 0.003 0.005 0.005 ± 20 % or 40 % 38 Trichloroethylene zero 0.005 0.005 ± 20 % or 40 % 39 Vinyl chloride zero 0.002 0.002 ± 45 % 40 Xylene (total) 10 10 0.005 ± 20 % or 40 % 

### Footnotes: 1. The MCLGs for inorganics are listed at 40 CFR 141.51. The MCLGs for organics are listed at 40 CFR 141.50. 2. The MCLs for inorganics are listed at 40 CFR 141. 62. The MCLs for organics are listed at 40 CFR 141.61. 3. The PQL for fluoride is published in 51 FR 11397 (A pril 1986). The PQLs for benzene, carbon tetrachloride, 1,4-dichlorobenzene, 1,2-dichloroethane , 1,1-dichloroethylene, 1,1,1-trichloroethane and vinyl chloride are published in 52 FR 25690 at 25700 (July 8, 1987). The PQLs for alachlor, cadmium, carbofuran, chlordane, chromium, 1,2-dibromo-3-chloropropane, 1,2-dichloropropane, heptachlor, heptachlor epoxide, ethylene dibromide, mercury, methoxychlor, PCBs, pentachlorophenol, tetrachloroethylene, toxaphene and xylene are published in 56 FR 3526 at 3552 (January 30, 1991). In the January 1991 FR, the PQL for pentachlorophenol was proposed but the final PQL was published in 56 FR 30266 (July 1, 1991) at 30270. The PQL for beryllium, benzo(a)pyrene, bis or di(2-ethylhexyl)phthalate dichloromethane, dioxin, diquat, glyphosate, hexachlorobenzene, hexachloro-cyclopentadiene, picloram and thallium 1, 1,1-trichloroethane are published in 57 FR 31776 at 31801 (July 17, 1992). 4. The acceptance limits inorganic can be found at CFR 141.23(k)(3)(ii). Acceptance limits for the organic chemicals are found at CFR 141.24(f)(17)(i)(C and D) and CFR 141.24(h)(19)(i)(B).



## IV. What Approaches Were Used to Reassess the PQLs of Contaminants Identified by the Six-Year Review Process? For this Six-Year Review process, several approaches could be used for the reassessment or re-evaluation of the PQLs for selected chemical contaminants. However, to be consistent with the policies and the process that the Agency has used in the past (50 FR 46880, November 13, 1985; 52 FR 25690, July 8, 1987; 54 FR 22062, May 22, 1989), only the "WS data" and the "MDL Multiplier" approaches were considered for the Six-Year Review process. Of these two approaches, the WS data approach is the preferred route since it relies on actual data to determine the level of quantitation. For the Six-Year Review, the MDL multiplier method is only used to estimate what a potential PQL could be if WS data are sufficient to indicate a change but insufficient to actually recalculate a PQL. There are advantages and disadvantages for each of these approaches. Some of the advantages and disadvantages for these PQL derivation approaches are as follows:

## 9 Methods Support Document for Six-Year Review Final - March 2003 

## (1) Analysis of WS PE Data- Uses data from WS studies to derive a new PQL. This value is compared to the old PQL (i.e., the one that is currently in place). The advantages of the WS PE Data methods of deriving a PQL -

< 

## Uses inter-laboratory data collected at concentrations near the MCL.

< 

## More representative of what methods are being used for the analysis of that contaminant.

< 

## May be the preferred approach for contaminants with MCLGs of zero. The disadvantages of the WS analysis method of deriving a PQL -

< 

## In the past, some stakeholders have felt that the PQL may be influenced by the set of WS data used (i.e., using data from all laboratories as opposed to only using data from EPA State and Regional laboratories).

< 

## Some stakeholders have felt that the laboratory performance on WS data may be skewed, because WS samples may be treated as special samples that are critical for laboratory certification.

< 

## The derivation of PQLs from WS data is a resource- and time-intensive process.

< 

## Because the WS samples are designed to test precision and accuracy around the MCL, the WS data may not cover concentrations several orders of magnitude below the current MCL. Hence, for some analytes, data points at lower levels may not be represented. (2) The MDL-Multiplier Approach- Using the MDL of the currently approved method(s) for each contaminant, the 5 or 10 multiplier method can be used to estimate the PQL. This value is then compared to the PQL that was derived before the 1996 SDWA Amendments. The advantage of the MDL multiplier approach - it is a relatively easy and clear process. The disadvantages of the MDL multiplier approach -

< 

## The WS studies test laboratory performance near the MCL as opposed to the MDL. A PQL derived from the MDL multiplier method may not be representative, because the reproducibility of a result obtained at the MDL is often not as good as that obtained near the MCL.

< 

## Because several methods may be approved for the same contaminant, it can be difficult to decide which MDL to select for the PQL calculation. However, knowledge of the methods that are the most widely used can be determined from the WS data since laboratories report which method was used to analyze spike samples. Acknowledging the advantages and disadvantages of the WS analysis and the MDL multiplier approach, EPA used the following steps for the Six Year Review to reassess analytical feasibility for the 40 chemical contaminants identified: • The first step is the methods comparisonstep. This step compared the method detection limits of the analytical methods which were available at the time the PQL was set to the method detection limits for the currently approved analytical methods. This methods comparison should help to identify whether the ability to detect (and therefore quantify) these contaminants at lower levels has increased.

## 10 Methods Support Document for Six-Year Review Final - March 2003 

## • The second step is the method usage over time . This step used information from the last eight Water Supply studies (WS 34 through WS 41; 1996 to 1999) to generate a bar graph of the distribution of the analytical methods used to analyze the spike samples in the WS studies. This analysis should give an idea of the analytical methods that appear to be the most widely used for the analysis of particular contaminants. Knowing which analytical methods are the most widely used and the MDL for these methods can aid in estimating where the quantitation may lie today. • The third and last step is the Water Supply data analysisstep. If Water Supply data are sufficient, more recent WS data can be used to recalculate the PQL (using linear regression or graphical analyses) and determine if the quantitation level has changed. Data may be considered insufficient if there are not enough data points around the 75 percent criteria to recalculate the PQL using linear regression or graphical analysis. This may occur if the laboratories evaluated exhibit high passing rates (>75 percent) for all of the WS studies evaluated and/or no WS spike samples were below the concentration of the current PQL. However, even if the WS data are insufficient to actually recalculate the PQL, the information may be useful to either confirm that the current PQL still appears to remain appropriate or it may give an indication as to whether the PQL is likely to change (if the data points at concentrations close to the current PQL are available). Using the information from these three steps helped EPA to determine if our ability to quantify contaminants at lower levels has increased. If there was an indication that the PQL has or could change, then pending the results of the health effects and occurrence review, as well as risk management considerations, these chemical contaminants may be subject to a full blown PQL reassessment (i.e., gathering data that sufficiently covers the area around the 75 percent laboratory passing criteria and the appropriate concentration range). Note: This document will not discuss whether afull blown PQL reassessment is necessary for specific contaminants. Instead, that decision will be made after the integration of these results with the health effects and occurrence and exposure reviews and discussed in the Six Year Notice of Intent.

## 11 Methods Support Document for Six-Year Review Final - March 2003 

## V. Results of the PQL Reassessment

Alachlor Results of the Method Comparison The approved drinking water methods for the determination of alachlor, a Phase II synthetic organic compound (SOC), were listed in the 1991 NPDWRs (56 FR 3526). These methods all utilize GC or GC/MS with several extraction and/or detector variations: EPA Methods 505, 507, and 525.1. Since promulgation of these original methods, the Agency has eliminated EPA Method 525.1 from the list of approved methods, and has approved the use of three new GC methods: EPA Methods 508.1, 525.2, and 551.1. The three new methods are approximately 10 to 100 times more sensitive than the earlier methods. The current EPA 505 is equivalent in sensitivity relative to the time of Phase II promulgation. Table 2 summarizes the current and previous EPA methods along with their MDLs.

Table 2. Results of the Analytical Methods Comparison for Alachlor (Newly Promulgated Methods are Indicated in Bold)

MCL = 2 : 

### g/L Current PQL = 2 : 

### g/L DL•

### = 0.2 : 

### g/L Acceptance Limit^

### = ± 45% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L)

EPA 505 1 

### Microextraction and GC 0.225 EPA 505 2 

### Microextraction and GC 0.225

EPA 507 1 

### GC with NPD 0.38 P 

### EPA 507 2 

### GC with ECD 0.14 EPA 525.1 1 

### LSE and GC/MS 1.0 EPA 508.1 2 

### LSE and GC with ECD 0.009 EPA 525.2 2 

### LSE and GC/MS 0.069 - 0.16* EPA 551.1 2 

### LLE and GC with ECD 0.005 - 0.025*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR §141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL.

## 12 Methods Support Document for Six-Year Review Final - March 2003 

### Alachlor

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method
505 507 508.1 525.1 525.2 other 

## Figure 2. Distribution of AnalyticalTechniques by WS Study: Alachlor Results of the Analysis of the WS Data a. Method Usage Over Time Figure 2 plots the distribution of analytical techniques used by the EPA and State laboratories in WS 34 to 41. Methods categorized as "other" represent methods which were not specifically identified by participating laboratories or were otherwise unknown. As shown in Figure 2, EPA Method 507 was used fairly consistently throughout WS 34 to 41. Use of EPA 525.1 was phased out after WS 36, while use of EPA Method 525.2 increased significantly during the same study. EPA Methods 508.1, 505, and "other" methods remained in use minimally throughout the study period.

b. Results of the PQL Analysis As PE data were not available at the time of the original PQL determination, the PQL of 2 : 

## g/L was derived using a multiplier of 10 on the interlaboratory MDL (0.15 : 

## g/L) based on a study conducted by the Environmental Monitoring and Support Laboratory in Cincinnati, Ohio (54 FR 22104). Data from WS 24 to 41 were used to attempt a PQL re-evaluation. Table 3 summarizes these data, indicating the study number, the true value (i.e., the spiked value) of the WS sample, the number of results from EPA and State laboratories,and the calculated percentage of laboratories whose results successfully passed within designated acceptance limits for alachlor (specified in 40 CFR §141.24(h)(19)(i) to be ± 45 percent).

## 13 Methods Support Document for Six-Year Review Final - March 2003 

## Table 3. Evaluation of Alachlor Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA Regional and State Labs % Labs Passing ± 45% Acceptance Limits 24a 0.735 19 100 26b 0.933 20 95.0 29 1.59 14 71.4 25a 1.87 13 100 32 2.33 43 86.0 31 2.50 25 76.0 30 3.21 40 97.5 34 3.43 48 100 27 3.80 17 88.2 33 4.27 30 86.7 24b 4.53 19 100 37 4.87 40 85.0 35 5.27 27 96.3 26a 5.66 20 95.0 36 7.34 50 100 38 9.52 49 93.9 25b 9.80 13 100 41 12.9 37 100 39 14.8 40 97.5 40 17.7 50 90.0



## The data from the available PE studies were not conducive to PQL re-evaluation, as the percentage of labs passing generally exceeded the standard 75 percent passing criterion needed to calculate the PQL using linear regression or graphical analysis (with the exception of one study - WS 29). However, even around the original PQL of 2 : 

## g/L, the percentage of laboratories passing is extremely variable and ranges from 71.4 percent in WS 29 to 100 percent for several WS studies at varying concentrations. Even at higher concentrations of 3.8 : 

## g/L (WS 27) and 4.87 : 

## g/L (WS 37) the laboratory passing rates dip to 88 and 85 percent, respectively. Based on this information, EPA believes the PQL for alachlor appears to still be in the appropriate range.

## 14 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Alachlor Since the promulgation of the 1991 NPDWR for alachlor and other Phase II SOCs, three new analytical methods (EPA Methods 525.2, 508.1, and 551.1) have been approved for the determination of alachlor in drinking water. Based on the distribution of method use over time (Figure 2), it appears that EPA and State laboratories did not utilize the increased analytical sensitivity of the newer methods, instead preferring use of EPA Method 507. Meanwhile, a PQL for alachlor could not be recalculated using the PE data from WS 24 to 41. Nearly every study exhibited a laboratory success rate above the 75 percent criterion needed for re-evaluating the PQL, and furthermore, the range of true values generally exceeded the current PQL value. Therefore, the available PE data provide very limited evidence for revising the current PQL of 2 : 

## g/L. Based on the available data, EPA believes the PQL for alachlor is most likely in the appropriate range.

Benzene Results of the Method Comparison In July 1987, the final NPDWR for eight Phase I VOCs approved the use of EPA Methods 502.2, 503.1, 524.1, and 524.2 for the determination of benzene in drinking water (52 FR 25690). The currently approved methods for benzene determination are EPA Methods 502.2 and 524.2. Table 4 summarizes the MDLs for both the original and current approved versions of the methods. As compared to the original methods, the updated methods are equal in sensitivity to the original methods.

Table 4. Results of the Analytical Methods Comparison for Benzene

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL  

### (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 502.2 1 

### Purge and Trap GC 0.01 EPA 502.2 2 

### Purge and Trap GC 0.01

EPA 503.1 1 

### Purge and Trap GC 0.02 EPA 524.2 2 

### Purge and Trap GC/MS 0.03 - 0.04*

EPA 524.1 1 

### Purge and Trap GC/MS 0.1

EPA 524.2 1 

### Purge and Trap GC/MS 0.03 - 0.04*

## 15 Methods Support Document for Six-Year Review Final - March 2003 

### Benzene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 3. Distribution of AnalyticalTechniques by WS Study: Benzene 1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.  

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1 lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for VOCs are listed at 40 CFR § 141.24(f)(17)(i). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).



## Results of the Analysis of the WS Data a. Method Usage Over Time Figure 3 summarizes the distribution of the different methods used by the EPA and State laboratories during WS studies 34 to 41. The category of "other" contains those methods that were either unknown or otherwise unidentified by the participating laboratories. As shown in Figure 3, use of EPA Method 524.2 during WS 34 to 41 generally increased over time while use of EPA Method 502.2 decreased slightly during the same period. Overall, usage of EPA Method 524.2 remained consistently dominant over that of EPA Method 502.2. Use of the original EPA Methods, 503.1 and 524.1, were not apparent during this period.

## 16 Methods Support Document for Six-Year Review Final - March 2003 

## b. Results of the PQL Analysis The original PQL of 5 : 

## g/L for benzene was determined by multiplying the regulatory detection limit of 0.5 : 

## g/L by a factor of 10 (52 FR 25700). To re-evaluate the PQL, multilaboratory performance data from WS 24 through 41 were reviewed. Table 5 summarizes the results of these water studies, providing the study number, the spiked value for the WS sample, the number of laboratory results, and the percentage of laboratories whose reported results fell within the acceptance limits of ± 20 percent for true values greater than 10 : 

## g/L and ± 40 percent for true values lower than 10 : 

## g/L (specified at 141.24(f)(17)(i)).

Table 5. Evaluation of Benzene Data from WS Studies Using the ± 20% or ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 24 4.32 57 98.2 34 4.94 60 100 27 7.09 38 100 36 7.49 61 100 39 9.39 43 97.7 30 9.51 60 100 26 10.3 59 91.5 33 12.0 35 94.3 37 12.5 48 93.8 31 12.6 37 89.2 25 13.5 37 86.5 35 14.0 34 97.1 29 15.3 34 91.2 38 15.3 55 96.4 32 16.5 65 93.8 40 16.7 58 96.6 41 18.7 41 100



## The overall data for benzene, as shown in Table 5, indicate that the passing rates for laboratories fall well above the 75 percent criterion for establishing a revised PQL value. However, as shown in Figure 4, the PE data for benzene display different relationships with true values concentration depending on the acceptance limits (20 or 40 percent). The data representing laboratories passing the 40 percent acceptance limits plot a horizontal line and do not contribute meaningfully to a PQL re-evaluation. For the laboratories passing the 20 percent

## 17 Methods Support Document for Six-Year Review Final - March 2003 Benzene

0 10 20 30 40 50 60 70 80 90 100

0 2 4 6 8 10 12 14 16 18 20 True Value (μg/L)% Labs Passing

% Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits Current PQL = 5 75% 

## Figure 4. Two-part Distribution of Benzene WS Dataacceptance limits, the regression line demonstrates a positive slope, although a PQL reevaluation is also not possible because the true values exceed the current PQL. However, the high percentages of laboratories passing around the current PQL of 5 : 

## g/L suggest that the PQL for benzene could possibly be lower.

Conclusion for Benzene The method comparison results show that, since the promulgation of analytical methods under the original NPDWR for benzene, two of these methods are no longer approved for determination of this contaminant and method sensitivity has remained about the same. Evaluation of the quantitative PE data shows that the laboratories conducting WS analyses exhibited very high passing rates. Because the percentage of laboratories passing the PE testing exceeds the 75 percent criterion, a re-evaluation of the PQL could not be performed using this approach. But the high percentages of laboratories passing around the current PQL of 5 : 

## g/L suggest that the PQL for benzene could possibly be lower.

## 18 Methods Support Document for Six-Year Review Final - March 2003 

## Benzo(a)pyrene Results of the Method Comparison With the Phase V synthetic organic compounds (57 FR 31776), three approved methods were listed for determination of benzo(a)pyrene in drinking water, including gas chromatography/mass spectrometry (GC/MS) with liquid-solid extraction (LSE; EPA Method 525.1), high performance liquid chromatography (HPLC) with liquid-liquid extraction (LLE; EPA Method 550), and HPLC with LSE (EPA Method 550.1). Since this regulation was promulgated, the Agency has replaced the old GC/MS - LSE method with an updated version, EPA Method 525.2.

Table 6. Results of the Analytical Methods Comparison for Benzo(a)pyrene (Newly Promulgated Methods Indicated in Bold)

MCL = 0.2 : 

### g/L Current PQL = 0.2 : 

### g/L DL•

### = 0.02 : 

### g/L Acceptance Limit^

### = ± 2xS.D. Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 525.1 1 

### LSE and GC/MS 0.04 - 0.1* EPA 525.2 3 

### LSE and GC/MS 0.032 - 0.23*

EPA 550 2 

### LLE, HPLC 0.029 EPA 550 2 

### LLE, HPLC 0.029 EPA 550.1 2 

### LSE, HPLC 0.016 EPA 550.1 2 

### LSE, HPLC 0.016

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement I," EPA/600/4-90/020, July 1990. 3

### "Methods for the Determination of Organic Compounds in Drinking Water–Supplement III," EPA/600/R95/131, August 1995. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits are listed at 40 CFR §141.24(h)(19)(i).



## Results of the WS Data Analysis a. Method Usage Over Time Figure 5 illustrates the distribution of the analytical techniques used by EPA and State laboratories in WS studies 34 to 41. The "other" techniques shown in this figure include unidentified, unknown, or unreported techniques. Figure 5 shows that, by the time of WS study 38, EPA Method 525.1 was almost completely phased out and replaced with EPA 525.2 (which, according to Table 6, is more sensitive).

## 19 Methods Support Document for Six-Year Review Final - March 2003 

## Benzo(a)pyrene

0% 10% 20% 30% 40% 50% 60% 70% 80%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 

### 550 525.1 550.1 525.2 other 

## Figure 5. Distribution of Analytical Techniques by WS Study: 

## Benzo(a)pyrene

b. Results of the PQL Analysis The original PQL was estimated at 0.2 : 

## g/L (57 FR 31802) based on PE data compiled from WS studies 23, 24, 26, and 27. The data used for the re-evaluation of the PQL were taken from WS studies 26 through 41. Table 7 summarizes the results of these studies. The table provides the WS study number, the spiked or "true value" for the WS sample, the number of laboratory results, and the percent of laboratories passing the WS proficiency test for benzo(a)pyrene within the acceptance limits. The acceptance limits were calculated to be plus or minus two standard deviations from the estimated mean recovery, as stipulated in CFR §141.24(h)(19)(i).

Table 7. Evaluation of PE Data for Benzo(a)pyrene from WS Studies Using 2 x S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True"Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing Acceptance Limits

31 0.202 14 79 32 0.337 29 93 30 0.485 12 92 38 0.53 38 90 36 0.64 40 90 34 0.75 28 93

### WS # Spiked "True"Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing Acceptance Limits



## 20 Methods Support Document for Six-Year Review Final - March 2003 Benzo(a)pyrene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 0.5 1 1.5 2 2.5 True Value (ug/L)% Labs Passing 75%

Current PQL= 0.2 

## Figure 6. PQL Evaluation from PE WS Data: Benzo(a)pyrene 37 0.94 37 87 33 1.29 22 91 40 1.48 43 98 35 1.53 27 89 26a 2.25 10 83 39 2.37 31 97 41 2.37 25 92 26b 15.5 12 90



## Figure 6 shows the plot of the benzo(a)pyrene data for WS 26 to 41, and the linear regression line. There is no meaningful relationship in these data, in large part because the true values of the samples are so high that a very large percentage of the labs passed all the PE series. Further, only one PE sample approached the current PQL (WS 31), and these results (79 percent passing) support the current PQL.

Conclusion for Benzo(a)pyrene As noted in the method comparison, a more sensitive method (EPA Method 525.2) has been approved since the promulgation of benzo(a)pyrene, replacing an older and less sensitive version (EPA Method 525.1). The method usage evaluation shows that in recent years, a majority of

## 21 Methods Support Document for Six-Year Review Final - March 2003 

## benzo(a)pyrene, replacing an older and less sensitive version (EPA Method 525.1). The method usage evaluation shows that in recent years, a majority of EPA and State laboratories in the PE studies have chosen to use this more sensitive method out of all the approved methods for benzo(a)pyrene. The WS data do not afford a re-evaluation of the PQL, and at best, support the current value. There is no clear evidence to support a change from the current PQL of 0.2 : 

## g/L. The current PQL appears to be appropriate.

Beryllium Results of the Method Comparison With the Phase V IOCs (57 FR 31776), EPA approved multiple analytical methods for determination of beryllium in drinking water, including an atomic absorption–furnace (AAF) method (EPA Method 210.2), an inductively coupled plasma-atomic emission spectroscopy (ICP-AES) method (EPA Method 200.7), ICP-mass spectroscopy method (ICP/MS) (EPA Method 200.8), and atomic absorption-platform (AAP) method (EPA Method 200.9), and three voluntary consensus standard methods, including Standard Methods 3113B (AAF) and 3120B (ICP/AES) and ASTM Method D3645-84B (AAF). EPA Method 210.2 and ASTM Method D3645-84B have since been removed from the approved list and replaced by one voluntary consensus standard method, ASTM Method D3645-93B (AAF). These methods are listed in Table 8. The MDLs of EPA Methods 200.7, 200.8 and 200.9 do not present any improved sensitivity capabilities.

## 22 Methods Support Document for Six-Year Review Final - March 2003 

## Table 8. Results of the Analytical Methods Comparison for Beryllium (Newly Promulgated Methods Indicated in Bold)

MCL = 4 : 

### g/L Current PQL = 1 : 

### g/L DL >

### = 0.02-0.3 : 

### g/L Acceptance Limit^

### = ± 15% Methods Approved At Promulgation Currently Approved Methods (141.23) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 200.7 2 

### ICP/AES 0.3 EPA 200.7 5 

### ICP/AES 0.3 EPA 200.8 2 

### ICP/MS 0.3 EPA 200.8 5 

### ICP/MS 0.02 -0.3* EPA 200.9 2 

### AAP 0.02 EPA 200.9 5 

### AAP 0.02 EPA 210.2 1 

### AAF 0.2 P



### 3113B 3 

### AAF N/A* 3113B 7 

### AAF N/A* 3120B 3 

### ICP N/A* 3120B 7 

### ICP N/A* D3645-84B 4 

### AAF N/A* D3645-93B 6 

### AAF N/A*

1 

### “Methods for Chemical Analysis of Water and Wastes (MCAWW),” EPA/600/4-79/020, March 1983. 2

### “Methods for the Determination of Metals in Environmental Samples,” EPA/600/4-91/101, June 1991. 3 

### 17th

### edition of Standard Methods for the Examination of Water and Waste, 1989. American Public Health Association, American Water Works Association, Water Pollution Control Federation. 4 

### Annual Book of ASTM Standards. Vols. 11.01 and 11.02, 1991. American Society for Testing Materials, 1916 Race Street, Philadelphia, PA 19103. 5

### “Methods for the Determination of Metals in Environmental Samples--Supplement I,” EPA/600/R-94/111, May 1994. 6 

### Annual Book of ASTM Standards . Vol. 11.01, 1994. American Society for Testing and Materials, 1961 Race Street, Philadelphia, PA 19103. 7 

### 18th

### and 19th

### edition of Standard Methods for the Examination of Water and Wastewater, 1992 and 1995. American Public Health Association, 1015 Fifteenth Street NW, Washington, DC 20005.

>

### Regulatory DLs for inorganic compounds are listed at 40 CFR §141.23(a)(4)(i). These values vary depending on analytical method. *MDLs are not specified for non-EPA (i.e ., voluntary consensus standard) methods. ^

### Acceptance limits are listed at 40 CFR §141.23(k)(3)(ii) for inorganic compounds.

P

### EDL = estimated detection limit, used to approximate the MDL.



## Results of the Analysis of the WS Data a. Method Usage Over Time The distribution of the analytical techniques used by the EPA and State laboratories in WS studies 34 to 41 is shown in Figure 7. The category of "other" techniques include additional methods used by participating laboratories, as well as "unknown" methods, i.e., methods for which laboratories did not report any information on the type of method used. As shown in Figure 7, EPA Methods 200.7 and 210.2 were the most widely used methods in WS 34 and 35. By WS 37, laboratories ceased to use EPA Method 210.2 and relied more on EPA Method 200.9. From WS 37 to 41, EPA Methods 200.7, 200.8, and 200.9 were most commonly used. The two 3000-series Standard Methods were used to a far lesser extent than these EPA Methods.

## 23 Methods Support Document for Six-Year Review Final - March 2003 Beryllium

0% 10% 20% 30% 40% 50% 60%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 200.7 200.8 200.9 210.2 3113B 3120B other 

## Figure 7. Distribution of AnalyticalTechniques by WS Study: Beryllium

b. Results of the PQL Analysis The current PQL (1.0 : 

## g/L) was originally determined using PE data from WS 24 through 27 (56 FR 60949). A PQL re-evaluation was attempted using more current data spanning WS 24 to 41. Table 9 summarizes the results of these water studies, providing the study number, the spiked value for the WS sample, the number of results from EPA and State laboratories, and the beryllium results evaluated using an acceptance limit of ± 15 percent (as indicated at 40 CFR §141.23(k)(3)(ii)).

Table 9. Evaluation of Beryllium Data from WS Studies Using the 15% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 15% Acceptance Limits 25b 0.400 20 70.0 26a 0.530 40 70.0 24 0.600 35 71.4 32 0.933 60 73.3 39 1.20 51 84.3 35 1.33 42 83.3

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 15% Acceptance Limits



## 24 Methods Support Document for Six-Year Review Final - March 2003 25a 2.00 24 91.7 41 2.58 46 91.3 31 3.27 33 93.9 37 4.26 49 98.0 27 4.67 24 75.0 34 5.33 60 90.0 40 6.60 64 90.6 36 7.70 61 95.1 30 8.47 49 91.8 33 9.07 39 84.6 29 9.76 25 80.0 38 10.1 63 90.5 26b 23.1 46 84.8



## The data in Table 9 seems to indicate that a linear relationship might exist between "true" value concentration and percentage of labs passing. Furthermore, a PQL re-evaluation appeared possible because the percentage of labs passing fell within the 75 percent criterion for some studies, and the true values from the water studies approximated the general range of the current PQL. Visual evaluation of the laboratory passing percentages around the current PQL of 1 :

## g/L indicate that this value is still appropriate and unlikely to change. The graph in Figure 8 illustrates this relationship between the spike concentrations and the laboratory passing rates. As shown in Figure 8, the recalculated PQL of 0.71 : 

## g/L, is slightly lower than the current PQL.

## 25 Methods Support Document for Six-Year Review Final - March 2003 Beryllium

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

-1 4 9 14 19 24 True Value (μg/L)% Labs Passing 75%Current PQL =1RPQL = 0.71 

## Figure 8. Two-part Distribution of Beryllium WS Data:

Conclusion for Beryllium The method comparison results indicate that EPA Method 200.9 is the most sensitive method for determination of beryllium in drinking water and its MDL has improved by five-fold over the most sensitive MDLs achieved at the time of promulgation. EPA Method 200.7 was used more widely in previous years but is less sensitive. As revealed by the results of method usage over time, EPA Method 200.9 is the most commonly employed method for beryllium determination in recent PE studies. These trends seem to imply a shift in analytical capabilities for beryllium determination toward greater sensitivity. Thus, EPA and State laboratories are likely to reach lower detection limits today compared to the year of NPDWR promulgation. The re-evaluation of the PQL using a linear regression was calculated to be 0.71 : 

## g/L, a value close to the current PQL of 1 : 

## g/L. Although it may be possible to lower the PQL slightly based on more recent PE data, the current PQL is still appropriate.

Bis(2-ethylhexyl)phthalate Results of the Method Comparison At the time of the Phase V SOC promulgation (57 FR 31776), EPA Methods 506 and 525.1 were the only approved methods for the analysisof bis(2-ethylhexyl)phthalate (also known as di(2-ethylhexyl)phthalate). Since that time,EPA Method 506, which uses LLE or LSE GC with PID, has remained on the approved methods list while EPA Method 525.1, which utilizes LSE GC/MS, has been replaced by a more sensitive version, EPA Method 525.2. This increased

## 26 Methods Support Document for Six-Year Review Final - March 2003 

## sensitivity, however, is only marginal, as evidenced by the similarity of their MDLs. Table 10 lists the approved methods, techniques, and MDLs, during and after the time of rule promulgation.

Table 10. Results of the Analytical Methods Comparison for Bis(2- ethylhexyl)phthalate (Newly Promulgated Methods are Indicated in Bold)

MCL = 6 : 

### g/L Current PQL = 6 : 

### g/L DL >

### = 0.6 : 

### g/L Acceptance Limit^

### = ± 2 x S.D. Methods Approved At Promulgation Currently Approved Methods (141.24)
Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 525.1 1 

### LSE and GC/MS 0.6 - 0.8* EPA 525.2 3 

### LSE and GC/MS 0.46 - 1.3* EPA 506 2 

### LLE or LSE and GC w/ PID 2.25 EPA 506 3 

### LLE or LSE and GC with PID 2.25

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement I," EPA/600/4-90/020, July 1990. 3

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.

*

### Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance.

>

### Regulatory DLs for organic compoundsare listed at 40 CFR 141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR 141.24(h)(19)(i).



## Results of the Analysis of the WS Data a. Method Usage Over Time The distribution of the analytical methods used during WS 34 to 41 by participating EPA and State laboratories are illustrated in Figure 9. The category of "other" represents any alternative or unreported methods. As shown in Figure 9, use of EPA Method 525.1 decreased significantly, corresponding to the introduction of EPA Method 525.2 during WS 36. By WS 38, EPA Method 525.1 was no longer used by any laboratories for analyzing bis(2- ethylhexyl)phthalate. Laboratories overwhelmingly chose to use the LSE GC/MS technique (either EPA Method 525.1 or its replacement, EPA Method 525.2) over EPA Method 506, which utilized the LLE or LSE GC with PID.

## 27 Methods Support Document for Six-Year Review Final - March 2003 

## Bis(2-ethylhexyl)phthalate

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 

### 525.2 525.1 506 other 

## Figure 9. Distribution of Analytical Techniques by WS Study: Bis(2- ethylhexyl)phthalate

b. Results of the PQL Analysis PE data from WS 24 to 41 were compiled to re-evaluate the PQL. Table 11 shows the WS number, the true value concentration, the number of participating laboratories, and the percent of laboratories passing within acceptance limits. These limits were calculated to be two times the standard deviation, as stipulated in 40 CFR §141.24(h)(19)(i).

Table 11. Evaluation of Bis(2-ethylhexyl)phthalate Data from WS Studies Using 2 x S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ±2 x S.D. Acceptance Limits 24a 3.18 14 35.7 29 4.58 8 75 30 6.40 15 60 26b 7.73 13 69.2 32 9.28 27 92.6 31 11.7 12 91.7

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ±2 x S.D. Acceptance Limits



## 28 Methods Support Document for Six-Year Review Final - March 2003 38 13.7 35 91.4 41 15.3 25 84 33 15.8 23 87 27 17.3 7 85.7 36 18.3 39 92.3 24b 19.1 15 93.3 37 21.3 33 93.9 34 21.3 33 93.9 39 27.7 26 100 40 32.4 38 89.5 26a 34.2 13 84.6 35 37.7 20 85



## Using the data in Table 11, a linear regression was performed by plotting the percentage of the laboratories passing for WS 24 to 41 (excluding WS 25) against the spiked value of bis(2- ethylhexyl)phthalate (Figure 10). Simple visual examination of the graph shows that the percentage of laboratories achieving acceptable results approximates 75 percent at a concentration of 7.84 : 

## g/L. This concentration is higher than the current PQL of 6.0 : 

## g/L, which was originally estimated using PE data from WS 23, 24, and 27 (57 FR 60953).

## 29 Methods Support Document for Six-Year Review Final - March 2003 Bis(2-ethylhexyl)phthalate

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 5 10 15 20 25 30 35 40 True Value (μg/L)% Labs PassingCurrent PQL=6 75%RPQL = 7 84 

## Figure 10. Two-part Distribution of Bis(2-ethylhexyl)phthalate WS Data

Conclusion for Bis(2-ethylhexyl)phthalate Since the time of the Phase V SOC rule promulgation, EPA Method 525.2 has replaced EPA Method 525.1. The EPA and State laboratories have overwhelmingly chosen to use EPA Method 525.2 over any other available methods as evidenced by the plot of method usage over time. The re-evaluation of the PQL using a linear regression calculated from WS 24a, 26b, 30 and 32 data showed that a new PQL could be derived. The re-evaluated PQL of 7.84 : 

## g/L is higher than the original PQL of 6 : 

## g/L (57 FR 31802).

Cadmium Results of the Method Comparison The 1991 NPDWRs for Phase II IOCs listed atomic absorption–furnace (AAF; EPA Method 213.2), inductively coupled plasma (ICP; EP A Method 200.7A), and Standard Method 304 as approved analytical methods for the determination of cadmium in drinking water (57 FR 31776). Since the promulgation of the rule, these methods have been replaced by four new or updated methods; three EPA methods (EPA Methods 200.7, 200.8, and 200.9), and one voluntary consensus standard method (Standard Method 3113B). Table 12 compares the detection limits of approved methods during and after promulgation of the NPDWR for cadmium and shows EPA Method 200.9 to be the most sensitive method for detecting cadmium in drinking water.

## 30 Methods Support Document for Six-Year Review Final - March 2003 

## Table 12. Results of the Analytical Methods Comparison for Cadmium (Newly Promulgated Methods Indicated in Bold)

MCL = 5 : 

### g/L Current PQL = 2 : 

### g/L DL >

### = 0.1-1.0 : 

### g/L Acceptance Limit^

### = ± 20% Methods Approved At Promulgation Currently Approved Methods (141.23) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 200.7A 1 

### ICP/AES 0.6 EPA 200.72 

### ICP/AES 1 EPA 213.2 5 

### AAF 0.1 P 

### EPA 200.8 2 

### ICP/MS 0.03 - 0.5*

SM 3044 

### AAF N/A " 

### EPA 200.9 2 

### AAP 0.05 SM 3113B 3 

### AAF N/A "

1 

### “Inductively Coupled Plasma-Atomic Emission Analysis of Drinking Water,” Appendix to Method 200.7, March 1987. 2

### "Methods for the Determination of Metals in Environmental Samples--Supplement I," EPA/600/R-94/111, May 1994. 3

### 18 th

### and 19 th

### editions of Standard Methods for the Examination of Water and Wastewater, 1992 and 1995, American Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 20005. 4

### 16th

### edition of Standard Methods for the Examination of Water and Wastewater, 1985, American Public Health Association, American Water Works Association, Pollution Control Federation. 5

### “Methods for Chemical Analysis of Water a nd Wastes (MCAWW),” EPA/600/4-79/020, March 1983..

>

### Regulatory DLs for inorganic compounds are listed at 40 CFR §141.23(a)(4)(i) and depend on analytical method. ^

### Acceptance limits are listed at 40 CFR §141.23(k)(3)(ii). *Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL. "

### MDLs are not specified for non-EPA (i.e., voluntary consensus standard) methods.



## Results of the Analysis of the WS Data a. Method Usage Over Time Figure 11 shows the distribution of analyticaltechniques used by EPA and State laboratories for WS studies 34 to 41. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as "unknown" methods, i.e., methods for which laboratories did not report any information on the type of method used. During WS 34 and 35, EPA Method 213.2 was the most widely used method for determining cadmium in drinking water. EPA Methods 200.7, 200.8, and 200.9 were all used with relatively the same frequency by the participating laboratories in the PE studies. Use of SM 3113B lessened over the period between WS 36 and 41.

## 31 Methods Support Document for Six-Year Review Final - March 2003 Cadmium



### 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS34 WS35 WS36 WS37 WS38 WS39 WS40 WS41 Water Study% Labs Using Method

200.7 200.8 200.9 21

3.2 311

3B OTHER 

## Figure 11. Distribution of AnalyticalTechniques by WS Study: Cadmium

b. Results of the PQL Analysis The current PQL of 2.0 : 

## g/L was originally set using PE data from WS 22 through 25 (56 FR 3549). With the availability of more current data from WS 24 to 41, a PQL re-evaluation was attempted. Table 13 summarizes the results of these water studies, providing the study number, the spiked value for the WS sample, the number of results from EPA and State laboratories, and the cadmium results evaluated using an acceptance limit of ± 20 percent, as designated in 40 CFR § 141.23(k)(3)(ii).

Table 13. Evaluation of Cadmium Data from WS Studies Using the 20% Acceptance Limits (In Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits 38 2.12 62 85.5 35 2.80 39 87.2 29 2.80 34 88.2 32 4.80 67 97.4 40 6.31 65 87.7 26b 9.20 62 91.9

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits



## 32 Methods Support Document for Six-Year Review Final - March 2003 37 10.2 51 98.0 24b 10.4 61 95.1 31 12.8 35 91.4 24a 15.4 61 90.2 41 18.2 45 95.6 34 23.0 65 96.9 25 27.6 40 100 39 28.5 54 98.1 27 29.3 40 92.5 36 34.0 66 98.5 30 39.0 66 98.5 33 49.0 38 97.4 26a 53.9 62 96.8



## The data in Table 13 were not adequate to perform a PQL re-evaluation. EPA’s preferred format for evaluating a PQL is to develop a regression (or graphical analysis) using the true value concentration and the percentage of laboratories passing the performance evaluation. The PQL is then set at a concentration in which 75 percent of those laboratories pass. In this instance, however, the participating laboratories passed the evaluation at an average rate of 93 percent, well above the 75 percent criterion. Also, all of the spiked "true" values were well above the original PQL of 2 : 

## g/L. Conclusion for Cadmium A comparison of the analytical methods approved during and after the promulgation of the NPDWR for cadmium show that the four current methods have sensitivities similar to, or slightly better than, those of the original methods, with EPA Method 200.9 being the most sensitive (with an MDL of 0.05 : 

## g/L). Laboratories that participated in the PE water studies chose to utilize EPA Method 213.2 in the WS studies prior to WS 36 but then chose to utilize EPA Methods 200.7, 200.8, and 200.9 with similar frequency. Review and analysis of the PE data did not result in the estimation of a new PQL because all of the EPA and State laboratories in the WS studies evaluated surpassed the required 75 percent criterion typically used to determine a new PQL. In addition, all of the WS spike concentrations were above the current PQL of 2 :

## g/L. However, laboratory passing rates of greater than 85 percent at concentrations slightly above the current PQL suggest that the PQL could be lower.

## 33 Methods Support Document for Six-Year Review Final - March 2003 

## Carbofuran Results of the Method Comparison At the promulgation of the NPDWRs for synthetic organic chemicals (56 FR 3552), one analytical method (EPA Method 531.1) was approved for determination of carbofuran in drinking water. One additional method, Standard Method (SM) 6610, has been included as a currently approved method for carbofuran analysis. Both current methods use the HPLC technique and have similar MDLs. Table 14 summarizes the approved methods, both past and present, for determination of carbofuran.

Table 14. Results of the Analytical Methods Comparison for Carbofuran (Newly Promulgated Methods in Bold)

MCL = 40 : 

### g/L Current PQL = 7 : 

### g/L DL >

### = 0.9 : 

### g/L Acceptance Limit^

### = ± 45% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 531.1 1 

### HPLC 1.5 P

### EPA 531.1 2 

### HPLC 0.52 SM 66103 

### HPLC 0.53

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. 3

### Supplement to the 18th edition of Standard Methods for the Examination of Water and Wastewater, 1994, American Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR § 141.24(h)(19)(i).

P

### EDL = estimated detection limit, used to approximate the MDL.



## Results of the Analysis of the WS Data a. Method Usage Over Time Figure 12 illustrates the methods chosen by EPA and State laboratories for carbofuran analysis during WS PE studies 34 to 41. The category of "other" includes any unidentified or unreported techniques used by participating laboratories. As shown in Figure 12, the predominant method used by laboratories participating in the WS studies is EPA Method 531.1. The smallest percentage of labs using this method is 91.7 percent (in WS 37), indicating wide usage compared to SM 6610 or any other available methods.

## 34 Methods Support Document for Six-Year Review Final - March 2003 

## Carbofuran

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method



### 531.1 other 

## Figure 12. Distribution of AnalyticalTechniques by WS Study: Carbofuran

b. Results of the PQL Analysis The current PQL of 7 : 

## g/L was derived from multiplying the interlaboratory method detection limit (IMDL) of 0.7 : 

## g/L by a factor of ten (54 FR 22062). To conduct a PQL reevaluation, the numerical data from WS 24 to 41 were analyzed (no data were available for WS 28). Table 15 summarizes each WS result including the spiked (or "true") value, the number of participating laboratories, and the percentage of laboratories passing within the specified acceptance limit for carbofuran (± 45 percent of the spiked value, as specified in 40 CFR §141.24(h)(19)(i)).

Table 15. Evaluation of Carbofuran Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits 29 4.00 10 100 30 5.78 26 92 32 7.67 36 94 31 11.3 14 86 24a 15.6 11 100

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits



## 35 Methods Support Document for Six-Year Review Final - March 2003 26b 17.5 13 92 34 18.5 43 91 27 20.7 8 88 25a 24.2 5 80 33 24.8 33 94 38 33.6 42 95 26a 36.3 13 100 36 37.8 47 98 35 42.8 60 92 41 43.7 29 97 24b 44.5 11 100 25b 48.3 5 100 37 48.9 36 97 40 55.0 42 100 39 74.5 31 97



## Re-evaluation of the PQL by a linear regression approach was not feasible using the data shown in Table 15. The percentage of laboratories passing within the acceptance limit was well above the 75 percent criterion historically used to calculate the PQL. Also, very few (e.g., only WS 29, 30, and 32) of the WS studies provided a sample with a true value concentration near the original PQL. Because of these data limitations, the PQL could not be re-evaluated using the historical linear regression approach. Instead, at concentrations approaching nearly half of the current PQL, laboratories in WS 29 were observed to achieve a 100 percent passing rate, implying strong analytical capabilities at a low concentration. This observation could have implications for lowering the PQL. Conclusion for Carbofuran Since the time of promulgation of the original methods, one new method (SM 6610) has been added for carbofuran analysis. The current EPA Method 531.1 is nearly twice as sensitive as the previous version, and the plot of method usage over time illustrates that EPA Method 531.1 was the most commonly used method for the determination of carbofuran. Together, these facts imply that analytical methods capabilities have improved over time. The PE data from WS studies 24 to 41, however, were not useful for a PQL re-evaluation because of the extremely high number of laboratories passing within the accepted limit for carbofuran. While the high success rate of laboratories at some low concentrations may present a potential argument for lowering the PQL from 7 : 

## g/L, there are no data available to support changing the original PQL.

## 36 Methods Support Document for Six-Year Review Final - March 2003 

## Carbon Tetrachloride Results of the Method Comparison In July 1987, the final NPDWR for eight Phase I VOCs approved the use of EPA Methods 502.1, 502.2, 524.1, and 524.2 for the determination of carbon tetrachloride in drinking water (52 FR 25690). The current approved methods for carbon tetrachloride determination are EPA Methods 502.2, 524.2, and 551.1. Table 16 summarizes the MDLs for both the original and currently approved versions of the methods. As shown in Table 16, EPA Method 551.1 has the greater detection sensitivity than EPA Methods 502.2 and 524.2.

Table 16. Results of the Analytical Methods Comparison for Carbon Tetrachloride (Newly Promulgated Methods are Indicated in Bold)

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods Method Technique MDL  

### (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.003 EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.02

EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.02* EPA 524.2 2 

### Purge and Trap GC/MS 0.08 - 0.21

EPA 524.1 1 

### Purge and Trap GC/MS 0.3 EPA 551.1 2 

### LLE and GC with ECD 0.002 - 0.006

EPA 524.2 1 

### Purge and Trap GC/MS 0.08 - 0.21*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. 

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for VOCs are listed at 40 CFR § 141.24(f)(17). 

## ^Acceptance limits are listed at 40 CFR § 141.24(f)(17)(i).



## Results of the Analysis of the WS Data a. Method Usage Over Time The distribution of the different methods used by the EPA and State laboratories during WS studies 34 to 41 are shown in Figure 13. The category of "other" contains those methods that were unknown or unidentified by the participating laboratories. As shown in Figure 13, EPA Methods 524.2 and 502.2 are currently the preferred methods used by laboratories for

## 37 Methods Support Document for Six-Year Review Final - March 2003 

## determination of carbon tetrachloride. Use of the original methods, EPA Methods 502.1 and 524.1, was not apparent over this time period; plotting data from studies prior to WS 34 might reveal more information on the use of these methods.

b. Results of the PQL Analysis The original PQL of 5 : 

## g/L (52 FR 25700) for carbon tetrachloride was determined from PE data from WS 8 to 11. Re-evaluation of the PQL was attempted using data from WS studies 24 through 41. Table 17 summarizes the results of these WS studies providing the study number, the spiked value for the WS sample, the number of participating laboratories, and the percent of laboratories passing the WS proficiency test for carbon tetrachloride within the specified acceptance limits for carbon tetrachloride (± 20 percent for a true value greater than10 :

## g/L, or ± 40 percent for a true value lower than 10 : 

## g/L as specified at 141.24(f)(17)(i)). Carbon Tetrachloride

0% 10% 20% 30% 40% 50% 60% 70% 80%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method



### 524.2 502.2 other 

## Figure 13. Distribution of Analytical Techniques by WS Study 

## : Carbon Tetrachloride

## 38 Methods Support Document for Six-Year Review Final - March 2003 

## Table 17. Evaluation of Carbon Tetrachloride Data from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 24 4.56 56 96 34 6.27 60 100 30 6.46 59 98 27 8.48 37 97 31 8.69 36 100 40 8.90 57 98 25 9.18 37 95 29 10.4 36 81 35 10.8 34 88 36 12.6 59 97 37 12.7 47 87 33 13.4 34 88 41 14.2 40 100 32 14.5 55 89 38 15.6 54 94 26 16.7 59 85 39 19.2 42 83



## From Table 17, it can be concluded that the available PE data for carbon tetrachloride are insufficient for a PQL re-evaluation. For the WS studies evaluated, the participating labs passed the proficiency exams at a passing rates greater than the standard 75 percent acceptance criterion used to determine the PQL. In addition, only one WS study (WS 24) had a concentration lower than the current PQL. However, passing rates of greater than 96 percent at concentrations close to the current PQL suggest that the current PQL of 5 : 

## g/L could be possibly be lower. Conclusion for Carbon T etrachloride The method comparison results show that since the promulgation of analytical methods under the NPDWR, three new methods (EPA Methods 502.2, 524.2, and 551.1) have replaced the two original analytical methods (EPA Methods 502.1 and 524.1). While EPA Method 551.1 is the most sensitive of the three currently approved methods, this method is not currently used by EPA or State laboratories according to the available WS data. Instead, EPA Method 524.2, the least sensitive of the three current methods, has been the primary method of choice. The MDL of EPA Method 524.2 is more sensitive than EPA 524.1 but less sensitive than EPA 502.1. Evaluation of the quantitative PE data showed that the majority of the laboratories conducting WS analyses surpassed the 75 percent criterion. Because of the high percentage of laboratories

## 39 Methods Support Document for Six-Year Review Final - March 2003 

## passing and a lack of spike samples at concentrations below the current PQL, a re-evaluation of the PQL could not be performed using this approach. However, high passing rates at values close to the current PQL of 5 : 

## g/L suggest that a lower PQL is possible.

Chlordane Results of the Method Comparison With the 1991 promulgation of the Phase II Rule for SOCs, three analytical methods were approved for the determination of chlordane in drinking water: EPA Methods 505 (GC/microextraction), 508 (GC/ECD), and 525.1 (LSE/GC/MS) (56 FR 3526). Since the promulgation of this rule, EPA Method 525.1 was removed and EPA Methods 525.2 (LSE, GC/MS) and 508.1 (GC/LSE/ECD) were added to the approved list. Table 18 lists detection limits for these methods. Using the highest value of the range of MDLs reported, EPA Methods 508 and 508.1 are both approximately 30 times more sensitive than EPA Method 505.

Table 18. Results of the Analytical Methods Comparison for Chlordane (Newly Promulgated Methods are Indicated in Bold)

MCL = 2 : 

### g/L Current PQL = 2 : 

### g/L DL•

### = 0.2 : 

### g/L Acceptance Limit^

### = ± 45%

Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L)

EPA 505 1 

### Microextraction and GC 0.14 EPA 505 2 

### Microextraction and GC 0.14

EPA 508 1 

### GC with ECD 0.0015 P 

### EPA 508 2 

### GC with ECD 0.0016 - 0.0041 * EPA 525.1 1 

### LSE and GC/MS 0.1 - 0.3* EPA 508.1 2 

### LSE and GC with ECD 0.001 - 0.004 *

EPA 525.2 2 

### LSE and GC/MS 0.05 - 0.17 *

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA-600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR §141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL.

## 40 Methods Support Document for Six-Year Review Final - March 2003 

### Chlordane

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 505 508 508.1 525.1 525.2 other 

## Figure 14. Distribution of AnalyticalTechniques by WS Study: Chlordane Results of the Analysis of the WS Data a. Method Usage Over Time Figure 14 plots the distribution of analytical techniques used by EPA and State laboratories in WS 34 to 41. The "other" techniques represent methods which were not specifically identified by participating laboratories or were otherwise unknown. As shown in Figure 14, the majority of laboratories used EPA Method 508 for determination of chlordane in WS 34 to 41. EPA Method 525.1, which was used quite minimally in earlier WS studies, was replaced by EPA Method 525.2 in WS 36. Laboratories also began to employ EPA Methods 508.1 and 525.2 during WS 36. For WS 34 to 41, EPA Method 505 consistently remained the second-most commonly used method after EPA Method 508.

b. Results of the PQL Analysis The Agency derived the current chlordane PQL of 2 : 

## g/L by multiplying the detection limit by a factor of ten (56 FR 3552). With the availability of recent PE WS data, efforts were made to reassess the PQL using PE data from WS 24 to 41. Table 19 summarizes the data from these WS studies, indicating the study number, the spiked or "true" value of the WS sample, the number of results from EPA and State laboratories,and the calculated percentage of laboratories whose results successfully passed within federally designated acceptance limits for chlordane. These acceptance limits are specified in 40 CFR §141.24(h)(19)(i) to be ± 45 percent.

## 41 Methods Support Document for Six-Year Review Final - March 2003 

## Table 19. Evaluation of Chlordane Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits 29 0.833 25 88.0 24a 1.32 40 87.5 27 1.84 28 96.4 26a 2.70 39 94.9 33 2.76 36 88.9 41 2.90 41 95.1 25a 3.30 22 95.5 39 3.57 41 95.1 30 4.20 49 93.9 37 4.44 46 93.5 24b 4.86 40 85.0 31 5.16 30 83.3 32 5.33 56 83.9 34 7.26 52 90.4 38 8.20 51 98.0 26b 9.60 39 97.4 40 11.8 56 94.6 25b 12.6 22 100 35 13.6 33 93.9 36 16.7 52 94.2



## Table 19 shows that EPA and State laboratories consistently demonstrated high success rates, surpassing the 75 percent criterion for all evaluated water studies. Therefore, a new PQL could not be re-evaluated using this approach. Even at low spiked concentrations, including three samples below the current PQL, well over 80 percent of participating laboratories successfully determined results within the acceptance limits. This observation suggests the possibility that laboratories may be capable of determining chlordane at levels below the current PQL.

Conclusion for Chlordane The plot of method usage over time (from WS studies) indicates consistent use of EPA Methods 508 and 505 over the duration of the selected studies, with laboratories favoring usage of EPA Method 508. EPA Method 508 represents the most sensitive currently approved method (Table 18). It appears that analytical capabilities for chlordane overall have improved since the

## 42 Methods Support Document for Six-Year Review Final - March 2003 

## time of NPDWR promulgation. The available WS data do not support a reassessment of the PQL based on the 75 percent criterion, however, because the passing rates of laboratories always exceeded this value. Because such high passing rates were observed for some low spiked concentrations (e.g., 88 percent laboratory success for a concentration 2.5 times lower than the current PQL), it is possible that a lowered PQL might be appropriate. However, the desired quantitative reassessment of the PQL could not be performed using the historical approach.

Chromium Results of the Method Comparison In 1991, the Phase II rule for IOCs listed EPA Methods 218.2 (AAF) and 200.7A (ICP) and Standard Method 304 (AAF) as the approved methods for determination of chromium in drinking water (57 FR 31776). Since that time, EPA Method 218.2 has been removed from the list of approved methods and four new methodshave been added: two EPA Methods (200.8, ICP/MS; and 200.9, AAP); and two Standard Methods (3113B, AAF; and 3120B, ICP). The sensitivity of EPA Method 200.9 exhibits approximately ten times the sensitivity of the prior methods. The detection limits of the Standard Methods are not specified. Table 20 summarizes the MDL information for all current and former approved methods.

Table 20. Results of the Analytical Methods Comparison for Chromium (Newly Promulgated Methods in Bold)

MCL = 100 : 

### g/L Current PQL = 10 : 

### g/L DL >

### = 1 - 7 : 

### g/L Acceptance Limit^

### = ± 15% Methods Approved At Promulgation Currently Approved Methods (141.23) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 200.7A 1 

### ICP 0.6 P

### EPA 200.7 3 

### ICP 4 EPA 218.2 2 

### AAF 1 P 

### EPA 200.8 3 

### ICP/MS 0.08 - 0.9*

SM 304 5 

### AAF N/A" 

### EPA 200.9 3 

### AAP 0.1 SM 3113B 4 

### AAF N/A" 

### SM 3120B4 

### ICP N/A"

## 43 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Inductively-Coupled Plasma Atomic Emission Analysis of Drinking Water," Appendix to Method 200.7, March 1987, U.S. EPA, Environmental Monitoring and Support Laboratory, Cincinnati, OH 45268. 2

### "Methods for Chemical Analysis of Water and Wastes (MCAWW)," EPA/600/4-79/020, March 1983. 3

### "Methods for the Determination of Metals in Environmental Samples Supplement I," EPA/600/R-94/111, May 1994. 4

### Standard Methods for the Examination of Water and Wastewater. American Public Health Association, 1015 Fifteenth Street NW, Washington, DC 20005. 5

### 16th

### edition of Standard Methods for the Examination of Water and Wastewater, 1985, American Public Health Association, American Water Works Association, Pollution Control Federation. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance.

>

### Regulatory DLs for inorganic compounds are listed at 40 CFR §141.23(a)(4)(i). The value may vary depending on analytical technique. ^

### Acceptance limits are listed at 40 CFR §141.23(k)(3)(ii) for inorganic compounds. "

### MDLs are not specified for non-EPA (i.e., voluntary consensus standard) methods.

P

### EDL = estimated detection limit, used to approximate the MDL.



## Results of the Analysis of the WS Data a. Method Usage Over Time The distribution of analytical methods used by participating laboratories from WS 34 to 41 is shown in Figure 15. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as "unknown" methods, i.e., methods for which laboratories did not report any information on the type of method used. During WS 34 and 35, EPA Methods 200.7 and 218.2 were the most widely used among laboratories participating in the PE studies. By WS 36, EPA Method 218.2 was no longer in use. Overall, EPA Method 200.7 remained the most commonly used method during WS 34- 41. Voluntary consensus standard methods SM 3120 and SM 3113B were also used in many WS studies.

## 44 Methods Support Document for Six-Year Review Final - March 2003 Chromium



### 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method
200.7 200.8 200.9 21

8.2 311

3B 31

20B other 

## Figure 15. Distribution of AnalyticalTechniques by WS Study: Chromium

b. Results of the PQL Analysis The current PQL of 10 : 

## g/L was derived using earlier PE data from WS 24 through 27 (56 FR 3549). For the PQL re-evaluation, data were taken from a broader range of studies, including more recent PE data (WS 24 to 41). The results of these water studies, providing the study number, the spiked value for the WS sample, the number of results from EPA and State laboratories, and the reported results evaluated using an acceptance limit of ± 15 percent (§141.23(k)(3)(ii)) are summarized in Table 21.

Table 21. Evaluation of Chromium Data from WS Studies Using the 15% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 15% Acceptance Limits 34 11.6 65 93.8 25a 15.0 41 92.7 39 23.9 50 94.0 24b 25.5 62 90.3 36 37.8 65 95.4 26a 50.2 64 95.3

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 15% Acceptance Limits



## 45 Methods Support Document for Six-Year Review Final - March 2003 41 55.5 47 100 25b 60.0 42 95.2 32 68.1 67 95.5 37 72.9 51 98.0 27 75.3 35 94.3 31 81.6 38 92.1 40 90.9 65 96.9 26b 94.6 64 93.8 29 110 33 87.9 35 119 43 90.7 24a 127 62 88.7 38 148 66 95.5 33 159 35 91.4 30 200 66 93.9



## A re-evaluation of the PQL could not be performed using the available PE data in Table 21. To conduct a graphical PQL analysis requires laboratory success rates ranging below the 75 percent criterion, which participating laboratories consistently surpassed (achieving a passing rate of greater than 87 percent for all the WS studies evaluated). Furthermore, the spiked concentrations used in each water study were above the original PQL (10 : 

## g/L). Conclusion for Chromium The method comparison results indicate that some methods approved after the promulgation of the Phase II Rule are more sensitive than the original methods (one of which was discontinued). Currently the most sensitive method is EPA Method 200.9 (AAP). However, according to the plot of method usage over time, EPA Method 200.7 (ICP) consistently has remained the most frequent choice for EPA and State laboratories, and the MDL of this method has not changed significantly. These facts suggest no significant alteration to the analytical capabilities of laboratories. Using the designated ± 15 percent acceptance limit, the evaluationof recent WS data revealed that these data are outside a range that would allow for a reevaluation of the PQL. Thus, the PE data continue to support the existing PQL of 10 : 

## g/L.

1,2-Dibromo-3-chloropropane (DBCP) Results of the Method Comparison The NPDWR for DBCP, a Phase II SOC, listed EPA Method 504 (GC with microextraction) as the only approved method for determination of this compound (56 FR 3526). Since then, EPA has replaced this method with EPA Methods 504.1 and 551.1. Table 22 summarizes the

## 46 Methods Support Document for Six-Year Review Final - March 2003 

## approved methods at promulgation and currently approved methods. EPA Method 504.1 has a MDL roughly equal to the MDL of the original EPA Method 504.

Table 22. Results of the Analytical Methods Comparison for DBCP (Newly Promulgated Methods are Indicated in Bold)

MCL = 0.2 : 

### g/L Current PQL = 0.2 : 

### g/L DL•

### = 0.02 : 

### g/L Acceptance Limit^

### = ± 40% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL* (: 

### g/L) Method Technique MDL* (: 

### g/L)

EPA 504 1 

### Microextraction and GC 0.01 EPA 504.1 2 

### Microextraction and GC 0.01

EPA 551.1 2 

### LLE and GC with ECD 0.006 - 0.009 *

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR §141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.



## Results of the Analysis of the WS Data a. Method Usage Over Time Figure 16 is a plot of the distribution of analytical techniques used by EPA and State laboratories in WS 34 to 41. The "other" techniques represent methods that were not specifically identified by participating laboratories or were otherwise unknown. As shown in Figure 16, the majority of laboratories used EPA Method 504.1 during WS studies 34 to 41. The other recently approved method, EPA Method 551, was only used minimally during WS 36 to 39. Participating laboratories chose "other" methods approximately 10 to 15 percent of the time.

## 47 Methods Support Document for Six-Year Review Final - March 2003 DBCP

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

504.1 551 other 

## Figure 16. Distribution of Analytical Techniques by WS Study: DBCP

b. Results of the PQL Analysis For DBCP, the original PQL of 0.2 : 

## g/L was derived by multiplying the detection limit of 0.02 : 

## g/L by a factor of ten (56 FR 3551). Recent PE data from WS 26 to 41 have enabled EPA to attempt a reassessment of the PQL. Table 23 summarizes the data from these WS studies (except WS 33 which did not contain data), indicating the study number, the true value of the WS sample, the number of results from EPA and State laboratories, and the calculated percentage of laboratories whose results succe ssfully passed within the 40 percent acceptance limits for DBCP.

Table 23. Evaluation of DBCP Data from WS Studies Using the ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 40% Acceptance Limits 36 0.196 50 92.0 32 0.233 24 95.8 39 0.246 36 91.7 37 0.286 42 88.1 34 0.363 45 88.9

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 40% Acceptance Limits



## 48 Methods Support Document for Six-Year Review Final - March 2003 38 0.429 48 97.9 41 0.451 34 100 40 0.527 50 98.0 35 0.589 29 93.1 27 0.653 18 88.9 29 0.980 39 94.9 26 1.13 35 88.6 31 1.78 44 97.7 30 2.65 24 91.7



## Based on the data in Table 23, a revised PQL value could not be estimated because the passing rate of participating laboratories surpassed the 75 percent criterion needed. Also, the true values of the spiked samples in all but one study (WS 36) were greater than the existing PQL, limiting potential conclusions regarding a lower PQL. Therefore, a regression analysis was not performed. However, high passing rates at concentrations around the current PQL of 0.2 : 

## g/L are suggestive of a change in the PQL. Conclusion for DBCP The MDL of EPA Method 504.1, a GC-microextraction technique, has not changed substantially since the promulgation of the NPDWR for DBCP. According to recent WS study data, laboratories have elected to use EPA Method 504.1 more often than EPA Method 551.1. These observations imply that detection limits for the overall contaminant have remained fairly constant over time. Using the data compiled from WS 26 to 41, the current PQL was reassessed.However, laboratories in all studies surpassed the 75 percent passing rate used in a PQL reevaluation, such that a regression analysis was not attempted. Furthermore, the true value concentrations exhibited in almost all of the studies were higher than the current PQL, meaning that the effects of lower PQL could not be determined. Although, the available PE data were not suitable to recalculate a new PQL, the high passing rates are suggestive of a change in the PQL.

1,4-Dichlorobenzene (para-dichlorobenzene) Results of the Method Comparison With the promulgation of the final rule for Phase I VOCs in July 1987 (52 FR 25690), fiveapproved methods were listed for the determination of 1,4-dichlorobenzene (also known as paradichlorobenzene) in drinking water: EPA Methods 502.1, 502.2, 503.1, 524.1, and 524.2. Since the promulgation of this rule, the Agency has removed EPA Methods 502.1, 503.1, and 524.1 from the list of approved methods. The detection limits of the currently approved methods have not changed significantly from the methods approved at the time of promulgation. Table 24 summarizes the original and current methods and their MDLs.

## 49 Methods Support Document for Six-Year Review Final - March 2003 

## Table 24. Results of the Analytical Methods Comparison for 1,4-Dichlorobenzene

MCL = 75 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL  

### (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC ND EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.04

EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.04* EPA 524.2 2 

### Purge and Trap GC/MS 0.03 - 0.04

EPA 503.1 1 

### Purge and Trap GC 0.006

EPA 524.1 1 

### Purge and Trap GC/MS 2.0

EPA 524.2 1 

### Purge and Trap GC/MS 0.03 - 0.04*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. 

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1 lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for VOCs are listed at 40 CFR § 141.24(f)(17). 

## ^Acceptance limits for organic compounds are listed at 40 CFR § 141.24(f)(17)(i). ND = Not determined.



## Results of the Analysis of the WS Data a. Method Usage Over Time The distribution of different methods used by EPA and State laboratories during WS 34 to 41 is charted in Figure 17. The category of "other" methods includes those methods that were unknown or otherwise unidentified by the participating laboratories. During WS 34 to 41, the use of EPA Method 524.2 increased while use of EPA Method 502.2 diminished slightly.

## 50 Methods Support Document for Six-Year Review Final - March 2003 

### 1,4 Dichlorobenzene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 17. Distribution of Analytical Techniques by WS Study: 1,4- Dichlorobenzene

b. Results of the PQL Analysis The original PQL of 5 : 

## g/L for 1,4-dichlorobenzene was determined by using PE data from Water Supply Studies 8 to 11 (50 FR 46880). For the six-year regulatory review, more recent WS data were compiled to provide a more accurate, updated assessment of laboratorycapabilities. Hence, data from WS studies 24 to 27 and 29 to 41 were used to attempt to reevaluate the PQL. Table 25 summarizes the available PE data by providing the study number, spiked value for the WS sample, number of laboratory results, and percentage of laboratories passing the proficiency test within the acceptance limits, meaning their reported results fall within the designated acceptance limits for a particular contaminant. The acceptance limits for 1,4-dichlorobenzene are ± 20 percent for a true value greater than 10 : 

## g/L, or ± 40 percent for a true value lower than 10 : 

## g/L (as specified at 40 CFR § 141.24(f)(17)(i)).

## 51 Methods Support Document for Six-Year Review Final - March 2003 

## Table 25. Evaluation of 1,4-Dichlorobenzene Data from WS Studies Using the ± 20% or ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 24 2.50 57 96.5 34 5.78 59 100 29 6.60 34 97.1 37 7.31 47 95.7 31 9.40 36 97.2 27 9.58 38 100 40 11.6 57 87.7 36 11.9 60 95.0 32 13.6 61 93.4 38 14.2 54 55.6 26 14.6 60 93.3 33 15.1 33 87.9 41 15.8 42 92.9 30 16.1 58 84.5 35 16.7 33 97.0 39 17.8 42 88.1 25 20.8 37 83.8



## Because a very large percentage of EPA and State laboratories passed the proficiency test within the bounds of the designated acceptance limits, the PQL could not be determined using the historical 75 percent criterion. Therefore,a regression analysis could not be conducted. However, the high passing rates suggest that the PQL could be lower. Conclusion for 1,4-Dichlorobenzene Since the promulgation of the NPDWR for 1,4-dichlorobenzene, the two analytical methods approved in 1987, EPA Methods 502.2 and 524.2, are still approved for use today. According to the distribution of analytical methods usage over time, EPA Method 524.2 was more widely used than EPA Method 502.2 during WS 34 to 41. Upon review of the WS data, a high percentage of laboratories successfully passed the proficiency tests, preventing a graphical estimated assessment of the PQL at the 75 percent passing rate. Although the available PE data are insufficient to recalculate the PQL, high passing rates are suggestive of a change in the PQL.

## 52 Methods Support Document for Six-Year Review Final - March 2003 

## 1,2-Dichloroethane Results of the Method Comparison The approved drinking water methods for the determination of 1,2-dichloroethane, a Phase I VOC (52 FR 25690) are EPA Methods 502.1, 502.2, 524.1, and 524.2. These methods all utilize GC or GC/MS with several extraction and/or detector variations. Since promulgation of these original methods, the Agency has removed EPA Methods 502.1 and 524.1 from the list of approved methods, and has continued to approve the use of EPA Methods 502.2 and 524.2. Table 26 summarizes the current and previous EPA methods along with their MDLs.

Table 26. Results of the Analytical Methods Comparison for 1,2-Dichloroethane

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods Method Technique MDL  

### (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.002 EPA 502.2 2 

### Purge and Trap GC 0.03

EPA 502.2 1 

### Purge and Trap GC 0.03 EPA 524.22 

### Purge and Trap GC/MS 0.02 - 0.06*

EPA 524.1 1 

### Purge and Trap GC/MS 0.2

EPA 524.2 1 

### Purge and Trap GC/MS 0.02 - 0.06*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.  

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1 lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for VOCs are listed at 40 CFR § 141.24(f)(17). 

## ^Acceptance limits are listed at 40 CFR § 141.24(f)(17)(i).

## 53 Methods Support Document for Six-Year Review Final - March 2003 

## 1,2-Dichloroethane

0% 10% 20% 30% 40% 50% 60% 70% 80%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method



### 524.2 502.2 other 

## Figure 18. Distribution of Analytical T echniques by WS Study: 1,2-Dichloroethane Results of the Analysis of the WS Data a. Method Usage Over Time The types of methods used over time by the EPA and State laboratories during WS studies 34 to 41 are illustrated in Figure 18. The results for "other" techniques in this figure include any unknown or unreported methods. Using Figure 18, it is apparent that the percentage of labs using EPA Method 502.2 has steadily declined while EPA Method 524.2 has experienced an increase in use over the time period between WS studies 34 and 41.

b. Results of the PQL Analysis The original PQL of 5 : 

## g/L (52 FR 25700) for 1,2-dichloroethane was established by using the data from WS PE studies 8 to 11. To re-evaluate the PQL, data were taken from WS 24 to 41. This data, including the study number, the spiked or "true" value for the WS sample, the number of laboratory results, and the percent of laboratories passing within the accepted limits of ± 20 percent for a spiked value of > 10 : 

## g/L and ± 40 percent for a spiked value of < 10 :

## g/L, are compiled and illustrated in Table 27.

## 54 Methods Support Document for Six-Year Review Final - March 2003 

## Table 27. Evaluation of 1,2-DichloroethaneData from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limit % Labs Passing ± 40% Acceptance Limit 27 4.88 37 100 30 7.69 59 98 36 9.00 59 100 31 9.25 36 100 26 10.8 59 95 34 12.1 60 98 29 12.9 34 79 24 13.2 56 89 37 13.2 47 81 32 13.3 63 94 41 13.7 41 93 35 14.1 34 94 25 15.5 38 90 38 15.6 54 93 40 15.6 57 88 33 16.9 35 97 39 17.6 42 86



## As shown in Table 27, the percentage of laboratories passing the acceptance limit averaged over 90 percent which is well above the 75 percent passing criterion selected to determine the PQL. Also, the spiked (or "true") values which the laboratories received were higher than the original PQL of 5 : 

## g/L (with the exception of WS 27). Therefore, recalculation of the PQL could not be performed with these data. However, the high passing rates at concentrations close to the current PQL suggest that the PQL could be lower. Conclusion for 1,2-Dichloroethane EPA Methods 502.2 and 524.2 have remained approved analytical methods for the determination of 1,2-dichloroethane in drinking water since promulgation of analytical methods under Phase I. One of the original methods, EPA Method 502.1, had the greatest detection sensitivity of the four methods mentioned but is currently not approved for analysis. The method usage evaluation shows that, of the two currently approved methods, EPA Method 524.2 has steadily become the more preferred method of analysis by laboratories. Based on an analysis of the WS data, there are not enough appropriate data to conduct a reassessment of the PQL. However, high laboratory passing rates at concentrations close to the PQL 5 : 

## g/L are suggestive of a change in the PQL.

## 55 Methods Support Document for Six-Year Review Final - March 2003 

## 1,1-Dichloroethylene Results of the Method Comparison The analytical methods approved for the determination of 1,1-dichloroethylene under the NPDWRs for Phase I VOCs include EPA Methods 502.1, 503.1, and 524.1 (52 FR 25899). Since the promulgation of the rule in 1987, the Agency has added EPA Methods 502.2 and 524.2, to the list of approved methods. The currently approved methods for 1,1-dichloroethylene determination are EPA Methods 502.2 and 524.2. Table 28 summarizes the MDLs for both the original and current approved versions of the methods.

Table 28. Results of the Analytical Methods Comparison for 1,1-Dichloroethylene (Newly Promulgated Methods Indicated in Bold)

MCL = 7 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods Method Technique MDL (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.003 EPA 502.2 2 

### Purge and Trap GC 0.04 - 0.10

EPA 524.1 1 

### Purge and Trap GC/MS 0.2 EPA 524.2 2 

### Purge and Trap GC/MS 0.05 - 0.12

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. 2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. 

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1 lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(f)(17). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).

## 56 Methods Support Document for Six-Year Review Final - March 2003 1,1-Dichloroethylene

0% 1 0% 20% 30% 40% 50% 60% 70% 80% 90% 1 00%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 W

ater Study% Labs Using Method



### 502.2 524.2 other 

## Figure 19. Distribution of Analytical Techniques by WS Study: 1,1- Dichloroethylene Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 19 shows the distribution of analytical techniques used by EPA and State laboratories for WS studies 34 to 41. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as "unknown" methods, i.e., methods for which laboratories did not report any information on the type of method used. As shown in Figure 19, EPA Method 502.2 was used less as EPA Method 524.2 was used more often (as shown from WS 34 to 41).

b. Results of the PQL Analysis

The current PQL of 5 : 

## g/L was originally set using previous PE data (54 FR 22102). With the availability of more current data from WS 24 to 41, a PQL re-evaluation was attempted. Table 29 summarizes the results of these studies, including the study number, the spiked (or "true") value for the sample, the number of laboratory results, and the percent of laboratories

## 57 Methods Support Document for Six-Year Review Final - March 2003 

## passing the WS proficiency test for 1,1-dichloroethylene within the acceptance limits. The acceptance limits were calculated as ± 20 percent for a spike value of >10 : 

## g/L and ± 40 percent for a spiked value of <10 : 

## g/L (as specified at 40 CFR §141.23(f)(17)(i)).

Table 29. Evaluation of 1,1-Dichloroethylene Data from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 41 5.25 41 97.6 24 5.36 57 87.7 26 6.64 60 95.0 31 7.02 37 97.3 34 7.64 60 98.3 36 8.49 60 98.3 32 9.13 63 100 27 9.45 37 89.2 29 11.7 35 74.3 38 11.7 56 19.6 39 12.4 43 79.1 33 12.9 33 75.8 35 13.9 35 88.6 30 14.2 45 77.8 25 14.9 38 94.7 37 16.5 48 83.3 40 18.3 58 86.2



## The data from the available PE studies were not conducive to PQL re-evaluation, as the percentage of labs passing generally exceeded the standard 75 percent passing criterion needed to estimate the PQL using the graphical approach (with the exception of two studies). However, high laboratory passing rates for those spike concentrations just above the PQL of 5 : 

## g/L suggest that the PQL could be lower.

## 58 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for 1,1-Dichloroethylene

The method comparison results indicate that EPA Method 502.2 is now the most sensitive method for determination of 1,1-dichloroethylene in drinking water. As revealed by the results of method usage over time, EPA Method 524.2 is the most commonly employed method for 1,1- dichloroethylene determination in recent PE studies. Based on the evaluation of more recent quantitative PE data, a recalculation of the PQL is not possible. However, the high laboratory passing rates for a couple spike samples with concentrations slightly above the current PQL of 5 : 

## g/L suggest that the PQL could change.

Dichloromethane (methylene chloride)

Results of the Method Comparison

At the promulgation of the Phase V rule for VOCs (57 FR 31776), four analytical methods were approved (EPA Methods 502.1, 502.2, 524.1, and 524.2) for the analysis of dichloromethane (also known as methylene chloride). Since that time, EPA Methods 502.1 and 524.1 have been removed from the approved list, leaving EPA Methods 502.2 and 524.2 as the remaining currently approved methods. Table 30 provides descriptions of the methods and their MDLs. The MDLs of the two current methods remain unchanged from their values at the promulgation of the rule.

Table 30. Results of the Analytical Methods Comparison for Dichloromethane

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC ND EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.02 EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.02* EPA 524.2 2 

### Purge and Trap GC/MS 0.03 - 0.09 EPA 524.1 1 

### Purge and Trap GC/MS 1.0 EPA 524.2 1 

### Purge and Trap GC/MS 0.03 - 0.09*

1 

### "Methods for the Determination of Organic Compounds in Finished Drinking Water and Raw Source Water," June 1985.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95- 131, August 1995.

>

### Regulatory DLS for organic compounds are listed at 40 CFR 141.24(f)(17). 

## ^Acceptance limits for VOCs are listed at 40 CFR 141.24(f)(17)(i).

*

### Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance. ND = Not determined.

## 59 Methods Support Document for Six-Year Review Final - March 2003 

## Dichloromethane

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

524.2 502.2 other 

## Figure 20. Distribution of Analytical T echniques by WS Study: Dichloromethane Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of methods used over WS studies 34 to 41 is illustrated in Figure 20. The designation "other" includes all unknown and unreported methods. As illustrated in Figure 20, EPA Method 524.2 was the predominant method used in these WS studies. Since WS 35, EPA Method 524.2 has steadily increased in its usage, experiencing only a slight decrease in WS 41. Even though EPA Method 502.2 features slightly better sensitivity than EPA Method 524.2, laboratories favored EPA Method 524.2, which utilizes GC/MS.

## 60 Methods Support Document for Six-Year Review Final - March 2003 

## b. Results of the PQL Analysis

Table 31 summarizes the results of the data from WS 26 to 41 for the use in the PQL reevaluation. Note that data for WS 24, 25, 27, 30, and 31 are not available for this analysis. Table 31 includes the WS number, the spiked "true" value, number of labs that participated in the studies, and the percentage of those passing within the acceptance limit designated for dichloromethane (± 20 percent if spiked "true" value is > 10 : 

## g/L or ± 40 percent if the spiked "true" value is < 10 : 

## g/L specified at 141.24(f)(17)(i)).

Table 31. Evaluation of Dichloromethane Data from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 35 5.83 35 97 40 6.2 57 97 39 7.31 42 100 32 7.77 51 94 37 8.41 47 92 36 12.3 59 90 33 12.8 34 94 38 14.7 54 98 29 14.7 33 97 26 15.2 51 71 41 15.9 40 85 34 18.4 59 86



## The original PQL of 5 : 

## g/L was derived from PE data from WS 22, 23, and 26 (57 FR 60953). As shown by Table 31, the WS data are not appropriate for a PQL re-evaluation using the linear regression approach. For most of the concentrations listed in Table 31, the percentage of laboratories passing were well above the 75 percent criterion necessary to recalculate the PQL. In summary, these data were not suitable for use in reassessing the current PQL using a graphical method. However, high laboratory passing rates at concentrations close to the current PQL suggest that the PQL may be lower.

## 61 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Dichloromethane

Since the promulgation of the Phase V rule, no new methods have been approved for the analysis of dichloromethane, and analytical capabilities have remained essentially constant. Of the currently approved methods, EPA Method 524.2 is used more frequently by laboratories for the detection of dichloromethane, although it is not the most sensitive method available (EPA Method 502.2). During WS 26 to 41, the percentage of laboratories passing was very high, limiting the possibilities of re-evaluating the PQL using the historical 75 percent criterion. Although, data are insufficient to recalculate the PQL, high passing rates at values close to the current PQL suggest that the PQL could change.

1,2-Dichloropropane

Results of the Method Comparison

The final NPDWR for 1,2-dichloropropane, a Phase II VOC, has four approved methods: EPA Methods 502.1, 502.2, 524.1, and 524.2. Since that time, EPA Methods 502.1 and 524.1 have been removed from the approved list, leaving EPA Methods 502.2 and 524.2 as the remaining currently approved methods. Table 32 provides descriptions of the methods and their MDLs. The MDLs of the two current methods remain unchanged from their values at the promulgation of the rule.

Table 32. Results of the Analytical Methods Comparison for 1,2-Dichloropropane

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limits^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC ND EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.03 EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.03* EPA 524.2 2 

### Purge and Trap GC/MS 0.02 - 0.04 EPA 524.1 1 

### Purge and Trap GC/MS 0.2 EPA 524.2 1 

### Purge and Trap GC/MS 0.02 - 0.04*

## 62 Methods Support Document for Six-Year Review Final - March 2003 1,2-Dichloropropane

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 21. Distribution of Analytical Techniques by WS Study: 1,2- Dichloropropane 1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance. ND = Not determined.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(f)(17). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).



## Results of the Analysis of the WS Data

a. Method Usage Over Time

For PE WS studies 34 to 41, the distribution of methods used by EPA and State laboratories is illustrated by Figure 21. The category of "other" contains those methods that were unknown or unidentified by participating laboratories.As Figure 21 shows, EPA Method 524.2 was the preferred method for laboratories participating in WS 34 to 41. For the most part, the use of EPA Method 502.2 decreased over time.

## 63 Methods Support Document for Six-Year Review Final - March 2003 

## b. Results of the PQL Analysis

The original PQL of 5 : 

## g/L (56 FR 3526) for 1,2-dichloropropane was determined by using PE data from WS 18. A re-evaluation of the PQL was attempted using more recent data from WS studies 29 through 41. Table 33 summarizes the results of these WS studies, including the study number, the true value concentration of the spiked sample, the number of laboratory results returned, and the percentage of laboratories passing the proficiency test within acceptance limits of ± 20 percent for a true value greater than 10 : 

## g/L, or ± 40 percent for a true value lower than 10 : 

## g/L (as specified in 141.24(f)(17)).

Table 33. Evaluation of 1,2-Dichloropropane Data from WS Studies Using the ± 20% or ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 32 6.46 61 100 35 9.00 34 100 30 10.9 58 98.3 39 12.2 43 93.0 34 12.3 59 96.6 37 14.2 47 91.5 33 14.3 32 93.8 41 15.4 40 97.5 29 15.8 33 87.9 36 16.4 59 93.2 38 18.3 55 94.5 40 19.0 57 94.7



## For this contaminant, the participating laboratories studies achieved success rates far greater than the 75 percent criterion typically used to estimate the PQL. Also, all of the true value concentrations used in the available studies exceeded the current PQL. Thus, the PQL could not be re-evaluated using the regression method. However, high passing rates of 100 percent for WS 32 with a spike concentration of 6.46 : 

## g/L is very close to the current PQL. This suggests that the PQL could be lower.

## 64 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for 1,2-Dichloropropane

The method comparison results show that no new methods have been approved since the promulgation of the NPDWR for 1,2-dichloropropane. Evaluation of the quantitative PE data showed that laboratories conducting WS analyses had surpassed the 75 percent criterion. Because the data featured a large percentage of laboratories passing, and very high true value concentrations, a re-evaluation of the PQL could not be performed using the typical graphical estimation approach. Thus, the available WS data are insufficient to recalculate the PQL for 1,2- dichloropropane. However, high laboratory passing rates for WS studies with concentrations close to the current PQL are suggestive of a change in the PQL.

2,3,7,8-TCDD (Dioxin)

Results of the Method Comparison

2,3,7,8-TCDD, commonly known as dioxin, was listed with the Phase V SOCs (57 FR 31776). Dioxin has not had any new methods approved for analysis since the promulgation of the NPDWRs for this contaminant. The MDL of the current method has remain unchanged from the value at the time of promulgation. Table 34 shows the specifications of EPA Method 1613 in both past and current periods.

Table 34. Results of the Analytical Methods Comparison for 2,3,7,8-TCDD

MCL = 30 pg/L Current PQL = 30 pg/L DL >

### = 5 pg/L Acceptance Limit^

### = ± 2*S.D. Methods Approved At Promulgation Currently Approved Methods (141.24)

Method Technique MDL (pg/L) Method Technique MDL (pg/L) EPA 1613 1 

### high resolution GC/MS (GC/HRMS) 10 EPA 1613 2 

### high resolution GC/MS (GC/HRMS) 10

1 Method 1613: Tetra-Through Octa-Chlorinated Dioxins a nd Furans by Isotope Dilution HRGC/HRMS: Revision A, USEPA, April 1990.

2"Tetra-through Octa-Chlorinated Dioxins and Furans by Isotope-Dilution HRGC/HRM S," EPA/821/B-94/005, October 1994.

>Regulatory DLs for organic compounds are listed at 40 CFR 141.24(h)(18). ^Acceptance limits for organic compoundsare listed at 40 CFR 141.24(h)(19)(i).

## 65 Methods Support Document for Six-Year Review Final - March 2003 

## Results of the Analysis of the WS Data

WS data were not available for dioxin; hence, no analyses on these data could be performed.

Conclusion

No new methods have been approved for the analysis of dioxin since the promulgation of the NPDWRs. The sensitivity of EPA Method 1613 has remained the same. A re-evaluation of the PQL could not be determined because no PE data were available for examination. Therefore, the current PQL is likely to remain unchanged.

Diquat

Results of the Method Comparison

Diquat became a regulated SDWA contaminant with the promulgation of the July 1992 Phase V rule for SOCs. Table 35 compares the approved methods at promulgation with currently approved methods. At the time of the Phase V regulation EPA Methods 549, was approved for determination of diquat in drinking water (57 FR 31776). In August 1992, EPA Method 549 was replaced by an updated method, EPA Method 549.1. Because Method EPA 549.1 received approval so soon after the promulgation of the Phase V rule, it is listed in the column of methods approved at promulgation in Table 35. In 1999 EPA approved EPA Method 549.2 (64 FR 67450) and discontinued EPA Method 549.1.

Table 35. Results of the Analytical Methods Comparison for Diquat (Newly Promulgated Methods Are Indicated in Bold)

MCL = 20 : 

### g/L Current PQL = 4 : 

### g/L DL•

### = 0.4 : 

### g/L Acceptance Limit^

### = ± 2*S.D. Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 549 1 

### LSE and with UV 0.44 EPA 549.2 3 

### LSE and HPLC with UV 0.72 EPA 549.1 2 

### LSE and HPLC with UV 0.44 - 0.51*

## 66 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water–Supplement I," EPA/600/4-90/020, July 1990.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement II," EPA/600/R92/129, August 1992. (Note this method was not actually approved at the time of July 1992 Phase V promulgation but was approved immediately after.)

3

### "Analytical Methods for Chemical and Microbiological Contaminants and Revisions to Laboratory Certification Requirements ," Federal Register, Vol. 64, No. 230, pp. 67450-67467. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance. ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR §141.24(h)(19)(i).



## Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of analytical techniques used by the EPA and State laboratories in WS 34 to 41 is shown in Figure 22. The "other" techniques represent methods which were not specifically identified by participating laboratories or were otherwise unknown. EPA has consistently approved a single method for diquat at any given time, EPA Method 549 was predominantly used prior to WS 36 and EPA Method 549.1 was used predominantly after WS 36.

## 67 Methods Support Document for Six-Year Review Final - March 2003 

### Diquat

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

549 549.1 other 

## Figure 22. Distribution of Analytical Techniques by WS Study: Diquat

b. Results of the PQL Analysis

The original PQL for diquat (4 : 

## g/L) was derived by using PE data from WS 23 to 27 (56 FR 60949). A reassessment of the PQL was attempted after compiling additional data from WS 24 to 41. However, for several of these available water studies, the number of participating laboratories were too few (under ten) to include for consideration in the analysis. After omitting these studies, the remaining usable PE data were summarized, including the study number, the true value of the WS sample, the number of results from EPA and State laboratories, and the calculated percentage of laboratories whose results successfully passed within federally designated acceptance limits (Table 36). The acceptance limits for diquat are specified in 40 CFR §141.24(h)(19)(i) to be twice the standard deviation, or ± 2*S.D., from the value "x" (where x = aT+b and T represents the true value).

Table 36 reveals that laboratory success rates ranged between 78.6 and 100 percent. Thus, use of the 75 percent criterion for estimation of the PQL by the graphical method would be meaningless. The dataset is also incompatible with the goals of a PQL reassessment–particularly a potential lowering of the PQL–because the concentrations of all the spiked samples exceeded the current PQL. Also, the concentration of the spike samples was well above the PQL of 4 : 

## g/L.

## 68 Methods Support Document for Six-Year Review Final - March 2003 

## Table 36. Evaluation of Diquat Data from WS Studies Using the ± 2* S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 2* S.D. Acceptance Limits 37 8.41 21 90.5 36 14.7 28 78.6 40 14.8 27 96.3 38 23.7 22 95.5 32 28.2 11 100 34 29.2 17 94.1 39 32.2 21 95.2 35 37.4 15 86.7 41 44.0 17 100



## Conclusion for Diquat

As shown by the results of the method comparison, few methods have been approved by EPA for the determination of diquat. The analytical technology supporting the determination of diquat has remained essentially unchanged over time. However, analytical capabilities have improved. The original method, EPA Method 549, was less sensitive than today's method, EPA Method 549.2, indicating significant analytical improvements. The plot of method usage over time reveals that the techniques predominantly used by participating laboratories were EPA Methods 549 (prior to WS 36) and 549.1 (subsequent to WS 36). Although the method comparison indicates increased analytical capabilities, the available WS data did not provide information suitable for a PQL reassessment. The percentage of laboratories passing within the acceptance window was generally well above the 75 percent criterion for use in the linear regression approach.

Ethylene Dibromide

Results of the Method Comparison

With the Phase II SOCs (56 FR 3526), EPA 504, was the only approved method listed for analysis of ethylene dibromide (EDB) in drinking water. Since this regulation was promulgated, the Agency has approved a new revision of GCwith microextraction (EPA Method 504.1) and approved an additional analytical method (EPA Method 551.1, LLE and GC with ECD). As

## 69 Methods Support Document for Six-Year Review Final - March 2003 

## shown in Table 37, the MDLs of EPA Methods 504 and 504.1 are equivalent, but EPA Method 551.1 offers a slightly greater level of sensitivity.

Table 37. Results of the Analytical MethodsComparison for Ethylene Dibromide (New Methods in Bold)

MCL = 0.05 : 

### g/L Current PQL = 0.05 : 

### g/L DL•

### = 0.01 : 

### g/L Acceptance Limit^

### = ± 40% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 504 1 

### Microextraction and GC 0.01 EPA 504.1 2 

### Microextraction and GC 0.01

EPA 551.1 2 

### LLE and GC with ECD 0.007 - 0.008*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18).
^

### Acceptance limits are listed at 40 CFR §141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 23 illustrates the distribution of the analytical techniques used by the EPA and State laboratories in WS studies 34 to 41. The "other" designation includes methods for which laboratories did not report any information on the method used or non-EPA methods. The use of EPA Method 504.1 greatly exceeds the use of any other method. This distribution is consistent through the duration of the WS studies shown in Figure 23.

## 70 Methods Support Document for Six-Year Review Final - March 2003 

## Ethylene Dibromide

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method



### 504.1 524.2 other 

## Figure 23. Distribution of Analytical Techniques by WS Study 

## : Ethylene Dibromide

b. Results of the PQL Analysis

The current PQL, 0.05 : 

## g/L, was derived from a multiplier of 5 from the MDL of 0.01 : 

## g/L (56 FR 3552). The data used for PQL re-evaluation were taken from WS studies 24 to 41. Table 38 summarizes the results of the WS studies, providing the study number, the true concentration of the spiked sample, the number of laboratories participating, and the percentage of laboratories passing the WS study (evaluated using acceptance limit of ± 40 percent for EDB as cited in 40 CFR § 141.24(h)(19)(i)).

Using the 75 percent criterion, it appears from the numerical data that EPA and regional laboratories are able to achieve acceptable results within the ± 40 percent acceptance window at concentrations from 0.14 to 2.3 : 

## g/L.

## 71 Methods Support Document for Six-Year Review Final - March 2003 

## Table 38. Evaluation of Ethylene Dibromide Data from WS Studies Using the ±40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing Acceptance Limits 37 0.138 42 81 33 0.143 24 75 39 0.227 36 94 36 0.283 51 94 38 0.336 48 96 41 0.344 34 100 34 0.406 45 87 26 0.434 35 91 24 0.480 32 100 35 0.609 30 90 31 0.637 25 84 40 0.638 50 98 29 0.850 25 84 25 0.944 18 100 30 1.39 39 92 27 1.45 17 88 32 2.29 44 98



## The percentages of the acceptable results for laboratories were not plotted, as these values all exceeded the 75 percent criterion and therefore could not contribute meaningful information toward the re-evaluation of a PQL using the linear regression approach. In addition, none of the WS studies evaluated had spike concentrations below the current PQL of 0.05 : 

## g/L. However, WS studies at concentrations slightly above the PQL (WS 37 and 33) had laboratory passing rates of 81 and 75 percent, respectively. This would indicate that the current PQL is probably appropriate and unlikely to change.

Conclusion for Ethylene Dibromide

The method comparison results indicate that the sensitivity of the available methods has not improved significantly since the promulgation of NPDWRs for EDB. Evaluation of more recent WS data provides no evidence that would support a change from the current PQL of 0.05 : 

## g/L.

## 72 Methods Support Document for Six-Year Review Final - March 2003 

## Fluoride

Results of the Method Comparison

Fluoride, a Phase II IOC, is unique among SDWA contaminants because it is often added to drinking water to provide well-known health benef its. Because low concentrations of fluoride are often added to public water supplies to protect dental health, EPA has not published a detection limit for this contaminant. Since the Agency's promulgation of the MCL for fluoride (April 1986, 51 FR 11397), this contaminant has gained several additional approved methods,mostly developed by voluntary consensus standard organizations. Currently, the only EPAapproved method for fluoride determination is EPA Method 300.0, an ion chromatography method with greater sensitivity than the EPA methods approved at the time of promulgation. Table 39 summarizes original and current methods, and their individual detection limits. The voluntary consensus standard method MDLs are not listed in this table because non-EPA methods are not required to document detection limits.

Table 39. Results of the Analytical Methods Comparison for Fluoride (Newly Promulgated Methods are Indicated in Bold)

MCL = 4 mg/L Current PQL = 0.5 mg/L DL = N/A>

### Acceptance Limit^

### = ± 10% Methods Approved At Promulgation Currently Approved Methods (141.23) Method Technique MDL (mg/L) Method Technique MDL (mg/L) EPA 340.1 1 

### Colorimetric SPADNS, with Bellack Distillation 0. 1- 1.4* EPA 300.0 6 

### Ion chromatography 0.01

EPA 340.2 1 

### Potentiometric, with ion-selective electrode (ISE) N/A >



### EPA 340.3 1 

### Automated Alizarin, with distillation (complexone) 0.05 - 1.5* D1179-93B 2 

### Manual electrode N/A >



### D1179-72A2 

### Colorimetric SPADNS, with distillation N/A > 

### D4327-91 7 

### Ion chromatography N/A >



### D1179-72B 2 

### Potentiometric, with ISE N/A > 

### 4500F-B,D 8 

### Manual distillation; colorimetric

SPADNS N/A >



### 43A; C 3 

### Colorimetric SPADNS, with distillation N/A > 

### 4500F-C 7 

### Manual electrode N/A >



### 413B 3 

### Potentiometric, with ISE N/A > 

### 4500F-E 7 

### Automated Alizarin N/A > 

### 413E 3 

### Automated Alizarin, w/distillation N/A > 

### 4110B 7 

### Ion chromatography N/A >



### 380-75WE 5 

### Automated electrode N/A > 

### 380-75WE 5 

### Automated electrode N/A >



### 129-71W4 

### Automated Alizarin, w/distillation N/A > 

### 129-71W4 

### Automated Alizarin N/A >

## 73 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods of Chemical Analysis of Water and Wastes (MCAWW)," EPA/600/4-79/020, EPA Environmental Monitoring Laboratory, Cincinnati, Ohio 45268. March 1983.

2 

### Annual Book of ASTM Standards, 1994, Vol. 11.01, American Society for Testing and Materials, 1961 Race Street. Philadelphia, PA 19103.

3 

### Standard Methods for the Examination of Water and Wastewater, 16 th

### edition. American Public Health Association, American Water Works Association, Water Pollution Control Federation, 1985.

4

### "Fluoride in Water and Wastewater, Industrial Met hod 129-71W," Technicon Industrial Systems, Tarrytown, New York 10591. December 1972.

5

### "Fluoride in Water and Wastewater," Technicon Industrial Systems, Tarrytown, New York 10591. February 1976.

6

### "Methods for the Determination of Inorganic Substances in Environmental Samples," EPA/600/R-94/111, August 1993.

7 

### Standard Methods for the Examination of Water and Wastewater, 19 th

### edition. American Public Health Association, American Water Works Association, Water Pollution Control Federation.

>

### MDLs are not specified for non-EPA (i.e., voluntary consensus standard) methods. ^

### Acceptance limits for inorganic compounds are listed at 40 CFR §141.23(k)(3)(ii). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.



## As shown in Table 39, multiple versions of methods exist for some technologies such as ion chromatography, automated electrode, automated alizarin, and manual electrode.

Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of the analytical techniques used by the EPA and State laboratories in WS 34 to 41 is shown in Figure 24. The results for "other" techniques include the use of other techniques identified by the laboratories participating in the WS study, as well as "unknown" methods, i.e., methods for which laboratories did not report any information on the type of method used.

## 74 Methods Support Document for Six-Year Review Final - March 2003 

### Fluoride

0% 10% 20% 30% 40% 50% 60% 70%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 300.0 340.1 340.2 340.3 380-75WE Manual Elec.* Auto. Alizarin** other 

## Figure 24. Distribution of AnalyticalTechniques by WS Study: Fluoride

* Manual electrode combines the methods D1179-93B (ASTM) and 4500F-C (SM). ** Automated Alizarin combines the methods 4500F-E (SM) and 129-71W (Technicon).



## Fluoride determination has involved the use of a wide variety of analytical methods. In earlier years, the most popular method was EPA Method 340.2, an ion selective electrode method, but its usage dropped significantly after WS 35. Since WS 36, method usage by laboratories participating in the water supply studies has been dominated by a non-EPA manual electrode method. Laboratories have also increasingly favored the use of EPA Method 300.0, though to a lesser extent relative to the manual electrode methods (D1179-93B, 4500F-C). A small fraction of participating laboratories have employed the voluntary consensus standard method 380-75WE (automated electrode) throughout WS 34 to 41.

b. Results of the PQL Analysis

The current PQL (500 : 

## g/L or 0.5 mg/L) was originally determined from older PE water supply study data (WS 8 to 12, see USEPA, "Monitoring for Fluoride in Drinking Water: Revised," March 1986). The PQL was re-evaluated using a broader range of PE data including more recent studies (WS 24 to 41). Table 40 summarizes the results of these studies, providing the study number, the spiked or "true" value for the WS sample, the number of results from EPA

## 75 Methods Support Document for Six-Year Review Final - March 2003 

## and State laboratories, and the actual responses returned by laboratories. For fluoride, EPA stipulates acceptance limits of ± 10 percent (§141.23(k)(3)(ii)).

Table 40. Evaluation of Fluoride Data from WS Studies Using the 10% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (mg/L) # Results from EPA and State Labs % Labs Passing ± 10% Acceptance Limits 29 0.33 33 84.8 34 1.10 65 93.8 26a 1.25 63 93.7 24b 1.30 62 96.8 40 1.40 66 60.6 25b 1.50 40 87.5 24a 1.72 62 93.5 37 1.80 55 87.3 32 2.00 67 92.5 25a 2.50 40 87.5 39 2.90 54 92.6 26b 3.41 64 89.1 35 3.80 43 97.7 27 4.35 37 86.5 38 4.70 65 98.5 31 5.70 33 97.0 41 6.20 46 95.3 33 6.60 35 94.3 36 7.20 61 95.1 30 7.90 61 93.4



## The WS data indicate that EPA and State laboratories performed with high success rates in WS studies involving fluoride determination. On average, 91 percent of participating laboratories achieved results within the ± 10 percent acceptance window. The range of true value concentrations contained many spikes above the current PQL (0.5 mg/L), preventing a thorough analysis of laboratory capabilities at or below the PQL. For WS 29, the only study where the true value was below the PQL, 85 percent of laboratories successfully passed within the specified acceptance limits, well above the 75 percent criterion. Thus, it might be possible

## 76 Methods Support Document for Six-Year Review Final - March 2003 

## for laboratories to pass the PE studies at even lower concentrations; however, such a conclusion is uncertain in the absence of additional data below the PQL value.

Conclusion for Fluoride

The MDL of the only currently approved EPA method, EPA Method 300.0, is much lower than those of previous EPA methods and use of this method has increased gradually over time. However, EPA Method 300.0 still accounts for less than a quarter of method usage for fluoride and thus cannot be representative of overall laboratory analytical capabilities. Based on the graph of method usage over time (Figure 24), the method most commonly used in recent years is a manual electrode method, whose detection limit is not specified. Hence, the combined results of the method comparison and method usage over time suggest that analytical capabilities have improved for only a subset of EPA and State laboratories.

Based on the evaluation of quantitative WS data, the current PQL of 0.5 mg/L is still supportable and appropriate, although an even lower value might be attainable based on the high success rates of laboratories in water studies. However, this hypothesis would require further analysis using WS data at spiked concentrations below 0.5 mg/L, and such data are currently not available.

Glyphosate

Results of the Method Comparison

In 1992, the Agency listed EPA 547 as the only approved method for determination of glyphosate in drinking water, according to the Phase V rule for SOCs (57 FR 31776). Since that time, EPA has added Standard Method (SM) 6651, a voluntary consensus standard method, to the approved list. The MDL of SM 6651 is not specified, but it is reasonable to expect a similar detection limit compared to EPA Method 547 due to the similarity in determinative technique. Because the MDL of EPA Method 547 has not changed over time and no additional EPA methods were approved, the analytical capabilities for determination of glyphosate have remained constant since the approval of EPA Method 547.

## 77 Methods Support Document for Six-Year Review Final - March 2003 

## Table 41. Results of the Analytical Methods Comparison for Glyphosate (Newly Promulgated Methods are Indicated in Bold)

MCL = 700.0 μg/L Current PQL = 60.0 μg/L DL•

### = 6.0 μg/L Acceptance Limit^

### = ± 2*S.D. Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (μg/L) Method Technique MDL (μg/L)

EPA 547 1 

### HPLC, post-column derivatization, fluorescence detection 5.99 - 8.99* EPA 547 1 

### HPLC, post-column derivatization, fluorescence detection 5.99 - 8.99 *

SM 6651 2 

### Liquid chromatography, post-column fluorescence N/A"

1 

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement I," EPA/600/4-90/020, July 1990.

2

### 18 th

### edition of Standard Methods for the Examination of Water and Wastewater, 1992, American Public Health Association, 1015 Fifteenth Street NW, Washington, DC 20005. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR §141.24(h)(19)(i). "

### MDLs are not specified for non-EPA (i.e., voluntary consensus standard) methods.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 25 is a plot of the distribution of analytical techniques used by the EPA and State laboratories during WS 34 to 41. As shown in Figure 25, the majority of the participating laboratories utilized EPA Method 547 for the determination of glyphosate. A small fraction of laboratories employed the voluntary consensus standard method, SM 6651 and a minority of laboratories used "other" methods or methods that were not specified.

## 78 Methods Support Document for Six-Year Review Final - March 2003 Glyphosate

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

547 6651 other 

## Figure 25. Distribution of AnalyticalTechniques by WS Study: Glyphosate

b. Results of the PQL Analysis

Glyphosate currently has a PQL of 0.06 mg/L (or 60 : 

## g/L) which was derived from previous WS results from EPA and State laboratories (WS 24 to 27, 56 FR 60949). In light of the availability of more recent PE WS data from WS studies 32 to 41, efforts were made to reassess the PQL. Table 42 summarizes the data from these water studies, indicating the study number, the true value of the WS sample, the number of results from laboratories, and the calculated percentage of laboratories whose results succe ssfully passed within the designated acceptance limits for glyphosate (± 2*S.D. as specified at 141.24(h)(19)(i).

Table 42 shows that the laboratories in these water studies were able to achieve results within the acceptance window with 73 to100 percent passing rates. Using the 75 percent criterion for estimation of the PQL will not be meaningful for this dataset because of the high success rate and the lack of spike values at concentrations around the current PQL of 60 : 

## g/L.

## 79 Methods Support Document for Six-Year Review Final - March 2003 

## Table 42. Evaluation of Glyphosate Data from WS Studies Using the ± 2* S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 2*S.D. Acceptance Limits 33 308 11 72.7 40 375 30 96.7 38 410 25 88.0 34 438 22 90.9 32 447 15 86.7 36 528 27 96.3 41 560 17 100 39 620 22 95.5 35 665 15 86.7 37 780 22 77.3



## Conclusion for Glyphosate

Currently, EPA Method 547 is the sole approved EPA method for determination of glyphosate and its MDL has not changed over time (Table 41). A voluntary consensus standard method (SM 6651) with similar determinative technology is also approved for use, but was used minimally over the duration of the selected studies according to PE records (Figure 25). The MDL of SM 6651 is not specified but in all likelihood, resembles the MDL of EPA Method 547. Therefore, the analytical methods capabilities for glyphosate determination have stayed constant for most laboratories. The available numerical WS data do not support a reassessment of the PQL based on the 75 percent criterion, because the passing rates of laboratories typically exceeded this value. In addition, the spike concentration of the WS samples were much higher than the current PQL.

Heptachlor

Results of the Method Comparison

The approved methods for the analysis of heptachlor, a Phase II SOC, in drinking water were listed in the NPDWRs (56 FR 3526). These original methods included gas chromatography with several extraction and/or detector variations (EPA Methods 505, 508, and 525.1). Since promulgation of the Phase II rule, EPA has removed one method (EPA Method 525.1) and approved the use of three new analytical methods (EPA Methods 508.1, 525.2, and 551.1). EPA

## 80 Methods Support Document for Six-Year Review Final - March 2003 

## Method 508.1 is nearly seven times more sensitive than it was at the time of NPDWR promulgation, and represents the most sensitive of the new methods, with a current MDL of approximately 0.0015 : 

## g/L. The MDLs of the newly approved methods, EPA Methods 508.1, 525.2, and 551.1, range from 0.5 to 15 times the MDLs of the most sensitive method at the time of the NPDWR promulgation.

Table 43. Results of the Analytical Methods Comparison for Heptachlor (Newly Promulgated Methods are Indicated in Bold)

MCL = 0.4 : 

### g/L Current PQL = 0.4 : 

### g/L DL•

### = 0.04 : 

### g/L Acceptance Limit^

### = ± 45% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L)

EPA 505 1 

### Microextraction and GC 0.003 EPA 505 2 

### Microextraction and GC 0.003

EPA 508 1 

### GC with ECD 0.01 P 

### EPA 508 2 

### GC with ECD 0.0015

EPA 525.1 1 

### LSE and GC/MS 0.04 - 0.2* EPA 508.1 2 

### LSE and GC with ECD 0.005

EPA 525.2 2 

### LSE and GC/MS 0.059 - 0.15* EPA 551.1 2 

### LLE and GC with ECD 0.002 - 0.081*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR §141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 26 is a plot of the distribution of analytical techniques used by the EPA and State laboratories in WS 34 to 41. The "other" techniques represent methods which were not specifically identified by participating laboratories or were otherwise unknown. As shown in Figure 26, the majority of laboratories used EPA Method 508 for determination of heptachlor in WS studies 34 to 41. EPA Method 525.1, which was used in earlier WS studies, was replaced by

## 81 Methods Support Document for Six-Year Review Final - March 2003 

## Heptachlor

0% 10% 20% 30% 40% 50% 60% 70%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 

### 525.2 525.1 508 505 508.1 other 

## Figure 26. Distribution of AnalyticalTechniques by WS Study: Heptachlor EPA Method 525.2 after WS 36. Other than this shift, there has been little overall change in method usage over time for this contaminant.

b. Results of the PQL Analysis

The original PQL for heptachlor (0.4 : 

## g/L) was derived via multiplication of the IMDL by a factor of 10 (56 FR 3552). With the availability of recent PE WS data, efforts were made to reassess the PQL using data from WS studies 24 to 41. Table 44 summarizes the data from these WS studies, indicating the study number, the true value of the WS sample, the number of results from EPA and State laboratories, and the calculated percentage of laboratories whose results successfully passed within federally designated acceptance limits for heptachlor. These acceptance limits are specified in 40 CFR §141.24(h)(19)(i) to be ± 45 percent from the true concentration of the spike sample.

## 82 Methods Support Document for Six-Year Review Final - March 2003 

## The numerical data in Table 44 demonstrate that the laboratories in these WS studies are able to achieve results within the ± 45 percent acceptance window with 82 to 100 percent passing rates. Using the 75 percent criterion for estimation of the PQL, the dataset are not adequate to re-evaluate the PQL. Further, the majority of the spike samples had concentrations in excess of the current PQL of 0.4 : 

## g/L. Nevertheless, the high passing rates of laboratories at concentrations around the PQL (e.g., 100 percent passing for a true value equal to 0.11 :

## g/L) support a possible reconsideration of the current PQL.

Table 44. Evaluation of Heptachlor Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits 25b 0.113 18 100 24a 0.263 33 94 29 0.370 24 95.8 32 0.443 44 94.6 37 0.563 42 95.6 27 0.642 24 100 39 0.667 36 97.6 36 0.751 51 94.5 41 0.83 34 93 34 0.914 45 90.2 38 1.20 48 94 30 1.38 47 93.6 25a 1.42 19 100 31 1.44 25 84.6 33 1.73 24 90.6 26 2.27 31 90.3 40 2.33 50 90.7 35 2.54 30 90.9 24b 3.15 33 93.9

## 83 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Heptachlor

The plot of the method usage over time (from WS studies) indicates consistent use of two methods, EPA Methods 508 and 505 over the duration of the selected studies, with laboratories slightly favoring usage of EPA Method 508. EPA Method 508 represents the most sensitive currently approved method, according to Table 43. The overall level of analytical sensitivity for this contaminant has improved approximately seven-fold from the time of NPDWR promulgation. The available numerical WS data do not support a reassessment of the PQL based on the 75 percent criterion, because the passing rates of laboratories always exceeded this value. Because such high passing rates were observed for some low spiked concentrations (e.g., 100 percent laboratory success for a concentration three times lower than the current PQL), it is possible that a lowered PQL might be appropriate. However, the desired quantitative reassessment of the PQL could not be performed using the historical approach.

Heptachlor Epoxide

Results of the Method Comparison

The approved methods designated in the Phase II rule for heptachlor epoxide (56 FR 3526) included EPA Methods 505, 508, and 525.1. These methods are variations of GC methods with different extraction and/or detection techniques as shown in Table 45. The most sensitive of the currently approved methods is EPA Method 508.1 (GC with ECD), with an MDL of 0.001 : 

## g/L. This method was introduced subsequent to the promulgation of the Phase II rule, along with two additional methods, EPA Methods 525.2 and 551.1.

Table 45. Results of the Analytical MethodsComparison for Heptachlor Epoxide (New Methods Indicated in Bold)

MCL = 0.2 : 

### g/L Current PQL = 0.2 : 

### g/L DL•

### = 0.02 : 

### g/L Acceptance Limit^

### = ± 45% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 505 1 

### Microextraction and GC 0.004 EPA 505 2 

### Microextraction and GC 0.004

EPA 508 1 

### GC with ECD 0.015 P 

### EPA 508 2 

### GC with ECD 0.0059 EPA 525.1 1 

### LSE and GC/MS 0.2 - 0.3* EPA 508.1 2 

### LSE and GC with ECD 0.001

EPA 525.2 2 

### LSE and GC/MS 0.048-0.13* EPA 551.1 2 

### LLE and GC with ECD 0.002 - 0.202*

## 84 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR 141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 27 illustrates the distribution of the analytical techniques used by the EPA and State laboratories in WS 34 to 41. Analytical methods which were not reported by laboratories or were otherwise unknown were grouped into the category of "other." As illustrated by Figure 27, EPA Method 508 represents the most commonly used method for heptachlor epoxide WS analyses. EPA Methods 505 and 525.2 were used to a lesser degree; together, these methods account for 40 to 50 percent of the techniques used during the indicated time frame.

## 85 Methods Support Document for Six-Year Review Final - March 2003 

## Heptachlor Epoxide

0% 10% 20% 30% 40% 50% 60% 70%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 

### 505 525.2 508 508.1 other 

## Figure 27. Distribution of Analytical Techniques by WS Study 

## : Heptachlor Epoxide

b. Results of the PQL Analysis

The PQL for heptachlor epoxide is currently 0.2 : 

## g/L. EPA obtained this value bymultiplying the estimated IMDL by a factor of 10 (56 FR 3552). The Agency wished to reevaluate the PQL using available WS data from WS studies 24 to 41 (although no data were available for WS 28). Table 46 summarizes these data, indicating the study number, the true value of the sample, the number of non-zero responses from laboratories, and the calculated passing rates of laboratories who satisfied the specified acceptance limits for heptachlor epoxide. These limits are designated as ± 45 percent (40 CFR §141.24(h)(19)(i)).

## 86 Methods Support Document for Six-Year Review Final - March 2003 

## Table 46. Evaluation of Heptachlor Epoxide Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits 24a 0.161 33 91 26a 0.198 31 87 29 0.267 25 92 39 0.340 43 98 32 0.346 55 95 37 0.403 45 93 27 0.533 24 88 34 0.55 51 94 41 0.63 43 95 33 0.679 31 94 38 0.742 51 96 25a 0.771 21 100 30 0.85 47 98 25b 0.094 20 100 40 1.48 54 94 35 1.49 33 97 24b 1.61 33 88 26b 1.81 30 97 31 1.92 27 82



## The values in the last column of Table 46 demonstrate that the laboratories participating in these WS studies achieved a very high rate of success with respect to the designated acceptance limits. While the 75 percent criterion has historically been used to evaluate PQLs, such an analysis would be impossible for heptachlor epoxide because none of the laboratories exhibited success rates below this threshold. Thus, a regression of the WS results was not performed, as the data did not appear to contribute meaningfully to recalculate the PQL. In addition, the concentrations of the spike samples generally exceeded the concentration of interest, the PQL (0.2 : 

## g/L).

## 87 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Heptachlor Epoxide

According to the method comparison results, the introduction of three new analytical methods since the promulgation of the Phase II rule has not presented any significant improvements in overall method sensitivity. The most sensitive method (EPA Method 508) at the time of NPDWR promulgation is no longer the most sensitive method today, due to its MDL change, as evident in Table 45. Based on the analysis of method usage over time, EPA Method 508 is more widely used than the current most sensitive method, EPA Method 508.1. In light of the usage patterns for heptachlor epoxide, analytical method capabilities for the overall contaminant are probably similar to those of the original methods. Although the WS data did not provide enough information to perform a regression analysis, the passing rates at concentrations around the current PQL of 0.2 : 

## g/L suggest that the PQL could be lower.

Hexachlorobenzene

Results of the Method Comparison

Hexachlorobenzene, a Phase V SOC, had three approved methods for drinking water analysis at the time NPDWRs were promulgated (57 FR 31776). All three original methods consisted of GC with extraction and/or detector variations (EPA Method 505, microextraction; 508, ECD; and 525.1, LSE). Since the Phase V rule was promulgated, the Agency has retained two of the old methods, removed EPA Method 525.1, and approved three additional analytical methods, EPA Methods 508.1, 525.2, and 551.1 (LSE, ECD; LSE; and LLE, ECD, respectively). As shown in Table 47, the most sensitive method of both the old and new categories is EPA Method 508.1, with an MDL of 0.001 : 

## g/L.

## 88 Methods Support Document for Six-Year Review Final - March 2003 

## Table 47. Results of the Analytical Methods Comparison for Hexachlorobenzene (Newly Promulgated Methods are Indicated in Bold)

MCL = 1 : 

### g/L Current PQL = 1 : 

### g/L DL >

### = 0.1 : 

### g/L Acceptance Limit^

### = ± 2 x S.D. Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 505 1 

### Microextraction and GC 0.002 EPA 505 2 

### Microextraction and GC 0.002

EPA 508 1 

### GC with ECD 0.0077 P 

### EPA 508 2 

### GC with ECD 0.0077 EPA 525.1 1 

### LSE and GC/MS 0.1 - 0.2* EPA 508.1 2 

### LSE and GC with ECD 0.001

EPA 525.2 2 

### LSE and GC/MS 0.049 - 0.13* EPA 551.1 2 

### LLE and GC with ECD 0.001 - 0.003*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95-131, August 1995.

>

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits are listed at 40 CFR §141.24(h)(19)(i). S.D. = standard deviation. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of the analytical techniques used by EPA and State laboratories in PE WS studies 34 to 41 is illustrated by Figure 28. Methods designated as "other" include methods for which laboratories did not specify the method used or were otherwise unknown. As shown by Figure 28, laboratories responding to these PE WS studies mainly determined hexachlorobenzene using EPA Method 508, with the exception of one study (WS 39) where use of EPA Method 525.2 was more prevalent. Use of EPA Method 525.2 began to appear in WS 36 and has increased slightly in recent years. The analytical methods used most recently (i.e., WS 41) for determination of hexachlorobenzene are divided between the several available current methods. Use of EPA Method 508.1 was quite small relative to the other methods used.

## 89 Methods Support Document for Six-Year Review Final - March 2003 

## Hexachlorobenzene

0% 10% 20% 30% 40% 50% 60%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 

### 505 525.1 508 525.2 508.1 other 

## Figure 28. Distribution of Analytical Techniques by WS Study: Hexachlorobenzene



## b. Results of the PQL analysis

The original PQL of hexachlorobenzene (1 : 

## g/L, 56 FR 3552) was determined using PE data from WS 27. The data used for the re-evaluation of the PQL were taken from WS 27 through 41. The results of these WS studies are summarized in Table 48, which provides the study number, the spiked value for the WS sample, the number of results from EPA and State laboratories, and the results evaluated using acceptance limits of ± 2 x S.D (as specified at 141.24(h)(19)(i)).

It appears from the numerical data that EPA Regional and State laboratories are able to achieve successful results within the ± 2 x S.D. acceptance limits at rates well above the 75 percent criterion typically used for determining a PQL. Thus, a regression analysis using the available PE data was not attempted due to the nature of these data. On average, the success rates of the WS laboratories were about 92 percent over spike concentrations ranging from 0.4 to 3.6 : 

## g/L. The high passing rates at concentrations around the PQL of 1 : 

## g/L suggest that the PQL could be lower.

## 90 Methods Support Document for Six-Year Review Final - March 2003 

## Table 48. Evaluation of Hexachlorobenzene Data from WS Studies Using the 2 x S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 2 x S.D. Acceptance Limits 29 0.417 18 83 27 0.483 15 100 38 0.538 45 93 35 0.635 31 90 30 0.667 38 95 37 0.806 42 95 36 0.847 50 88 32 0.857 44 89 41 1.03 38 97 33 1.32 29 93 39 1.68 37 97 31 2.4 23 87 40 2.9 48 92 34 3.57 46 89



## Conclusion for Hexachlorobenzene

Together, the results from the method comparison and the method usage over time show that the one of the most sensitive methods, EPA Method 508, has been consistently used since the promulgation of the NPDWRs and is one of the more frequently used methods for determination of hexachlorobenzene. Thus, the MDL for the overall contaminant appears to be unchanged since the original methods were promulgated. Other less sensitive methods that are also currently in use include EPA Methods 505 and 525.2. Examination of the quantitative PE WS data reveal that the percentage of laboratories successfully passing the proficiency exams is too high to provide insight toward a re-evaluated PQL. However, the high laboratory passing rates at concentrations around the current PQL are suggestive of a change in the PQL.

## 91 Methods Support Document for Six-Year Review Final - March 2003 

## Hexachlorocyclopentadiene

Results of the Method Comparison

With the promulgation of the NPDWRs for Phase V SOCs, the approved methodology for determination of hexachlorocyclopentadiene included two EPA gas chromatography methods, EPA Methods 505 and 525.1. Since that time, EPA Method 525.1 was discontinued and four new methods were added (EPA Methods 525.2, 508.1, 551.1, and 508). As indicated in Table 49, the MDLs for the newer methods (EPA Methods 508.1 and 551.1) are lower than the MDLs of both original methods, while the MDLs of EPA Methods 505 and 525.2 are comparable to the MDL of the original EPA Method 505.

Table 49. Results of the Analytical Methods Comparison for Hexachlorocyclopentadiene (Newly Promulgated Methods are Indicated in Bold)

MCL = 50 : 

### g/L Current PQL = 1 : 

### g/L DL >

### = 0.1 : 

### g/L Acceptance Limit^

### = ± 2*S.D. Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 505 1 

### Microextraction and GC 0.13 EPA 505 2 

### Microextraction and GC 0.13

EPA 525.1 1 

### LSE and GC/MS 0.03 - 0.1* EPA 525.2 2 

### LSE and GC/MS 0.072 - 0.16* EPA 508 2 

### GC with ECD N/A EPA 508.1 2 

### LSE and GC with ECD 0.004 EPA 551.1 2 

### LLE and GC with ECD 0.018

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR §141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

 

### MDLs are not specified for non-EPA (i.e., voluntary consensus standard) methods.

## 92 Methods Support Document for Six-Year Review Final - March 2003 

### Hexachlorocyclopentadiene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 505 508 508.1 525.1 525.2 other 

## Figure 29. Distribution of Analytical Techniques by WS Study: Hexachlorocyclopentadiene Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 29 illustrates the distribution of the analytical techniques used by EPA and State laboratories in WS studies 34 to 41. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as methods for which laboratories did not report any information on the type of method used. The distribution of methods used by EPA and State laboratories has been fairly well-mixed. During WS 34 and 35, EPA Method 505 was the predominant choice for determination of hexachlorocyclopentadiene. From WS 36 to 41, however, use of EPA Methods 508 and 525.2 began to eclipse that of EPA Method 505. The remaining methods were used minimally throughout WS 34 to 41.

b. Results of the PQL Analysis

The current PQL of 1.0 : 

## g/L was originally set from PE data from WS 23 through 27 (57 FR 31801). The PQL re-evaluation used data from WS 24 to 41. Table 50 summarizes the results of these studies, providing the study number, the spiked value for the WS sample, the number of results from EPA Regional and State laboratories, and the passing rates of these laboratories

## 93 Methods Support Document for Six-Year Review Final - March 2003 

## when evaluated using an acceptance limit of ± twice the standard deviation (as specified at 141.24(h)(19)(i)).

Table 50. Evaluation of Hexachlorocyclopentadiene Data from WS Studies Using the ± 2* S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 2* S.D. Acceptance Limits 25b 0.267 11 54.5 29 0.313 14 92.9 26b 0.367 21 95.2 24b 0.736 21 95.2 27 0.774 14 100 32 0.823 41 87.8 31 1.11 16 93.8 40 1.22 47 93.6 38 1.47 44 93.2 30 1.72 35 100 35 1.84 27 92.6 25a 1.87 12 83.3 41 1.93 35 97.1 34 2.14 43 95.3 26a 2.47 21 81.0 37 2.49 40 95.0 33 2.92 26 96.2 39 3.26 35 94.3 24a 4.42 21 90.5 36 4.71 47 93.6



## As shown in Table 50, laboratories exhibited passing rates over 75 percent in all WS studies with the exception of one (WS 25b). Because the passing rates for laboratories determining hexachloropentadiene were well above 75 percent, a re-evaluation of the PQL was not feasible. However, the demonstrated success of laboratories at concentrations well below the existing PQL of 1 : 

## g/L (e.g., WS 27, 29 and 32) suggests that a lower PQL may be possible.

## 94 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Hexachlorocyclopentadiene

The method comparison results indicate that method sensitivities have either remained similar or improved slightly (e.g., for EPA Methods 508.1 and 551.1). A review of method usage over time shows that EPA Methods 505, 525.2, and 508 were the most commonly used methods in recent WS studies. Because the more sensitive methods were not used with great frequency, it would appear that method capabilities for hexachlorocyclopentadiene have remained more or less unchanged over time. Although it was not possible to recalculate the PQL, high laboratory passing rates at concentrations below the current PQL suggest that a lower PQL may be feasible.

Mercury

Results of the Method Comparison

The analytical methods approved for the determination of mercury under the NPDWRs for Phase II IOCs include EPA Methods 245.1 and 245.2 (56 FR 3526). Since the time of promulgation, EPA Method 200.8 has been approved. The currently approved methods for mercury determination include EPA Methods 200.8, 245.1, and 245.2. Table 51 summarizes the MDLs for both the original and current approved versions of the methods. As shown in Table 51, the MDLs for current methods are equal in sensitivity to past methods.

## 95 Methods Support Document for Six-Year Review Final - March 2003 

## Table 51. Results of the Analytical Methods Comparison for Mercury (Newly Promulgated Methods Indicated in Bold)

MCL = 2 : 

### g/L Current PQL = 0.5 : 

### g/L DL >

### = 0.2 : 

### g/L Acceptance Limit^

### = ± 30% Methods Approved At Promulgation Currently Approved Methods Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 245.1 1 

### Manual, Cold Vapor 0.2 i 

### EPA 245.1 1 

### Manual, Cold Vapor 0.2 i 

### EPA 245.2 1 

### Automated, Cold Vapor 0.2 i 

### EPA 245.2 1 

### Automated, Cold Vapor 0.2 i 

### EPA 200.8 2 

### ICP/MS 0.2 D3223-80 4 

### Manual, Cold Vapor N/A* D3223-91 5 

### Manual, Cold Vapor N/A* SM 303F 3 

### Manual, Cold Vapor N/A* SM 3112B 6 

### Manual, Cold Vapor N/A*

1 

### "Methods for Chemical Analysis of Water and Wastes," EPA/600/4-79/020, March 1983.

2

### "Methods for the Determination of Metals in Environmental Samples–Supplement I," EPA/600/R-94/111, May 1994.

3

### 16th

### edition of Standard Methods for the Examination of Water and Wastewater, 1985. American Public Health Association, American Water Works Association, Pollution Control Federation.

4 

### Annual Book of ASTM Standards, Vol. 11.01, American Society for Testing and Materials, 1961 Race Street, Philadelphia, PA 19103.

5 

### Annual Book of ASTM Standards, 1994 and 1996, Vols. 11.01 and 11.02, American Society for Testing and Materials.

6

### 18 th

### and 19 th

### editions of Standard Methods for the Examination of Water and Wastewater, 1992 and 1995, American Public Health Association.

>

### Regulatory DLs for inorganic compounds are listed at 40 CFR §141.23(a)(4)(i) and depend on analytical method. ^

### Acceptance limits are listed at 40 CFR §141.23(k)(3)(ii) for inorganic compounds.

i

### This value is the lower limit of the analytical range and was not determined using the MDL procedure.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 30 shows the distribution of analytical techniques used by EPA and State laboratories for WS studies 34 to 41. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as "unknown" methods, (i.e., methods for which laboratories did not report any information on the type of method used).

## 96 Methods Support Document for Six-Year Review Final - March 2003 Mercury



### 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS34 WS35 WS36 WS37 WS38 WS39 WS40 WS41 Water Study% Labs Using Method

245.1 245.2 200.8 311

2B OTHER 

## Figure 30. Distribution of AnalyticalTechniques by WS Study: Mercury As shown in Figure 30, EPA Method 245.1 (automated cold vapor) was the most widely used method in WS 34 and 35. From WS 36 to WS 41, EPA Methods 245.1 (manual cold vapor) and 245.2 were most commonly used.

b. Results of the PQL Analysis

The current PQL of 0.5 : 

## g/L was originally set using previous PE data (56 FR 3549). With the availability of more current data from WS 24 to 41, a PQL re-evaluation was attempted. Table 52 summarizes the results of these water studies, providing the study number, the spiked value for the WS sample, the number of results from EPA and State laboratories, and the mercury results evaluated using an acceptance limit of ± 30 percent, as designated in 40 CFR § 141.23(k)(3)(ii).

## 97 Methods Support Document for Six-Year Review Final - March 2003 

## Table 52. Evaluation of Mercury Data from WS Studies Using the 30% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 30% Acceptance Limits 29 0.506 31 87.1 25a 0.720 37 70.3 35 0.897 37 94.6 31 0.908 31 87.1 27 1.29 33 97.0 40 1.50 60 93.3 33 1.77 34 94.1 24b 2.16 59 94.9 26b 2.47 61 93.4 36 3.00 61 95.1 30 3.46 62 100.0 39 3.80 47 83.0 25b 4.32 37 91.9 26a 4.56 61 96.7 34 5.09 61 100.0 24a 5.76 59 96.9 41 5.82 44 100.0 32 6.23 64 96.9 38 6.39 60 95.0 37 8.16 47 91.5



## The data from the available WS studies were not conducive to recalculation of the PQL because the percentage of labs passing (with the exception of one study) generally exceeded the standard 75 percent passing criterion needed to evaluate the PQL using the either a linear regression or graphical approach. In addition, the majority of the true values were above the original PQL of 0.5 : 

## g/L. However, at values slightly above the current PQL (e.g., WS 29 and 25a) the passing rates of 87 and 70 percent would indicate that the current PQL is most likely in the appropriate range.

## 98 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Mercury

Since the promulgation of the NPDWR for mercury, EPA Method 200.8 has been added to the original two analytical methods approved for the measurement of mercury in drinking water (EPA Methods 245.1 and 245.2). According to the distribution of analytical methods usage over time, EPA Method 245.1 was more widely used than EPA Method 245.2 during WS 34 to 35. From WS 36 to 41, these two methods were utilized with approximately the same frequency. Upon review of the WS data, a high percentage of laboratories successfully passing the WS studies prevented a recalculation of the PQL at the 75 percent passing rate. Thus, the available PE data provided little evidence for a lower PQL using this approach. Observation of laboratory passing rates at concentrations slightly above the current PQL of 0.5 : 

## g/L suggests that this PQL is still in all likelihood appropriate.

Methoxychlor

Results of the Method Comparison

At the promulgation of the NPDWRs for methoxychlor, three methods were approved for the determination of this compound: EPA Methods 505, 508, and 525.1 (56 FR 3552). Since that time, use of EPA Method 525.1 has been discontinued and additional methods have been approved, including EPA Methods 508.1, 525.2, and 551.1. All approved methods utilize GC in various forms. As shown in Table 53, the MDL of EPA Method 505 has remained unchanged over time, whereas the MDL of EPA Method 508 has improved in sensitivity. The MDLs of the newer methods (in bold) range from 0.003 to 0.13 : 

## g/L. The most sensitive method currently available (EPA Method 508.1) has about 125 times the sensitivity of the original EPA Method 505.

## 99 Methods Support Document for Six-Year Review Final - March 2003 

## Table 53. Results of the Analytical Methods Comparison for Methoxychlor (Newly Promulgated Methods in Bold)

MCL = 40 : 

### g/L Current PQL = 10 : 

### g/L DL >

### = 0.1 : 

### g/L Acceptance Limit^

### = ± 45% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 505 1 

### Microextraction and GC 0.96 EPA 505 2 

### Microextraction and GC 0.96

EPA 508 1 

### GC with ECD 0.05 EPA 508 2 

### GC with ECD 0.022 EPA 525.1 1 

### LSE and GC/MS 0.04 - 0.3* EPA 508.1 2 

### LSE and GC with ECD 0.003

EPA 525.2 2 

### LSE and GC/MS 0.033 - 0.13* EPA 551.1 2 

### LLE and GC with ECD 0.008 - 0.023*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR § 141.24(h)(19)(i). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of methods used by EPA and State laboratories participating in WS 34 to 41 is depicted in Figure 31. The category of "other" includes any unidentified techniques used by participating laboratories. As Figure 31 shows, EPA Method 508 was used most widely by participating laboratories during WS 34 to 41. As EPA Method 525.1 was phased out in WS 36, use of newer methods, EPA Methods 525.2 and 508.1, began. EPA Method 505 and other unidentified methods were used intermittently throughout WS 34 to 41.

## 100 Methods Support Document for Six-Year Review Final - March 2003 

### Methoxychlor

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 505 508 508.1 525.1 525.2 other 

## Figure 31. Distribution of AnalyticalTechniques by WS Study: Methoxychlor

b. Results of the PQL Analysis

The PQL for methoxychlor was originally proposed at 0.001 mg/L, but was finalized in 1991 at 0.01 mg/L (or 10 : 

## g/L). The method for deriving this value was multiplication of the detection limit by a factor of ten (56 FR 3551). Recently, with the availability of more recent laboratory performance data from WS 24 to 41, a reassessment of the existing PQL was conducted. Table 54 summarizes each WS result including the spiked (or "true") concentration in the test sample, the number of participating laboratories, and the calculated percentage of laboratories successfully passing within the specified ± 45 percent acceptance limit for methoxychlor (141.24(h)(19)(i)).

Table 54. Evaluation of Methoxychlor Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits 26b 2.18 59 98.3 25a 3.17 37 94.6 29 5.21 33 97.0

### WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits



## 101 Methods Support Document for Six-Year Review Final - March 2003 24b 5.37 61 93.4 31 12.9 32 81.3 34 14.2 52 92.3 27 16.6 39 89.7 32 17.4 59 88.1 37 18.5 45 93.3 41 26.8 43 90.7 36 28.9 56 92.9 30 34.2 54 88.9 38 34.8 51 88.2 33 42.3 35 97.1 40 42.8 54 96.3 25b 48.8 37 94.6 39 53.8 43 93.0 35 62.6 30 96.7 24a 73.2 62 91.9 26a 92.8 59 93.2



## Table 54 reveals that the percentage of passing laboratories was well above the 75 percent criterion, and thus, the PQL could not be re-evaluated using the regression technique. Table 53 also shows that even at very low concentrations (e.g., one-fifth of the existing PQL), a large percentage of EPA and State laboratories was able to pass the WS study, suggesting that a lower PQL may be feasible.

Conclusion for Methoxychlor

EPA Methods 505, 508, and 525.1 were originally approved for the determination of methoxychlor with the promulgation of the NPDWRs for Phase II SOCs in 1991. Since then, EPA Method 525.1 has been removed while EPA Methods 508.1, 525.2, and 551.1 have been added to the approved list. A review of the method usage over time shows that laboratories participating in WS 34 to 41 utilized EPA Method 508 more frequently than all other approved methods, although this margin of difference began to decrease in more recent WS studies. A revised PQL for methoxychlor could not be determined due to the large percentage of laboratories surpassing the 75 percent criterion. However, the data do reveal a possible basis for lowering the PQL based on the high success rates of laboratories at concentrations well below the current PQL.

## 102 Methods Support Document for Six-Year Review Final - March 2003 

## Oxamyl

Results of the Method Comparison

Oxamyl is one of several SOCs first regulated under the Phase V Rule (57 FR 31776). Under this rule, EPA Method 531.1 (a HPLC method) was approved for determination of oxamyl. More recently, the Agency has approved an additional analytical method, Standard Method (SM) 6610 (HPLC followed by post-column reaction and fluorescence detection), while retaining the use of EPA Method 531.1. The MDL for SM 6610 is not specified, as methods published by organizations outside the Agency are not required to calculate an MDL. The MDL for EPA Method 531.1 has not changed since the 1988 Phase V Rule promulgation, signifying no change in analytical sensitivity for this contaminant.

Table 55. Results of the Analytical Methods Comparison for Oxamyl (Newly Promulgated Methods in Bold)

MCL = 200 : 

### g/L Current PQL = 20 : 

### g/L DL >

### = 2 : 

### g/L Acceptance Limit^

### = ± 2*S.D. Methods Approved At Promulgation Currently Approved Methods Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 531.1 1 

### HPLC 2.0 P

### EPA 531.1 2 

### HPLC 0.86

SM 6610 3 

### HPLC-post column reaction/ fluorescence detection N/A*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995.

3

### Standard Method 6610. Supplement to the 18th edition of Standard Methods for the Examination of Water and Wastewater, 1994, American Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.

>

### Regulatory DLs for inorganic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits are listed at 40 CFR §141.24(h)(19)(i). * MDLs are not specified for non-EPA (i.e., voluntary consensus standard) methods.

P

### EDL = estimated detection limit, used to approximate the MDL.

## 103 Methods Support Document for Six-Year Review Final - March 2003 

### Oxamyl

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

531.1 6610 other 

## Figure 32. Distribution of Analytical Techniques by WS Study: Oxamyl Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of the methods used by EPA Regional and State laboratories in WS studies 34 to 41 is shown in Figure 32. The results for "other" techniques in this figure include methods for which laboratories did not report any information on the type of method used or reported codes that could not be identified. As shown in Figure 32, EPA Method 531.1 was the most widely used analytical method for determination of oxamyl during WS 34 to 41. By contrast, the more recently approved SM 6610 was only used minimally during WS 40.

b. Results of the PQL Analysis

The current PQL of 20 : 

## g/L was originally determined using a ten times MDL multiplier (56 FR 30370). In re-evaluating the PQL, a broader range of PE data from WS 24 to 41 were analyzed. Table 56 summarizes the results of these water studies, providing the study number, the spiked (or "true") value for the WS sample, the number of results from EPA and State laboratories, and the percentage of laboratories that successfully passed the test using an acceptance limit of +2*S.D. (specified at 141.24(h)(19)(i)).

## 104 Methods Support Document for Six-Year Review Final - March 2003 

## Table 56. Evaluation of Oxamyl Data from WS Studies Using the ± 2* S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA Regional and State Labs % Labs Passing ± 2* S.D. Acceptance Limits 29 4.60 10 10.0 31 5.72 14 0.00 30 6.47 25 24.0 27 12.4 8 25.0 24a 12.5 8 75.0 32 12.8 36 50.0 25a 17.6 5 60.0 34 22.5 43 76.7 26a 22.6 13 76.9 33 26.2 13 46.2 24b 31.3 8 87.5 41 33.8 29 86.2 36 34.1 47 80.9 40 42.7 42 95.2 37 46.4 36 83.3 26b 46.4 13 76.9 35 47.2 30 83.3 25b 53.5 5 80.0 38 58.8 42 90.5 39 78.7 32 90.6



## The WS data for the EPA Regional and State laboratories shown in Table 56 were also used to develop a linear regression. The spiked value concentration is the independent variable ( x) and the percentage of laboratories achieving acceptable results (within the acceptance window) is the dependent variable ( y). For the equation y= mx+ b , mstands for the slope of the regression line (change in the percentage of laboratories passing as spiked concentration increases) and bstands for the y-intercept.

The use of regression techniques assumes that the data from the various WS studies form a single continuous data set. In reality, the study results do not form a continuous data set, but represent results from samples spiked at specific discrete concentrations of oxamyl and analyzed

## 105 Methods Support Document for Six-Year Review Final - March 2003 

## a few at a time over an extended period. However, through the use of a linear regression, the data can be used to create a model (the regression line) that may be useful in predicting accuracy and precision as a function of the concentration of the samples. The regression determines the linear relationship that best fits the observed results, in effect smoothing the curve and ensuring that there is a unique concentration that corresponds to any percentage of acceptable laboratories.

Calculating the regression equations also provides the correlation coefficient (r) for the regression, which is a measure of the degree to which the actual data fit the linear model represented by the regression line. An r value of one would indicate a perfect fit with a positive slope of the data to the model. A value, p, can also be calculated for the regression that indicates the probability of concluding the null hypothesis (in this case that the spiked value concentration is linearly correlated with the percentage of labs achieving acceptable results) is false, when in fact the null hypothesis is true, for the given data set. In statistical terms, p indicates the probability of a Type I error. The results for the regression equation are summarized in Table 57.

Table 57. Regression Results for Oxamyl Regression Term ±2*S.D. Acceptance Limits

m 0.0125 b 0.223 r 0.819 p 0.005

The r value of 0.82 indicates that the data fit the linear model fairly well. The p value of 0.005 indicates that the spiked value and the percentage acceptable are linearly correlated with more than 99 percent confidence. Figure 33 shows the graphical results of the regression. The observed data were plotted against the WS spiked value concentration and the results predicted from the linear regression line were superimposed. The observed success rate for the EPA and State laboratories is noticeably lower than the predicted success rate in the region below 20 : 

## g/L. While attempts might be made to model the observed results using a second order (nonlinear) regression, the Agency does not believe that there is a scientifically valid reason to do so.

## 106 Methods Support Document for Six-Year Review Final - March 2003 Oxamyl

75%

current PQL = 20 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 10 20 30 40 50 60 70 80 True Value (ug/L)% Labs Passing 

## Figure 33. Two-part Distribution of Oxamyl WS Data 

## The oxamyl PE data illustrate the expected outcome from PE testing: a lower percentage of labs passing at the lowest true values, with an increasing percentage of labs passing as true values increase, due to increasing lab analytical capabilities at higher concentrations. As true values increase further, the percentage of labs passing approaches a stable plateau beyond which lab analytical capabilities do not improve. This results in a two-part distribution: the lower true values (<30 : 

## g/L) are characterized by a line of steeper slope, while higher true values (>30 : 

## g/L), are characterized by a line that is nearly flat (see Figure 34). Using this graph to visually estimate a re-evaluated PQL, the original choice of 20 : 

## g/L appears to be appropriate. Figure 34 also shows that the percentage of laboratories achieving acceptable results reaches 75 percent at a concentration of 39.5 : 

## g/L which, by the graphical method, indicates the value of the reevaluated PQL (RPQL). This concentration is higher than the existing PQL of 20 : 

## g/L.

## 107 Methods Support Document for Six-Year Review Final - March 2003 Oxamyl

75%

current PQL = 20 RPQL = 42

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 10 20 30 40 50 60 70 80 True Value (ug/L)% Labs Passing

R-squared = 0.67 

## Figure 34. PQL Evaluation of PE WS Data: Oxamyl

Conclusion for Oxamyl

Although a new method for the determination of oxamyl was introduced (SM 6610), this method was rarely used, as seen in the graph of method usage over time (Figure 32). Analytical method capabilities have increased in sensitivity for EPA Method 531.1 overtime. Based on the PQL reassessment, it is apparent that laboratory success follows a linear relationship with true value concentration to a point, after which the success rate plateaus. Using the standard linear regression approach, the new RPQL was determined to be 39.5 : 

## g/L, which may be linked to higher spiked concentrations exhibited in more recent PE WS data. However, if the data are not plotted on a single line but rather in the two-part manner of Figure 34, the RPQL would most likely resemble the existing value of 20 : 

## g/L. It is likely that the PQL may lie somewhere between 20 and 40 : 

## g/L.

PCBs

Results of the Method Comparison

For the NPDWRs, all polychlorinated biphenyls (PCBs) were collectively grouped and identified by the particular aroclor decachlorobiphenyl (DCBP). In 1991, EPA approved EPA Method 508A for determination of DCBP, a Phase II SOC (56 FR 3526), in drinking water. This

## 108 Methods Support Document for Six-Year Review Final - March 2003 

## analytical method utilizes gas chromatography withperchlorination. Since promulgation of the Phase II rule, EPA has not changed the status of EPA Method 508A and its MDL remains at 0.08 : 

## g/L (Table 58).

Table 58. Results of the Analytical Methods Comparison for PCBs

MCL = 0.5 : 

### g/L Current PQL = 0.5 : 

### g/L DL•

### = 0.1 : 

### g/L Acceptance Limit^

### = ± 100% Methods Approved At Promulgation Currently Approved Methods Method Technique MDL* (: 

### g/L) Method Technique MDL* (: 

### g/L)

EPA 508A 1 

### Perchlorination with GC 0.08 - 0.23 EPA 508A 1 

### Perchlorination with GC 0.08 - 0.23

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR §141.24(h)(19)(i). * Multiple MDL values result from variability of reagents, instrumentation and/or laboratory performance.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Because only one method, EPA Method 508A, was approved for determination of PCBs (as DCBP) over the duration of WS 34 to 41, its usage was not plotted.

b. Results of the PQL Analysis

The original PQL for PCBs was proposed at five times the MDL of 0.08 : 

## g/L. For the final rule, EPA compared this value with multilaboratory performance data from WS studies 22 to 24, and found the PE data to support the proposed value, 0.5 : 

## g/L (56 FR 3552). For the six-year regulatory review, new efforts have been made to reassess the PQL using more recent PE WS data from WS 31 to 41. These data are summarized in Table 59, which indicates the study number, the true value of the WS sample, the number of results returned by EPA and State laboratories, and the calculated percentage of laboratories whose results successfully passed within designated acceptance limits for PCBs (±100 percent, as specified at 40 CFR §141.24(h)(19)(i)).

## 109 Methods Support Document for Six-Year Review Final - March 2003 

## Table 59. Evaluation of PCBs Data from WS Studies Using the ± 100% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 100% Acceptance Limits 31 0.445 13 69.2 37 0.527 27 92.6 35 0.596 15 80.0 39 0.667 26 96.2 38 0.733 27 92.6 33 0.807 14 92.9 32 0.959 22 95.5 34 1.08 26 96.2 36 1.13 30 93.3 40 1.23 27 100 41 1.80 21 100



## A PQL is historically derived from a concentration at which 75 percent of the participating laboratories pass, or report concentrations that fall within the specified acceptance limits. However, the data in Table 59 indicate that laboratories exceeded the required 75 percent criterion in almost all studies (with the exception of WS 31). Because of the high laboratory passing rates and a lack of sufficient spike concentrations below 0.5 : 

## g/L, the PQL for PCBs could not be re-evaluated graphically with these data. However, the two of the three lowest spike concentrations close to the current PQL, WS 31 (0.445 : 

## g/L) and WS 35 (0.596 :

## g/L), had passing rates of 69 and 80 percent, respectively. These passing rates suggest that the current PQL of 0.5 : 

## g/L is unlikely to change.

Conclusion for PCBs

Since the promulgation of the NPDWR for PCBs, EPA Method 508A has been the only method approved for PCB determination. As the current PQL was derived from the MDL multiplier method rather than multi-laboratory performance data, a PQL re-evaluation was attempted using current PE data from WS 31 to41. The high percentage of laboratories passing the PE testing within the designated acceptance limits and the relatively high spike concentrations prevented a conclusive re-evaluation of the PQL using the historical approach. However, spike concentrations close to the current PQL had laboratory passing rates close to 75 percent. This suggests that the current PQL is appropriate and unlikely to change.

## 110 Methods Support Document for Six-Year Review Final - March 2003 

## Pentachlorophenol

Results of the Method Comparison

With the promulgation of NPDWRs for Phase II SOCs, two methods were approved for the determination of pentachlorophenol in drinking water: EPA Methods 515.1 and 525.1 (56 FR 3526). Since promulgation of this rule, EPA removed EPA Method 525.1 and approved the use of five new or updated methods: EP A Methods 515.2, 515.3, 555, 525.2, and ASTM Method D5317-93 (GC with ECD), a voluntary consensus method. The MDLs of these methods are indicated in Table 60.

Table 60. Results of the Analytical Methods Comparison for Pentachlorophenol (Newly Promulgated Methods Are Indicated in Bold)

MCL = 1 : 

### g/L Current PQL = 1 : 

### g/L DL•

### = 0.04 : 

### g/L Acceptance Limit^

### = ± 50% Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 515.1 1 

### GC with ECD 0.076 P

### EPA 515.1 2 

### GC with ECD 0.032 EPA 525.1 1 

### LSE and GC/MS 0.3 - 3.0* EPA 515.2 2 

### LSE and GC with ECD 0.16

EPA 515.3 4 

### LLE, derivatization and GC with ECD 0.021 - 0.085* EPA 525.2 2 

### LSE and GC/MS 0.72 - 1.0*

EPA 555 3 

### LLE, derivatization and GC with ECD 0.15 - 1.6*

D5317-93 5 

### GC with ECD N/A"

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995.

3

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement II," EPA/600/R92/129, August 1992.

4

### "Determination of Chlorinated Acids in Drinking Water by Liquid-liquid Extraction, Derivatization and Gas Chromatography with Electron Capture Detection," Revision 1.0, EPA/815/B-99/001, July 1996.

5 

### Annual Book of ASTM Standards, 1994, Vol. 11.01. American Society for Testing and Materials, 1961 Race Street. Philadelphia, PA 19103. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR §141.24(h)(19)(i). * Multiple MDL values result from variability of reagents, instrumentation and/or laboratory performance. "

### N/A = not available. MDLs for voluntary consensus standard methods are not specified.

P

### EDL = estimated detection limit, used to approximate the MDL.

## 111 Methods Support Document for Six-Year Review Final - March 2003 

### Pentachlorophenol

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 515.1 515.2 525.2 555 other 

## Figure 35. Distribution of Analytical T echniques by WS Study: Pentachlorophenol

As shown in Table 60, most of the current EPA methods for pentachlorophenol do not display a significant increase in analytical sensitivities as compared to the methods approved at the time of the Phase II rule promulgation. The exception is EPA Method 515.1, which has approximately twice the sensitivity of the prior version of the same method approved at the time of promulgation.
Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of analytical methods used by the EPA and State laboratories in WS 34 to 41 is plotted in Figure 35. The "other" techniques represent methods which were not specifically identified by participating laboratories or were otherwise unknown. As shown in Figure 35, despite the addition of several new analytical methods, the majority of laboratories still favored the use of EPA Method 515.1 for determination of pentachlorophenol during WS 34 to 41. The more recently approved EPA Methods 515.2 and 555 were used much less frequently, by comparison. EPA Method 525.2 was only used intermittently during the study period.

## 112 Methods Support Document for Six-Year Review Final - March 2003 

## b. Results of the PQL Analysis

EPA determined the current PQL of 1 : 

## g/L (0.001 mg/L) for pentachlorophenol using earlier water supply data (WS 22 to 25, 56 FR 3552). A re-evaluation of the PQL was attempted using more recent PE data from WS 24 to 41. Table 61 summarizes the data from these WS studies (with the exception of WS 25, 27, and 30), indicating the study number, the true value of the WS sample, the number of results from EPA and State laboratories, and the percentage of laboratories whose results successfully passed the acceptance limits of ± 50 percent for pentachlorophenol (40 CFR §141.24(h)(19)(i)).

Table 61. Evaluation of Pentachlorophenol Data from WS Studies Using the ± 50% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 50% Acceptance Limits 24a 0.924 13 84.6 33 2.72 24 83.3 26a 3.75 16 87.5 37 6.59 40 75.0 29 6.73 11 72.7 35 8.91 35 74.3 32 10.7 35 85.7 31 11.4 16 62.5 36 14.6 46 87.0 38 14.7 48 87.5 24b 16.2 13 76.9 40 22.3 47 95.7 34 22.6 45 66.7 41 34.6 36 91.7 26b 38.5 16 75.0 39 43.7 41 85.4



## Examination of the data show that with the exception of three WS studies (WS 29, 35 and 34), the laboratory passing rates exceeded the 75 percent criterion and only one WS study had a spike concentration below the current PQL of 1 : 

## g/L. Because many of the laboratories achieved high success rates during PE testing for pentachlorophenol, the resulting regression line, shown in Figure 36, failed to intersect the 75 percent line that would have indicated the new

## 113 Methods Support Document for Six-Year Review Final - March 2003 Pentachlorophenol

75%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 5 10 15 20 25 30 35 40 45 True Value (ug/L)% Labs Passing

Current PQL = 1 

## Figure 36. Evaluation of PE WS Data: Pentachlorophenol estimated PQL. Furthermore, there were very few water studies with spiked samples below the current PQL. Thus, a new PQL could not be derived using this procedure.

Conclusion for Pentachlorophenol

The plot of the method usage over time for WS 34 to 41 indicates laboratories consistently used EPA Method 515.1 more frequently than other methods. The detection limit for EPA 515.1 has not changed over time, as shown by the results of the method comparison (Table 60). The available WS data did not provide a basis for lowering the PQL for two reasons: the passing rates of laboratories were generally greater than the 75 percent criterion for PQL estimation and the true value concentrations typically exceeded the current PQL.

## 114 Methods Support Document for Six-Year Review Final - March 2003 

## Picloram

Results of the Method Comparison

Picloram became a regulated SDWA contaminant in 1992 with the promulgation of NPDWRs for Phase V SOCs (57 FR 31776). At that time, the sole method approved for determination of picloram in drinking water was EPA Method 515.1. Since promulgation of the Phase V rule, EPA has added two methods to the approved list: EPA Methods 515.2 and 555. Table 62 summarizes MDL information for the current and former approved methods for picloram.

Table 62. Results of the Analytical Methods Comparison for Picloram (Newly Promulgated Methods Are Indicated in Bold)

MCL = 500 : 

### g/L Current PQL = 1 : 

### g/L DL•

### = 0.1 : 

### g/L Acceptance Limit^

### = 2*S.D. Methods Approved At Promulgation Currently Approved Methods Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 515.1 1 

### GC with ECD 0.14 P 

### EPA 515.1 2 

### GC with ECD 0.15 EPA 515.2 3 

### LSE and GC with ECD 0.35

EPA 515.3 4 

### LLE, derivatization and GC with ECD 0.47 - 1*

EPA 555 2 

### HPLC with a Photodiode Array Ultraviolet Detector 0.5

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water Supplement II," EPA/600/R-92/129, August 1992.

3

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R-95/131, August 1995.

4

### "Determination of Chlorinated Acids in Drinking Water by Liquid-liquid Extraction, Derivatization and Gas Chromatography with Electron Capture Detection," Revision 1.0, EPA/815/B-99/001, July 1996. •

### Regulatory DLs for organic compoundsare listed at 40 CFR §141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at are listed at 40 CFR §141.24(h)(19)(i).

P

### EDL = estimated detection limit, used to approximate the MDL. * Multiple MDL values result from variability of reagents, instrumentation and/or laboratory performance.

## 115 Methods Support Document for Six-Year Review Final - March 2003 

### Picloram

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

515.1 515.2 555 other 

## Figure 37. Distribution of AnalyticalTechniques by WS Study: Picloram Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of analytical methods used during each water study from WS 34 to 41 were plotted (Figure 37). The "other" techniques represent methods which were not specifically identified by participating laboratories or were otherwise unknown. As shown in Figure 37, during WS 34 to 36, the majority of laboratories used EPA Method 515.1 for determination of picloram. Use of EPA Method 515.2 gradually increased over this period but was still greatly outweighed by use of EPA Method 515.1. Laboratories employed EPA Method 555 only minimally.

b. Results of the PQL Analysis

The original PQL for picloram of 1.0 : 

## g/L was derived by multiplying the detection limit (DL) by a factor of 10 (57 FR 31776). With the availability of more recent PE data, a reassessment of the PQL was attempted. Table 63 summarizes the data from WS 24 to 41 (with the exception of WS 25, 27, and 29, which lacked data), indicating the study number, the true value of the WS sample, the number of results from EPA and State laboratories, and the percentage of laboratories whose results succe ssfully passed within the acceptance limits for

## 116 Methods Support Document for Six-Year Review Final - March 2003 

## picloram. These limits (± 2*S.D.) are not fixed but essentially represent a function of the true value (40 CFR §141.24(h)(19)(i)).

Table 63. Evaluation of Picloram Data from WS Studies Using the ± 2* S.D. Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 2* S.D. Acceptance Limits 26b 1.33 11 63.6 24b 2.63 12 91.7 32 10.6 32 93.8 34 13.2 43 93.0 33 17.4 24 100 24a 17.5 11 100 30 22.4 26 88.5 37 23.3 38 100 31 26.7 12 91.7 26a 31.2 12 91.7 36 42.2 45 100 40 44.0 43 95.3 38 56.4 43 93.0 41 62.1 35 97.1 35 62.5 24 79.2 39 74.9 37 100



## As shown by Table 63, participating EPA and State laboratories in every water study but one (WS 26b) achieved a passing rate above the 75 percent criterion for determination of the PQL. Therefore, estimation of the PQL is likely to not bemeaningful for this dataset. In addition, the entire range of true values for this contaminant exceeded the current PQL, some by nearly two orders of magnitude, preventing any assertions on the appropriateness of a lower PQL.

Conclusion for Picloram

The available WS data do not support a reassessment of the PQL based on the 75 percent criterion because the passing rates of laboratories almost always exceeded this value. Therefore,

## 117 Methods Support Document for Six-Year Review Final - March 2003 

## a quantitative reassessment of the PQL could not be performed using the graphical approach. The current PQL of 1 : 

## g/L appears to still be appropriate.

Tetrachloroethylene

Results of the Method Comparison

The final January 1991 NPDWR for Phase II VOCs (56 FR 3526) approved several analytical methods for tetrachloroethylene. These included EPA Methods 502.1, 502.2, 503.1, 524.1, and 524.2. Since this regulation was promulgated, the Agency retained EPA Methods 502.2 and 524.2 for determination of tetrachloroethylene and introduced a new GC variation, EPA Method 551.1. Table 64 summarizes the MDLs for both the original and currently approved versions of the methods. As shown in Table 64, EPA Methods 502.2 and 551.1 have greater detection sensitivity than EPA Method 524.2.

Table 64. Results of the Analytical Methods Comparison for Tetrachloroethylene (Newly Promulgated Methods in Bold)

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limits^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.001 EPA 502.2 2 

### Purge and Trap GC 0.02 - 0.05*

EPA 502.2 1 

### Purge and Trap GC 0.02 - 0.05* EPA 524.2 2 

### Purge and Trap GC/MS 0.05 - 0.14*

EPA 503.1 1 

### Purge and Trap GC 0.01 EPA 551.1 2 

### LLE and GC with ECD 0.002

EPA 524.1 1 

### Purge and Trap GC/MS 0.3

EPA 524.2 1 

### Purge and Trap GC/MS 0.05 - 0.14*

## 118 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(f)(17). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).



## Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of the different methods used by EPA and State laboratories during WS studies 34 to 41 are shown in Figure 38. The category of "other" contains those methods that were unknown or unidentified by the participating laboratories. During WS 34 to 41, EPA Method 524.2 was the favored method for determining tetrachloroethylene among participating laboratories. Use of EPA Method 524.2 generally increased slightly over time while usage of EPA Method 502.2 declined. No use of EPA Method 551.1 was observed during these studies.

## 119 Methods Support Document for Six-Year Review Final - March 2003 

### Tetrachloroethylene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 38. Distribution of Analytical Techniques by WS Study: Tetrachloroethylene

b. Results of the PQL Analysis

The Agency set the original PQL at 5 : 

## g/L (52 FR 25700 and 56 FR 3526) for all VOCs except vinyl chloride. More recent data from WS 27 through 41 were used to re-evaluate the PQL for tetrachloroethylene. Table 65 summarizes the results of these WS studies providing the study number, the spiked value for the WS sample, the number of laboratory results reported, and the percent of laboratories passing the WS prof iciency test for tetrachloroethylene within the acceptance limits of ± 20 percent for a true value greater than10 : 

## g/L, or ± 40 percent for a true value less than 10 : 

## g/L (specified at 141.24(f)(17)(i)).

## 120 Methods Support Document for Six-Year Review Final - March 2003 

## Table 65. Evaluation of Tetrachloroethylene Data from WS Studies Using the ± 20% or ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 32 7.43 63 100 39 7.60 45 97.8 27 7.76 35 100 30 9.00 60 100 37 9.60 48 100 41 11.5 41 92.7 31 11.6 33 97.0 35 11.6 36 91.7 33 12.9 34 91.2 38 14.1 56 94.6 40 14.7 58 91.4 29 15.6 34 85.3 34 16.5 60 96.7 36 18.5 61 91.8



## The data for tetrachloroethylene could not be used to re-evaluate the PQL because State and EPA laboratories, on average, passed the performance evaluation at a rate over 90 percent. Thus, laboratories surpassed the standard 75 percent acceptance criterion typically used to determine the PQL. In addition, the true value concentrations observed in the available WS data were all greater than the current PQL of 5 : 

## g/L. At concentrations close to the current PQL (7.43, 7.60 and 7.76 : 

## g/L), the passing rates were 100, 98 and 100 percent, respectively. This data suggest that the current PQL of 5 : 

## g/L could be lower.

Conclusion for T etrachloroethylene

The method comparison results show that since the promulgation of analytical methods for tetrachloroethylene under the NPDWR, one method was retained (EPA Method 524.2) and two methods were added (EPA Methods 502.2 and 551.1). The most commonly used method in recent WS studies has been EPA Method 524.2, which is also the least sensitive method of the past and present methods. The MDL and method usage information together imply that observable analytical sensitivities for this contaminant have not improved since the promulgation of the Phase I rule. This conclusion is further supported by the observation that EPA 551.1, the most sensitive of the three currently approved methods, appears from the WS data to not be employed by EPA or State laboratories. Evaluation of the quantitative PE data showed that the

## 121 Methods Support Document for Six-Year Review Final - March 2003 

## majority of the laboratories conducting WS analyses had surpassed the 75 percent criterion. The high percentage of laboratories passing and high true value concentrations apparent in the WS data prevented a re-evaluation of the PQL using the graphical approach. However, the high laboratory passing rates at concentrations slightly above the current PQL may suggest that the PQL could be lower.

Thallium

Results of the Method Comparison

With the Phase V IOCs (57 FR 31776), furnace atomic absorption (AAF; EPA Method 279.2), inductively coupled plasma (ICP)/MS (EPA Method 200.8), and platform AA spectrometry (EPA Method 200.9) were the approved methods listed for analysis of thallium in drinking water. Since this regulation was promulgated, the only change in approved analytical methods made by the Agency was the removal of EPA 279.2 from the list of approved analytical methods. MDLs for EPA Methods 200.8 and 200.9 havenot changed, as indicated in Table 66. This table also shows that the discontinued EPA Method 279.2 was less sensitive than EPA Methods 200.8 and 200.9, meaning that the collective methods approved since promulgation are, on average, more sensitive than the methods approved at the time of promulgation. EPA Method 200.8 is approximately twice as sensitive than the other currently approved method, EPA Method 200.9.

Table 66. Results of the Analytical Methods Comparison for Thallium

MCL = 2 : 

### g/L Current PQL = 2 : 

### g/L DL >

### = 0.3 - 0.7 : 

### g/L Acceptance Limit^

### = ± 30% Methods Approved At Promulgation Currently Approved Methods Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 279.2 1 

### AAF 1 P

### EPA 200.8 2 

### ICP/MS 0.01 - 0.3* EPA 200.8 1 

### ICP/MS 0.3 EPA 200.9 2 

### AAP 0.7 EPA 200.9 1 

### AAF 0.7

1 

### "Methods for Chemical Analysis of Water and Wastes (MCAWW)," EPA/600/4-79/020, March 1983.

2

### "Methods for the Determination of Metals in Environmental Samples--Supplement I," EPA/600/R-94/111, May 1994.

>

### Regulatory DLs for inorganic compounds are listed at 40 CFR §141.23(a)(4)(i) and depend on analytical methodology. ^

### Acceptance limits are listed at 40 CFR §141.23(k)(3)(ii). * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

P

### EDL = estimated detection limit, used to approximate the MDL.

## 122 Methods Support Document for Six-Year Review Final - March 2003 

### Thallium

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 200.9

279.2

200.8

other 

## Figure 39. Distribution of AnalyticalTechniques by WS Study: Thallium Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 39 shows the variety of analytical techniques used by EPA and State laboratories in WS studies 34 to 41. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as "unknown" methods, i.e., techniques for which laboratories did not report the type of method used. In recent years, method usage by laboratories participating in the water studies has been dominated by EPA Method 200.9 (AAP) which is actually less sensitive than the other approved method, EPA Method 200.8 (ICP/MS).

b. Results of the PQL Analysis

The current PQL (2 : 

## g/L) was originally set using PE data from WS 24 through 27. For the PQL re-evaluation, data were taken from WS 24 to 41 (57 FR 31801). Table 67 summarizes the results of these water studies, providing the study number, the spiked value for the WS sample, the number of results from EPA and State laboratories, and the results evaluated using acceptance limits of ± 30 percent (specified at 141.23(k)(3)(ii)).

## 123 Methods Support Document for Six-Year Review Final - March 2003 

## Table 67. Evaluation of Thallium Data from WS Studies Using the 30% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 30% Acceptance Limit 31 1.44 27 82 24a 2.00 30 80 37 2.38 43 91 32 2.56 60 88 25b 3.00 21 81 41 3.50 44 96 26 4.00 37 87 36 4.50 61 98 30 5.30 48 92 39 5.60 47 98 34 6.19 58 97 35 8.00 41 93 38 8.91 59 95 33 9.56 32 91 29 9.74 21 95 40 10.0 59 98 24b 18.0 35 89 27 26.9 23 91 25a 36.0 26 96



## Using the 75 percent criterion, EPA and regional laboratories were able to achieve acceptable results within the ± 30 percent acceptance window over the entire range of tested concentrations, i.e., 1.44 to 36 : 

## g/L. Upon examination of the data, the current PQL of 2 : 

## g/L appears to be easily supportable, as over 75 percent of laboratories successfully passed within the acceptance limits when tested at those concentration. It might even be possible for the labs to pass at a slightly lower concentration; however, a conclusion is uncertain in the absence of additional data below the PQL concentrations.

## 124 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for Thallium

The method comparison results indicate that use of the least sensitive method was discontinued since promulgation of NPDWRs. In addition, the MDLs of all the possible methods do not differ much between themselves (only by about a factor of two) with the ICP/MS method having greater sensitivity. The method usage over time shows that EPA Method 200.9, the less sensitive method, was the preferred choice for EPA and State laboratories. Based on the evaluation of more recent quantitative PE data, the current PQL of 2 : 

## g/L using a ± 30 percent acceptance limit appears to still be supportable and appropriate. Data do suggest that it may possible for the labs to pass at a slightly lower concentration.

Toluene

Results of the Method Comparison

The NPDWR for Phase II VOCs (56 FR 3526) approved several analytical methods for toluene. These included EPA Methods 502.2, 503.1, 524.1, and 524.2. Since this regulation was promulgated, the Agency retained EPA Methods 502.2 and 524.2 for determination of toluene. Table 68 summarizes the MDL for both the original and currently approved versions of the methods. As shown in Table 68, the MDLs of the two current methods remain essentially unchanged from their values at promulgation of the rule.

Table 68. Analytical Methods Comparison for Toluene

MCL = 1 mg/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA502.2 1 

### Purge and Trap GC 0.01 - 0.02* EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.02*

EPA 503.1 1 

### Purge and Trap GC 0.02 EPA 524.2 2 

### Purge and Trap GC/MS 0.08 - 0.11*

EPA 524.1 1 

### Purge and Trap GC/MS 0.1 EPA 524.2 1 

### Purge and Trap GC/MS 0.08 - 0.11*

## 125 Methods Support Document for Six-Year Review Final - March 2003 Toluene



### 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method



### 502.2 524.2 other 

## Figure 40. Distribution of AnalyticalTechniques by WS Study: Toluene 1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance.

>

### Regulatory DLs for VOCs are listed at 40 CFR § 141.24(f)(17)(i). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).



## Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of analytical methods used by participating laboratories from WS 34 to 41 is shown in Figure 40. The category of "other" contains those methods that were unknown or unidentified by the participating laboratories.As shown in Figure 40, EPA Method 524.2 was the preferred method for laboratories participating in WS 34 to 41 and the use of EPA Method 502.2 decreased over time.

## 126 Methods Support Document for Six-Year Review Final - March 2003 

## b. Results of the PQL Analysis

The Agency set the original PQL at 5 : 

## g/L (52 FR 25700 and 56 FR 3526) for all VOCs except vinyl chloride. More recent data from WS 29 through 41were used to re-evaluate the PQL for toluene. Table 69 summarizes the results of these WS studies providing the study number, the spiked value for the WS sample, the number of laboratory results, and the percent of laboratories passing the WS proficiency test for toluene within specified acceptance limits. The acceptance limits for toluene are ± 20% for a true value greater than10 : 

## g/L or ± 40% for a true value lower than 10 : 

## g/L (as specified at 141.24(f)(17)(i)).

Table 69. Evaluation of Toluene Data from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % EPA and State Passing ± 20% Acceptance Limit % EPA and State Passing ± 40% Acceptance Limit 37 5.7 48 100 32 6.54 63 100 30 8.02 59 98.0 35 9.92 35 100 29 11.5 35 94.3 33 12.3 33 90.9 36 13.2 60 96.7 40 14.6 58 96.6 31 15.3 35 100 34 15.6 60 98.3 38 16.2 56 96.4 41 18.7 42 95.2 39 24.4 44 88.6



## A re-evaluation of the PQL for toluene could not be performed using the available PE data in Table 4. All of the passing rates in Table 4 were well above the 75 percent criterion necessary to recalculate the PQL. In addition, the true value concentrations observed in the available WS data were all greater than the current PQL of 5 : 

## g/L. However, at concentrations close to the current PQL (spikes of 5.7, 6.54, and 8.02 : 

## g/L), the passing rates were 100, 100 and 98 percent, respectively. These data suggest that the a lower PQL may exist for toluene.

## 127 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for T oluene

The method comparison results show that since the promulgation of analytical methods under the NPDWR, no new methods have been approved for the analysis of toluene, and analytical capabilities have remained essentially constant. The most commonly used method has been EPA Method 524.2, which is also the least sensitive method of the past and present methods. Evaluation of the PE data show that the majority of the laboratories conducting WS analyses surpassed the 75 percent criterion typically used to derive a PQL. However, the high laboratory passing rates (> 95%) at concentrations slightly above the current PQL of 5 :

## g/L suggest that the PQL for toluene could be lower.

Toxaphene

Results of the Method Comparison

At the promulgation of the NPDWRs for Phase II SOCs, three GC methods, EPA Method 505 (GC with microextraction), EPA Method 508 (GC with ECD), and EPA Method 525.1 (GC/MS with LSE), were approved for the determination of toxaphene in drinking water (56 FR 3552). Since that time, EPA has approved two additional GC and GC/MS methods, respectively: EPA Methods 508.1 and 525.2 (both featuring LSE extraction). Table 70 provides a summary of MDLs for the approved methods. As shown in Table 70, EPA Method 508 does not specify the MDL for toxaphene. The MDL for EPA Method 525.2 is comparable to that of EPA Method 505. The MDL of EPA Method 505 has not changed over time, 1 : 

## g/L. The MDLs of the newer methods range from about 0.03 to 1.7 : 

## g/L. The most sensitive method currently available, EPA Method 508.1, has about eight times the sensitivity of EPA Method 505.

Table 70. Results of the Analytical Methods Comparison for Toxaphene (Newly Promulgated Methods in Bold)

MCL = 3 : 

### g/L Current PQL = 3 : 

### g/L DL >

### = 1 : 

### g/L Acceptance Limit^

### = ± 45%

Methods Approved At Promulgation Currently Approved Methods (141.24)
Method Technique MDL (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 505 1 

### Microextraction and GC 1.0 EPA 505 2 

### Microextraction and GC 1.0 EPA 508 1 

### GC with ECD ND EPA 508 2 

### GC with ECD ND EPA 525.1 1 

### LSE and GC/MS 15 EPA 508.1 2 

### LSE and GC with ECD 0.13 EPA 525.2 2 

### LSE and GC/MS 1.0 - 1.7*

## 128 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.

*

### Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance.

> 

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(h)(18). ^

### Acceptance limits for organic compounds are listed at 40 CFR § 141.24(h)(19)(i). ND = Not determined.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 41 illustrates the methods chosen by EPA and State laboratories for toxaphene analysis during WS PE studies 34 to 41. The category of "other" includes any unidentified or unreported techniques used by participating laboratories. As shown in Figure 41, the predominant method used by laboratories participating in the WS studies was EPA Method 508, followed by EPA Method 505. Other methods such as EPA Methods 525.1, 525.2, and other unidentified methods were used intermittently throughout WS 34 to 41. EPA Method 508.1 was not used by laboratories according to the PE data.

## 129 Methods Support Document for Six-Year Review Final - March 2003 

### Toxaphene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 505 508 525.1 525.2 other 

## Figure 41. Distribution of AnalyticalTechniques by WS Study: Toxaphene

b. Results of the PQL Analysis

The current PQL of 3 : 

## g/L was derived by multiplying the IMDL by factor of five (56 FR 3526). With the availability of more recent WS data, EPA reviewed the data from WS studies 24 to 41 to attempt a PQL re-evaluation. Table 71 summarizes each WS result including the spiked (or "true") value, the number of participating laboratories, and the percentage of laboratories passing within the specified acceptance limit for toxaphene (± 45 percent as designated in 40 CFR §141.24(h)(19)(i)).

## 130 Methods Support Document for Six-Year Review Final - March 2003 

## Table 71. Evaluation of Toxaphene Data from WS Studies Using the 45% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 45% Acceptance Limits 25b 1.41 35 97.1 24b 2.33 59 91.5 30 2.80 54 92.6 31 3.31 31 93.5 39 3.65 41 92.7 26b 3.68 58 94.8 32 3.71 56 92.9 25a 4.22 35 94.3 34 5.37 54 94.4 27 6.39 34 91.2 41 6.90 39 92.3 24a 7.58 60 91.7 29 7.60 33 97.0 37 8.81 46 87.0 33 9.23 33 90.9 26a 10.8 58 96.6 38 12.7 50 92.0 36 14.7 52 90.4 40 16.5 56 94.6 35 18.3 34 97.1



## EPA prefers to evaluate the PQL as the concentration at which 75 percent of laboratories are able to pass the proficiency exam within the 45 percent acceptance limits. In the case of toxaphene, however, this approach could not be used, since the percentage of laboratories passing within acceptance limits was well above the 75 percent criterion. Also, very few WS studies (e.g., 24b, 25b and 30) involved true value concentrations near the current PQL; all other studies involved spiked values above 3 : 

## g/L. Because of these data limitations, the PQL could not be re-evaluated using the historical linear regression approach. However, the observed high success rates of laboratories suggests that the PQL may be lowered. Since 97 percent of participating laboratories, on average, were able to determine concentrations at about half of the existing PQL, this success rate suggests that a lower PQL probably would not challenge most laboratories' analytical capabilities.

## 131 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for T oxaphene

The 1991 NPDWR for toxaphene approved the use of EPA Methods 505, 508, and 525.1 for toxaphene determination in drinking water.EPA Methods 508.1 and 525.2, using similar GC technologies, were approved more recently. The MDL of EPA Method 508.1 was the most sensitive compared to all other methods; however, data on method usage over time revealed that this method was not employed by laboratories. Instead, laboratories participating in the PE studies used EPA Method 508 with the greatest frequency. Unfortunately, no data are available regarding the MDL of this method. A PQL re-evaluation could not be completed due to the high success rates (well above the 75 percent criterion) in each water study as well as the high spiked concentrations in all but three water studies. The high success rates of laboratories during PE testing at concentrations well below the current PQL leads to the inference that a lower PQL would not greatly lessen laboratory performance.

1,1,1-Trichloroethane

Results of the Method Comparison

The NPDWRs for 1,1,1-trichloroethane approved certain analytical methods for the determination of this contaminant (52 FR 25690) and seven other Phase I VOCs. These methods included EPA Methods 502.1, 502.2, 503.1, 542.1, and 524.2. Since this regulation was promulgated, the Agency retained EPA Methods 502.2 and 524.2 for determination of 1,1,1- trichloroethane and introduced a new GC variation, EPA Method 551.1, LLE/GC with ECD. Table 72 summarizes the MDLs for both the original and current methods.

Table 72. Results of the Analytical Methods Comparison for 1,1,1-Trichloroethane (Newly Promulgated Methods in Bold)

MCL = 200 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL  

### (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.003 EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.03

EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.03* EPA 524.2 2 

### Purge and Trap GC/MS 0.04 - 0.08

EPA 524.1 1 

### Purge and Trap GC/MS 0.3 EPA 551.1 2 

### LLE and GC with ECD 0.005 - 0.012

EPA 524.2 1 

### Purge and Trap GC/MS 0.04 - 0.08*

## 132 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.

 

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

> 

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(f)(17)(i). 

## ^Acceptance limits are listed at 40 CFR § 141.24(f)(17)(i)



## .

Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of the different methods used by the EPA and State laboratories during WS studies 34 to 41 are shown in Figure 42. The category of "other" contains those methods that were unknown or unidentified by the participating laboratories. As shown in Figure 42, the increase in EPA and State laboratory usage of EPA Method 524.2 was accompanied by a gradual decrease in use of EPA Method 502.2 during WS 34 to 41. Although EPA Method 551.1 was approved during this time, laboratories participating in WS studies did not report usage of this method.

## 133 Methods Support Document for Six-Year Review Final - March 2003 

### 1,1,1-Trichloroethane

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 42. Distribution of Analytical Techniques by WS Study: 1,1,1- Trichloroethane

b. Results of the PQL Analysis

As with the majority of the Phase I VOCs, the current PQL for 1,1,1-trichloroethane of 5 : 

## g/L was determined using a multiplier of ten times the detection limit of 0.5 : 

## g/L (52 FR 25700). Re-evaluation of the PQL was attempted using data from WS studies 24 through 41. Table 73 summarizes the results of these WS studies, providing the study number, the spiked value for the WS sample, the number of laboratory results, and the percent of laboratories passing the WS proficiency test for 1,1,1-trichloroethane within the specified acceptance limits (± 20 percent for true values greater than10 : 

## g/L and ± 40 percent for true values less than 10 : 

## g/L as specified at 141.24(f)(17)(i)).

## 134 Methods Support Document for Six-Year Review Final - March 2003 

## Table 73. Evaluation of 1,1,1-Trichloroethane Data from WS Studies Using the ± 20% or ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 24 3.21 57 98.2 34 5.73 59 100 30 7.13 59 98.3 40 7.20 57 98.2 27 7.38 37 97.3 35 8.78 34 100 29 8.80 35 100 32 10.1 62 95.2 37 10.3 47 87.2 39 11.2 43 90.7 25 11.3 37 83.8 41 12.6 41 100 31 13.0 36 100 26 13.6 59 86.4 36 14.5 59 100 33 14.6 33 87.9 38 17.2 54 96.3



## The 1,1,1-trichloroethane data from Table 73 are insufficient for a PQL re-evaluation using the graphical or linear regression approach. The high laboratory passing rates do not permit evaluation of the PQL using the 75 percent criterion. In addition, only one spike concentration (WS 24) was below the current PQL of 5 : 

## g/L. However, the laboratory passing rates at spike concentrations around the current PQL exceeded 98 percent. This information suggests that a lower PQL could be possible.

Conclusion for 1,1,1-T richloroethane

The method comparison results show that since the promulgation of analytical methods under the NPDWR, EPA Methods 502.2 and 524.2 have remained in use whereas EPA Method 551.1 was more recently approved. While EPA Method 551.1 is the most sensitive of the three currently approved methods, this method is not currently used by EPA or State laboratories according to the available WS data. However, all current methods are more sensitive than the

## 135 Methods Support Document for Six-Year Review Final - March 2003 

## methods approved at promulgation, as shown in Table 72. Evaluation of the quantitative PE data showed that the majority of the laboratories conducting WS analyses were able to surpass the 75 percent criterion needed to evaluate the PQL. Because of the high percentage of laboratories passing and an insufficient number of spike concentrations below the 5 : 

## g/L, a re-evaluation of the PQL could not be performed using the graphical approach. However, the high passing rates at concentrations slightly above 5 : 

## g/L are suggestive of a potential change in the current PQL.

1,1,2-Trichloroethane

Results of the Method Comparison

As determined by the Phase I rules for volatile organic compounds (57 FR 31776), the approved methods listed for analysis of 1,1,2-trichloroethane in drinking water were purge and trap GC and GC/MS. Since this regulation was promulgated, the detection capability of EPA Method 524.2 has become slightly more sensitive. One new analytical method, LLE/GC with ECD (EPA 551.1), has been approved by the EPA since the promulgation of the original methods. As shown in Table 74, all three currently approved methods have comparable MDLs. However, EPA Method 502.1, which is no longer approved for analysis, has the greatest sensitivity level of all the approved methods, past and present.

Table 74. Results of the Analytical Methods Comparison for 1,1,2-Trichloroethane (New Methods in Bold)

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL•

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL  

### (: 

### g/L) Method Technique MDL (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.007 EPA 502.2 2 

### Purge and Trap GC 0.04 EPA 502.2 1 

### Purge and Trap GC 0.04 EPA 524.2 2 

### GC/MS 0.03 - 0.1*

EPA 524.1 1 

### GC/MS ND EPA 551.1 2 

### LLE and GC with ECD 0.012 - 0.014*

EPA 524.2 1 

### GC/MS 0.03 - 0.1*

## 136 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.

 

### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance. •

### Regulatory DLs for organic compounds are listed at 40 CFR §141.24(f)(17)(i). ^

### Acceptance limits are listed at 40 CFR §141.24(f)(17)(i). ND = Not determined.



## Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 43 shows the distribution of methods used by the EPA and State laboratories during WS 34 to 41. The category of "other" includes any unknown or unreported techniques used by the participating laboratories. As shown in Figure 43, the predominant methods used since the time of promulgation are EPA Methods 524.2 and 502.2. Although EPA approved a new method (EPA Method 551.1), none of the laboratories that responded used it for analysis.

## 137 Methods Support Document for Six-Year Review Final - March 2003 

## 1,1,2-Trichloroethane

0% 10% 20% 30% 40% 50% 60% 70% 80%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method 

### 524.2

502.2

other 

## Figure 43. Distribution of Analytical Techniques by WS Study: 1,1,2- Trichloroethane

b. Results of the PQL analysis

The original PQL for 1,1,2-trichloroethane was estimated from PE data (specifically WS 20, 23, and 26) to be 5 : 

## g/L (55 FR 30414). The PQL re-evaluation data were taken from WS 24 through 41 (note that data were not available for WS 24, 25, 27 to 29, and 31). Table 75 summarizes the results of these studies, including the study number, the spiked (or "true") value for the sample, the number of laboratory results, and the percent of laboratories passing the WS proficiency test for 1,1,2-trichloroethane within the specified acceptance limits (± 20 percent for a spiked value of >10 : 

## g/L and ± 40 percent for a spiked value of <10 : 

## g/L, as stipulated in 40 CFR §141.23(f)(17)(i)).

## 138 Methods Support Document for Six-Year Review Final - March 2003 

## Table 75. Evaluation of 1,1,2-Trichloroethane Data from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 36 6.46 59 98.3 34 8.50 59 100 37 10.7 47 89.4 30 11.5 50 94.0 39 12.3 42 97.6 35 12.8 35 90.9 32 13.2 51 90.6 41 13.3 40 95.1 33 15.7 34 91.4 38 16.3 54 98.1 40 17.2 57 98.2 26 26.9 54 94.4



## The standard approach to develop or evaluate a PQL could not be performed with 1,1,2- trichloroethane because the high laboratory passing percentage data (as shown in Table 75) does not permit the plotting of a useful linear regression line. Therefore, the re-evaluation of the PQL could not be done using these WS data. However, high laboratory passing rates at concentrations slightly above the current PQL of 5 : 

## g/L suggest that a lower PQL may be possible.

Conclusion for 1,1,2-T richloroethane

The method comparison shows that since the promulgation of the original analytical methods for 1,1,2-trichloroethane, one new method (EPA Method 551.1) has been approved for contaminant analysis. However, laboratories who responded to the WS studies primarily chose to use EPA Methods 524.2 and 502.2 rather than EPA Method 551.1, as shown by the plot of method usage over time. The MDL for EPA Method 524.2 has decreased slightly over time, indicating slightly greater sensitivity. While EPA Method 502.1 had a maximum MDL of 0.007 : 

## g/L, the lowest of any methods, it is currently not approved for 1,1,2-trichloroethane analyses. The evaluation of the WS data show that the majority of participating labs surpassed the 75 percent EPA criterion. Hence, because of the high percentage of labs passing and the lack of spike concentrations below the current PQL, a re-evaluation of the PQL could not be performed using linear regression or graphical analysis. However, the high passing rates at concentrations slightly above 5 : 

## g/L are suggestive of a potential change in the current PQL.

## 139 Methods Support Document for Six-Year Review Final - March 2003 

## Trichloroethylene

Results of the Method Comparison

The analytical methods approved for the determination of trichloroethylene under the NPDWRs for Phase I VOCs include EPA Methods 502.1, 502.2, 524.1, and 524.2 (52 FR 25899). Since the promulgation of the rule in 1987, the Agency has added EPA Method 551.1, a GC method with liquid-liquid extraction (LLE) and electron capture detector, to the list of approved methods. The currently approved methods for trichloroethylene determination are EPA Methods 502.2, 524.2, and 551.1. Table 76 summarizes the MDLs for both the original and current approved versions of the methods.

Table 76. Results of the Analytical Methods Comparison for Trichloroethylene (Newly Promulgated Methods in Bold)

MCL = 5 : 

### g/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL  

### (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.001 EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.06 EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.06* EPA 524.2 2 

### Purge and Trap GC/MS 0.02 - 0.19

EPA 503.1 1 

### Purge and Trap GC 0.01 EPA 551.1 2 

### LLE and GC with ECD 0.002 - 0.004

EPA 524.1 1 

### Purge and Trap GC/MS 0.4

EPA 524.2 1 

### Purge and Trap GC/MS 0.02 - 0.19*

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.



### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(f)(17)(i). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).

## 140 Methods Support Document for Six-Year Review Final - March 2003 

### Trichloroethylene

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 44. Distribution of Analytical T echniques by WS Study: Trichloroethylene Results of the Analysis of the WS Data

a. Method Usage Over Time

Figure 44 shows the distribution of the different methods used by the EPA and State laboratories during WS studies 34 to 41. The category of "other" contains those methods that were unknown or unidentified by the participating laboratories. As shown in Figure 44, laboratories participating in studies WS 34 to 41 used EPA Method 524.2 with increasing frequency over EPA Method 502.2. No laboratories used EPA Method 551.1 for PE determinations of trichloroethylene.

b. Results of the PQL Analysis

The original PQL of 5 : 

## g/L for trichloroethylene was determined by evaluation of data from WS studies 8 to 11 (50 FR 46880). For the PQL reassessment, updated data from WS 24 to 41 were reviewed. Table 77 summarizes the results of these WS studies providing the study number, the spiked value for the WS sample, the number of laboratory results, and the percent of

## 141 Methods Support Document for Six-Year Review Final - March 2003 

## laboratories passing the WS proficiency test for trichloroethylene within the acceptance limits (± 20 percent for a true value greater than10 : 

## g/L, or ± 40 percent for a true value lower than 10 : 

## g/L).

Table 77. Evaluation of Trichloroethylene Data from WS Studies Using the ± 20% or ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limits % Labs Passing ± 40% Acceptance Limits 40 5.80 58 98.3 35 6.13 34 97.1 26 6.63 59 100 41 6.87 41 100 24 7.36 57 100 31 7.46 36 97.2 37 8.70 48 97.9 34 8.89 60 100 30 9.45 38 100 25 10.4 37 83.8 32 11.2 63 95.2 38 12.4 55 94.5 27 14.0 37 91.9 33 14.9 34 94.1 29 15.9 34 85.3 39 16.4 44 95.5 36 17.4 61 96.7



## Table 77 reveals that the percentage of laboratories passing the acceptance limit averaged over 90 percent. Because the laboratories exceeded the standard 75 percent criterion used to estimate the PQL, the typical regression method could not be successfully employed to estimate a new PQL value. Another limitation of the data was that the true value concentrations in the available studies were all greater than 0.5 : 

## g/L, preventing evaluation of laboratory performance at concentrations below the current PQL. However, high laboratory passing rates at concentrations slightly above the current PQL of 5 : 

## g/L suggest that a lower PQL may be possible.

## 142 Methods Support Document for Six-Year Review Final - March 2003 

## Conclusion for T richloroethylene

The method comparison results show that, since the promulgation of analytical methods under the original NPDWR for trichloroehtylene,two of these methods are no longer approved for determination of this contaminant. While EPA Method 551.1 is the most sensitive of the three currently approved methods, this method is not currently used by EPA or State laboratories according to the available WS data. Instead, EPA Method 524.2, the least sensitive of the three current methods, has been the primary method of choice. Evaluation of the quantitative PE data shows that the majority of the laboratories conducting WS analyses had surpassed the 75 percent criterion. Because of the high percentage of laboratories passing, a re-evaluation of the PQL could not be performed using this approach. However, the high laboratory passing rates at concentrations slightly above 5 : 

## g/L are suggestive of a change in the PQL.

Vinyl Chloride

Results of the Method Comparison

With the promulgation of NPDWRs for Phase I VOCs (proposed November 1985, 50 FR 46905; finalized July 1987, 52 FR 25690), EPA Methods 502.1, 502.2, 524.1, and 524.2 were listed as approved methods for the determination of vinyl chloride in drinking water. Since promulgation of this rule, EPA Methods 502.1 and 524.1 were removed. As shown in Table 78, the MDLs of the current methods are comparable in sensitivity to previously approved methods.

Table 78. Results of the Analytical Methods Comparison for Vinyl Chloride

MCL = 2 : 

### g/L Current PQL = 2 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 40% Methods Approved At Promulgation Currently Approved Methods Method Technique MDL  

### (: 

### g/L) Method Technique MDL* (: 

### g/L) EPA 502.1 1 

### Purge and Trap GC 0.01 EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.18

EPA 502.2 1 

### Purge and Trap GC 0.01 - 0.18* EPA 524.2 2 

### Purge and Trap GC/MS 0.04 - 0.17

EPA 524.1 1 

### Purge and Trap GC/MS 0.3

EPA 524.2 1 

### Purge and Trap GC/MS 0.04 - 0.17 *

## 143 Methods Support Document for Six-Year Review Final - March 2003

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995.



### The MDLs of the original methods for this contaminant ranged from 0.2 - 0.5 :

### g/L according to the July 1987 Federal Register notice promulgating NPDWRs for the VOCs (52 FR 25690). However, the 1988 methods manual cited in footnote 1lists the MDLs shown above. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation and/or laboratory/analyst performance.

>

### Regulatory DLs for organic compounds are listed at 40 CFR § 141.24(f)(17)(i). 

## ^Acceptance limits for vinyl chloride are listed at 40 CFR §141.24(f)(17)(i).



## Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of methods used by EPA and State laboratories during WS studies 34 to 41 is plotted in Figure 45. The category of "other" contains those methods that were unknown or unidentified by the participating laboratories. As shown in Figure 45, over the course of the past eight WS Studies, the use of EPA Method 524.2 has grown while the use of EPA Method 502.2 has decreased. EPA Method 524.2 has consistently remained the most commonly used method for vinyl chloride determination.

## 144 Methods Support Document for Six-Year Review Final - March 2003 

### Vinyl Chloride

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 45. Distribution of Analytical Techniques by WS Study: Vinyl Chloride

b. Results of the PQL Analysis

The original PQL of 2 : 

## g/L for vinyl chloride was determined by using multi-laboratory performance data, rather than the multiplier procedure used for other VOCs (52 FR 25700). A re-evaluation of the PQL was attempted using more recent PE data from WS 24 to 41. Table 79 summarizes the results of these studies, providing the study number, the spiked value for the WS sample, the number of laboratory results, and the percentage of laboratories passing the performance evaluation within the +40 percent acceptance limits (40 CFR § 141.24(f)(17)(ii)).

## 145 Methods Support Document for Six-Year Review Final - March 2003 

## Table 79. Evaluation of Vinyl Chloride Data from WS Studies Using ± 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 40% Acceptance Limits 32 2.57 43 79.1 27 3.57 39 79.5 24 4.35 57 80.7 35 4.91 36 100 30 5.48 58 82.8 39 6.19 45 91.1 33 7.35 34 79.4 26 8.70 59 86.4 36 9.47 60 88.3 31 11.9 39 79.5 25 12.4 38 86.8 34 14.1 59 93.2 29 14.6 38 78.9 37 14.8 50 88.0 38 17.9 54 96.3 41 22.3 41 92.7 40 27.2 58 94.8



## EPA prefers to estimate the PQL by choosing the spiked value at which 75 percent of laboratories can determine the concentration within the appropriate 40 percent acceptance window. In the case of vinyl chloride, the results from participating laboratories listed in Table 79 could not be used to re-evaluate the PQL because the laboratory success rate exceeded this 75 percent criterion. The other limitation of these data was the high range of spiked concentrations exhibited during the WS studies, which exceeded the current PQL of 2 : 

## g/L. Therefore, the available data do not provide sufficient data to recalculate the PQL. However, passing rates of 79 to 81 percent for the three lowest concentrations (2.57, 3.57 and 4.35 : 

## g/L) above the current PQL of 2 : 

## g/L suggest that the current PQL is in the appropriate range and unlikely to change.

Conclusion for V inyl Chloride

As shown by the method comparison table, EPA Methods 502.2 and 524.2 were approved with the Phase I Rule promulgation for VOCs and continue to be approved today. The sensitivity of newer versions of the methods are comparable older versions. According to the

## 146 Methods Support Document for Six-Year Review Final - March 2003 

## plot of methods usage over time, the laboratories who participated in WS 34 to 41 employed EPA Method 524.2 more frequently than EPA Method 502.2. The available PE data were reviewed but did not provide sufficient data to recalculate the PQL. Evaluation of the available WS data suggest that the current PQL of 2 : 

## g/L vinyl chloride is unlikely to change.

Xylenes (total)

Results of the Method Comparison

The NPDWR for total xylenes, a Phase II VOC, approved four methods: EPA Methods 502.2, 503.1, 524.1, and 524.2. Since this regulation was promulgated, EPA Methods 503.1 and 524.1 have been removed from the approved list, leaving EPA Methods 502.2 and 524.2 as the only currently approved methods; no new methods have been introduced. Table 80 provides descriptions of the methods and their MDLs. The MDLs of the two current methods remain essentially unchanged from their values at promulgation of the rule.

Table 80. Analytical Methods Comparison for Xylenes (total)

MCL = 10 mg/L Current PQL = 5 : 

### g/L DL >

### = 0.5 : 

### g/L Acceptance Limit^

### = ± 20% (>10 : 

### g/L) or ± 40% (<10 : 

### g/L) Methods Approved At Promulgation Currently Approved Methods (141.24) Method Technique MDL * (: 

### g/L) Method Technique MDL* (: 

### g/L)

EPA502.2 1 

### Purge and Trap GC 0.01 -0.02 EPA 502.2 2 

### Purge and Trap GC 0.01 - 0.02

EPA 503.1 1 

### Purge and Trap GC 0.002 - 0.004 EPA 524.2 2 

### Purge and Trap GC/MS 0.03 - 0.13

EPA 524.1 1 

### Purge and Trap GC/MS 0.2 - 0.3

EPA 524.2 1 

### Purge and Trap GC/MS 0.03 - 0.13

1 

### "Methods for the Determination of Organic Compounds in Drinking Water," EPA/600/4-88/039, December 1988.

2

### "Methods for the Determination of Organic Compounds in Drinking Water--Supplement III," EPA/600/R95/131, August 1995. * Multiple method detection limit (MDL) values result from variability of reagents, instrumentation, and/or laboratory/analyst performance.

>

### Regulatory DLs for VOCs are listed at 40 CFR § 141.24(f)(17)(i). 

## ^Acceptance limits for VOCs are listed at 40 CFR § 141.24(f)(17)(i).

## 147 Methods Support Document for Six-Year Review Final - March 2003 Xylenes (total)

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

WS 34 WS 35 WS 36 WS 37 WS 38 WS 39 WS 40 WS 41 Water Study% Labs Using Method

502.2 524.2 other 

## Figure 46. Distribution of Analytical Techniques by WS Study: Xylenes (total) Results of the Analysis of the WS Data

a. Method Usage Over Time

The distribution of analytical methods used by participating laboratories from WS 34 to 41 is shown in Figure 46. The results for "other" techniques in this figure include the use of any other technique identified by the laboratories participating in the WS study, as well as "unknown" methods, i.e., methods for which laboratories did not report the method used. As Figure 46 shows, EPA Method 524.2 was the preferred method for laboratories participating in WS studies 34 to 41. The use of EPA Method 502.2 appears to decrease over time.

b. Results of the PQL Analysis

The Agency set the original PQL at 5 : 

## g/L (52 FR 25700 and 56 FR 3526) for all VOCs except vinyl chloride. Data from WS 24 through 41 were used to re-evaluate the PQL for total xylenes. Table 81 summarizes the results of these WS studies providing the study number, the spiked “true” value for the WS sample, the number of results from EPA and State laboratories, and the percent of laboratories passing the WS prof iciency test for total xylenes within specified acceptance limits. The acceptance limits for total xylenes are ± 20% for a true value greater than10 : 

## g/L or ± 40% for a true value lower than 10 : 

## g/L (as specified at 40 CFR § 141.24(f)(17)(i)).

## 148 Methods Support Document for Six-Year Review Final - March 2003 

## Table 81. Evaluation of Xylenes (total) Data from WS Studies Using Either 20% or 40% Acceptance Limits (in Order of Increasing Concentration)

WS # Spiked "True" Value (: 

### g/L) # Results from EPA and State Labs % Labs Passing ± 20% Acceptance Limit % Labs Passing ± 40% Acceptance Limit 32 7.54 61 95.1 27 8.45 32 90.6 36 10.4 61 95.1 33 11.6 34 91.2 29 12.0 34 88.2 25 12.5 33 87.9 37 12.9 49 87.8 34 13.1 60 90.0 31 13.2 38 84.2 24 14.0 45 80.0 30 15.0 59 83.0 35 17.4 37 91.9 38 22.9 56 92.9 39 24.4 44 88.6 40 30.3 58 91.4 41 30.9 43 97.7



## A re-evaluation of the PQL could not be performed using the available PE data in Table 81. All of the passing rates in Table 81 were well above the 75 percent criterion necessary to recalculate the PQL. High laboratory passing rate s (greater than 90 percent) at concentrations slightly above (i..e., ~ 7 and 8 : 

## g/L) the current PQL suggest that a lower PQL may exist.

Conclusion for Xylenes (total)

Since the promulgation of the Phase II rule, no new methods have been approved for the analysis of total xylenes, and analytical capabilities have remained essentially constant. Of the currently approved methods, EPA Method 524.2 is used more frequently by laboratories for the detection of total xylenes (although it is not the most sensitive method available). Evaluation of WS studies 24 to 41 show that the percentage of laboratories passing are higher than the 75% criterion typically used to develop a PQL. Also, all of the true values for the WS PE studies were above the current PQL. At the lowest concentrations tested (~ 7 and 8 : 

## g/L), the laboratory

## 149 Methods Support Document for Six-Year Review Final - March 2003 

## passing rates were quite high (greater than 90 percent). Although not definitive, high passing rates at values slightly above the current PQL of 5 : 

## g/L suggest that a lower PQL may exist for total xylenes.

VI. Conclusion

As part of the 1996-2002 Six-Year Reviewof National Primary Drinking Water Regulations, EPA's Office of Ground Water and Drinking Water re-evaluated the analytical feasibility for 40 selected NPDWRs. Table 82 summarizes the results of the analytical feasibility analysis. Upon review, EPA found that the majority of the available WS data were insufficient for the recalculation of the PQL for many of the 40 contaminants of interest. The data were considered insufficient because either the true value of the spike concentrations used in the WS studies were above the concentration of interest and/or the percentages of labs passing exceeded the 75 percent criterion used to calculate a PQL. However, for many of the 40 contaminants, the available data were sufficient to indicate whether the PQL might change or if the current PQL is still appropriate. Of the 40 NPDWRs evaluated, the available information indicates that the PQL for 25 may possibly be lower. The PQL for the remaining 15 appears to still be appropriate.

For the 25 analytes where the WS data indicate that a lower PQL may exist, EPA used the information about method usage over time, the MDLs for these methods, and the 10 x MDL multiplier to estimate what the potentially lower PQL might be. These estimates are shown in Appendix A. Pending the outcome of the health effects review, the majority of these estimated values will be used as thresholds in the occurrence and exposure analyses to determine whether an improvement in public health protection might be possible if EPA were to consider gathering more definitive data to recalculate the PQL and possibly lower the MCL.

## 150 Methods Support Document for Six-Year Review Final - March 2003 

## Table 82. Summary of Results from the Methods Comparison and WS Analysis

SDWA Chemical

Contaminant Current PQL (mg/L) 1 (PQL at the time of the original promulgation) 

## Result of the Six-Year Analytical Feasibility Reassessment 1 Alachlor 0.002 Current PQL still appropriate 2 Benzene 0.005 WS Data indicative of change 3 Benzo(a)pyrene 0.0002 Current PQL still appropriate 4 Beryllium 0.001 Current PQL still appropriate 5 Bis (2-ethylhexyl)phthalate (also known as Di(2-ethylhexyl) phthalate or DEHP) 0.006 Current PQL still appropriate

6 Cadmium 0.002 WS Data indicative of change 7 Carbofuran 0.007 WS Data indicative of change 8 Carbon tetrachloride 0.005 WS Data indicative of change 9 Chlordane 0.002 WS Data indicative of change 10 Chromium (total - Cr III and VI) 0.01 Current PQL still appropriate 11 1,2-Dibromo-3-chloropropane (DBCP) 0.0002 WS Data indicative of change 12 1,4-Dichlorobenzene (para) 0.005 WS Data indicative of change 13 1,2-Dichloroethane 0.005 WS Data indicative of change 14 1,1-Dichloroethylene 0.005 WS Data indicative of change 15 Dichloromethane (methylene chloride) 0.005 WS Data indicative of change 16 1,2-Dichloropropane 0.005 WS Data indicative of change 17 Dioxin - 2,3,7,8-TCDD 3 x 10-8 PQL most likely still appropriate - no data but unlikely to change since no new method approved 18 Diquat 0.004 Current PQL still appropriate 19 Ethylene dibromide 0.00005 Current PQL still appropriate 20 Fluoride 0.5 Current PQL still appropriate 21 Glyphosate 0.06 Current PQL still appropriate 22 Heptachlor 0.0004 WS Data indicative of change 23 Heptachlor epoxide 0.0002 WS Data indicative of change 24 Hexachlorobenzene 0.001 WS Data indicative of change 25 Hexachlorocyclopentadiene 0.001 WS Data indicative of change 26 Mercury 0.002 Current PQL still appropriate 27 Methoxychlor 0.01 WS Data indicative of change 28 Oxamyl 0.02 PQL could range from 0.02 to 0.04 mg/L 29 Polychlorinated biphenyls (PCBs) (as decachlorobiphenyl) 0.0005 Current PQL still appropriate

## Table 82. Summary of Results from the Methods Comparison and WS Analysis

SDWA Chemical

Contaminant Current PQL (mg/L) 1 (PQL at the time of the original promulgation) 

## Result of the Six-Year Analytical Feasibility Reassessment

151 Methods Support Document for Six-Year Review Final - March 2003

30 Pentachlorophenol 0.001 Current PQL still appropriate 31 Picloram 0.001 Current PQL still appropriate 32 Tetrachloroethylene 0.005 WS Data indicative of change 33 Thallium 0.002 WS Data indicative of change 34 Toluene 0.005 WS Date indicative of change 35 Toxaphene 0.003 WS Data indicative of change 36 1,1,1-Trichloroethane 0.005 WS Data indicative of change 37 1,1,2-Trichloroethane 0.005 WS Data indicative of change 38 Trichloroethylene 0.005 WS Data indicative of change 39 Vinyl chloride 0.002 Current PQL still appropriate 40 Xylenes (total) 0.005 WS Data indicative of change

1 

### The PQL values were converted from μg/L to mg/L to allow for comparison of values in other support documents.

## 152 Methods Support Document for Six-Year Review Final - March 2003 

## References USEPA. 1985. National Primary Drinking Water Regulations; Volatile Synthetic Organic Chemicals; Final Rule and Proposed Rule. Federal Register. Vol. 50, No. 219, p. 46880, November 13, 1985. USEPA. 1987. National Primary Drinking Water Regulations – Synthetic Organic Chemicals; Monitoring for Unregulated Contaminants; Final Rule. Federal Register. Vol. 52, No. 130, p. 25690, July 8, 1987. USEPA. 1989. National Primary and Secondary Drinking Water Regulations; Proposed Rule. Federal Register. Vol. 54, No. 97, p. 22062, May 22, 1989. USEPA. 1991. National Primary Drinking Water Regulations – Synthetic Organic Chemicals and Inorganic Chemicals; Monitoring for Unregulated Contaminants; National Primary Drinking Water Regulations Implementation; National Secondary Drinking Water Regulations; Final Rule. Federal Register. Vol. 56, No. 30, p. 3526, January 30, 1991.
USEPA. 1996. Performance Evaluation Studies Supporting Administration of the Clean Water Act and the Safe Drinking Water Act. Federal Register. Vol. 61, No. 139, p. 37464, July 18, 1996. USEPA. 1997. National Primary Drinking Water Regulations: Analytical Methods for Radionuclides; Final Rule and Proposed Rule. Federal Register. Vol. 62, No. 43, p. 10167, March 5, 1997.
USEPA. 1997. Performance Evaluation Studies Supporting Administration of the Clean Water Act and the Safe Drinking Water Act. Federal Register. Vol. 62, No. 113, p. 32112, June 12, 1997. USEPA. 1999. National Primary and Secondary Drinking Water Regulations: Analytical Methods for Chemical and Microbiological Contaminants and Revisions to Laboratory Certification Requirements; Final Rule. Federal Register. Vol. 64, No. 230, p. 67449, December 1, 1999. USEPA. 2001a. Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act; National Primary Drinking Water Regulations; and National Secondary Drinking Water Regulations; Methods Update; Proposed Rule. Federal Register. Vol. 66, p. 3526, January 16, 2001. USEPA. 2001b. National Primary Drinking Water Regulations; Arsenic and Clarifications to Compliance and New Source Contaminants Monitoring; Final Rule. Federal Register. Vol. 66, No. 14, p. 6976, January 22, 2001.1 

### For those contaminants where occurrence is evaluated with respect to the revise/not revise decision, EPA is using the Stage 2 occurrence analysis for the 16 State data base to determine the percentage of PWSs that could be impacted, and the percentage of the exposed population served by these systems. In making the revise/not revise decision, EPA will consider the difference between levelsof occurrence and exposure above the current MCL and the occurrence and exposure at threshold levels of interest (e.g. potential MCLs and/or MCLGs).



## A-1 Methods Support Document for Six-Year Review Final - March 2003 

## Appendix A

After re-evaluating more recent Water Supply data for the Six-Year Review, EPA found that insufficient data were available around the 75 percent criterion to actually recalculate the PQL. However, in many cases, the passing rates for the EPA Regional and State laboratories exceeded the 75 percent at values close to the current PQL. If the passing rates were greater than 80 to 85 percent at spike concentrations close to the current PQL, then this information was considered to be indicative of a possible change in the PQL. If data indicated a possible change in the PQL, EPA then evaluated the distribution of the analytical methods used to analyze the spike samples in the WS studies. Evaluation of the method usage over time allowed EPA to determine the analytical methods that appear to be the most widely used for the analysis of a particular contaminants. Knowledge of which analytical methods are the most widely used, along with the MDL for these methods, and a ten times MDL multiplier allowed EPA to estimate where the potential lower limit of quantitation may lie today. These values are shown in Table 83. Most of these estimated PQLs have or will be used as a threshold value in the occurrence and exposure (O/E) 1 

## analysis to help the Agency determine if there may be a meaningful opportunity for health risk reduction if EPA were to consider gathering the information needed to recalculate the PQL (and therefore consider changes to the MCL).

## A-2 Methods Support Document for Six-Year Review Final - March 2003 

## Table 83. Estimated PQLs Based on Method Usage and 10 x MDL Multiplier Estimated values to use in the Occurrence and Exposure (O/E) analyses (units converted from μg/L to mg/L to allow for comparison of values in other support documents)

Chemical analyte Current PQL 1 

### (mg/L) Most commonly used methods with published MDL(mg/L) Estimated value for O/E (mg/L)

1 Benzene 0.005 EPA 524.2 EPA 502.2 0.00004 (upper MDL) 0.00001 0.0004 0.0001

Use upper value of 0.0004 mg/L 2 Cadmium 0.002 EPA 200.7 EPA 200.8 EPA 200.9 all used equally 0.001 0.0005 0.00005 0.01 0.005 0.0005

If use upper or intermediate value - these are higher than current MCL. Could use 0.0005 mg/L as a value for O/E but this would probably be the lower edge of the quantitation limit. 3 Carbofuran 0.007 EPA 531.1 0.00052 0.0052

Round to 0.005 mg/L 4 Carbon tetrachloride 0.005 EPA 524.2 EPA 502.2 0.00021 (upper MDL) 0.00002 (upper MDL) 0.0021 0.0002

Use upper value of 0.0021 and since this value is close to one-half MCL, use 0.0025 mg/L. 5 Chlordane 0.002 EPA 505 EPA 508 0.00014 0.0000041 (upper MDL) 0.0014 0.000041

Because there is an order of magnitude difference between these two values, use the average and round up. Average = 0.00072 mg/L Round up to 0.001 mg/L 6 1,2-Dibromo-3- chloropropane (DBCP) 0.0002 EPA 504.1 0.00001 0.0001 mg/L
7 1,4-Dichlorobenzene (para) 0.005 EPA 502.2 EPA 524.2 0.00004 (upper MDL) 0.00004 (upper MDL) 0.0004 0.0004

Use upper value of 0.0004 mg/L

### Chemical analyte Current PQL 1 

### (mg/L) Most commonly used methods with published MDL(mg/L) Estimated value for O/E (mg/L)



## A-3 Methods Support Document for Six-Year Review Final - March 2003 8 1,2-Dichloroethane 0.005 EPA 502.2 EPA 524.2 0.00003 0.00006 (upper MDL) 0.0003 0.0006

Use upper value and round to 0.001 mg/L 9 1,1-Dichloroethylene 0.005 EPA 524.2 EPA 502.2 0.00012 (upper MDL) 0.00007 (upper MDL) 0.0012 0.0007

Could use either both round to 0.001 mg/L 10 Dichloromethane (methylene chloride) 0.005 EPA 524.2 EPA 502.2 0.00009 (upper MDL) 0.00002 (upper MDL) 0.0009 0.0002

Used average for these two since close to one-half MCL Average = 0.00055 mg/L 11 1,2-Dichloropropane 0.005 EPA 524.2 EPA 502.2 0.00004 (upper MDL) 0.00003 (upper MDL) 0.0004 0.0003

Use upper value 0.0004 mg/L 12 Heptachlor 0.0004 EPA 525.2 EPA 505 EPA 508 0.00015 (upper MDL) 0.000003 0.0000015 0.0015 0.00003 0.000015

Because of widespread between these - use the intermediate value and round to 0.0001 mg/L to be conservative 13 Heptachlor epoxide 0.0002 EPA 525.2 EPA 508 EPA 505 0.00013 (upper MDL) 0.0000059 0.000004 0.0013 0.000059 0.00004

Because of widespread between these - use the intermediate value and round to 0.0001 mg/L to be conservative 14 Hexachlorobenzene 0.001 EPA 508 EPA 505 EPA 525.2 0.0000077 0.000002 0.00013 (upper MDL) 0.000077 0.00002 0.0013

Average = 0.0005 mg/L

### Chemical analyte Current PQL 1 

### (mg/L) Most commonly used methods with published MDL(mg/L) Estimated value for O/E (mg/L)



## A-4 Methods Support Document for Six-Year Review Final - March 2003 15 Hexachlorocyclopentadien e 0.001 EPA 508 EPA 505 EPA 525.2 N/A 0.00013 0.00016 (upper MDL) ----- 0.0013 (rounds to 0.001) 0.0016

Use 0.001 mg/L 16 Methoxychlor 0.01 EPA 505 EPA 525.2 EPA 508 0.00096 0.00013 (upper MDL) 0.000022 0.0096 0.0013 0.00022

Use intermediate value and round to 0.001 mg/L 17 Oxamyl 0.02 ------------ ------------ PQL could range from 0.02 to 0.04 mg/L 18 Tetrachloroethylene 0.005 EPA 524.2 EPA 502.2 0.00014 (upper MDL) 0.00005 (upper MDL) 0.0014 0.0005

In this case, used the lower value of 0.0005 mg/L because of the 95-100 % passing rates around the current PQL. 19 Thallium 0.002 EPA 200.9 EPA 200.8 0.0007 0.0003 0.007 0.003

These values higher than current MCL, could not estimate using 10 multiplier. 20 Toluene 0.005 EPA 502.2 EPA 524.2 0.00002 (upper MDL) 0.00011 (upper MDL) 0.0002 0.0011

Average = 0.00065 mg/L 21 Toxaphene 0.003 EPA 508 EPA 505 N/A (Not Available) 0.001 ----------- 0.01 (higher than current MCL) 22 1,1,1-Trichloroethane 0.005 EPA 524.2 EPA 502.2 0.00008 (upper MDL) 0.00003 (upper MDL) 0.0008 0.0003

Average = 0.0005 mg/L

### Chemical analyte Current PQL 1 

### (mg/L) Most commonly used methods with published MDL(mg/L) Estimated value for O/E (mg/L)



## A-5 Methods Support Document for Six-Year Review Final - March 2003 23 1,1,2-Trichloroethane 0.005 EPA 524.2 EPA 502.2 0.0001 (upper MDL) 0.00004 0.001 0.0004

Average = 0.0007 mg/L Estimated value is lower than MCLG of 0.003 mg/L. So should use MCLG value as threshold in O/E analysis. 24 Trichloroethylene 0.005 EPA 502.2 EPA 524.2 0.00006 (upper MDL) 0.00019 (upper MDL) 0.0006 0.0019

Average = 0.00125 mg/L 25 Xylenes (total) 0.005 EPA 502.2 EPA 524.2 0.00002 (upper MDL) 0.00013 (upper MDL) 0.0002 0.0013

Average = 0.00075 mg/L

1

### PQL at the time of the original promulgation.

## B-1 Methods Support Document for Six-Year Review Final - March 2003 

## Appendix B

Water Supply Raw Data

Below are tables that contain the raw Water Supply (WS) data used to construct the Distribution of Analytical Techniques figures and Evaluation of Data tables.

## B-2 Methods Support Document for Six-Year Review Final - March 2003 Alachlor Water Study: 24a True Value: 0.735 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 0.690 505 0.771 505 0.824 other 0.900 other 0.913 505 0.703 other 0.777 507 0.829 507 0.908 505 0.945 507 0.732 507 0.791 other 0.860 other 0.909 other 0.980 507 0.763 507 0.822 other 0.879 507 0.910 Water Study: 24b True Value: 4.53 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 3.400 507 4.030 other 4. 250 505 4.540 other 5.020 507 3.630 505 4.060 505 4.470 507 4.610 507 5.420 other 3.765 507 4.160 other 4 .500 507 4.610 other 6.400 505 3.900 507 4.170 other 4.500 other 4.730 Water Study: 25a True Value: 1.87 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.479 507 1.600 507 1. 800 507 1.910 other 2.590 other 1.560 505 1.630 507 1.860 507 2.000 507 1.560 other 1.760 505 1.860 507 2.300 Water Study: 25b True Value: 9.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 7.310 507 7.670 507 9.630 other 10.200 507 11.800 507 7.400 505 8.520 other 9.660 22 10.300 other 7.446 507 9.460 505 9.670 507 11.000 Water Study: 26a True Value: 5.66 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 4.400 507 5.150 other 5.300 507 5.570 507 5.890 505 4.550 other 5.220 507 5.400 507 5.570 505 7.130 505 4.870 other 5.230 507 5.500 other 5.600 other 7.350 507 5.140 other 5.270 505 5.560 507 5.600 507 42.500

## B-3 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 0.933 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 0.588 505 0.810 other 0.900 other 0.953 other 1.130 other 0.600 507 0.875 507 0. 910 other 0.971 507 1.200 507 0.730 507 0.890 other 0.921 507 0.980 505 1.210 505 0.779 507 0.894 507 0.939 505 1.030 507 7.000 Water Study: 27 True Value: 3.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.900 other 3.200 507 3.370 507 3.710 507 4.080 507 4.300 505 2.060 507 3.240 other 3.490 507 3.960 other 4.160 other 4.610 507 3.000 505 3.270 507 3.500 507 4.030 other 4.160 Water Study: 29 True Value: 1.59 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.161 other 1.310 507 1.460 507 1.690 505 2.000 other 0.237 507 1.400 507 1. 500 507 1.750 other 1310.000 507 0.700 507 1.420 other 1.570 507 1.860 Water Study: 30 True Value: 3.21 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 2.130 507 2.620 other 2.950 507 3.156 other 3.370 507 3.760 507 2.260 other 2.750 507 3.000 505 3.270 507 3.380 other 3.890 other 2.301 507 2.810 other 3. 050 other 3.270 507 3.390 505 4.410 other 2.310 other 2.820 other 3 .050 505 3.280 507 3.390 other 4.500 other 2.400 other 2.900 507 3.050 507 3.300 other 3.450 other 5.590 505 2.480 other 2.910 505 3. 060 507 3.350 other 3.490 507 2.500 other 2.940 507 3.110 505 3.360 507 3.700 Water Study: 31 True Value: 2.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.975 507 1.260 507 2.200 other 2.420 other 2.680 507 1.000 507 1.740 other 2.250 507 2.470 507 2.720 other 1.030 other 1.870 other 2.300 507 2.510 other 2.720 other 1.040 505 2.170 507 2.310 507 2.570 507 2.930 505 1.200 507 2.200 507 2.318 507 2.650 507 3.230

## B-4 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 2.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 0.0387 other 1.960 525.1 2. 110 525.1 2.410 505 2.690 505 3.860 507 1.170 other 2.030 507 2.160 507 2.420 507 2.690 505 5.800 525.1 1.410 507 2.040 507 2. 190 505 2.430 507 2.700 other 9.430 other 1.710 505 2.050 505 2.240 507 2.470 525.1 2.940 507 1.800 507 2.060 507 2.260 other 2.520 507 2.960 525.1 1.880 other 2.078 507 2.330 507 2.600 507 3.120 505 1.919 525.1 2.080 505 2.340 other 2.600 525.1 3.280 other 1.920 other 2.100 505 2.400 505 2.670 525.1 3.435 Water Study: 33 True Value: 4.27 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 1.110 507 3.380 505 3.960 525.1 4.140 507 4.344 505 4.920 525.1 1.830 505 3.800 507 3.990 505 4.240 other 4.350 507 5.340 507 3.250 507 3.830 505 4.000 507 4.290 525.1 4.740 525.1 5.670 other 3.350 525.1 3.910 507 4.000 507 4.290 507 4.800 other 12.700 507 3.370 other 3.950 505 4.130 other 4.310 525.1 4.850 505 56.200 Water Study: 34 True Value: 3.43 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 1.910 505 2.759 505 3.140 505 3.460 505 3.600 505 3.700 507 2.090 525.2 2.820 other 3. 140 505 3.490 525.1 3.630 505 3.810 505 2.230 505 2.880 525.1 3.210 507 3.510 507 3.640 507 3.896 507 2.280 505 2.890 507 3.220 505 3.520 507 3.650 525.1 3.910 525.1 2.510 other 2.900 507 3. 250 507 3.560 507 3.652 525.1 4.000 other 2.580 507 2.910 507 3.260 525. 1 3.560 525.1 3.670 525.1 4.010 507 2.650 507 3.100 other 3.260 525.1 3.560 507 3.670 507 4.020 507 2.750 525.1 3.110 525.1 3. 310 505 3.596 507 3.690 507 4.160 Water Study: 35 True Value: 5.27 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 3.130 507 4.120 507 4.950 525.1 5 .410 other 5.720 507 7.350 507 3.230 525.2 4.430 505 5.050 525. 1 5.430 525.1 5.740 505 10.000 507 3.580 505 4.490 507 5.120 507 5.460 other 5.820 525.1 3.810 507 4.860 507 5.270 507 5.550 525.1 5.960 507 4.020 507 4.870 505 5.280 507 5.600 525.1 6.220

## B-5 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 7.34 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 4.840 507 6.060 507 6.650 507 7.135 505 7.490 505 8.200 507 4.890 507 6.310 505 6.710 525.2 7.190 505 7.610 507 8.510 525.2 5.160 other 6.380 508.1 6. 710 525.2 7.200 525.2 7.620 507 9.040 507 5.370 507 6.390 525.2 6.750 525. 2 7.210 507 7.790 508.1 9.750 507 5.590 507 6.490 505 6.790 507 7.230 525.2 7.840 525.1 10.300 other 5.600 507 6.490 507 6.960 525.2 7.310 507 7.860 other 5.660 507 6.550 525.2 6 .960 525.2 7.330 525.2 8.060 525.2 5.710 507 6.580 505 7.020 507 7.410 507 8.190 other 6.040 other 6.620 other 7.060 507 7.430 other 8.110 Water Study: 37 True Value: 4.87 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 2.320 other 3.920 525.2 4. 683 525.2 4.920 507 5.220 505 6.277 507 2.660 525.2 4.140 505 4.750 525. 2 4.930 other 5.380 507 7.190 505 2.750 525.2 4.150 505 4.770 507 4.950 505 5.480 507 7.280 507 3.190 507 4.500 other 4.810 525.2 4.970 525.2 5.580 507 7.410 505 3.480 507 4.580 505 4.840 505 5. 060 other 5.890 508.1 8.340 507 3.490 507 4.620 508.1 4. 880 525.2 5.070 525.2 6.170 507 3.700 507 4.680 507 4.890 505 5.100 525.2 6.250 Water Study: 38 True Value: 9.52 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 2.470 507 7.670 507 8.960 507 9.520 525.2 10.000 525.2 10.900 525.2 4.670 508.1 7.700 505 9.010 507 9.680 507 10.100 525.2 11.800 507 5.110 507 7.840 507 9.080 505 9.710 507 10.100 525.2 13.000 505 5.370 507 8.060 507 9.150 525. 2 9.800 525.2 10.120 507 13.600 507 5.580 507 8.470 507 9.150 525.2 9.810 525.2 10.200 507 6.150 507 8.550 507 9.220 525.2 9.840 505 10.290 507 6.830 508.1 8.560 525.2 9.230 507 9.910 507 10.670 525.2 7.220 507 8.650 505 9.320 other 9.980 525.2 10.700 other 7.500 507 8.950 507 9.500 525.2 10.000 507 10.800

## B-6 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 14.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 6.600 508.1 12.600 525.2 13.600 505 14.170 507 15.100 525.2 16.400 507 10.500 525.2 12.700 507 13.900 507 14.200 525.2 15.600 525.2 16.430 other 10.600 507 12.800 507 13.900 other 14.500 505 15.600 507 16.500 507 12.100 507 12.900 507 13.900 507 14.540 525.2 15.900 525.2 18.300 507 12.200 507 12.900 507 13.900 505 14.600 525.2 16.000 505 18.900 507 12.300 525.2 13.200 507 13. 900 525.2 14.790 525.2 16.200 508.1 12.400 525.2 13.500 525.2 14.000 525.2 14.800 525.2 16.300 Water Study: 40 True Value: 17.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 507 0.480 507 12.900 507 16.000 507 17.800 525.2 18.700 507 19.800 508.1 2.260 507 13.400 525.2 16.600 507 18.000 525.2 18.700 507 20.290 507 8.620 525.2 13.700 507 16.800 507 18.200 507 18.800 525.2 22.000 508.1 8.680 507 14.000 507 16.900 525. 2 18.300 525.2 18.900 525.2 23.300 507 9.020 505 14.500 505 16.900 505 18.400 525.2 19.100 525.2 24.100 507 10.000 507 14.900 525.2 17.100 525.2 18.400 507 19.200 other 10.900 508.1 14.900 507 17.400 525.2 18.430 507 19.200 507 12.500 507 15.400 505 17.400 525.2 18.500 525.2 19.400 507 12.700 508.1 15.600 507 17. 800 507 18.700 other 19.700 Water Study: 41 True Value: 12.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 8.950 507 10.300 525.2 12.040 525.2 12.700 525.2 13.800 507 15.800 507 9.150 507 10.300 508.1 12.200 505 12.700 525.2 13.900 525.2 15.900 525.2 9.580 525.2 11.100 507 12.300 525.2 12.800 507 14.100 507 9.740 508.1 11.300 507 12.500 505 13.000 525.2 14.280 other 9.800 507 11.500 507 12.500 505 13.200 525.2 14.800 507 10.000 505 12.000 525.2 12.500 505 13.500 505 14.800 507 10.100 other 12.000 507 12.600 other 13.600 other 15.400

## B-7 Methods Support Document for Six-Year Review Final - March 2003 Benzene Water Study: 24 True Value: 4.32 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 2.600 524.2 3.890 524.2 4.110 524. 2 4.320 other 4.600 502.2 4.890 524.1 3.340 502.2 3.920 524.1 4.133 524.2 4.350 502.2 4.650 503.1 4.930 502.2 3.420 524.1 4.000 524.2 4.140 524.2 4.390 502.2 4.660 524.2 4.940 502.2 3.640 524.2 4.008 524.2 4.200 502.2 4.400 524.2 4.660 502.2 4.960 503.1 3.710 502.2 4.012 502.2 4.200 502.1 4.440 524.2 4.690 502.2 5.200 502.2 3.780 524.2 4.050 524.2 4.210 other 4.480 524.2 4.700 503.1 5.250 502.2 3.800 502.2 4.070 502.2 4.220 524. 1 4.570 other 4.700 other 6.700 524.1 3.830 503.1 4.100 524.2 4 .267 524.2 4.580 524.2 4.730 524.2 3.870 502.2 4.100 502.2 4 .300 524.1 4.590 524.2 4.800 502.1 3.890 524.2 4.100 524.2 4 .300 502.2 4.590 502.2 4.890 Water Study: 25 True Value: 13.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.400 524.2 12.940 524.1 13.400 524.2 14.000 502.2 14.500 524.2 21.300 524.1 9.700 524.1 13.000 502.2 13.400 503. 1 14.100 524.1 14.600 other 26.200 502.2 11.800 502.2 13.000 502.2 13.500 502.2 14.100 502.2 14.900 524.2 12.080 502.2 13.000 524.2 13.600 524.2 14.100 502.2 15.000 502.2 12.500 502.2 13.020 other 13.620 524.2 14.100 502.2 15.000 524.2 12.690 524.2 13.190 other 13.800 502.2 14.200 524.1 15.100 503.1 12.900 524.2 13.400 502.2 14.000 524.2 14.400 524.2 17.400 Water Study: 26 True Value: 10.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 503.1 7.170 524.1 9.590 524.1 10.100 524.2 10.280 524.2 10.700 524.2 11.900 524.1 8.970 502.2 9.600 502.2 10.100 524.2 10.300 524.2 10.800 524.2 11.900 502.2 9.140 503.1 9.630 502.2 10.100 524.2 10.330 524.2 10.900 524.2 12.000 502.2 9.190 524.2 9.630 502.2 10.100 524. 2 10.400 502.2 11.000 other 12.100 502.2 9.200 524.2 9.640 524.2 10.170 524.2 10.400 524.2 11.000 524.2 12.200 503.1 9.240 524.2 9.650 502.2 10.200 502.2 10.500 503.1 11.100 524.1 12.400 other 9.300 502.2 9.690 502.2 10.200 524.1 10.500 524.2 11.200 502.2 12.700 503.1 9.350 502.2 9.700 524.2 10.200 524.2 10.500 502.2 11.520 502.2 12.700 524.2 9.360 524.2 9.750 502.2 10.200 502.2 10.550 524.2 11.600 503.1 17.700 502.2 9.550 502.2 9.900 502.2 10.200 524.2 10.700 502.2 11.700

## B-8 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 7.09 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 5.900 502.2 6.520 503.1 6.810 502.2 7.140 503.1 7.740 524.2 8.470 524.2 5.910 524.2 6.570 524.2 6.840 524.2 7.160 524.2 7.900 524.2 8.590 other 6.010 502.2 6.600 524.2 6.900 524.2 7.200 502.2 7.940 524.1 9.930 524.2 6.390 502.2 6.660 502.2 6 .910 502.2 7.210 524.1 7.940 other 6.400 502.2 6.660 502.2 7 .020 524.2 7.310 other 7.960 502.2 6.410 502.2 6.670 502.2 7 .100 502.2 7.400 502.2 8.070 524.2 6.490 524.2 6.780 502.2 7 .110 502.2 7.550 502.2 8.410 Water Study: 29 True Value: 15.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 12.520 524.2 14.300 502.2 15.200 524. 1 15.900 other 16.400 other 18.300 502.2 13.300 524.2 14.700 502.2 15.220 524.2 15.980 502.2 16.700 502.2 19.300 524.2 14.000 524.2 14.900 502.2 15.300 502.2 16.000 524.2 17.200 524.2 16.500 524.2 14.140 524.2 14.900 524.2 15.700 524.1 16.400 524.2 17.200 502.2 21.600 502.2 14.200 502.2 15.100 502.2 15.700 502.2 16.400 502.2 17.720 524.2 14.200 524.2 15.100 502.2 15. 740 524.2 16.400 other 18.000 Water Study: 30 True Value: 9.51 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 7.060 524.2 8.880 524.1 9.210 524.2 9.560 other 9.890 524.2 10.300 502.2 7.640 502.2 8.920 524.2 9.220 524.2 9.580 524.1 9.970 524.2 10.300 524.2 8.150 502.2 8.960 503.1 9.220 524.2 9.660 502.2 9.980 524.2 10.400 524.2 8.200 502.2 8.990 524.2 9.300 524.2 9.680 524.2 10.000 502.2 10.500 502.2 8.210 524.2 9.000 502.2 9.330 502.2 9.700 503.1 10.020 502.2 10.580 524.2 8.700 502.2 9.050 502.2 9.340 524.2 9.700 502.2 10.100 502.2 10.600 524.2 8.700 502.2 9.070 502.2 9.400 524.2 9.740 502.2 10.100 502.2 10.700 502.2 8.720 524.2 9.100 524.2 9.410 502.2 9.770 502.2 10.140 502.2 10.700 502.2 8.790 502.1 9.170 524.1 9.480 524.2 9.800 524.2 10.200 502.2 10.800 524.2 8.840 524.2 9.200 524.2 9.500 524. 2 9.880 other 10.290 other 12.800

## B-9 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 12.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.110 503.1 11.700 524.1 12.100 502.2 12.700 502.2 13.400 502.2 15.300 other 8.590 524.2 11.710 524.2 12.100 502.2 12.900 524.2 13.600 502.2 19.100 503.1 10.200 524.2 11.900 524.2 12.100 502.2 12.900 524.2 13.600 503.1 11.200 502.2 11.900 524.2 12.200 502.2 12.900 502.1 13.900 502.2 11.400 524.2 11.900 524.2 12.200 502.2 13.000 524.2 14.050 524.2 11.590 502.2 11.970 524.2 12.600 524.2 13.100 502.2 14.600 502.2 11.600 524.2 12.000 524.2 12.600 502.2 13.300 502.2 14.900 Water Study: 32 True Value: 14.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 13.400 502.2 15.300 524.2 16.160 524.2 16.500 502.1 17.200 502.2 18.100 503.1 13.600 502.2 15.300 524.2 16.200 524.2 16.600 524.2 17.200 502.2 18.300 524.2 13.800 524.2 15.400 502.2 16.300 524.2 16.800 524.2 17.200 502.2 18.500 524.2 14.300 524.2 15.400 524.2 16.300 524.2 16.800 524.2 17.200 502.2 18.700 502.2 14.700 503.1 15.400 524.2 16.390 524.2 16.840 524.2 17.300 503.1 18.900 524.2 14.700 524.2 15.600 524.2 16.400 524.2 16.900 502.2 17.300 524.2 19.300 502.2 14.900 524.2 15.700 524.2 16.400 502. 2 17.000 502.2 17.400 other 20.000 502.2 14.900 524.2 15.840 other 16.400 other 17.000 502.2 17.600 524.2 20.000 502.2 15.000 524.2 16.000 502.2 16.500 502.2 17.100 524.2 17.600 524.2 20.500 502.2 15.000 524.2 16.000 502.2 16.500 502.2 17.200 502.2 17.800 502.2 20.900 524.2 15.200 524.2 16.100 502.2 16.500 524.1 17.200 502.2 18.000 Water Study: 33 True Value: 12.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 9.920 524.1 11.100 524.2 11.700 502.2 12.000 524.2 12.400 502.2 13.400 other 10.420 524.2 11.100 502.2 11.700 502.2 12.200 other 12.700 524.2 13.800 502.1 10.500 524.2 11.300 502.2 11.700 502.2 12.200 502.2 12.700 524.2 14.400 502.2 10.580 524.2 11.380 524.2 11.800 502.2 12.200 524.2 12.900 524.2 14.800 502.2 10.800 524.2 11.440 524.2 11.900 502.2 12.300 502.2 13.100 502.2 30.300 502.2 10.830 524.2 11.500 502.1 12.000 502.2 12.400 524.2 13.200

## B-10 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 4.94 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 3.600 502.2 4.440 502.2 4.720 524.2 4.910 524.2 5.100 524.2 5.260 502.2 3.850 524.2 4.440 502.2 4.750 502.2 4.920 502.2 5.110 524.2 5.260 524.2 4.150 524.2 4.470 524.2 4.750 502.2 4.950 524.2 5.120 524.2 5.300 502.2 4.230 524.2 4.500 524.2 4.830 502.2 4.980 524.2 5.120 524.2 5.300 502.2 4.290 other 4.600 524.2 4.840 502.2 5.000 524.2 5.130 524.2 5.410 502.2 4.320 502.2 4.610 502.2 4.850 502.2 5.020 502.2 5.140 502.2 5.520 502.2 4.356 502.2 4.620 524.2 4.870 524.2 5.040 502.2 5.150 524.2 5.550 524.2 4.420 502.2 4.700 524.2 4.900 524.2 5.050 524.2 5.170 502.2 5.570 503.1 4.430 524.2 4.710 524.2 4.900 524. 2 5.070 other 5.200 502.2 5.730 524.2 4.440 502.2 4.710 524.2 4.900 502.2 5.080 502.2 5.250 524.2 6.080 Water Study: 35 True Value: 14.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.500 502.2 13.040 502.2 13.600 524.2 13.900 524.2 14.700 524.2 15.600 524.2 12.000 524.2 13.100 502.2 13.600 524.2 13.900 502.2 14.710 524.2 16.170 502.2 12.200 524.2 13.170 524.2 13.700 524.2 14.000 502.2 14.960 502.2 16.300 524.2 12.400 524.2 13.300 502.2 13.700 524.2 14.200 524.2 15.400 502.2 17.000 524.2 12.900 502.2 13.300 other 13.740 502.2 14.300 502.2 15.500 524.2 13.000 502.2 13.500 502.2 13. 900 524.2 14.700 other 15.600 Water Study: 36 True Value: 7.49 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.900 524.2 6.920 524.2 7.140 other 7.340 524 7.630 other 8.500 502.2 6.000 524.2 6.930 524.2 7.160 524.2 7.360 502.2 7.660 524.2 8.590 524.2 6.300 524.2 7.000 524.2 7.190 524.2 7.370 524.2 7.670 524.2 8.670 524.2 6.640 502.2 7.000 524.2 7.200 502. 2 7.400 other 7.750 502.2 8.680 502.2 6.730 502.2 7.030 524.2 7.210 524.2 7.420 524.2 7.810 524.2 8.700 502.2 6.730 524.2 7.030 other 7.220 524.2 7.420 502.2 7.940 other 8.930 524.2 6.850 524.2 7.040 524.2 7 .290 502.2 7.460 524.2 7.970 502.2 6.860 524.2 7.050 524.2 7 .300 524.2 7.510 502.2 8.140 524.2 6.880 502.2 7.060 502.2 7 .300 524.2 7.530 524.2 8.350 524.2 6.890 502.2 7.070 502.2 7 .310 524.2 7.560 502.2 8.400 524.2 6.900 502.2 7.120 502.2 7 .320 524.2 7.600 502.2 8.440

## B-11 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 12.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.970 524.2 11.900 502.2 12.300 524.2 12.600 524.2 13.100 502.2 13.900 524.2 11.200 524.2 12.000 524.2 12.300 502.2 12.600 524.2 13.200 502.2 14.000 524.2 11.300 502.2 12.000 524.2 12.370 502. 2 12.700 524.2 13.400 other 14.300 502.2 11.400 other 12.100 502.2 12.400 other 12.800 524.2 13.400 524.2 14.500 502.2 11.500 524.2 12.100 502.2 12.400 502.2 12.800 524.2 13.400 502.2 14.500 524.2 11.600 502.2 12.200 524.2 12.400 524.2 13.000 524.2 13.430 524.2 16.800 502.2 11.800 524.2 12.200 502.2 12.500 502.2 13.100 524.2 13.800 524.2 16.900 524.2 11.900 524.2 12.250 524.2 12.500 524.2 13.100 502.2 13.800 524.2 24.800 Water Study: 38 True Value: 15.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 12.500 524.2 14.500 502.2 15.000 502.2 15.600 502.2 16.200 524.2 16.800 524.2 13.100 524.2 14.500 other 15.000 524.2 15.600 524.2 16.200 524.2 17.100 524.2 13.300 502.2 14.500 524.2 15.000 502.2 15.600 524.2 16.200 502.2 17.100 524.2 13.500 524.2 14.500 524.2 15.000 502.2 15.700 524.2 16.300 524.2 18.800 502.2 14.000 524.2 14.600 524.2 15.100 502.2 15.800 524.2 16.300 524.2 20.800 524.2 14.000 other 14.600 524.2 15.100 502.2 15.900 502.2 16.400 524.2 14.100 other 14.800 524.2 15.400 524.2 15.900 502.2 16.600 524.2 14.140 524.2 14.900 524.2 15.400 524.2 16.000 502.2 16.600 524.2 14.200 524.2 14.900 502.2 15.400 524.2 16.100 524.2 16.600 502.2 14.300 502.2 14.950 524.2 15.600 524.2 16.130 502.2 16.600 Water Study: 39 True Value: 9.39 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.600 524.2 8.900 524.2 9.290 502.2 9.640 524.2 10.100 524.2 11.400 524.2 8.250 502.2 9.000 524.2 9.300 502.2 9.650 524.2 10.200 524.2 12.400 524.2 8.300 502.2 9.060 524.2 9.320 524.2 9.730 524.2 10.300 524.2 16.990 502.2 8.330 524.2 9.100 502.2 9 .330 502.2 9.740 524.2 10.400 502.2 8.450 502.2 9.130 524.2 9 .390 524.2 9.750 524.2 10.400 524.2 8.540 524.2 9.150 524.2 9 .400 502.2 9.820 524.2 10.530 other 8.830 502.2 9.180 524.2 9 .400 524.2 9.980 524.2 10.600 524.2 8.840 524.2 9.280 502.2 9 .440 502.2 10.100 524.2 11.000

## B-12 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 16.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 9.100 524.2 15.400 524.2 16.300 524.2 16.600 502.2 17.200 524.2 18.400 524.2 13.400 524.2 15.500 524.2 16.300 524.2 16.700 502.2 17.300 524.2 18.500 524.2 14.000 524.2 15.800 502.2 16.300 524.2 16.700 502.2 17.400 524.2 18.600 524.2 14.000 524.2 15.800 524.2 16.400 502.2 16.800 524.2 17.400 502.2 18.700 502.2 14.300 524.2 16.000 524.2 16.400 other 16.800 524.2 17.500 502.2 18.700 524.2 14.900 502.2 16.100 524.2 16.430 524. 2 16.800 524.2 17.600 other 19.500 524.2 15.100 524.2 16.100 524.2 16.500 502.2 16.800 524.2 17.700 524.2 20.000 524.2 15.100 502.2 16.200 524.2 16.500 502.2 16.800 524.2 17.900 524.2 20.300 524.2 15.300 524.2 16.200 524.2 16.600 524.2 16.900 502.2 17.900 other 15.400 524.2 16.300 524.2 16.600 502.2 17.000 502.2 18.100 Water Study: 41 True Value: 18.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 16.040 502.2 17.000 524.2 17.400 502.2 18.000 524.2 18.300 524.2 18.700 502.2 16.300 524.2 17.000 502.2 17.500 other 18.000 502.2 18.300 524.2 19.000 502.2 16.500 524.2 17.100 524.2 17.600 524.2 18.000 524.2 18.400 502.2 19.400 524.2 16.600 524.2 17.100 524.2 17.700 524.2 18.100 524.2 18.400 502.2 19.700 524.2 16.600 502.2 17.100 502.2 17.900 524.2 18.200 524.2 18.500 524.2 19.800 524.2 16.800 524.2 17.300 other 17.900 502.2 18.200 524.2 18.600 502.2 20.300 524.2 16.900 524.2 17.300 524.2 17.900 524.2 18.300 524.2 18.700

Benzo(a)pyrene Water Study: 26a True Value: 2.25 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.690 525 1.150 other 1.790 525 1.840 550 2.000 525 0.810 other 1.260 525 1.840 525 1.960 525 3.920 Water Study: 26b True Value: 15.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 10.500 525 13.200 525 14.000 550 15.000 525 16.310 other 30.400 525 11.800 other 14.000 other 14.900 525 15.300 525 18.900 525 76.000

## B-13 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 0.485 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 0.190 550 0.200 550 0.280 525 0.340 other 0.371 550 0.630 550.1 0.200 525 0.280 525 0.328 525 0.355 525 0.405 550 0.749 Water Study: 31 True Value: 0.202 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 550.1 0.100 other 0.180 550 0.209 550.1 0.231 525.1 0.690 525.1 0.160 525.1 0.182 550. 1 0.219 550 0.250 550 1.310 550 0.166 550.1 0.182 525.1 0.220 other 0.380 Water Study: 32 True Value: 0.337 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 550.1 0.015 525.1 0.210 525.1 0.228 525. 1 0.280 other 0.325 525.1 0.370 525.1 0.162 525.1 0.214 550 0.238 550 0.291 525.1 0.342 550.1 0.414 550.1 0.167 525.1 0.220 550 0.260 525. 1 0.304 other 0.353 525.1 0.450 550 0.197 other 0.220 525.1 0.264 550 0.310 other 0.360 550 1.380 525.1 0.204 550 0.220 525.1 0 .272 525.1 0.322 550 0.367 Water Study: 33 True Value: 1.29 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 0.200 525.1 0.688 other 0.930 550 1.083 525.1 1.310 other 1.800 525.1 0.300 525.1 0.690 525.1 0.930 550. 1 1.090 550.1 1.350 other 9.710 525.1 0.394 550.1 0.690 other 1 .020 525.1 1.110 550.1 1.370 525.1 0.620 525.1 0.851 525.1 1 .070 550.1 1.220 550.1 1.580 Water Study: 34 True Value: 0.751 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 0.090 525.1 0.442 other 0. 570 525.1 0.639 550 0.760 525.1 0.870 525.1 0.261 525.1 0.478 550 0.577 525.1 0.656 550 0.778 550.1 0.990 550 0.356 525.1 0.478 525.1 0.615 525. 1 0.678 other 0.796 550 1.524 525.1 0.416 525.1 0.560 525.1 0 .620 550.1 0.701 525.1 0.820 550.1 0.426 550.1 0.566 550.1 0. 637 other 0.728 525.1 0.870

## B-14 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 1.53 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 0.200 550.1 0.642 525.1 1.120 550 1.390 550.1 1.490 other 1.640 525.1 0.290 525.1 0.661 550.1 1.120 550. 1 1.402 525.1 1.500 other 2.400 550 0.407 525.1 0.711 525.1 1. 200 525.1 1.415 525.1 1.522 525.1 0.556 550.1 1.020 550 1. 201 550 1.460 other 1.530 550 0.611 525.1 1.100 525.1 1. 220 525.1 1.470 other 1.600 Water Study: 36 True Value: 0.636 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 0.040 525.1 0.358 550.1 0.440 other 0.500 550 0.546 525.2 0.626 525.2 0.162 525.2 0.360 525.2 0.460 550. 1 0.505 other 0.547 525.2 0.640 other 0.190 550.1 0.370 525.2 0.462 525.2 0.524 525.2 0.550 550.1 0.659 550.1 0.207 other 0.380 550 0.468 525.2 0.526 525.2 0.566 525.2 0.919 other 0.313 525.2 0.418 550 0.493 525.2 0.530 550.1 0.566 550.1 514.000 525.1 0.320 525.1 0.423 550.1 0 .495 other 0.534 550 0.590 525.2 0.338 550.1 0.427 550 0. 497 525.2 0.540 525.2 0.624 Water Study: 37 True Value: 0.937 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 550.1 0.084 525.2 0.505 550.1 0.636 525.2 0.732 550 0.807 525.2 1.290 550.1 0.172 525.2 0.506 525.2 0.638 525. 2 0.734 other 0.826 525.2 1.320 525.2 0.215 525.2 0.510 525.2 0 .663 525.2 0.740 525.2 0.860 525.1 0.243 550.1 0.536 550.1 0. 672 525.2 0.762 other 0.875 other 0.429 525.2 0.552 550.1 0 .682 525.2 0.768 525.2 0.910 550 0.478 550 0.566 550 0.698 525.2 0.790 525.2 0.910 550.1 0.504 other 0.572 525. 2 0.728 525.2 0.790 550 0.990 Water Study: 38 True Value: 0.527 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 550.1 0.045 525.2 0.350 525.2 0.388 525.2 0.480 550 0.536 525.2 0.648 525.2 0.119 550.1 0.355 525.2 0.393 550.1 0.480 525.2 0.541 550 0.716 525.2 0.158 525.1 0.360 525.2 0.406 525. 2 0.484 other 0.541 550.1 4.490 550 0.168 525.2 0.370 550 0.412 other 0.493 525.2 0.548 525.2 0.233 550 0.378 525.2 0. 422 525.2 0.510 550.1 0.550 525.2 0.290 550.1 0.380 525. 2 0.428 550 0.522 550 0.550 525.2 0.310 525.2 0.382 other 0 .462 525.2 0.530 525.2 0.636

## B-15 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 2.37 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 0.240 525.2 1.617 525.2 1.990 525.2 2.120 550.1 2.390 525.2 2.800 550.1 0.750 550 1.650 525.2 2. 010 550.1 2.140 525.2 2.420 550.1 1.190 525.2 1.700 525.2 2 .020 550 2.220 525.2 2.460 525.2 1.240 525.2 1.920 550 2. 060 525.2 2.270 525.2 2.510 550.1 1.330 550.1 1.970 525.2 2 .070 525.2 2.310 525.2 2.550 525.2 1.600 525.2 1.980 550 2. 090 525.2 2.320 525.2 2.660 Water Study: 40 True Value: 1.48 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.480 550 0.899 550 1.010 525. 2 1.220 525.2 1.370 525.2 1.520 525.2 0.550 550.1 0.912 525.2 1.130 550.1 1.280 550 1.400 525.2 1.732 550.1 0.614 550 0.941 525.2 1.170 550 1.280 525.2 1.440 525.2 5.700 525.2 0.710 550.1 0.951 other 1 .180 550.1 1.280 525.2 1.440 550 0.724 525.2 0.960 525.2 1. 190 525.2 1.320 550.1 1.470 525.2 0.779 525.2 0.970 525.2 1 .200 525.2 1.320 525.2 1.490 other 0.790 525.2 0.999 525.2 1 .210 525.2 1.340 550.1 1.490 550.1 0.800 550.1 1.000 525.2 1 .220 525.2 1.350 550 1.500 Water Study: 41 True Value: 2.37 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 550.1 0.190 525.2 1.340 550 1. 620 525.2 1.860 525.2 2.270 other 0.660 525.2 1.350 525.2 1 .640 525.2 1.880 525.2 2.400 550.1 0.990 550 1.490 525.2 1. 650 525.2 1.940 525.2 2.400 550.1 1.140 550 1.600 550.1 1. 670 525.2 2.000 other 2.660 525.2 1.320 525.2 1.610 525.2 1 .700 525.2 2.140 525.2 6.270

## B-16 Methods Support Document for Six-Year Review Final - March 2003 Beryllium Water Study: 24 True Value: 0.600 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7A 0.490 200.7A 0.560 210.1 0.600 210.2 0.615 210.2 0.660 210.2 0.700 210.2 0.500 210.2 0.590 210.2 0.600 210.2 0.620 210.1 0.675 200.7A 0.800 210.2 0.520 210.2 0.591 200.7A 0.600 210.2 0.643 210.2 0.690 210.2 0.800 210.2 0.540 200.7A 0.600 other 0.604 210.2 0.650 210.2 0.699 200.7A 1.000 210.2 0.540 200.7A 0.600 210.2 0.610 210. 1 0.650 210.1 0.700 other 1.000 210.2 0.560 210.1 0.600 210.2 0. 610 other 0.660 200.7A 0.700 Water Study: 25a True Value: 2.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7A 1.360 200.7A 1.900 200.7A 2.000 200.7A 2.000 210.2 2.050 210.2 2.130 200.7A 1.590 210.1 1.950 other 2.000 210.2 2.000 other 2.060 210.2 2.140 200.7A 1.900 200.7A 1.950 200.7A 2.000 210.2 2.000 210.2 2.100 210.2 2.160 200.7A 1.900 210.2 1.980 210.2 2.000 210.1 2.040 210.2 2.100 210.2 2.200 Water Study: 25b True Value: 0.400 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7A 0.300 210.1 0.346 other 0 .380 210.2 0.400 other 0.440 210.2 0.300 210.2 0.370 200.7A 0.390 200.7A 0.410 210.1 0.446 200.7A 0.300 210.2 0.374 200.7A 0.400 210.2 0.416 200.7A 0.500 210.2 0.330 210.2 0.379 210.2 0 .400 210.2 0.440 210.2 0.500 Water Study: 26a True Value: 0.530 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7A 0.400 210.2 0.500 210.2 0.520 210. 2 0.552 other 0.600 210.2 0.675 200.7A 0.430 200.7A 0.500 210.2 0.523 210.2 0.560 210.2 0.600 210.2 0.765 210.2 0.440 200.7A 0.500 210.2 0.529 210.2 0.560 210.2 0.610 200.7A 0.800 210.2 0.480 200.7A 0.500 210.2 0.530 200.7A 0.560 210.2 0.620 210.2 0.950 210.2 0.480 200.7A 0.500 200.7A 0.530 200.7A 0.569 210.2 0.636 210.2 7.600 210.2 0.490 200.7A 0.500 200.7A 0.550 210.2 0.588 210.2 0.638 200.7A 0.490 200.7A 0.516 210.2 0 .550 210.2 0.600 210.2 0.660

## B-17 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 23.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 210.2 2.000 200.7A 20.200 210.2 21.700 200.7A 22.000 210.2 22.800 200.7A 24.700 200.7A 13.000 200.7A 20.800 200.7A 21.700 210.2 22.300 200.7A 22.800 210.2 24.700 210.2 13.700 200.7A 21.000 210.2 21.800 210.2 22.300 210.2 22.900 210.2 24.800 210.2 18.700 200.7A 21.200 210.2 21.800 210.2 22.380 200.7A 23.000 210.2 26.000 other 19.100 210.2 21.200 210.2 21.900 other 22.400 200.7A 23.600 210.2 27.400 210.2 19.900 210.2 21.400 200.7A 22.000 200.7A 22.400 200.7A 23.600 210.2 30.000 200.7A 20.000 other 21.400 210.2 22.000 200.7A 22.400 210.2 24.000 210.2 20.000 200.7A 21.500 other 22.000 210.2 22.600 210.2 24.400 Water Study: 27 True Value: 4.67 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 304 2.610 other 4.000 200.7A 4.410 210.2 4.610 200.7A 4.900 200.8 5.150 210.2 3.400 other 4.200 200.7A 4.500 210.2 4.700 210.2 4.920 210.2 5.370 200.7A 3.790 200.7A 4.400 200.7A 4.550 200.7A 4.820 210.2 4.980 210.2 5.500 200.7A 3.930 200.7A 4.400 other 4.600 210.2 4.860 other 5.000 210.2 7.840 Water Study: 29 True Value: 9.76 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 210.2 7.700 other 9.000 other 9.300 210.2 9.920 200.7A 10.200 210.2 8.050 other 9.000 210.2 9 .400 200.7A 9.970 210.2 10.300 200.7A 8.120 210.2 9.080 200.7A 9.480 200.7A 10.000 210.2 10.900 210.2 8.220 200.7A 9.300 200.7A 9.500 200.7A 10.000 210.2 11.100 other 8.900 200.7A 9.300 210.2 9 .600 other 10.000 210.2 12.500 Water Study: 30 True Value: 8.47 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 210.2 4.720 200.7 7.690 other 8.000 200.7 8.250 210.2 8.500 210.2 9.200 200.7 6.000 200.7 7.700 200.7 8.000 200. 7 8.270 other 8.500 210.2 9.200 200.9 7.050 210.2 7.700 210.2 8.060 200.7 8.300 200.7 8.600 210.2 9.690 200.7 7.120 200.7 7.760 210.2 8.070 200.7 8.300 210.2 8.670 210.2 9.700 210.2 7.200 210.2 7.800 200.7 8 .100 210.2 8.400 200.7 8.700 210.2 7.310 200.7 7.900 210.2 8 .165 210.2 8.400 210.2 8.800 200.7 7.400 200.9 7.900 200.7 8 .200 200.9 8.400 210.2 8.800 200.9 7.600 210.2 7.900 200.8 8 .200 210.2 8.450 200.7 8.920 200.7 7.680 210.2 7.920 200.7 8 .210 200.7 8.500 210.2 9.100

## B-18 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 3.27 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 2.450 200.7 3.030 210.2 3.200 210.2 3.210 200.7 3.300 200.7 3.450 210.2 2.920 210.2 3.030 other 3.200 200.9 3.250 200.7 3.300 200.9 3.500 200.7 2.940 210.2 3.050 200.7 3.200 210.2 3.270 210.2 3.322 210.2 3.900 200.9 2.950 210.2 3.100 210.2 3 .200 200.9 3.280 200.7 3.370 200.7 2.990 200.7 3.100 200.7 3 .200 200.7 3.300 210.2 3.400 210.2 3.000 200.7 3.190 200.7 3 .200 200.7 3.300 200.9 3.400 Water Study: 32 True Value: 0.933 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.570 200.9 0.849 200.7 0.900 210.2 0.9500 210.2 0.997 200.7 1.140 other 0.750 210.2 0.850 200.7 0.918 200.7 0.950 210.2 1.000 200.9 1.156 200.7 0.761 210.2 0.851 200.7 0.920 210.2 0.953 210.2 1.000 200.7 1.180 210.2 0.770 210.2 0.870 200.9 0.920 200.9 0.955 200.7 1.020 200.7 1.300 210.2 0.798 200.9 0.870 200.8 0.924 210.2 0.960 210.2 1.020 200.7 1.700 200.9 0.800 200.7 0.890 210.2 0.930 200.8 0.960 200.9 1.040 200.7 1.930 200.7 0.800 210.2 0.890 200.9 0.930 210.2 0.970 210.2 1.050 210.2 2.200 200.7 0.820 200.7 0.890 210.2 0.935 210.2 0.970 200.7 1.060 200.9 9.000 210.2 0.829 200.7 0.900 210.2 0.940 210.2 0.973 200.7 1.090 200.7 9.980 other 0.835 200.7 0.900 210.2 0.941 200.9 0.979 210.2 1.100 200.7 92.300 Water Study: 33 True Value: 9.07 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 5.780 200.7 7.880 200.7 8.400 200.9 8.640 200.7 8.990 210.2 9.500 200.7 7.000 200.7 7.950 other 8.400 200.7 8.690 200.9 9.000 210.2 9.630 210.2 7.400 200.7 8.000 210.2 8.440 200.7 8.700 210.2 9.000 210.2 9.675 200.9 7.400 210.2 8.100 200.9 8.450 210.2 8.700 200.9 9.150 210.2 9.700 200.8 7.520 210.2 8.100 200.7 8.530 200.7 8.740 200.9 9.270 210.2 14.690 210.2 7.750 200.7 8.100 200.7 8 .570 200.7 8.900 200.7 9.350 other 7.790 210.2 8.400 200.7 8 .580 210.2 8.900 200.7 9.410

## B-19 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 5.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 3.680 210.2 4.850 200.9 5.000 200.7 5.100 210.2 5.170 210.2 5.270 200.7 3.920 200.7 4.860 210.2 5.000 200.7 5.100 210.2 5.190 200.9 5.270 210.2 4.200 200.9 4.880 other 5.000 210.2 5.100 200.7 5.190 210.2 5.300 200.7 4.310 200.7 4.900 200.9 5.000 210.2 5.100 200.7 5.200 200.7 5.330 200.8 4.410 200.7 4.900 200.7 5.010 200. 7 5.100 210.2 5.200 other 5.330 other 4.600 200.7 4.900 200.7 5.020 other 5.100 200.8 5.200 200.9 5.400 200.8 4.680 210.2 4.920 200.7 5.040 210.2 5.100 210.2 5.200 210.2 5.410 210.2 4.720 200.9 4.930 210.2 5.060 200.7 5.103 200.7 5.200 210.2 5.420 200.7 4.730 200.7 4.940 210.2 5.090 200.7 5.120 200.8 5.213 200.7 5.480 210.2 4.850 200.7 4.970 200.7 5.100 200.9 5.130 200.7 5.260 200.7 10.200 Water Study: 35 True Value: 1.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.8 1.000 210.2 1.210 200.7 1.290 200.9 1.310 200.7 1.390 210.2 1.500 200.9 1.040 210.2 1.210 200.9 1.290 210.2 1.310 200.9 1.400 200.7 1.500 200.9 1.100 200.9 1.240 200.7 1.300 210.2 1.310 210.2 1.420 200.9 1.520 210.2 1.140 210.2 1.250 200.7 1.300 210.2 1.340 200.9 1.430 210.2 1.580 200.9 1.200 200.7 1.260 200.7 1.300 200. 8 1.350 210.2 1.430 other 1.700 210.2 1.200 210.2 1.270 200.7 1.300 200. 7 1.350 200.7 1.450 other 1.700 200.7 1.200 210.2 1.280 200.7 1.300 200.7 1.370 200.9 1.470 200.7 2.000 Water Study: 36 True Value: 7.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 210.2 5.200 200.8 7.020 3113B 7.340 200. 8 7.490 200.7 7.660 other 8.130 200.9 5.840 other 7.080 200.8 7. 340 200.9 7.500 200.7 7.720 3113B 8.170 200.7 5.900 200.7 7.150 200.8 7.370 other 7.500 200.7 7.730 210.2 8.300 200.9 6.700 200.7 7.150 200.9 7. 380 200.7 7.500 3113B 7.800 3113B 8.310 3113B 6.780 200.7 7.160 200.7 7.390 200.9 7.510 200.8 7.800 3113B 8.500 200.7 6.780 200.9 7.200 200.7 7.400 200.7 7.520 3113B 7.810 200.9 8.500 200.8 6.880 200.7 7.230 200.9 7 .400 200.7 7.525 200.8 7.900 200.7 6.900 200.8 7.290 200. 8 7.400 3113B 7.550 3113B 7.950 200.9 6.940 other 7.300 200.7 7 .450 200.9 7.560 200.9 8.000 200.8 6.970 200.9 7.300 200.7 7 .460 200.7 7.570 200.7 8.000 200.7 7.000 200.7 7.320 200.7 7 .470 200.9 7.590 200.7 8.050

## B-20 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 4.26 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 1.000 3113B 4.120 200.9 4.200 200. 7 4.270 200.7 4.400 200.8 4.600 200.7 3.700 200.9 4.120 200.9 4.200 200.7 4.270 200.7 4.400 200.8 4.630 200.9 3.750 200.8 4.130 200.7 4. 200 3113B 4.300 200.7 4.420 3113B 4.690 200.7 3.880 200.7 4.130 200.9 4.200 3113B 4.310 200.7 4.420 200.7 4.780 200.7 3.970 200.9 4.160 200.7 4 .200 200.9 4.320 200.9 4.450 200.7 4.000 200.9 4.170 200.9 4 .230 200.8 4.320 200.9 4.480 3113B 4.040 200.9 4.190 200.8 4. 240 200.7 4.350 200.9 4.500 200.7 4.090 200.7 4.200 200.7 4 .250 200.8 4.350 200.9 4.550 200.8 4.100 200.7 4.200 200.7 4 .260 200.9 4.350 3113B 4.550 Water Study: 38 True Value: 10.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 2.620 200.8 9.550 200.7 9.800 200.9 9.990 200.7 10.100 200.7 11.000 200.9 5.140 200.9 9.600 200.7 9.800 200. 7 9.996 200.8 10.300 other 11.000 200.9 7.680 200.9 9.600 200.9 9.800 200.9 10.000 200.8 10.300 200.7 11.000 200.7 8.880 3113B 9.630 200.7 9.850 200.8 10.000 3113B 10.400 200.9 11.600 200.9 9.060 200.7 9.630 200.7 9.850 200.7 10.000 200.7 10.500 200.9 11.600 200.7 9.120 200.8 9.650 200.9 9.880 200.8 10.000 200.7 10.500 3113B 12.300 200.8 9.210 200.7 9.700 200.9 9.880 200.7 10.100 200.9 10.500 200.7 15.200 200.8 9.360 200.9 9.750 200.8 9.900 200.7 10.100 200.8 10.600 200.9 34.400 200.9 9.400 200.7 9.760 200.9 9 .910 200.7 10.100 200.9 10.800 200.7 9.400 other 9.790 200.7 9 .920 200.8 10.100 other 10.800 200.8 9.400 200.7 9.800 200.8 9 .950 3113B 10.100 200.8 11.000 Water Study: 39 True Value: 1.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 1.000 200.9 1.100 200.9 1.190 3113B 1.210 200.8 1.280 200.7 1.370 200.7 1.000 200.7 1.110 200.7 1.190 200.9 1.210 200.8 1.280 200.9 1.430 200.9 1.000 200.9 1.120 200.9 1.200 3113B 1.210 200.9 1.290 200.8 1.470 200.7 1.050 200.9 1.140 200.7 1.200 200.9 1.210 3113B 1.300 200.7 1.580 200.7 1.060 200.7 1.150 200.9 1.200 200.7 1.220 200.9 1.300 200.7 1.600 200.9 1.070 200.9 1.160 200.8 1.200 200.8 1.230 200.7 1.300 200.7 1.730 200.7 1.100 200.9 1.180 3113B 1. 200 200.8 1.230 200.9 1.320 200.7 1.100 200.9 1.180 200.7 1 .200 200.7 1.240 3113B 1.330 3113B 1.100 200.9 1.190 200.8 1. 200 200.8 1.270 200.9 1.350

## B-21 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 6.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 3113B 2.900 3113B 6.250 200.8 6.420 200. 7 6.500 200.9 6.600 200.8 6.980 200.7 5.500 200.9 6.290 200.9 6.430 200.8 6.500 3113B 6.630 200.8 6.990 200.8 5.600 200.8 6.290 200.8 6.450 200. 9 6.510 other 6.650 200.9 7.000 200.7 5.700 200.7 6.290 200.9 6.450 200.8 6.520 200.7 6.650 200.7 7.140 200.7 6.000 200.7 6.300 200.7 6.470 other 6.520 200.8 6.650 200.8 7.310 3113B 6.090 200.9 6.330 200.8 6.470 200. 7 6.530 200.7 6.690 200.7 7.350 200.7 6.140 200.7 6.350 200.7 6.480 200.7 6.550 200.9 6.700 3113B 7.660 200.7 6.150 200.9 6.370 200.9 6.480 3120B 6.560 200.9 6.720 200.9 7.840 other 6.200 200.8 6.400 200.8 6. 480 3113B 6.570 200.9 6.870 200.9 8.000 200.7 6.240 200.9 6.400 200.8 6 .490 200.7 6.580 200.8 6.900 200.7 6.250 200.8 6.400 200.7 6 .500 3113B 6.580 200.8 6.971 Water Study: 41 True Value: 2.58 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.8 2.180 200.9 2.500 200.7 2.600 200.7 2.650 200.8 2.780 200.7 2.820 3113B 2.420 200.9 2.500 200.8 2.600 200. 7 2.670 200.8 2.780 200.9 2.830 3120B 2.420 200.7 2.510 200.7 2.640 200.9 2.700 200.9 2.790 3113B 2.830 200.7 2.440 200.9 2.540 3113B 2.640 200. 9 2.700 200.7 2.800 200.9 3.000 200.7 2.460 200.8 2.560 200.8 2.640 200.7 2.700 200.7 2.800 200.7 3.050 200.7 2.460 200.8 2.560 200.9 2.640 200.7 2.700 200.9 2.800 200.9 5.020 200.8 2.470 200.8 2.590 200.9 2 .650 200.9 2.740 200.7 2.800 200.9 2.500 200.9 2.600 200.9 2. 650 200.8 2.760 other 2.800

Bis(2-ethylhexyl)phthalate Water Study: 24a True Value: 3.18 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 2.430 525 3.880 other 6.360 other 8.950 other 19.000 525 2.640 525 4.100 525 7.770 525 10.260 other 19.600 525 3.080 525 5.860 525 8.300 other 12.300

## B-22 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24b True Value: 19.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 12.000 other 14.600 other 16.000 525 17.500 525 21.900 525 13.200 525 15.000 525 16.700 525 18.500 525 27.200 other 14.000 525 15.200 525 17.000 other 20.500 other 42.000 Water Study: 26a True Value: 34.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 17.200 525 21.000 525 30.900 other 39.400 other 70.300 525 20.000 other 27.300 525 33.200 525 47.400 other 20.600 other 29. 700 525 38.260 other 60.000 Water Study: 26b True Value: 7.73 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 4.060 other 6.840 525 8. 180 525 12.450 other 25.600 other 6.570 525 7.030 525 8.440 525 14.000 other 6.840 other 8. 040 525 9.390 other 20.000 Water Study: 27 True Value: 17.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 6.180 525 11.000 525 13.000 other 18.100 525 9.990 525 12.200 525 14.900 Water Study: 29 True Value: 4.58 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 2.200 525 2.740 525 3.000 525 7.700 525 2.460 525 2.910 525 4.010 525 17.800 Water Study: 30 True Value: 6.40 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 1.730 525 5.350 other 5. 920 other 9.300 506 12.300 525 4.230 other 5.400 525 6. 060 525 9.900 other 12.600 506 4.610 525 5.800 525 6.430 525 11.100 525 14.300

## B-23 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 11.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 3.680 other 7.400 525.1 8. 750 525.1 9.870 525.1 10.600 506 12.710 525.1 5.567 525.1 7.910 506 8.780 525.1 10.000 other 12.000 other 13.500 Water Study: 32 True Value: 9.28 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 4.200 525.1 7.330 525.1 8.360 other 9.110 525.1 9.590 525.1 14.600 506 4.310 other 7.460 525.1 8.670 525.1 9.190 525.1 11.400 525.1 43.500 other 4.650 525.1 7.540 525.1 8 .950 525.1 9.320 other 12.800 525.1 4.880 525.1 8.000 525.1 8 .990 525.1 9.400 525.1 12.900 525.1 5.980 506 8.020 525.1 9 .035 506 9.560 525.1 12.900 Water Study: 33 True Value: 15.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 506 3.430 506 9.210 525.1 13.760 525.1 14.900 other 18.400 525.1 21.670 506 4.050 525.1 10.900 525.1 14.100 525.1 15.610 other 18.500 other 25.700 506 8.370 other 11.800 525.1 14.100 525.1 16.300 525.1 19.200 525.1 31.000 525.1 8.950 525.1 12.600 525.1 14.400 506 16.400 525.1 20.160 Water Study: 34 True Value: 21.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 7.400 525.1 16.300 525.1 19.700 506 22.000 525.1 24.600 506 10.200 525.1 18.000 525.1 20. 200 525.1 23.250 525.1 27.180 525.1 12.600 525.1 18.100 506 20. 200 525.1 23.600 525.1 27.200 525.1 13.400 525.1 18.400 525.1 20.200 525.1 24.000 506 30.000 506 13.800 506 19.100 525.1 20. 200 525.1 24.100 525.1 31.800 525.1 14.900 525.1 19.200 other 20.500 525.1 24.500 525.1 42.700 other 15.700 525.1 19.600 525.1 20.900 Water Study: 35 True Value: 37.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 16.200 525.1 29.600 525.1 40. 650 other 44.900 525.1 48.000 506 22.150 525.1 36.600 525.1 41. 200 525.1 45.860 other 49.000 506 23.600 525.1 36.750 506 43. 200 525.1 45.900 525.1 59.400 525.1 27.450 525.1 37.500 525.1 43. 900 other 46.700 other 65.000

## B-24 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 18.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 1.240 525.1 13.600 506 16.600 525. 2 17.900 525.2 19.600 525.2 21.800 other 5.090 525.2 14.200 525.2 16. 800 525.2 18.000 525.2 19.700 506 23.400 506 8.800 525.2 14.400 525.2 17.200 other 18.900 525.2 20.000 506 27.600 506 9.840 506 14.400 506 17.400 525.2 18.900 525.2 20.600 525.1 29.300 525.2 11.100 525.2 15.600 other 17.700 525.2 19.100 506 20.600 525.2 12.400 506 15.800 525.2 17. 800 525.2 19.100 525.2 21.000 other 13.600 other 16.300 other 17.830 525.2 19.200 525.2 21.500 Water Study: 37 True Value: 21.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 5.100 525.2 14.700 525.2 19.900 525.2 20.900 525.2 22.800 525.2 26.600 506 9.350 506 16.600 525.2 20.300 other 21.000 525.2 22.900 525.2 31.500 525.2 11.510 525.2 18.800 525.2 20.550 525.2 21.100 525.2 24.100 525.2 35.600 506 12.000 525.2 19.000 506 20. 600 506 21.800 other 24.600 525.1 13.500 506 19.200 525.2 20. 600 525.2 22.200 525.2 24.700 other 14.260 other 19.400 525. 2 20.700 525.2 22.700 525.2 25.200 Water Study: 38 True Value: 13.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 4.410 525.2 12.300 525.2 13.200 525.2 14.200 525.2 15.900 525.2 18.100 525.2 6.370 525.2 12.500 525.2 13.600 525.2 14.700 525.2 16.800 525.2 18.500 other 9.710 other 12.700 525.2 13.600 525.2 14.800 525.2 16.800 other 20.610 506 10.500 525.2 12.700 506 13.600 525.2 15.000 other 17.300 525.2 24.800 525.2 10.600 506 12.800 525.2 13.900 525. 2 15.300 525.2 17.400 525.2 25.900 525.2 12.000 525.2 13.030 506 14. 000 other 15.500 506 18.100 Water Study: 39 True Value: 27.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 17.200 506 24.300 525.2 25.800 506 29.500 525.2 38.400 525.2 42.400 506 20.000 525.2 24.500 525.2 27. 400 525.2 30.600 525.2 39.100 525.2 20.300 525.2 24.700 525.2 28.400 525.2 30.900 525.2 39.600 525.2 22.640 525.2 25.400 525.2 29.400 525.2 30.900 525.2 40.900 525.2 23.700 525.2 25.600 525.2 29.500 525.2 36.500 506 41.900

## B-25 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 32.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 506 1.950 506 22.400 506 27.300 525.2 30.600 525.2 35.780 525.2 42.900 525.2 8.250 525.2 23.380 525.2 27.400 525.2 30.800 525.2 35.900 525.2 52.200 525.2 12.100 525.2 24.300 525.2 28.000 525.2 31.500 525.2 35.900 525.2 65.400 other 17.100 525.2 25.800 525.2 28.300 525.2 32.500 525.2 36.600 other 19.300 525.2 26.800 525.2 28. 300 other 32.600 other 40.200 525.2 19.500 525.2 27.100 525.2 28.400 506 33.400 525.2 40.800 525.2 20.300 506 27.300 525.2 29.200 506 34.800 525.2 41.000 Water Study: 41 True Value: 15.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 506 6.000 525.2 13.400 other 14.800 525.2 16.700 525.2 20.300 506 9.780 525.2 14.090 525.2 14. 800 525.2 17.200 525.2 21.100 525.2 12.200 525.2 14.500 525.2 15.200 525.2 18.100 525.2 24.300 525.2 12.300 525.2 14.700 506 15. 600 525.2 19.400 525.2 25.700 525.2 13.040 525.2 14.700 525.2 16.000 525.2 20.100 525.2 42.000

Cadmium Water Study: 24a True Value: 15.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 11.600 213.1 14.800 200.7A 15.100 213.1 15.600 213.2 16.350 213.2 17.800 213.1 13.400 200.7A 14.800 213.2 15.200 213.1 15.700 213.2 16.400 213.2 18.500 213.2 13.600 200.7A 14.800 213.2 15.200 213. 2 15.700 other 16.500 213.2 19.400 213.2 14.400 200.7A 14.900 200.7A 15.200 other 15.800 213.1 16.500 213.2 19.500 213.1 14.400 213.2 15.000 213.2 15.200 213.2 15.900 213.2 16.500 213.2 20.000 213.2 14.500 200.7 15.000 213.1 15.300 213.2 15.900 213.2 16.500 213.2 168.000 213.2 14.600 213.1 15.000 200.7A 15.300 213.1 16.000 213.2 16.600 200.7A 14.600 200.7A 15.000 200.7A 15.400 213.2 16.000 213.2 17.100 213.2 14.600 213.2 15.000 213.1 15.400 213.2 16.000 213.2 17.200 213.2 14.700 213.2 15.000 other 15.500 213.2 16.000 213.2 17.300 213.2 14.700 213.2 15.100 213.2 15. 500 other 16.100 213.2 17.600

## B-26 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24b True Value: 10.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 9.200 213.2 9.840 213.1 10.100 213.2 10.300 213.1 10.800 213.2 11.500 213.1 9.220 213.1 10.000 other 10.100 213.1 10.400 213.2 10.800 213.2 11.800 200.7A 9.300 213.2 10.000 200.7A 10.100 213. 2 10.500 other 10.800 213.2 12.200 213.2 9.370 200.7A 10.000 213.2 10.200 213.2 10.500 213.2 11.000 213.2 13.200 213.1 9.420 other 10.000 213.1 10.200 213.2 10.500 213.1 11.000 213.2 14.100 213.2 9.500 213.2 10.000 200.7A 10.200 213.2 10.500 213.2 11.000 213.2 39.000 213.2 9.540 213.1 10.000 200.7A 10.200 213.2 10.500 213.2 11.000 213.2 9.660 200.7A 10.000 213.2 10.200 213.1 10.600 213.2 11.000 213.2 9.750 213.2 10.000 213.2 10.200 200.7A 10.600 213.2 11.100 200.7A 9.800 other 10.100 213.2 10.200 213.2 10.600 213.2 11.200 213.2 9.800 200.7A 10.100 213.2 10.300 200.7A 10.700 213.2 11.400 Water Study: 25 True Value: 27.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 22.500 213.2 25.000 213.2 26.800 213.2 27.600 213.2 28.000 213.2 31.000 213.2 23.500 213.1 25.100 213.2 26.900 other 27.800 200.7 28.100 213.2 31.600 213.2 24.500 200.7 26.000 213.2 27.000 200.7 27.900 213.2 29.000 213.2 31.700 213.2 24.500 213.2 26.000 213.1 27.000 213.2 27.900 213.2 29.600 213.2 31.800 213.2 24.500 213.1 26.400 213.2 27.000 213.2 28.000 213.2 29.900 213.2 32.100 200.7 25.000 213.2 26.600 213.2 27.000 213.1 28.000 213.2 30.000 213.2 25.000 213.2 26.700 213.2 27.400 213.2 28.000 200.7 30.900 Water Study: 26a True Value: 53.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 42.000 213.1 49.600 200.7 51.830 213.2 53.100 213.2 54.100 213.2 57.700 213.2 44.100 213.2 49.800 other 52.000 213.2 53.200 other 54.100 213.2 58.800 213.2 44.400 213.2 50.000 200.7 52.000 213.2 53.300 213.2 54.200 213.1 59.000 213.2 44.500 213.1 50.400 213.1 52.300 213.2 53.400 213.2 54.200 200.7 60.000 213.2 45.000 213.2 50.600 other 52.400 213.1 53.400 213.1 54.300 213.2 60.000 213.2 46.100 200.7 51.000 213.2 52.500 200.7 53.700 200.7 54.300 213.2 60.000 213.2 47.800 213.2 51.000 213.2 52.500 213.1 53.700 200.7 56.100 213.2 67.900 213.2 48.000 200.7 51.000 213.2 52. 600 213.2 53.800 other 56.100 213.2 48.000 other 51.400 213.2 52.600 213.1 53.900 200.7 56.200 other 48.000 213.1 51.600 200.7 52.800 213.1 54.000 200.7 56.900 213.2 48.400 213.1 51.600 213.2 52.800 213.2 54.000 200.7 57.500

## B-27 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 9.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 6.450 213.2 8.720 213.2 9.000 213.1 9.300 213.2 9.630 213.2 10.800 200.7 6.700 other 8.800 213.1 9.020 other 9.300 213.2 9.700 213.2 10.800 213.2 7.420 213.1 8.800 213.2 9.100 213.2 9.320 213.2 9.700 213.1 10.900 213.2 7.860 213.2 8.860 213.2 9.150 213.1 9.320 200.7 9.800 213.1 11.000 213.2 8.080 213.2 8.900 213.2 9.180 200. 7 9.400 213.2 9.810 other 11.200 213.2 8.250 200.7 8.900 200.7 9.200 213.2 9.400 213.2 10.000 213.2 11.900 213.1 8.400 213.1 8.970 200.7 9.250 200.7 9.400 200.7 10.000 200.7 12.000 213.2 8.430 200.7 8.970 213.1 9 .250 213.2 9.400 213.2 10.100 213.2 8.550 other 9.000 213.2 9 .250 213.2 9.430 213.2 10.200 213.1 8.600 213.2 9.000 213.1 9 .250 213.2 9.600 213.2 10.400 other 8.700 213.2 9.000 200.7 9 .300 other 9.620 200.7 10.800 Water Study: 27 True Value: 29.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 20.400 213.2 27.700 200.7 28.500 213.2 29.600 200.7 30.000 213.2 33.000 213.2 26.000 213.2 27.700 213.2 29.000 213.2 29.600 213.2 30.300 213.2 33.000 other 26.100 213.2 27.700 213.2 29.000 213.2 29.700 200.7 30.400 213.2 34.700 200.7 26.700 200.7 28.000 213.2 29.000 200.7 29.800 213.2 30.700 213.2 36.800 213.2 26.900 213.1 28.000 213.2 29.200 200.7 29.800 213.2 30.900 213.2 158.000 213.2 27.060 213.2 28.000 200.7 29.200 213.1 30.000 200.7 30.940 213.2 27.600 other 28.400 213.2 29.400 213.1 30.000 213.2 31.200 Water Study: 29 True Value: 2.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 2.000 200.7 2.600 213.2 2.750 213.2 2.875 213.2 2.910 213.2 3.110 213.2 2.200 other 2.650 213.2 2.780 200.7 2.900 213.2 2.930 213.2 3.300 other 2.200 213.2 2.670 other 2. 800 213.2 2.900 213.2 3.000 213.2 3.400 other 2.300 213.1 2.690 213.1 2.810 other 2.900 213.2 3.000 other 191.000 200.7 2.410 213.2 2.720 200.7 2 .860 213.2 2.900 213.2 3.090 213.2 2.500 213.2 2.740 213.2 2 .870 213.2 2.900 213.2 3.100

## B-28 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 39.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 32.000 213.1 37.000 other 37. 800 200.7 39.000 213.2 40.000 213.2 41.700 213.2 32.000 213.1 37.000 213.2 37.900 213.1 39.000 213.2 40.100 213.2 41.700 213.2 32.100 213.1 37.000 213.2 38.000 200.7 39.200 213.2 40.100 213.1 41.700 213.2 32.500 200.7 37.190 other 38.000 213.2 39.200 213.2 40.160 213.2 42.000 213.1 33.000 200.7 37.200 213.2 38.100 200.7 39.200 213.2 40.300 213.1 42.000 200.7 35.000 213.2 37.400 213.2 38.500 213.1 39.400 200.7 40.500 213.1 42.000 213.2 35.000 200.7 37.500 200.7 38.600 200. 7 39.500 213.2 40.800 other 42.000 213.2 35.500 213.1 37.500 213.2 38.700 other 39.500 213.1 41.000 213.2 42.190 213.2 36.000 200.7 37.500 213.2 38.800 200.7 39.600 213.2 41.070 213.2 42.300 213.2 36.800 200.7 37.600 213.2 38.900 213.2 39.900 200.7 41.200 213.2 45.700 213.1 36.900 213.2 37.800 other 39.000 213.1 40.000 200.7 41.300 200.7 47.200 Water Study: 31 True Value: 12.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 7.080 213.2 11.600 213.2 12.200 200.7 12.900 213.2 13.000 213.2 13.600 213.2 9.990 213.2 11.950 200.7 12.300 213.2 12.900 213.2 13.000 213.1 14.200 213.2 10.500 213.1 12.000 213.2 12.500 213. 2 12.930 other 13.000 213.2 14.200 213.2 11.300 213.2 12.000 213.2 12.500 213. 2 13.000 213.2 13.400 other 14.500 other 11.400 213.2 12.080 213.2 12.700 200.7 13.000 200.7 13.400 213.2 15.800 213.2 11.500 213.1 12.200 other 12. 700 other 13.000 other 13.500 Water Study: 32 True Value: 4.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 3.970 213.2 4.540 200.7 4.740 213.2 4.900 213.2 5.040 213.2 5.690 213.2 4.200 other 4.570 213.2 4.740 200.7 4.900 213.2 5.050 other 5.690 213.2 4.200 213.2 4.590 other 4.740 200.7 4.900 213.2 5.080 213.2 5.700 213.1 4.220 213.2 4.600 213.2 4.750 213.2 4.920 213.2 5.103 200.7 5.770 213.2 4.280 200.7 4.600 213.2 4.760 213.1 4.980 213.2 5.170 213.2 6.030 200.7 4.370 213.2 4.640 213.2 4.770 213.2 4.990 200.7 5.200 213.2 7.300 213.2 4.400 213.2 4.690 213.2 4.790 213. 2 5.000 other 5.200 213.2 7.500 213.2 4.430 213.2 4.690 213.2 4 .790 200.7 5.000 213.2 5.200 213.2 4.490 213.2 4.700 200.7 4 .800 213.2 5.000 213.2 5.300 213.2 4.500 213.2 4.700 213.2 4 .820 213.2 5.000 200.7 5.370 213.2 4.500 213.2 4.700 200.7 4 .880 213.2 5.000 213.2 5.400 213.2 4.500 213.2 4.730 200.7 4. 880 other 5.000 200.7 5.530

## B-29 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 49.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 41.700 213.2 46.500 other 47.700 213.2 48.580 other 49.000 213.2 51.200 200.7 44.700 other 46.800 213.2 47.800 other 48.700 213.2 49.000 200.7 54.700 213.2 45.000 200.7 47.000 200.7 47.900 213.2 48.700 200.7 49.100 213.2 59.800 200.7 45.500 3113B 47.000 200.7 48. 000 other 48.800 213.2 49.200 other 45.900 200.7 47.000 other 48.000 213.2 49.000 213.2 49.400 213.2 46.000 213.2 47.400 200.7 48.300 213.2 49.000 213.2 50.000 213.2 46.300 200.7 47.600 213.2 48. 500 213.1 49.000 other 51.200 Water Study: 34 True Value: 23.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 213.2 16.700 other 22.000 213.2 22.400 200.7 22.900 213.2 23.600 200.7 24.300 213.2 19.300 200.7 22.000 213.1 22.500 213. 2 22.900 other 23.700 200.7 24.300 213.2 19.600 213.2 22.000 213.2 22.500 other 23.000 213.2 23.700 213.2 24.500 200.7 20.000 200.7 22.000 other 22.500 213.2 23.000 213.2 23.700 213.2 24.500 213.2 20.700 213.2 22.000 200.7 22.500 213.2 23.000 200.7 23.900 213.2 24.600 213.2 21.500 213.2 22.100 other 22.600 213.2 23.100 200.7 23.900 213.2 25.000 213.2 21.600 213.2 22.100 213.2 22.600 other 23.110 213.2 23.900 213.2 25.200 200.7 21.700 other 22.100 213.2 22.620 213.2 23.200 213.2 24.000 213.2 26.200 other 21.700 213.2 22.100 200.7 22.700 200.7 23.300 200.7 24.000 213.2 27.200 213.2 21.900 200.7 22.200 213.2 22.700 other 23.400 200.7 24.000 200.7 47.400 213.2 21.900 213.2 22.400 200.7 22.900 200.7 23.500 200.7 24.200 Water Study: 35 True Value: 2.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 3113B 1.800 200.7 2.650 213.2 2.720 213. 2 2.890 200.7 3.000 200.7 3.280 200.7 2.100 3113B 2.650 213.2 2.740 213.2 2 .890 other 3.000 other 3.300 200.7 2.210 213.2 2.660 213.2 2.750 213.2 2.900 213.2 3.050 213.2 3.860 other 2.560 213.2 2.670 other 2.800 213.2 2.930 other 3.090 other 27.300 213.2 2.600 213.2 2.700 213.2 2 .800 213.2 2.960 200.7 3.090 213.2 2.600 other 2.700 213.2 2 .850 213.2 3.000 other 3.110 213.2 2.620 other 2.700 213.2 2 .860 213.2 3.000 213.2 3.160

## B-30 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 34.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 29.400 200.8 32.800 3113B 33.600 200.8 34.300 3113B 35.100 200.7 36.000 3113B 30.000 200.9 32.800 3113B 33.700 200. 9 34.400 200.7 35.400 200.8 36.000 200.7 30.000 3113B 33.000 200.9 33.700 200. 7 34.400 213.2 35.400 other 36.300 other 30.800 200.7 33.000 200.8 33. 700 213.2 34.400 3113B 35.400 3113B 36.400 3113B 31.300 200.9 33.000 3113B 33.900 3113B 34.500 3113B 35.400 200.7 36.500 200.8 32.000 213.2 33.300 213.2 34.000 200.7 34.500 200.7 35.600 3113B 36.500 3113B 32.100 other 33.300 200.7 34.100 200. 7 34.700 200.9 35.600 other 36.500 200.7 32.200 200.8 33.400 200.9 34.100 200.9 34.700 200.7 35.800 200.7 36.900 other 32.200 3113B 33.400 200.7 34.100 3113B 34.800 200.7 35.900 200.9 37.000 200.8 32.300 200.7 33.500 200.8 34.100 200.7 34.800 200.7 36.000 200.9 38.300 200.7 32.700 3113B 33.500 200.7 34.200 200. 8 34.900 200.7 36.000 213.2 56.300 Water Study: 37 True Value: 10.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 3113B 5.350 200.7 9.210 200.9 9.550 200. 7 9.830 200.9 10.100 200.9 10.300 3113B 8.310 200.7 9.340 3113B 9.560 3113B 9.860 200.8 10.100 200.9 10.300 200.9 8.600 200.9 9.430 200.7 9.600 200.8 9.880 3113B 10.100 200.7 10.700 3113B 8.950 200.7 9.480 200.7 9.630 other 9.900 200.8 10.100 200.9 10.800 200.9 8.990 200.8 9.480 200.9 9.650 200.9 9.900 3113B 10.100 200.7 10.900 200.9 9.000 3113B 9.500 200.9 9.680 200.9 9.980 3113B 10.200 200.7 11.100 200.7 9.050 200.9 9.520 200.7 9 .700 200.9 10.000 200.7 10.200 200.7 9.100 200.8 9.540 200.7 9 .700 200.7 10.000 200.8 10.200 213.2 9.110 200.9 9.540 200.8 9 .800 200.9 10.000 3113B 10.300 Water Study: 38 True Value: 2.12 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 1.100 200.9 1.950 200.8 2.040 3113B 2.110 200.8 2.180 200.9 2.480 3113B 1.170 200.9 1.960 200.9 2.040 200.8 2.130 3113B 2.180 200.9 2.560 200.9 1.800 200.7 1.980 200.8 2.050 200.7 2.130 200.8 2.200 200.7 2.650 200.9 1.800 200.7 2.000 200.8 2.070 200.8 2.140 200.9 2.200 200.7 2.660 200.8 1.810 200.9 2.000 200.7 2.090 200.9 2.150 3113B 2.250 other 2.890 200.9 1.840 200.8 2.000 200.7 2.100 200.9 2.150 200.7 2.300 3113B 3.150 3113B 1.877 3113B 2.000 200.7 2.100 3113B 2.150 200.8 2.300 200.7 3.460 3113B 1.880 200.8 2.000 200.8 2. 100 200.9 2.160 200.7 2.300 200.9 1.900 200.8 2.000 200.9 2. 100 200.7 2.160 other 2.300 200.9 1.900 200.9 2.020 200.9 2 .100 200.8 2.160 200.9 2.360 200.8 1.910 200.8 2.040 200.9 2 .100 200.9 2.170 3113B 2.410

## B-31 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 28.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 3113B 24.500 3113B 27.300 200.7 27.700 200. 9 28.000 200.7 28.700 200.8 29.500 3113B 24.600 3113B 27.400 200.9 27.800 200. 8 28.100 200.9 28.800 200.7 29.600 200.7 26.400 200.9 27.400 200.7 27.800 200.7 28.200 200.9 28.800 200.8 29.700 3113B 26.600 200.7 27.600 200.7 27.840 3113B 28.300 200.9 28.800 200.9 29.800 200.8 27.200 200.9 27.600 200.9 27.900 200.8 28.300 200.7 28.900 200.7 30.600 200.8 27.200 200.9 27.600 3113B 27.900 3113B 28.400 200.7 28.900 200.9 31.300 200.9 27.200 200.9 27.600 200.9 28.000 200.8 28.500 200.7 29.000 200.9 31.400 200.9 27.300 200.7 27.600 200.7 28.000 200.7 28.600 200.8 29.000 200.7 31.600 200.7 27.300 3113B 27.600 200.8 28.000 200. 9 28.700 200.7 29.500 200.9 44.900 Water Study: 40 True Value: 6.31 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 1.720 200.9 6.100 200.7 6.240 200.8 6.340 200.8 6.500 200.7 6.840 200.9 3.900 200.9 6.130 200.9 6.250 200.8 6.360 200.9 6.520 200.7 6.880 200.9 4.000 200.9 6.160 3113B 6.250 200. 8 6.380 200.8 6.564 200.7 6.880 200.7 4.300 200.8 6.180 200.8 6.260 200.7 6.400 3113B 6.570 200.8 6.960 200.7 4.510 3113B 6.180 200.8 6.260 200. 7 6.400 200.9 6.580 200.7 7.000 200.9 5.590 200.8 6.190 200.8 6.270 200.8 6.400 200.8 6.580 200.9 7.100 200.8 5.700 200.9 6.200 200.7 6.320 200.8 6.400 3113B 6.640 200.9 7.480 200.9 5.840 200.8 6.200 200.9 6.320 200.8 6.410 3113B 6.640 200.7 7.630 3113B 5.990 3113B 6.200 3113B 6.320 200.9 6 .490 200.7 6.800 200.7 8.280 200.7 6.000 3113B 6.230 other 6.330 200. 7 6.500 other 6.800 200.7 9.810 3113B 6.080 200.7 6.230 200.8 6. 330 200.7 6.500 200.9 6.830 Water Study: 41 True Value: 18.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 13.600 200.7 17.700 200.7 18.500 200.7 18.800 200.7 19.100 200.7 19.600 3113B 15.000 200.9 17.900 200.8 18.500 200. 8 18.800 200.9 19.200 200.7 19.900 200.8 15.500 200.7 18.000 200.7 18.600 200.8 19.000 200.8 19.200 200.7 21.160 200.9 16.400 200.7 18.000 200.8 18.600 200.9 19.000 200.8 19.200 200.9 25.600 200.9 17.000 3113B 18.100 200.9 18. 600 200.7 19.000 200.9 19.300 200.9 17.000 200.7 18.200 200.8 18.700 3113B 19.000 200.7 19.300 200.8 17.500 200.8 18.400 200.8 18.700 200.7 19.000 200.9 19.300 3113B 17.600 200.9 18.400 200.9 18.800 201 19.000 3113B 19.300 200.7 17.600 200.9 18.500 200.7 18.800 200.9 19.000 3113B 19.300

## B-32 Methods Support Document for Six-Year Review Final - March 2003 Carbofuran

Water Study: 24a True Value: 15.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 11.300 531.1 15.300 other 15.750 531.1 16.000 531.1 16.800 531.1 20.400 531.1 15.000 531.1 15.400 other 15.800 531.1 16.700 531.1 17.200 Water Study: 24b True Value: 44.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 33.000 531.1 38.400 531.1 41.700 531.1 44.000 531.1 46.700 531.1 57.900 531.1 37.100 531.1 40.800 531.1 43. 800 other 45.040 other 53.550 Water Study: 25a True Value: 24.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 7.980 531.1 19.300 531.1 23.400 531.1 24.360 531.1 26.190 Water Study: 25b True Value: 48.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 43.700 531.1 44.300 531.1 47.700 531.1 51.430 531.1 52.060 Water Study: 26a True Value: 36.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 21.000 other 32.400 531.1 35.200 531.1 37.400 531.1 47.700 531.1 27.400 531.1 33.690 531.1 35.600 531.1 38.600 other 32.000 531.1 34.100 531.1 36.900 531.1 45.800 Water Study: 26b True Value: 17.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 8.650 other 15.600 531.1 17.300 531.1 18.100 531.1 22.100 531.1 12.900 other 15.600 531.1 17.500 531.1 19.000 531.1 15.100 531.1 17.240 531.1 17.700 531.1 21.700

## B-33 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 20.7

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 4.290 531.1 18.200 531.1 21.700 531.1 26.800 531.1 17.400 531.1 18.500 531.1 23.300 531.1 27.500 Water Study: 29 True Value: 4.00

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 3.900 531.1 4.030 531.1 4 .220 531.1 4.670 531.1 5.000 531.1 3.960 other 4.170 531.1 4 .510 531.1 4.970 531.1 6.490 Water Study: 30 True Value: 5.78 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 5.100 531.1 5.500 531.1 5.970 other 6.330 531.1 7.500 531.1 8.950 531.1 5.230 531.1 5.560 531.1 6 .210 531.1 6.470 531.1 7.820 531.1 5.240 531.1 5.610 531.1 6 .260 531.1 6.720 531.1 7.890 531.1 5.320 531.1 5.650 531.1 6 .280 531.1 7.270 531.1 8.200 531.1 5.390 531.1 5.720 531.1 6 .310 531.1 7.320 531.1 8.880 Water Study: 31 True Value: 11.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 4.890 531.1 8.750 531.1 10.500 531.1 11.700 531.1 12.000 531.1 5.430 531.1 9.430 531.1 10.700 531.1 11.800 531.1 12.300 531.1 8.250 531.1 10.300 531.1 11.400 531.1 11.900 Water Study: 32 True Value: 7.67 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 4.230 531.1 7.070 531.1 7.440 531. 1 7.640 other 7.880 531.1 8.320 531.1 6.540 531.1 7.110 531.1 7.450 531.1 7.740 531.1 7.910 531.1 8.370 531.1 6.580 531.1 7.160 531.1 7.460 531.1 7.760 531.1 7.910 531.1 8.700 531.1 6.700 531.1 7.190 531.1 7.520 531.1 7.850 531.1 8.030 531.1 9.960 531.1 6.780 531.1 7.340 531.1 7.610 531.1 7.850 531.1 8.070 531.1 12.500 531.1 7.000 531.1 7.420 531.1 7.640 531.1 7.860 531.1 8.230 531.1 13.700

## B-34 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 24.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 1.560 531.1 21.610 531.1 22.800 531.1 24.900 531.1 25.500 531.1 31.100 531.1 10.300 531.1 21.700 531.1 23.800 531.1 25.100 531.1 25.700 531.1 33.160 other 15.200 531.1 21.800 531.1 23.900 531.1 25.200 531.1 26.300 531.1 33.500 531.1 19.000 531.1 21.870 531.1 23.900 531.1 25.300 531.1 28.400 531.1 19.700 531.1 22.100 531.1 24.500 531.1 25.500 531.1 28.600 531.1 20.400 531.1 22.600 531.1 24.800 531.1 25.500 531.1 29.600 Water Study: 34 True Value: 18.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 0.017 531.1 16.600 531.1 17.600 531.1 18.000 531.1 19.600 531.1 25.700 531.1 6.010 531.1 16.700 531.1 17.700 531.1 18.100 531.1 19.900 531.1 31.200 531.1 15.200 531.1 16.800 531.1 17.700 531.1 18.200 531.1 20.070 531.1 37.300 531.1 15.900 531.1 17.000 531.1 17.800 531.1 18.200 531.1 20.100 531.1 16.000 531.1 17.300 531.1 17.900 531.1 18.500 531.1 21.400 531.1 16.000 531.1 17.300 531.1 17.900 531.1 18.600 531.1 21.600 531.1 16.400 531.1 17.310 531.1 18.000 531.1 18.900 531.1 21.700 531.1 16.600 531.1 17.500 531.1 18.000 531.1 19.100 531.1 22.400 Water Study: 35 True Value: 42.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 22.100 531.1 33.920 531.1 38.490 531.1 40.600 531.1 43.200 531.1 49.200 531.1 26.900 531.1 34.700 531.1 39.400 531.1 41.500 531.1 43.800 531.1 65.300 531.1 28.900 531.1 35.600 531.1 39.570 531. 1 42.000 531.1 44.000 other 66.400 531.1 32.900 531.1 36.400 531.1 39.700 531.1 42.200 531.1 45.200 531.1 67.000 531.1 33.600 531.1 38.100 531.1 40.600 531.1 42.300 531.1 46.600 531.1 84.800

## B-35 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 37.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 22.900 531.1 31.800 531.1 34.700 531.1 37.600 531.1 38.700 531.1 40.900 531.1 26.000 531.1 33.100 531.1 34.900 531.1 37.800 531.1 39.300 531.1 41.400 531.1 26.200 531.1 33.200 531.1 35.000 531.1 37.900 531.1 39.300 531.1 42.300 531.1 28.900 531.1 34.000 531.1 35.300 531.1 38.300 531.1 40.000 531.1 43.600 531.1 31.000 531.1 34.100 531.1 36.300 531. 1 38.300 531.1 40.000 other 47.700 531.1 31.100 531.1 34.200 531.1 36.400 531.1 38.500 531.1 40.400 531.1 48.700 531.1 31.200 531.1 34.200 531.1 36.800 531.1 38.500 531.1 40.400 531.1 496.000 531.1 31.300 531.1 34.400 531.1 37.300 531.1 38.700 531.1 40.500 Water Study: 37 True Value: 48.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 7.920 531.1 40.560 531.1 43. 300 531.1 45.100 531.1 46.700 531.1 48.400 531.1 30.600 531.1 41.000 531.1 44. 000 531.1 45.200 531.1 46.730 531.1 49.700 531.1 36.000 531.1 41.400 531.1 44. 100 531.1 45.500 531.1 47.400 531.1 51.100 531.1 38.500 531.1 41.900 531.1 44.600 531.1 46.000 other 47.700 other 52.600 531.1 39.000 531.1 43.000 531.1 44. 700 531.1 46.500 531.1 48.300 531.1 54.800 531.1 39.000 531.1 43.100 531.1 45. 000 531.1 46.700 531.1 48.300 531.1 61.300 Water Study: 38 True Value: 33.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 4.250 531.1 33.100 531.1 35.200 531.1 37.000 531.1 39.200 531.1 41.500 other 22.600 531.1 33.600 531.1 35.500 531.1 37.500 531.1 39.300 531.1 41.600 531.1 27.400 531.1 34.000 531.1 35.600 531.1 38.200 531.1 40.000 531.1 42.100 531.1 29.500 531.1 34.000 531.1 36.300 531.1 38.300 531.1 41.000 531.1 43.600 531.1 30.200 531.1 34.300 531.1 36.400 531.1 38.400 531.1 41.000 531.1 45.400 531.1 31.200 531.1 34.360 531.1 36.800 531.1 38.400 531.1 41.180 531.1 48.000 531.1 31.700 531.1 34.900 531.1 37.000 531.1 38.600 531.1 41.400 531.1 76.700

## B-36 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 74.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 40.600 531.1 65.000 531.1 66.300 531.1 67.700 531.1 81.500 531.1 94.800 531.1 52.300 531.1 65.500 531.1 66.500 531.1 67.700 531.1 81.700 531.1 52.500 531.1 65.500 531.1 66.800 531.1 68.100 531.1 83.260 531.1 63.200 531.1 65.500 531.1 67.100 531.1 70.500 531.1 84.100 531.1 63.500 531.1 65.870 531.1 67.100 531.1 73.300 531.1 85.900 531.1 64.300 531.1 66.000 531.1 67.100 531.1 79.900 531.1 89.000 Water Study: 40 True Value: 55.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 41.800 531.1 50.400 531.1 53.300 531.1 54.700 531.1 56.900 531.1 62.900 531.1 43.200 531.1 50.500 531.1 54.300 531.1 55.200 531.1 57.000 531.1 63.300 other 43.500 531.1 50.640 531.1 54.300 531.1 55.400 531.1 57.800 531.1 65.200 531.1 45.100 531.1 51.000 531.1 54.400 531.1 55.800 531.1 59.700 531.1 65.900 531.1 45.300 531.1 51.800 531.1 54.500 531.1 56.200 531.1 60.300 531.1 69.300 531.1 47.100 531.1 52.100 531.1 54.600 531.1 56.700 531.1 60.400 531.1 71.500 531.1 50.000 531.1 52.500 531.1 54.600 531.1 56.770 531.1 61.100 531.1 71.700 Water Study: 41 True Value: 43.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 10.800 531.1 36.050 531.1 40.400 531.1 41.300 531.1 42.700 531.1 45.400 531.1 24.800 531.1 36.800 531.1 40.500 531.1 41.800 531.1 42.900 531.1 46.900 531.1 28.200 531.1 37.320 531.1 40.800 531.1 41.800 531.1 43.000 531.1 47.000 531.1 32.100 531.1 40.000 531.1 41.100 531.1 42.500 531.1 43.500 531.1 52.400 531.1 32.100 531.1 40.300 531.1 41.300 531.1 42.600 531.1 44.900

## B-37 Methods Support Document for Six-Year Review Final - March 2003 Carbon Tetrachloride Water Study: 24 True Value: 4.56 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 3.420 524.1 3.840 502.2 4.180 502.2 4.490 502.2 4.880 524.2 5.480 524.1 3.500 502.2 3.840 524.1 4.180 502.2 4.490 502.2 4.890 502.2 5.600 502.1 3.530 524.2 3.860 other 4.300 502.1 4.500 502.2 4.900 524.2 5.620 524.2 3.583 502.1 3.900 524.2 4.310 524.2 4.600 502.2 4.960 524.2 5.779 524.1 3.590 524.2 3.980 524.2 4.330 other 4.700 502.1 4.970 502.2 6.500 524.1 3.613 502.2 4.000 502.2 4.400 524.2 4.700 502.2 5.100 524.2 15.400 502.2 3.680 502.1 4.000 502.2 4 .410 524.2 4.780 502.1 5.200 502.2 3.740 502.2 4.030 502.2 4 .420 502.2 4.780 524.2 5.400 502.2 3.780 524.2 4.090 524.2 4 .460 524.2 4.800 502.2 5.400 524.2 3.790 524.2 4.180 524.2 4 .490 524.2 4.850 524.1 5.450 Water Study: 25 True Value: 9.18 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 5.800 524.1 8.500 524.2 9.050 524.2 9.440 524.2 10.100 502.2 13.000 502.2 7.250 502.2 8.600 502.2 9.050 502. 1 9.650 other 10.110 other 17.500 502.2 7.300 524.2 8.790 502.1 9 .160 524.2 9.680 524.2 10.140 524.1 8.240 524.2 8.880 524.2 9 .300 502.2 9.700 502.2 10.400 502.2 8.270 524.2 8.890 502.2 9 .350 524.2 9.930 502.2 10.900 502.2 8.360 524.2 8.966 502.2 9 .350 524.1 10.000 524.2 11.000 502.2 8.400 502.2 9.020 502.2 9. 370 other 10.000 524.1 11.300 Water Study: 26 True Value: 16.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 12.000 524.1 15.200 524.2 16.400 524.2 17.200 502.2 18.200 502.1 19.700 502.2 12.300 502.2 15.400 524.2 16.430 502.1 17.300 502.2 18.400 524.1 19.700 502.2 12.900 524.2 15.520 524.2 16.700 502.2 17.400 524.2 18.500 524.2 19.800 524.2 13.400 524.2 15.800 524.1 16.700 524.2 17.500 502.2 18.500 502.2 20.300 502.2 13.500 502.2 15.800 524.1 16.800 524.2 17.600 524.2 18.600 502.1 21.300 502.2 13.900 502.2 15.900 502.2 16.900 502.2 17.600 524.2 18.800 502.2 21.320 502.2 13.900 524.2 16.000 524.2 17.000 502.2 17.600 524.2 19.000 502.2 21.400 524.2 14.700 502.2 16.040 524.2 17.100 524.1 17.900 502.2 19.200 502.2 23.700 other 14.700 other 16.300 524.2 17. 100 502.1 18.000 524.2 19.500 524.2 25.300 502.2 15.100 502.1 16.380 524.2 17.200 502.1 18.200 524.2 19.700

## B-38 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 8.48 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 3.930 502.2 7.540 502.1 8.270 524.2 8.600 502.2 9.220 524.1 11.300 other 5.750 524.2 7.590 502.2 8.370 502.2 8.600 524.1 9.220 502.2 11.400 502.2 6.280 502.2 7.700 502.2 8 .430 524.2 8.640 524.2 9.890 502.2 6.940 502.2 7.900 524.2 8. 490 524.2 8.680 other 9.990 524.2 6.990 502.2 7.900 502.2 8 .520 524.2 8.740 502.2 10.100 502.2 7.200 524.2 8.160 502.2 8 .540 502.2 8.950 524.2 10.470 524.2 7.300 524.2 8.180 524.2 8. 570 other 9.100 502.2 10.800 Water Study: 29 True Value: 10.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.500 502.2 9.540 524.2 10.200 524. 1 10.900 other 11.440 524.2 12.500 other 8.600 other 9.580 502.2 10. 200 524.2 10.900 502.2 11.500 502.2 12.890 502.2 8.670 other 9.640 502.2 10.600 502.2 11.200 524.2 12.000 524.2 13.400 524.2 8.880 524.2 9.820 502.2 10.610 524.2 11.200 524.2 12.100 502.2 13.400 502.2 9.170 524.2 10.000 524.2 10.700 502.2 11.400 524.1 12.300 502.2 13.700 502.2 9.290 502.2 10.000 524.2 10.700 524.2 11.400 502.2 12.410 502.2 14.400 Water Study: 30 True Value: 6.46 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 4.160 524.2 5.830 524.2 6.220 502. 2 6.440 524.2 6.860 other 7.198 524.2 5.150 502.2 5.840 524.2 6.240 524.2 6.500 524.2 6.900 524.2 7.200 other 5.260 502.2 5.900 502.2 6.250 524.2 6.550 other 6.960 524.2 7.360 524.2 5.400 524.2 5.940 524.1 6.310 other 6.560 524.1 6.990 524.2 7.400 524.2 5.430 502.2 5.950 502.2 6.340 502.2 6.600 502.2 7.000 502.2 7.580 502.2 5.740 524.2 6.010 502.1 6.340 502.2 6.600 524.2 7.000 502.2 7.620 524.2 5.760 502.2 6.100 502.2 6.360 502.2 6.650 524.2 7.020 524.2 7.700 524.2 5.770 502.2 6.130 502.2 3.391 502.2 6.700 502.2 7.050 502.1 8.530 524.2 5.800 524.2 6.150 524.2 6.400 524.2 6.700 502.2 7.060 502.2 10.250 524.2 5.800 524.2 6.160 502.2 6 .400 524.1 6.730 502.2 7.150

## B-39 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 8.69 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.670 502.2 7.390 502.2 8.050 502.1 8.550 524.2 9.100 502.2 9.680 502.2 6.540 524.2 7.620 524.2 8.100 502.1 8.560 502.2 9.140 524.2 9.720 502.2 6.930 524.2 7.700 502.2 8.220 502.2 8.710 502.2 9.170 502.2 10.100 502.2 6.949 524.2 7.860 502.2 8.490 524. 2 9.000 other 9.240 502.1 10.400 524.1 7.040 524.2 7.990 524.2 8.500 524.2 9.020 524.2 9.400 502.2 10.500 502.1 7.360 524.2 8.010 524.2 8.520 524.2 9.060 524.2 9.480 502.2 11.000 Water Study: 32 True Value: 14.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.800 524.2 13.400 524.2 13.800 other 14.4000 524.2 15.100 502.2 15.900 524.2 11.000 524.2 13.400 502.2 13.800 524.2 14.500 502.2 15.200 524.2 16.100 502.1 11.100 502.2 13.400 502.2 13.900 524.2 14.500 524.2 15.230 502.2 16.200 502.2 11.600 502.2 13.500 502.2 13.900 524.2 14.530 502.2 15.300 524.2 16.200 502.2 11.900 524.2 13.600 502.2 14.000 524.2 14.580 524.2 15.340 524.1 16.700 502.2 12.300 524.2 13.600 502.2 14.000 524.2 14.600 502.2 15.400 524.2 17.700 524.2 12.700 524.2 13.700 other 14.000 524.2 14.600 502.2 15.500 524.2 17.700 502.2 12.800 502.1 13.700 524.2 14.200 524.2 14.700 524.2 15.600 524.2 17.900 524.2 12.800 524.2 13.800 502.1 14.200 502.1 14.800 524.2 15.700 524.2 12.900 502.2 13.800 502.2 14.300 524.2 14.930 524.2 15.900 502.2 13.000 502.2 13.800 502.2 14. 400 524.2 15.100 other 15.900 Water Study: 33 True Value: 13.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.460 524.1 12.100 502.2 13.000 502.2 13.700 524.2 14.600 502.1 15.400 other 10.530 502.2 12.600 524.2 13.100 502.2 13.800 524.2 14.600 524.2 16.000 502.2 10.800 502.2 12.600 502.2 13.100 524.2 14.000 524.2 14.600 524.2 16.100 502.1 11.000 524.2 12.690 524.2 13.500 524.2 14.000 502.2 14.900 524.2 21.400 502.2 11.570 502.2 12.700 524.2 13.600 524.2 14.200 524.2 15.030 502.2 11.700 524.2 12.970 502.2 13.600 502.2 14.500 502.2 15.100

## B-40 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 6.27 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.710 502.2 5.560 524.2 5.860 524.2 6.080 502.2 6.490 524.2 6.800 524.2 4.750 524.2 5.600 524.2 5.880 502.2 6.090 524.2 6.550 502.2 6.910 524.2 4.960 524.2 5.650 524.2 5.910 other 6.100 524.2 6.580 524.2 7.010 502.2 4.980 502.2 5.660 524.2 5.960 502.2 6.170 524.2 6.600 502.2 7.030 502.2 5.010 524.2 5.720 502.2 5.960 502.2 6.240 524.2 6.600 524.2 7.130 502.2 5.450 502.2 5.728 502.2 5.970 524.2 6.250 502.2 6.620 524.2 7.200 502.1 5.460 502.2 5.760 524.2 6.000 524.2 6.260 502.2 6.630 502.2 7.210 502.2 5.490 524.2 5.820 524.2 6.000 524.2 6.290 502.2 6.640 524.2 7.380 other 5.500 502.2 5.840 502.2 6.030 502.2 6.340 524.2 6.800 524.2 7.670 502.1 5.530 524.2 5.850 502.2 6.070 524.2 6.460 502.2 6.800 524.2 7.830 Water Study: 35 True Value: 10.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.990 524.2 10.000 502.2 10.380 524. 2 11.000 524.2 11.700 other 12.200 502.2 8.500 524.2 10.100 502.2 10.500 524.2 11.000 524.2 11.800 524.2 12.200 502.2 8.563 502.2 10.100 502.2 10.650 524.2 11.160 502.2 11.800 524.2 12.490 other 9.958 502.2 10.200 524.2 10.700 524.2 11.200 502.2 11.900 502.2 13.500 502.2 9.960 524.2 10.200 502.2 10.700 502.2 11.500 502.2 12.000 524.2 10.000 524.2 10.300 524.2 10.900 524.2 11.500 524.2 12.000 Water Study: 36 True Value: 12.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.760 502.2 11.500 524.2 11.800 502.2 12.200 524.2 12.730 524.2 13.400 502.2 10.300 524.2 11.500 524.2 11.900 502.2 12.200 502.2 12.800 524.2 13.500 502.2 10.400 524.2 11.500 524.2 11.900 524. 2 12.200 524.2 12.860 other 13.600 502.2 10.600 524.2 11.530 524.2 11.900 524.2 12.300 502.2 12.900 524.2 13.700 524.2 10.700 524.2 11.600 502.2 11.900 502. 2 12.320 524.2 12.900 other 13.700 502.2 10.900 502.2 11.600 502.2 11.900 524.2 12.400 524.2 12.900 502.2 14.000 502.2 10.900 524.2 11.600 502.2 12.000 502.2 12.400 502.2 13.000 524.2 14.570 524.2 11.300 524.2 11.700 524.2 12.000 524. 2 12.500 524.2 13.000 other 15.000 524.2 11.400 524.2 11.730 524.2 12.000 524.2 12.600 502.2 13.200 524.2 15.630 502.2 11.400 524.2 11.800 502.2 12.100 524.2 12.700 524.2 13.200

## B-41 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 12.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.200 502.2 12.100 524.2 12.500 524.2 12.800 524.2 13.420 524.2 15.200 524.2 10.600 502.2 12.100 524.2 12.500 502.2 12.800 524.2 13.600 524.2 15.300 502.2 11.000 524.2 12.200 502.2 12.500 524.2 12.900 524.2 13.820 524.2 16.000 502.2 11.300 502.2 12.200 524.2 12.500 524.2 12.900 502.2 13.900 502.2 16.400 524.2 11.300 524.2 12.200 524.2 12.600 524.2 13.000 502.2 14.200 524.2 19.400 502.2 11.400 524.2 12.300 524.2 12.600 524. 2 13.100 other 14.300 502.2 19.900 524.2 11.730 524.2 12.300 502.2 12.700 502. 2 13.300 other 14.600 524.2 27.600 524.2 11.900 502.2 12.400 502.2 12.700 524.2 13.300 524.2 14.800 Water Study: 38 True Value: 15.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.100 other 13.700 502.2 14.900 502.2 15.500 524.2 16.000 524.2 16.800 502.2 12.200 other 13.800 502.2 15.000 502.2 15.500 502.2 16.100 502.2 16.900 524.2 12.700 524.2 14.100 524.2 15.000 524.2 15.600 524.2 16.200 524.2 17.200 502.2 12.800 524.2 14.200 524.2 15.030 524.2 15.600 524.2 16.400 524.2 17.400 524.2 12.900 502.2 14.200 502.2 15.300 524.2 15.600 524.2 16.400 524.2 17.700 502.2 12.900 502.2 14.600 524.2 15.300 524.2 15.600 524.2 16.400 524.2 18.000 524.2 12.900 524.2 14.600 524.2 15.400 502.2 15.700 524.2 16.500 524.2 18.200 524.2 13.100 502.2 14.860 502.2 15.400 502.2 15.700 502.2 16.500 524.2 18.680 502.2 13.600 524.2 14.900 524.2 15.500 524.2 16.000 524.2 16.700 524.2 18.800 Water Study: 39 True Value: 19.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 14.300 524.2 17.900 524.2 18.500 524.2 19.200 524.2 20.100 524.2 21.500 502.2 14.800 502.2 17.900 524.2 18.500 524.2 19.300 524.2 20.100 524.2 22.000 524.2 15.200 524.2 17.900 524.2 18.800 502.2 19.500 502.2 20.100 524.2 22.500 502.2 15.800 524.2 18.000 524.2 18.880 502.2 19.700 502.2 20.200 524.2 23.100 524.2 16.000 502.2 18.000 502.2 18.900 524.2 19.700 524.2 20.700 524.2 23.300 524.2 16.400 524.2 18.200 502.2 19.000 502.2 20.000 524.2 20.700 524.2 34.900 502.2 16.700 502.2 18.300 524.2 19.100 524.2 20.000 524.2 21.500 524.2 65.140

## B-42 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 8.90 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.380 524.2 8.050 524.2 8.400 502.2 8.720 502.2 9.100 502.2 9.970 502.2 6.800 524.2 8.110 524.2 8.420 524. 2 8.730 other 9.140 502.2 10.000 524.2 6.800 524.2 8.150 524.2 8.520 502.2 8.760 502.2 9.150 524.2 10.400 524.2 6.920 524.2 8.160 524.2 8.560 524.2 8.760 524.2 9.160 524.2 10.600 524.2 6.980 524.2 8.200 502.2 8.580 502.2 8.810 502.2 9.210 524.2 10.680 524.2 7.530 524.2 8.200 524.2 8.640 524.2 8.900 524.2 9.240 524.2 11.500 524.2 7.580 524.2 8.270 524.2 8.640 524.2 8.950 524.2 9.260 524.2 20.700 other 7.870 524.2 8.270 524.2 8 .680 502.2 8.970 524.2 9.320 524.2 7.910 524.2 8.360 524.2 8 .680 524.2 8.970 502.2 9.360 502.2 8.000 524.2 8.400 502.2 8 .680 502.2 9.060 524.2 9.670 Water Study: 41 True Value: 14.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.400 524.2 12.600 524.2 13.500 524.2 13.900 524.2 14.300 524.2 15.800 524.2 11.600 502.2 12.600 502.2 13.600 524.2 14.000 502.2 14.600 524.2 15.800 502.2 11.800 502.2 12.700 524.2 13.600 502.2 14.000 524.2 14.700 502.2 15.900 502.2 12.200 524.2 12.900 524.2 13.800 524.2 14.100 524.2 14.720 524.2 16.700 524.2 12.400 524.2 13.100 524.2 13.800 524.2 14.200 524.2 14.800 502.2 16.800 524.2 12.500 524.2 13.400 524.2 13.800 524.2 14.300 502.2 15.500 524.2 12.500 524.2 13.400 524.2 13. 800 other 14.300 502.2 15.500

Chlordane Water Study: 24a True Value: 1.32 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.102 505 0.954 other 1 .100 505 1.180 505 1.332 505 1.440 other 0.234 other 1.000 other 1 .120 other 1.200 505 1.370 505 1.470 505 0.410 505 1.000 505 1.120 other 1.210 505 1.380 other 1.500 505 0.736 other 1.040 505 1. 130 505 1.230 505 1.380 505 1.950 other 0.860 other 1.040 505 1. 150 505 1.280 other 1.400 505 554.000 505 0.881 other 1.070 other 1 .160 505 1.280 other 1.400 505 0.936 other 1.094 other 1 .170 other 1.320 505 1.408

## B-43 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24b True Value: 4.86 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.378 505 3.490 other 4.190 other 4.470 other 4.800 other 5.270 other 0.854 other 3.780 other 4 .280 other 4.500 505 4.800 505 5.450 505 0.978 505 3.790 505 4.297 other 4.597 505 4.830 505 5.530 505 2.280 other 3.930 505 4. 311 505 4.610 505 4.850 505 7.920 505 3.140 other 4.120 other 4. 319 505 4.640 other 4.870 505 3680.000 other 3.170 505 4.120 505 4. 330 505 4.780 other 5.000 505 3.280 505 4.130 other 4. 420 other 4.790 505 5.004 Water Study: 25a True Value: 3.30 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 1.310 other 2.660 other 2 .780 508 2.910 508 3.221 508 3.370 508 2.300 508 2.700 508 2.810 505 3.020 other 3.290 505 4.010 505 2.350 508 2.760 505 2.820 508 3.060 505 3.340 508 2.530 other 2.770 508 2. 840 other 3.080 508 3.360 Water Study: 25b True Value: 12.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 7.320 505 9.600 other 10. 530 508 11.730 508 12.400 505 14.200 508 8.300 508 9.770 508 11.000 508 12.100 508 12.500 505 14.900 other 9.140 other 10.300 508 11.400 508 12.100 other 12.900 508 9.450 other 10.400 508 11.700 508 12.200 505 13.290 Water Study: 26b True Value: 9.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.780 other 7.690 508 8.610 508 9.030 508 9.720 505 11.100 505 7.251 505 8.010 other 8. 617 505 9.079 508 9.760 508 12.000 other 7.400 other 8.030 other 8.660 505 9.270 508 9.830 505 12.100 505 7.520 other 8.070 508 8. 700 508 9.530 508 9.830 508 12.500 other 7.540 505 8.163 505 8. 740 other 9.540 505 9.850 505 7.540 508 8.550 505 8.780 508 9.550 other 9.870 505 7.670 525.1 8.552 508 8.840 505 9.610 505 10.300

## B-44 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26a True Value: 2.70 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.870 other 2.280 other 2.575 508 2.690 505 3.000 505 3.615 505 2.060 505 2.360 other 2.580 505 2.710 other 3.020 508 3.740 other 2.110 508 2.380 other 2 .580 508 2.710 505 3.020 508 3.960 505 2.179 508 2.400 508 2.630 508 2.720 505 3.130 508 32.600 525.1 2.200 505 2.420 505 2.670 505 2.760 other 3.200 other 2.240 508 2.430 508 2.670 508 2.840 505 3.200 other 2.270 508 2.460 505 2.680 505 2.877 505 3.450 Water Study: 27 True Value: 1.84 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 1.220 508 1.500 505 1.760 508 1. 899 other 1.980 other 2.420 other 1.360 other 1.595 508 1.840 508 1.910 508 2.010 508 2.600 508 1.370 508 1.600 508 1.850 other 1.931 508 2.020 508 2.800 508 1.410 other 1.610 508 1.860 508 1.960 508 2.080 508 1.470 505 1.620 505 1.860 other 1.970 505 2.260 Water Study: 29 True Value: 0.833 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.646 508 0.727 508 0.782 other 0.830 508 1.060 508 0.677 505 0.748 508 0.785 505 0.830 other 1.120 508 0.688 508 0.760 508 0.802 508 0.841 505 1.830 508 0.696 other 0.763 508 0.806 508 0.894 508 4.710 505 0.720 other 0.767 other 0. 810 other 0.939 other 5.739 Water Study: 30 True Value: 4.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 1.340 505 3.280 508 3.790 508 3. 990 other 4.290 other 5.080 505 1.700 508 3.341 505 3.810 508 4.000 other 4.300 505 5.150 other 1.865 508 3.350 508 3.870 other 4.000 508 4.340 505 5.930 508 2.310 508 3.420 508 3.870 505 4.080 508 4.380 508 5.970 508 3.060 other 3.640 505 3. 880 508 4.200 other 4.490 508 3.100 508 3.690 508 3.880 other 4.230 505 4.490 508 3.180 505 3.700 508 3.920 other 4.240 508 4.550 508 3.230 508 3.710 508 3.980 508 4.280 other 4.911 505 3.260 other 3.730 other 3.990 508 4.290 508 4.930

## B-45 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 5.16 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.787 508 3.160 508 4.040 508 4.539 505 4.890 508 5.240 505 2.340 508 3.480 508 4.100 508 4.570 508 5.000 508 5.280 508 2.360 505 3.610 505 4.370 508 4.600 505 5.050 other 5.650 508 2.400 508 3.780 508 4.464 508 4.730 other 5.130 508 5.800 508 2.660 508 3.810 508 4.500 508 4.850 508 5.240 other 6.360 Water Study: 32 True Value: 5.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 1.010 508 4.060 other 4.560 508 4.9560 other 5.310 505 5.930 525.1 1.060 508 4.109 508 4.600 508 4.980 508 5.360 505 6.090 525.1 1.348 505 4.136 508 4.610 508 5.020 508 5.400 508 6.320 525.1 1.740 508 4.190 508 4.690 508 5.100 505 5.450 505 6.490 508 2.190 other 4.250 508 4. 780 505 5.100 505 5.500 505 7.800 508 2.580 508 4.290 508 4.840 505 5.160 other 5.570 505 8.010 525.1 2.920 508 4.310 508 4.850 508 5.180 505 5.620 505 3.790 508 4.370 508 4.860 508 5.220 505 5.630 508 3.800 508 4.500 505 4.890 508 5.230 508 5.640 508 3.870 508 4.520 508 4.940 508 5.300 508 5.680 Water Study: 33 True Value: 2.76 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 0.680 508 2.350 508 2.500 508 2.630 505 2.900 505 3.660 508 1.720 508 2.360 508 2.540 508 2.640 508 2.940 other 3.750 505 2.130 525.1 2.370 508 2.600 other 2.690 508 2.950 525.1 3.900 508 2.180 508 2.370 508 2.610 508 2.730 508 3.000 508 4.550 525.1 2.270 508 2.400 505 2.620 508 2.730 508 3.200 508 4.630 508 2.290 505 2.400 508 2.620 508 2.872 508 3.460 505 6.180

## B-46 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 7.26 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.740 508 5.595 508 6.270 508 6.840 505 7.349 508 8.040 525.1 1.250 508 5.630 508 6.580 505 6.850 other 7.350 508 8.070 525.1 3.460 505 5.760 508 6.580 508 6.860 505 7.380 508 8.410 508 4.390 508 5.790 505 6.680 508 6.910 508 7.390 505 8.410 508 4.640 other 6.000 525.1 6. 690 508 6.920 505 7.470 505 10.400 508 4.990 508 6.010 508 6.740 505 6.930 525.1 7.520 508 10.670 508 5.080 508 6.090 505 6.800 other 6.970 508 7.590 508 13.100 508 5.210 505 6.130 508 6.810 508 7.060 505 7.700 508 5.220 508 6.190 508 6.820 508 7.110 505 7.979 Water Study: 35 True Value: 13.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 2.930 508 11.000 508 11.800 505 13.400 508 14.400 505 17.630 525.1 9.000 505 11.100 505 12.200 505 13.430 508 14.600 508 17.700 508 9.590 508 11.600 508 12.300 508 13.500 508 14.700 other 20.200 508 9.595 508 11.620 508 12.400 508 13.700 508 14.900 505 10.100 508 11.700 505 12.600 508 13.700 508 15.700 508 10.800 508 11.800 505 13.400 508 13.900 508 17.530 Water Study: 36 True Value: 16.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 5.300 508 13.200 508 15.300 505 16.100 505 16.600 508 18.800 other 7.000 508 13.200 508 15. 400 505 16.100 508 16.600 508 18.900 508 10.000 508.1 13.300 525.2 15.400 508.1 16.200 508 16.600 508 19.000 508 11.500 508 13.500 505 15.500 508 16.300 508 16.700 other 21.440 508 12.200 508 14.000 508 15.600 505 16.400 508.1 16.800 505 22.400 505 12.400 508.1 14.000 508 15.700 other 16.410 505 17.300 508 24.200 508.1 12.400 508 14.000 508 15.900 505 16.480 505 17.600 525.2 24.500 508 12.900 508 14.000 505 16.000 505 16.500 505 17.900 508 13.100 508 14.500 508 16.000 508 16.500 505 17.920

## B-47 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 4.44 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.679 505 3.800 508 4.170 508 4.370 505 4.650 525.2 5.390 505 1.159 508 3.800 508 4.170 505 4.450 505 4.800 505 5.640 other 1.260 508 3.840 508 4. 200 505 4.450 505 4.910 508 5.920 508 3.270 508 3.900 508 4.300 other 4.470 508 4.930 505 5.970 508 3.420 505 3.950 508 4.300 525. 2 4.520 505 4.940 525.2 6.200 508 3.650 508 3.990 508 4.350 508.1 4.570 508 4.970 508 6.420 508 3.670 508.1 4.010 508 4.350 508 4.590 508.1 5.100 other 3.780 508 4.160 508 4.360 505 4.630 508 5.260 Water Study: 38 True Value: 8.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 2.960 508 6.150 525.2 7.220 508 7.900 508 8.250 508.1 9.150 508 4.800 508.1 6.400 508 7.240 508 7.950 508 8.280 525.2 9.150 508 4.830 508 6.420 508 7.290 508 7.960 505 8.360 505 9.200 other 5.330 508 6.530 508 7. 490 508 7.990 508 8.430 508 9.610 508 5.660 508 6.720 505 7.490 525.2 8.040 505 8.470 505 10.100 508.1 5.680 508 6.760 525.2 7.500 505 8.060 other 8.710 505 10.290 508 5.890 508 6.870 508 7.650 508.1 8.100 505 8.720 508 6.118 508 7.080 505 7.720 505 8.110 508 8.730 508 6.130 508.1 7.180 508 7.800 508 8.210 other 8.940 Water Study: 39 True Value: 3.57 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.000 508 3.020 508 3.430 508 3.780 505 3.980 525.2 4.360 other 0.603 508 3.200 505 3. 500 505 3.820 508 3.980 508 4.510 508.1 2.790 508 3.250 505 3.520 525.2 3.880 508 3.980 505 4.560 508.1 2.820 508.1 3.255 505 3.530 508 3.940 525.2 4.040 525.2 4.620 508 2.840 508 3.270 505 3.540 508 3.950 508 4.078 other 5.030 508.1 2.910 508 3.430 508 3.600 508 3.950 505 4.080 508 5.030 508 2.930 525.2 3.430 508 3.680 505 3.970 508.1 4.090

## B-48 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 11.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 5.280 508 9.980 508 10.700 508 11.700 508 12.800 508 14.400 508 6.930 508 10.000 508 10.800 508 11.700 505 13.000 other 14.600 508 6.960 508 10.200 508.1 10.870 505 11.800 505 13.200 505 15.270 508 7.580 508 10.300 508 10.900 505 11.900 505 13.400 508 16.300 508 8.000 508.1 10.400 525.2 11.000 508 12.100 505 13.400 other 17.500 508.1 8.130 525.2 10.500 other 11.200 525.2 12.200 508.1 13.400 508.1 21.000 508 8.290 508 10.600 508 11.200 508 12.300 508 13.700 508.1 8.560 508 10.600 505 11.300 525.2 12.500 508 13.700 505 9.210 508 10.600 other 11.330 508 12.700 525.2 13.900 508 9.410 508 10.600 505 11.500 508 12.700 525.2 14.200 Water Study: 41 True Value: 2.90 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 1.140 508 2.400 508.1 2. 540 508 2.740 505 2.960 505 3.330 508.1 1.740 508 2.420 508 2.540 508 2. 770 other 2.990 other 3.410 508 1.780 505 2.420 508.1 2.550 525. 2 2.830 508.1 2.990 505 3.420 508 2.110 508 2.430 508 2.560 525.2 2.850 505 3.040 505 3.560 508 2.140 508 2.470 508 2.630 525.2 2.870 505 3.040 505 4.180 508.1 2.160 525.2 2.470 508 2. 710 505 2.910 508 3.083 508 4.740 508 2.220 525.2 2.500 508 2.720 508 2.930 525.2 3.220

Chromium Water Study: 24a True Value: 127 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7A 12.800 218.2 117.000 218.2 125.000 218.2 128.000 200.7A 132.000 218.1 137.800 218.1 26.600 218.2 117.700 218.2 125.000 200.7A 128.000 218.2 132.000 218.2 138.000 218.2 86.000 other 119.000 218.2 125.000 218.2 129.000 218.2 132.000 218.1 140.000 218.2 90.800 218.2 119.300 218.2 126.000 200.7A 129.000 218.2 132.500 218.1 140.000 218.2 93.000 218.2 120.000 other 126.500 200.7A 129.000 218.2 132.900 218.2 146.000 218.2 111.000 200.7A 122.000 200.7A 127.000 218. 1 130.000 218.1 133.000 other 153.000 218.2 113.000 218.1 122.000 200.7A 127.000 218.2 130.000 218.2 133.000 218.1 164.000 218.2 113.000 218.1 123.000 200.7A 127. 000 other 130.000 218.2 133.700 200.7A 114.000 200.7A 123.000 218.2 128.000 218.2 130.000 218.2 133.900 218.2 115.000 218.2 124.000 218.1 128.000 200.7A 130.200 218.2 134.000 218.1 117.000 200.7A 125.000 200.7A 128. 000 other 131.000 218.2 137.000

## B-49 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24b True Value: 25.5ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.2 18.500 218.2 23.700 218.2 24.800 218.2 25.700 218.1 26.100 218.2 28.000 218.2 19.000 218.2 23.800 218.2 24.800 200.7A 25.800 218.2 26.200 218.2 28.000 218.2 20.000 200.7A 24.000 200.7A 24.900 200.7A 25.800 218.1 26.400 218.2 28.800 218.1 21.000 218.1 24.000 218.2 25.000 218. 1 25.900 218.2 26.400 other 29.000 200.7A 21.800 200.7A 24.100 200.7A 25.100 other 26.000 218.1 26.400 218.1 29.000 218.2 22.500 218.1 24.100 other 25.200 200.7A 26.000 218.2 26.600 218.1 32.000 other 22.900 200.7A 24.300 218.2 25.200 218.2 26.000 218.2 26.800 218.1 126.000 218.2 23.000 218.2 24.500 other 25.300 200.7A 26.000 218.2 26.800 218.2 23.200 200.7A 24.600 200.7A 25.400 218.2 26.000 218.2 27.200 218.2 23.500 200.7A 24.600 218.2 25.500 218.2 26.060 218.2 27.300 218.1 23.700 218.2 24.700 218.2 25.700 200.7A 26.100 218.2 27.500 Water Study: 25a True Value: 15.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.1 1.700 218.2 14.000 200.7A 14.600 200. 7A 15.000 218.2 15.400 other 16.000 218.2 3.070 218.1 14.000 200.7A 14.800 218.1 15.200 218.2 15.500 218.2 16.070 218.1 11.000 218.2 14.000 200.7A 14.800 218.2 15.200 218.2 15.500 218.2 16.200 218.2 13.000 218.2 14.200 218.2 14.800 218.2 15.200 218.2 15.700 218.2 16.300 218.2 13.000 218.2 14.380 218.2 15.000 218.2 15.400 218.2 15.900 200.7A 16.400 218.2 13.700 218.1 14.500 200.7A 15.000 200.7A 15.400 218.2 15.910 200.7A 16.400 218.2 14.000 218.2 14.500 other 15.000 218.1 15.400 218.2 16.000 Water Study: 25b True Value: 60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.1 7.300 218.2 56.500 218.2 58.800 218.1 60.700 218.2 62.000 218.2 64.400 218.2 11.000 218.1 57.000 200.7A 58.900 218.2 60.900 200.7A 62.000 218.2 65.000 218.2 52.000 218.1 57.100 218.2 59.500 218.2 61.000 218.2 62.100 218.2 65.300 218.2 52.500 218.1 57.200 218.2 59.600 218.2 61.000 200.7A 62.500 218.2 65.900 200.7A 54.800 218.2 57.200 218.2 59.700 218.2 61.000 218.2 63.200 200.7A 66.200 218.2 55.000 218.1 58.000 200.7A 60.000 other 61.200 200.7A 63.300 218.2 66.300 200.7A 55.500 218.2 58.210 218.1 60.000 218. 2 61.200 218.2 63.900 other 68.000

## B-50 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 94.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.094 200.7A 90.800 218.1 92.500 218.2 94.500 218.1 96.000 200.7A 101.000 218.2 77.500 200.7A 91.000 218.2 92.900 218.1 94.600 200.7A 96.100 218.2 102.000 200.7A 82.100 218.2 91.190 218.1 93.000 218. 2 94.700 other 96.100 218.1 102.000 218.2 82.900 218.1 91.400 218.2 93.000 200.7A 94.800 200.7A 96.200 218.2 103.000 218.2 83.800 218.2 91.700 218.2 93.100 200.7A 94.800 218.1 96.600 200.7A 104.000 200.7A 84.000 other 91.900 other 93. 300 218.2 94.900 200.7A 97.000 218.2 105.000 218.2 84.900 200.7A 92.000 218.2 93.480 218.2 95.000 218.2 97.200 200.7A 107.000 218.2 84.900 200.7A 92.400 200.7A 93.500 218.2 95.800 218.2 97.500 218.1 113.600 218.2 87.000 218.1 92.400 218.2 93.800 200.7A 95.880 218.1 98.000 218.1 114.000 218.2 87.500 218.2 92.500 218.2 93. 800 other 96.000 200.7A 98.600 200.7A 90.000 200.7A 92.500 218.2 93. 800 other 96.000 218.2 100.000 Water Study: 26a True Value: 50.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.054 200.7A 48.000 200.7A 49.300 other 50.300 200.7A 51.000 218.1 53.000 218.2 39.100 other 48.100 200.7A 49.300 218.2 50.300 200.7A 51.160 218.1 53.400 200.7A 43.200 other 48.300 200.7A 49.500 218.2 50.400 218.2 51.300 218.1 54.000 200.7A 44.000 218.2 48.600 200.7A 49.600 218.2 50.400 200.7A 51.400 218.2 54.000 218.2 45.000 218.1 48.900 218.1 49.700 218.2 50.400 218.2 51.500 218.1 54.300 218.2 45.550 218.2 49.000 218.2 49.900 218.2 50.500 200.7A 51.700 200.7A 54.800 218.2 45.780 218.2 49.000 200.7A 50.000 218. 2 50.800 other 52.000 218.1 55.000 218.2 46.000 218.2 49.000 200.7A 50.000 200.7A 51.000 218.2 52.000 218.1 55.200 218.2 46.000 200.7A 49.000 218.1 50.000 218.1 51.000 218.2 52.100 218.1 60.000 218.2 46.100 218.2 49.200 218.2 50. 200 other 51.000 200.7A 52.200 200.7A 47.200 218.2 49.300 218.2 50.300 200.7A 51.000 218.2 52.800 Water Study: 27 True Value: 75.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.2 19.100 218.2 72.000 200.7A 73.400 200. 7A 74.700 other 75.800 218.2 80.200 218.2 56.500 218.1 72.300 other 73.900 200.7A 74.700 218.2 76.000 218.2 81.000 200.7A 65.400 218.2 72.400 200.7A 74.000 200.7A 74.900 200.7A 76.600 218.2 81.900 200.7A 65.900 218.2 72.600 200.7A 74.000 218.2 75.300 218.2 77.200 218.1 82.000 218.2 70.000 200.7A 72.600 218.2 74.000 218.2 75.400 218.1 78.000 218.2 83.300 218.2 70.600 200.7A 73.000 200.7A 74. 200 200.7A 75.800 other 79.000

## B-51 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 110 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.1 73.000 218.2 102.500 other 107.000 200.7A 110.000 218.2 112.000 other 118.000 218.2 76.000 200.7A 104.000 218.2 108.000 200.7A 110.000 200.7A 113.000 218.2 125.000 218.2 81.100 218.1 104.000 200.7A 108.000 218. 2 110.000 other 113.000 218.2 125.000 other 92.000 200.7A 105.000 other 108.000 200.7A 111.000 218.2 113.000 200.7A 101.000 218.2 106.000 200.7A 108.000 200.7A 111.000 218.1 115.000 200.7A 102.000 218.2 106.000 218.2 108.500 200.7A 112.000 218.2 115.000 Water Study: 30 True Value: 200 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.2 40.000 218.2 189.000 218.2 197.000 218. 2 199.000 218.2 202.000 other 207.000 218.1 116.000 218.2 190.000 218.1 197.800 218.2 200.000 218.2 202.100 200.7A 209.000 218.2 175.000 200.7A 192.000 200.7A 198.000 200.7A 200.000 200.7A 204.000 218.1 212.000 other 175.000 200.7A 192.000 218.2 198.000 200.7A 200.000 218.2 205.000 218.2 213.000 218.2 178.000 200.7A 192.800 200.7A 198.000 218.1 200.000 218.2 205.000 200.7A 214.000 200.7A 181.000 218.1 195.000 200.7A 198.000 200.7A 200.000 218.2 205.000 200.7A 218.000 218.1 185.000 other 195.000 200.7A 198.000 200.7A 200.000 218.2 205.500 218.1 220.000 218.2 185.000 218.2 195.000 other 198.000 218.2 200.000 218.2 206.000 218.2 227.500 218.2 188.000 218.1 195.000 218.2 199.000 200.7A 201.000 218.1 206.000 200.7A 230.000 200.7A 188.500 218.2 195.000 200.7A 199.000 200. 7A 201.000 other 206.000 218.1 285.000 218.2 189.000 218.2 197.000 other 199.000 200.7A 201.000 218.2 207.000 218.2 294.000 Water Study: 31 True Value: 81.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.2 68.000 other 77.000 218.1 79.000 200.7A 80.900 218.2 83.000 other 92.700 218.1 73.000 other 77.100 218.2 79.000 218.2 81.000 other 83.200 200.7A 113.000 218.2 73.200 200.7A 77.300 200.7A 79.800 200.7A 81.000 218.2 83.700 218.2 122.300 200.7A 73.300 218.2 78.000 218.2 79.800 218.2 81.500 218.2 84.000 200.7A 74.000 218.2 78.000 218.1 80. 000 218.2 81.900 other 86.500 200.7A 75.000 218.2 78.000 other 80.000 218.2 82.000 218.2 86.600

other 77.000 200.7A 78.600 218.2 80.900 200.7A 82.800 200.7A 86.800

## B-52 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 68.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 59.400 200.7 64.900 218.2 66.800 200.7 68.8000 218.2 70.000 218.2 74.000 218.2 59.800 200.7 65.000 200.7 67.000 200.7 68.800 218.2 70.200 200.7 76.900 200.7 60.000 other 65.000 218.2 67.300 218.2 68.900 200.7 70.600 218.2 77.900 218.2 61.000 200.7 65.100 218.2 67.300 218.2 68.900 218.2 71.100 218.2 78.200 218.2 61.500 200.7 65.700 218.2 67.600 218.2 69.000 218.2 71.150 200.7 80.900 218.2 61.500 200.7 66.000 200.7 67.600 200. 7 69.000 other 71.300 218.2 86.500 218.1 61.600 200.7 66.000 200.7 67.900 218.2 69.000 218.2 71.700 218.2 99.780 218.2 61.600 200.7 66.000 200.7 68.000 200.7 69.000 218.2 72.100 218.2 62.800 200.7 66.100 200.7 68.000 218.2 69.200 218.2 72.500 218.2 63.600 200.7 66.100 218.2 68.100 200.7 69.200 200.7 72.500 218.1 64.000 218.2 66.600 200.7 68.360 200.7 69.300 218.2 72.700 200.7 64.000 218.2 66.600 218.2 68.500 218.1 69.500 218.2 73.500 Water Study: 33 True Value: 159 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 120.000 200.7 154.000 200.7 157.000 200.7 159.000 218.2 166.000 200.7 176.000 218.1 125.000 200.7 154.000 200.7 157.000 other 160.000 218.2 167.800 218.2 176.600 other 144.000 200.7 156.000 200.7 157.000 200.7 160.000 200.7 171.000 218.2 177.000 218.2 144.900 200.7 156.000 200.7 158.000 218.2 160.000 218.2 172.000 218.2 181.000 other 150.000 200.7 156.000 200.7 159.000 218.2 160.000 218.2 172.000 218.2 187.500 other 152.000 200.7 157.000 200.7 159.000 218.2 163.000 218.2 175.000 Water Study: 34 True Value: 11.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.2 9.000 200.7 11.000 other 11.530 218.2 11.800 218.2 12.300 200.7 12.600 218.1 10.000 200.7 11.000 218.2 11.600 200.7 11.900 218.2 12.300 218.2 12.700 200.7 10.200 other 11.200 200.7 11.600 200.7 11.900 218.2 12.400 200.7 12.700 218.2 10.200 200.7 11.200 200.7 11.600 200. 7 11.900 218.2 12.400 other 12.700 218.2 10.500 200.7 11.300 200.7 11.600 218.2 12.000 200.7 12.500 218.2 13.000 218.2 10.700 200.7 11.300 200.7 11.600 200.7 12.000 200.7 12.500 200.7 13.000 218.2 10.700 218.2 11.300 200.7 11.700 218.2 12.000 218.2 12.500 218.2 13.000 218.2 10.700 218.2 11.400 200.7 11.700 218.2 12.000 200.7 12.600 200.7 13.400 200.7 10.800 218.2 11.500 other 11.700 218.2 12.100 218.2 12.600 218.2 13.800 218.2 10.900 218.2 11.500 other 11.700 218.2 12.200 218.2 12.600 200.7 21.100 218.2 11.000 218.2 11.500 218.2 11.800 218.2 12.200 218.2 12.600

## B-53 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 119 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 218.1 99.000 200.7 113.000 200.7 117.000 200.7 118.000 218.2 124.000 200.7 139.000 other 106.000 200.7 114.400 other 117. 000 200.7 120.000 218.2 125.000 218.2 140.000 200.7 108.000 200.7 115.000 200.7 117.000 200. 7 120.000 200.7 125.000 other 147.000 other 108.800 other 115.000 218.2 117.400 other 120.000 200.7 126.000 218.2 112.000 200.7 115.000 200.7 118. 000 200.7 121.000 other 128.000 218.2 112.000 218.2 115.000 200.7 118.000 218.2 121.000 200.7 129.000 200.7 113.000 200.7 116.000 218.2 118.000 218.2 122.000 200.7 130.000 218.2 113.000 218.2 116.000 other 118.000 218.2 122.500 218.2 130.700 Water Study: 36 True Value: 37.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 32.100 200.7 36.000 200.8 37.300 200.7 38.000 201 38.700 other 40.500 200.9 32.400 3113B 36.100 200.7 37.400 other 38.000 200.9 38.800 200.7 40.700 200.7 34.400 200.7 36.100 3113B 37.500 200. 8 38.100 200.7 38.800 200.7 40.800 200.9 34.600 other 36.100 200.7 37.500 other 38.100 200.7 39.100 200.9 41.000 200.8 34.900 200.7 36.200 200.9 37.500 200.7 38.300 200.8 39.100 200.7 41.000 200.7 35.000 other 36.300 200.7 37.500 other 38.300 200.7 39.300 3113B 41.300 200.7 35.000 200.7 36.600 200.7 37.700 200.7 38.400 200.9 39.700 3113B 41.400 200.7 35.200 200.7 37.100 other 37.700 3113B 38.500 3113B 40.000 3113B 42.700 200.8 35.600 200.7 37.100 200.8 37. 800 3113B 38.600 200.8 40.000 3113B 48.000 3113B 35.800 200.8 37.100 3113B 38.000 3113B 38.600 200.9 40.000 200.8 337.900 3113B 35.900 200.7 37.300 other 38.000 200.7 38.600 3113B 40.300 Water Study: 37 True Value: 72.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 59.300 200.9 68.500 200.9 70.890 200.8 72.000 200.7 73.000 200.7 75.500 other 60.000 200.7 68.600 200.8 71.000 200.8 72.000 200.9 73.000 200.7 75.800 200.7 64.200 3113B 68.800 200.9 71.200 200.7 72.200 200.8 73.100 3113B 77.000 200.7 64.900 200.7 70.000 200.7 71.300 200.7 72.400 200.9 73.300 3113B 77.200 200.7 66.600 200.7 70.100 200.7 71.500 200.7 72.400 200.7 73.700 200.7 80.300 200.7 67.000 3113B 70.100 200.7 71.600 200.7 72.500 200.7 73.800 3113B 84.600 other 67.900 200.7 70.400 200.7 71.800 200.8 72.600 200.7 73.900 200.7 68.400 3113B 70.700 200.9 72.000 200.7 72.900 3113B 75.000 200.9 68.500 200.8 70.700 200.9 72.000 200.9 73.000 200.8 75.100

## B-54 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 148 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 74.300 200.7 136.000 200.9 138.000 200.8 141.000 200.7 144.000 200.7 147.000 200.7 116.000 200.8 136.000 200.8 138.000 other 141.000 200.9 144.000 200.7 148.000 200.7 120.000 200.7 137.000 200.9 139.000 200.9 141.000 200.7 144.000 3113B 149.000 200.9 130.000 200.9 137.000 200.7 140.000 200. 7 141.100 200.7 144.000 other 149.000 200.9 130.000 200.9 137.000 200.7 140.000 200.7 142.000 200.8 144.000 3113B 150.000 200.9 131.000 200.9 137.000 200.7 140.000 200.7 142.000 3113B 145.000 200.7 151.000 3113B 132.000 200.8 137.000 200.8 140.000 200. 9 142.000 200.9 145.000 200.9 151.000 200.8 133.000 200.7 137.000 200.7 140.000 200.8 143.000 200.7 145.000 3113B 153.000 200.8 134.000 200.7 137.000 200.7 140.200 200.7 143.200 200.7 146.000 3113B 158.000 200.8 134.000 200.9 137.000 200.7 141.000 200.7 144.000 200.7 146.000 200.7 160.000 200.8 136.000 200.7 138.000 200.8 141.000 200.7 144.000 3113B 146.000 200.9 165.000 Water Study: 39 True Value: 23.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 22.000 200.7 23.600 3113B 24.000 200. 7 24.400 200.9 25.000 200.7 26.900 200.7 22.000 200.8 23.600 200.8 24.000 200.7 24.600 200.9 25.100 200.9 27.500 200.9 22.000 200.7 23.700 200.7 24.040 200. 7 24.700 200.7 25.200 other 28.100 3113B 22.500 200.7 23.800 3113B 24.200 200. 7 24.700 200.8 25.300 200.9 29.000 200.9 22.900 200.7 23.800 3113B 24.200 200. 7 24.800 200.9 25.500 200.8 29.600 200.9 23.000 200.8 23.800 200.9 24.280 200.8 24.800 200.7 25.500 200.8 23.400 3113B 23.900 200.9 24. 300 200.9 24.900 200.7 25.600 200.7 23.600 200.7 24.000 200.8 24.300 200.7 25.000 200.7 26.000 200.7 23.600 200.7 24.000 200.7 24.300 200.7 25.000 200.9 26.000 Water Study: 40 True Value: 90.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 3113B 81.600 200.7 90.000 200.8 91.700 200. 8 93.000 200.7 95.200 200.9 96.800 200.9 82.000 200.8 90.000 3113B 91.700 200. 9 93.100 200.9 95.200 200.8 97.000 200.9 84.400 3113B 90.500 200.8 91.700 200. 8 93.570 200.8 95.400 200.7 98.000 200.7 86.100 200.7 90.700 200.7 92.000 200.7 94.000 200.9 95.500 200.7 98.400 200.7 87.000 200.8 90.700 200.7 92.000 200.7 94.000 200.7 95.600 200.8 98.500 200.7 87.000 200.8 90.900 200.7 92.000 3113B 94.000 200.7 95.700 200.9 99.500 200.8 87.200 200.8 91.000 200.8 92.000 200.7 94.400 3113B 95.700 200.7 101.000 200.9 88.000 200.7 91.400 200.7 92.200 200.7 94.600 200.9 96.000 200.7 104.000 200.7 88.500 200.7 91.400 200.8 92.400 200.8 94.600 200.7 96.200 200.9 109.000 3113B 89.300 200.7 91.500 200.7 92.800 200. 8 94.700 200.7 96.200 other 121.000 200.8 89.700 3120B 91.600 200.7 93. 000 200.7 94.900 other 96.700

## B-55 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 55.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 47.800 200.8 51.900 200.7 53.300 200.7 54.700 200.9 55.900 3113B 57.300 200.8 49.400 200.9 52.000 200.7 53.500 200.7 54.800 200.8 56.000 200.8 57.700 200.7 50.900 200.7 52.600 200.9 54.000 200.9 55.000 200.8 56.400 200.8 58.000 other 51.000 200.9 52.800 200.7 54.000 200.7 55.100 200.8 56.500 200.7 58.270 200.8 51.100 200.7 52.900 200.8 54.300 200.7 55.400 200.7 57.000 3113B 58.600 200.8 51.300 200.7 53.000 200.7 54.400 200.7 55.500 200.9 57.000 3113B 59.800 200.7 51.700 3113B 53.100 200.7 54.500 200.9 55.700 200.8 57.100 3113B 63.000 200.7 51.900 200.7 53.300 200.8 54.600 200.7 55.900 200.9 57.300

1,2-Dibromo-3-chloropropane (DBCP) Water Study: 26 True Value: 1.13 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.661 other 0.910 other 1. 000 other 1.050 504 1.120 504 1.260 504 0.808 504 0.920 504 1.000 504 1.070 504 1.120 504 1.420 other 0.830 504 0.932 504 1.003 504 1.080 other 1.140 other 3.970 other 0.860 504 0.950 504 1. 017 504 1.080 504 1.140 504 5.478 504 0.874 504 0.980 504 1.030 504 1.100 504 1.150 other 7.820 504 0.904 504 0.998 504 1.046 other 1.100 504 1.160 Water Study: 27 True Value: 0.653 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.473 504 0.560 504 0.580 other 0.624 other 0.674 504 0.847 504 0.479 504 0.564 504 0.584 504 0.650 504 0.677 504 1.110 other 0.537 504 0.568 504 0. 600 504 0.660 504 0.702 504 3.490 Water Study: 29 True Value: 1.91 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.952 504 1.480 504 1.640 504 1.680 other 1.710 504 1.810 504 1.400 504 1.560 504 1.640 504 1.680 504 1.740 504 2.020 504 1.407 504 1.620 504 1.660 551 1.690 504 1.750 504 2.810 504 1.480 other 1.635 504 1. 670 504 1.700 other 1.760

## B-56 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 0.98 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.621 504 0.780 504 0. 820 504 0.864 504 0.923 504 1.050 504 0.660 504 0.786 504 0.830 504 0. 870 other 0.929 other 1.420 504 0.680 504 0.790 504 0.832 504 0.870 504 0.930 504 2.200 504 0.732 504 0.800 other 0. 841 504 0.875 504 0.936 504 4.880 other 0.735 504 0.807 504 0.850 504 0.897 504 0.948 504 0.736 504 0.810 504 0.858 504 0.908 504 0.954 504 0.760 other 0.819 504 0.859 504 0.920 504 0.990 Water Study: 31 True Value: 2.65 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 1.710 504 2.110 504 2.200 504 2.300 504 2.375 504 2.429 504 1.760 other 2.110 504 2. 250 504 2.320 504 2.400 504 2.970 504 1.890 other 2.130 504 2. 260 504 2.361 504 2.410 504 12.000 504 2.020 504 2.160 504 2.290 504 2.370 504 2.420 504 17.200 Water Study: 32 True Value: 1.78 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.560 504 1.380 504 1.490 504 1.600 504 1.700 504 1.920 other 1.090 504 1.400 504 1. 500 504 1.630 504 1.700 504 1.940 504 1.200 504 1.400 504 1.500 504 1.630 504 1.730 504 1.970 504 1.270 504 1.412 504 1.500 504 1.640 504 1.750 504 2.460 other 1.290 504 1.421 504 1.570 504 1.650 504 1.760 504 1.330 other 1.450 504 1.570 504 1.660 504 1.790 504 1.360 504 1.470 504 1.580 504 1.670 504 1.790 504 1.370 504 1.470 504 1.600 504 1.680 504 1.800

## B-57 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 0.363 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.067 504 0.281 other 0.312 other 0.333 504 0.354 504 0.420 504 0.078 504 0.284 504 0.313 504 0.333 504 0.360 504 0.455 504 0.130 504 0.284 504 0.317 504 0.336 504 0.373 504 0.463 504 0.239 504 0.289 504 0.318 504 0.336 504 0.377 504 1.530 504 0.251 504 0.304 504 0.320 other 0.340 504 0.385 other 1.900 504 0.269 504 0.305 504 0.323 504 0.341 504 0.388 504 0.276 other 0.306 504 0.325 504 0.350 504 0.390 504 0.280 504 0.307 504 0.327 504 0.352 504 0.390 Water Study: 35 True Value: 0.589 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.350 504 0.454 504 0.500 504 0.527 504 0.567 504 0.394 504 0.465 504 0.504 504 0.530 other 0.592 504 0.408 504 0.473 504 0.508 504 0.539 504 0.663 other 0.438 504 0.476 504 0. 510 504 0.540 other 2.907 other 0.443 504 0.481 504 0.519 504 0.545 504 7.000 504 0.446 504 0.500 other 0.524 504 0.557 Water Study: 36 True Value: 0.196 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.127 504.1 0.176 504.1 0.190 504.1 0.199 504.1 0.210 504.1 0.259 504.1 0.135 504.1 0.179 551 0.192 504. 1 0.200 504.1 0.212 504.1 0.272 504.1 0.145 504.1 0.180 504.1 0.192 504.1 0.201 504.1 0.214 504.1 0.308 504.1 0.156 504.1 0.182 504.1 0.192 other 0.201 504.1 0.217 504.1 0.357 other 0.157 504.1 0.182 504.1 0.192 504. 1 0.203 other 0.220 other 0.580 504.1 0.158 504.1 0.187 other 0 .193 other 0.205 504.1 0.224 504.1 0.170 504.1 0.188 504.1 0 .193 504.1 0.206 504.1 0.227 504.1 0.172 504.1 0.189 504.1 0 .195 504.1 0.210 504.1 0.235 504.1 0.175 504.1 0.190 504.1 0. 196 504.1 0.210 other 0.242

## B-58 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 0.286 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.112 504.1 0.256 504.1 0.273 504. 1 0.283 other 0.302 504.1 0.364 504.1 0.229 504.1 0.259 504.1 0.275 504.1 0.284 504.1 0.303 504.1 0.365 other 0.231 504.1 0.260 504.1 0.275 504.1 0.286 504.1 0.309 504.1 0.377 504.1 0.240 504.1 0.263 other 0.275 504.1 0.289 504.1 0.316 504.1 0.410 504.1 0.245 504.1 0.265 504.1 0.279 504. 1 0.295 other 0.316 504.1 0.468 504.1 0.248 other 0.268 504.1 0. 281 504.1 0.295 551 0.354 504.1 0.843 504.1 0.250 504.1 0.270 other 0.281 504.1 0.299 504.1 0.354 504.1 1.410 Water Study: 38 True Value: 0.429 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.305 504.1 0.367 504.1 0.404 504.1 0.420 504.1 0.449 504.1 0.502 504.1 0.318 504.1 0.370 504.1 0.408 504. 1 0.426 504.1 0.450 other 0.512 504.1 0.331 504.1 0.376 504.1 0.410 504.1 0.437 551 0.456 504.1 0.513 504.1 0.338 504.1 0.400 504.1 0.412 504.1 0.437 504.1 0.469 504.1 0.522 504.1 0.347 504.1 0.400 504.1 0.416 504.1 0.438 504.1 0.471 504.1 0.542 504.1 0.350 504.1 0.401 504.1 0.416 504.1 0.439 504.1 0.473 504.1 0.555 504.1 0.350 other 0.403 551 0.417 other 0.445 504.1 0.486 504.1 0.562 504.1 0.355 504.1 0.404 other 0.419 504.1 0.449 504.1 0.494 504.1 3.960 Water Study: 39 True Value: 0.246 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.175 504.1 0.214 504.1 0.238 504.1 0.250 504.1 0.258 504.1 0.284 504.1 0.184 504.1 0.224 504.1 0.238 504.1 0.254 504.1 0.269 504.1 0.285 504.1 0.193 504.1 0.226 504.1 0.239 504. 1 0.255 504.1 0.275 other 0.308 504.1 0.194 504.1 0.226 504.1 0.239 other 0.255 504.1 0.277 504.1 0.348 504.1 0.212 504.1 0.227 504.1 0.242 504.1 0.255 504.1 0.280 504.1 2.150 504.1 0.212 504.1 0.234 504.1 0.244 504.1 0.255 504.1 0.280 551 2.280

## B-59 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 0.527 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.262 504.1 0.457 504.1 0.491 504.1 0.508 504.1 0.530 504.1 0.545 504.1 0.381 504.1 0.457 504.1 0.494 other 0.511 504.1 0.534 other 0.581 other 0.430 504.1 0.472 504.1 0.495 504.1 0.516 504.1 0.535 504.1 0.643 504.1 0.431 504.1 0.474 504.1 0.496 504. 1 0.518 other 0.537 504.1 0.645 504.1 0.445 504.1 0.474 504.1 0.496 504.1 0.519 504.1 0.537 504.1 0.650 504.1 0.446 504.1 0.475 504.1 0 .501 504.1 0.521 504.1 0.538 504.1 0.452 504.1 0.483 504.1 0 .502 504.1 0.524 504.1 0.538 504.1 0.453 504.1 0.486 504.1 0 .502 504.1 0.529 504.1 0.543 504.1 0.454 other 0.487 other 0.504 504.1 0.530 504.1 0.547 Water Study: 41 True Value: 0.451 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.333 504.1 0.380 504.1 0.399 504.1 0.413 504.1 0.447 504.1 0.520 504.1 0.356 504.1 0.392 504.1 0.403 504.1 0.425 504.1 0.450 504.1 0.526 504.1 0.360 504.1 0.394 504.1 0.406 504.1 0.432 504.1 0.470 504.1 0.532 504.1 0.361 504.1 0.399 504.1 0.409 other 0.432 504.1 0.475 504.1 0.532 504.1 0.370 504.1 0.399 504.1 0 .410 504.1 0.434 504.1 0.491 504.1 0.377 504.1 0.399 504.1 0. 412 504.1 0.446 other 0.516

1,4-Dichlororbenzene Water Study: 24 True Value: 2.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 1.100 502.1 1.970 503.1 2.300 502.2 2.420 524.2 2.520 524.2 2.820 502.1 1.200 502.2 2.020 502.2 2.300 524.2 2.430 524.2 2.530 502.1 2.900 524.1 1.670 524.2 2.106 524.2 2.300 502.2 2.470 502.2 2.580 502.2 2.930 502.2 1.710 524.2 2.180 524.2 2.300 502.2 2.480 524.2 2.580 502.2 3.000 502.2 1.730 524.2 2.200 524.1 2.320 502.2 2.493 524.2 2.590 502.2 3.000 524.2 1.870 502.2 2.200 502.2 2.330 other 2.500 502.2 2.600 524.2 3.160 524.1 1.900 524.2 2.220 502.2 2.360 524.1 2.500 524.2 2.700 524.2 3.310 502.2 1.900 503.1 2.260 502.2 2 .370 524.2 2.520 502.2 2.730 502.2 1.940 524.1 2.280 524.2 2 .390 524.2 2.520 524.2 2.759 502.1 1.960 502.2 2.290 other 2 .400 524.1 2.520 502.2 2.770

## B-60 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 25 True Value: 20.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 13.840 524.2 18.720 502.2 20.000 524. 2 20.900 502.1 21.900 other 26.800 524.2 15.600 502.2 19.000 502.2 20.000 524. 2 20.900 other 22.400 524.2 28.000 502.2 15.600 502.1 19.300 other 20.070 524.2 21.300 502.2 23.400 502.2 16.200 524.2 19.59 524.2 20.380 524.1 21.400 524.1 23.400 502.2 17.000 524.1 19.600 502.2 20.400 502.2 21.400 502.2 24.000 524.2 18.600 502.2 19.900 502.2 20.410 524.2 21.800 502.2 24.400 524.1 18.700 524.1 20.000 524.2 20.600 524.2 21.800 502.2 24.600 Water Study: 26 True Value: 14.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.520 502.2 13.100 502.2 14.100 502.2 14.500 502.2 15.300 524.2 16.000 524.1 10.600 502.2 13.100 524.2 14.100 524.2 14.600 502.2 15.300 503.1 16.100 502.1 11.500 502.2 13.400 502.2 14.100 502.2 14.800 502.2 15.400 502.2 16.190 502.1 11.700 502.2 13.400 502.2 14.150 502.2 14.800 502.2 15.500 524.2 16.200 524.2 12.300 503.1 13.500 524.2 14.180 502.2 14.800 524.2 15.500 524.2 16.500 524.2 12.800 524.2 13.800 503.1 14.200 524.2 14.800 524.2 15.500 524.1 16.900 other 12.800 524.2 13.900 524.2 14.210 524.2 14.900 524.2 15.600 502.1 16.900 502.2 12.800 524.2 14.000 524.2 14.300 502.2 15.100 524.2 15.700 524.1 17.500 524.2 12.810 524.2 14.000 524.2 14.400 502.2 15.100 524.2 15.700 502.2 17.500 502.2 13.000 524.1 14.100 other 14.400 524.2 15.100 502.2 15.900 524.1 22.100 Water Study: 27 True Value: 9.58 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 7.570 524.2 8.810 524.2 9.280 524.2 9.750 524.2 10.200 502.2 11.000 502.2 7.650 502.2 8.840 502.2 9.320 524.2 9.780 502.2 10.300 524.2 12.030 502.2 7.850 524.2 8.930 502.2 9.340 524.2 9.800 524.2 10.300 524.2 12.820 524.2 8.290 other 9.000 502.2 9 .530 524.1 9.820 502.2 10.500 502.2 8.320 other 9.060 other 9.550 502.2 9.900 524.1 10.600 502.2 8.600 502.2 9.090 502.2 9 .630 524.2 9.950 524.1 10.700 524.2 8.800 502.2 9.210 502.2 9 .720 524.2 10.100 502.2 10.900

## B-61 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 6.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.420 524.2 5.700 502.2 6.177 524.2 6.800 502.2 7.360 524.1 7.910 524.2 4.660 other 5.950 other 6. 240 502.2 6.810 502.2 7.480 524.2 8.300 524.2 5.000 524.1 6.040 524.2 6.420 502.2 6.980 524.2 7.600 502.2 8.960 502.2 5.150 524.2 6.040 502.2 6.498 other 7.013 524.2 7.700 524.2 10.600 502.2 5.170 502.2 6.070 524.2 6 .620 524.2 7.030 502.2 7.730 502.2 5.680 other 6.120 502.2 6 .620 502.2 7.180 524.2 7.800 Water Study: 30 True Value: 16.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 10.800 502.1 14.210 502.2 15.300 502.2 16.000 502.2 16.510 524.2 17.100 524.2 11.400 502.2 14.400 524.1 15.500 524.2 16.000 502.2 16.600 524.2 17.200 524.2 11.500 524.2 14.400 524.2 15.500 502.2 16.000 524.1 16.700 502.2 17.500 524.2 12.200 524.2 14.420 524.2 15.500 524.2 16.100 502.2 16.700 524.2 18.100 502.2 12.500 524.2 14.700 524.2 15.500 502.2 16.110 524.2 16.800 502.2 18.300 502.2 12.700 524.2 14.760 524.2 15.700 502.2 16.200 524.2 16.800 524.2 19.400 524.2 13.740 524.2 14.980 524.2 15.700 other 16.200 503.1 16.820 502.2 20.100 524.2 13.900 524.2 15.100 502.2 15.800 524.1 16.300 524.2 16.900 502.2 22.500 502.2 14.000 524.2 15.100 502.2 15.800 502.2 16.300 502.2 16.900 502.2 14.100 502.2 15.300 other 15.980 502.2 16.500 502.2 17.000 Water Study: 31 True Value: 9.40 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 6.610 524.2 8.000 524.2 8.680 524.2 9.200 524.2 9.770 524.2 10.100 503.1 7.630 524.2 8.080 502.1 8.890 502.2 9.270 524.2 9.830 524.2 10.200 502.2 7.840 524.1 8.200 502.2 8.990 502.2 9.300 502.2 9.940 524.2 10.220 502.2 7.850 502.2 8.260 524.2 8.990 524.2 9.590 502.1 9.940 502.2 11.000 502.2 7.880 502.2 8.356 502.2 9.090 503.1 9.600 502.2 10.000 502.2 11.700 502.2 7.900 524.1 8.390 502.2 9.180 524. 2 9.620 524.2 10.000 other 14.900

## B-62 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 13.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.150 502.2 12.200 524.2 12.760 other 13.4000 502.2 13.800 502.2 15.200 502.1 10.600 502.2 12.300 524.2 12.800 524.2 13.400 524.2 13.800 502.2 15.400 502.2 10.800 524.2 12.340 502.2 12.800 524.2 13.500 524.2 13.900 502.2 15.500 502.2 11.100 524.2 12.400 503.1 12.900 other 13.500 502.2 14.000 524.2 15.800 502.2 11.700 524.2 12.600 524.2 12.900 502.2 13.500 524.2 14.000 524.2 15.900 524.2 11.800 524.2 12.700 524.2 12.900 502.2 13.600 524.2 14.140 502.2 19.200 524.2 11.800 524.2 12.700 524.2 13.000 502.2 13.600 524.2 14.400 524.2 12.000 502.2 12.700 502.2 13.100 502.2 13.600 524.2 14.400 524.1 12.000 502.1 12.700 502.2 13.200 524.2 13.630 502.2 14.500 502.2 12.100 502.1 12.700 524.2 13.270 524.2 13.700 524.2 14.900 502.2 12.200 524.2 12.700 524.2 13.360 502.2 13.700 524.2 15.000 Water Study: 33 True Value: 15.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.980 524.2 12.810 524.2 13.800 524.2 14.800 524.2 15.200 524.2 17.000 other 10.730 502.2 13.000 502.2 14.000 502.2 14.900 502.2 15.500 524.2 17.400 524.2 11.500 524.2 13.300 524.2 14.200 524.2 14.990 502.1 16.000 524.2 19.000 502.2 11.800 502.2 13.400 524.2 14.400 502.2 15.000 502.2 16.100 502.2 12.190 524.2 13.600 502.2 14.420 502.2 15.000 502.1 16.200 524.1 12.500 502.2 13.600 502.2 14.500 502.2 15.200 502.2 16.800 Water Study: 34 True Value: 5.78 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 3.750 502.2 4.888 502.2 5.250 502.2 5.490 502.2 5.800 524.2 6.110 524.2 3.760 502.2 4.970 524.2 5.260 502.2 5.490 502.2 5.820 524.2 6.130 524.2 4.300 524.2 5.040 524.2 5.260 524.2 5.510 502.2 5.840 524.2 6.130 524.2 4.530 524.2 5.060 502.2 5.290 502.2 5.530 524.2 5.860 502.2 6.160 502.2 4.580 502.2 5.060 524.2 5.300 524.2 5.580 524.2 5.900 502.2 6.160 502.2 4.710 524.2 5.080 524.2 5.330 524.2 5.600 502.2 5.920 524.2 6.530 502.2 4.780 502.2 5.080 524.2 5.400 524. 2 5.620 524.2 5.940 other 6.800 502.2 4.800 502.2 5.130 502.2 5.430 524.2 5.700 524.2 5.990 524.2 7.060 502.2 4.800 502.2 5.150 524.2 5.440 524.2 5.700 524.2 6.000 524.2 7.790 524.2 4.860 502.2 5.250 524.2 5 .460 502.2 5.800 502.2 6.030

## B-63 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 16.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 13.300 524.2 14.700 524.2 15.600 524.2 16.100 524.2 16.700 524.2 18.200 502.2 13.800 502.2 15.000 524.2 15.800 524.2 16.200 524.2 16.700 524.2 18.290 502.2 13.800 524.2 15.000 524.2 16.000 502.2 16.370 524.2 16.800 502.2 22.300 502.2 13.930 524.2 15.400 502.2 16.000 502.2 16.400 502.2 16.900 502.2 14.560 502.2 15.600 502.2 16.000 524.2 16.400 502.2 17.700 other 14.620 524.2 15.600 502.2 16.100 524.2 16.600 524.2 17.700 Water Study: 36 True Value: 11.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.390 524.2 10.500 524.2 11.000 524.2 11.500 502 11.900 other 12.400 524.2 9.220 502.2 10.600 524.2 11.000 502. 2 11.500 524.2 12.000 other 12.500 502.2 10.000 502.2 10.610 524.2 11.090 524.2 11.600 502.2 12.000 524.2 12.500 524.2 10.010 524.2 10.800 524.2 11.100 502.2 11.600 524.2 12.090 502.2 12.600 524.2 10.100 524.2 10.900 524.2 11.100 502.2 11.700 502.2 12.100 524.2 12.800 502.2 10.100 502.2 10.900 502.2 11.200 524.2 11.700 524.2 12.110 502.2 13.000 524.2 10.200 524.2 10.950 502.2 11.300 524.2 11.700 502.2 12.200 502.2 13.100 524.2 10.300 502.2 11.000 524.2 11.300 524. 2 11.740 524.2 12.300 other 13.200 524.2 10.300 524.2 11.000 524.2 11.400 524.2 11.800 524.2 12.300 524.2 14.000 502.2 10.300 524.2 11.000 524.2 11.400 502.2 11.900 502.2 12.300 524.2 15.800 Water Study: 37 True Value: 7.31 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.730 524.2 6.010 524.2 6.500 524.2 7.000 502.2 7.570 524.2 8.180 502.2 4.870 502.2 6.100 524.2 6.500 502.2 7.060 524.2 7.830 524.2 8.280 524.2 5.280 502.2 6.240 502.2 6.520 502.2 7.060 502.2 7.840 524.2 8.470 502.2 5.370 524.2 6.340 502.2 6.570 502. 2 7.180 502.2 7.890 other 9.500 524.2 5.480 502.2 6.360 524.2 6.630 524.2 7.230 502.2 7.920 524.2 9.580 524.2 5.560 502.2 6.390 524.2 6.690 524.2 7.260 524.2 8.000 524.2 11.500 524.2 5.670 524.2 6.390 524.2 6.920 524.2 7.350 524.2 8.110 524.2 14.200 524.2 5.800 502.2 6.460 524.2 7. 000 502.2 7.450 other 8.150

## B-64 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 14.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.890 502.2 10.300 502.2 11.000 524.2 11.600 524.2 12.000 502.2 12.600 524.2 9.370 524.2 10.400 524.2 11.100 524.2 11.600 502.2 12.000 524.2 12.700 524.2 9.560 524.2 10.500 524.2 11.100 524.2 11.600 502.2 12.100 502.2 12.800 524.2 9.630 502.2 10.500 502.2 11.100 502.2 11.600 502.2 12.100 524.2 13.000 524.2 9.860 524.2 10.500 524.2 11.100 502.2 11.600 524.2 12.100 524.2 13.000 524.2 9.980 other 10.600 524.2 11.200 524.2 11.640 524.2 12.300 524.2 13.000 502.2 10.000 502.2 10.750 524.2 11.400 502.2 11.700 524.2 12.300 524.2 13.100 502.2 10.000 502.2 10.800 524.2 11.500 524.2 11.900 502.2 12.400 524.2 13.500 502.2 10.300 524.2 11.000 other 11.500 524.2 12.000 524.2 12.500 524.2 13.630 Water Study: 39 True Value: 17.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 11.200 524.2 15.800 502.2 16.500 524.2 17.000 524.2 17.700 524.2 18.600 524.2 12.200 502.2 15.900 502.2 16.500 524.2 17.100 524.2 17.770 502.2 18.700 502.2 14.200 524.2 15.900 524.2 16.600 524.2 17.100 502.2 18.000 524.2 19.200 524.2 15.300 524.2 16.200 524.2 16.800 502.2 17.200 524.2 18.000 524.2 19.300 502.2 15.300 524.2 16.200 524.2 16.800 502.2 17.300 502.2 18.000 524.2 20.100 524.2 15.600 524.2 16.400 502.2 16.900 524.2 17.600 524.2 18.300 524.2 22.800 524.2 15.700 524.2 16.400 524.2 17.000 502.2 17.600 502.2 18.300 524.2 40.170 Water Study: 40 True Value: 11.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 7.930 524.2 10.000 502.2 10.700 524.2 11.100 524.2 11.500 502.2 12.300 502.2 8.100 524.2 10.100 524.2 10.700 524.2 11.200 524.2 11.600 524.2 13.400 524.2 8.240 502.2 10.400 524.2 10.700 524.2 11.200 502.2 11.600 524.2 13.600 502.2 9.210 524.2 10.500 524.2 10.800 502.2 11.200 524.2 11.800 524.2 13.800 524.2 9.320 502.2 10.500 524.2 10.800 524.2 11.200 524.2 11.800 524.2 14.200 502.2 9.500 524.2 10.500 other 10.800 524.2 11.300 502.2 11.900 502.2 14.500 524.2 9.880 524.2 10.600 502.2 10.800 502.2 11.300 524.2 12.100 524.2 15.000 524.2 9.910 524.2 10.600 524.2 10.800 524.2 11.400 502.2 12.100 524.2 9.940 524.2 10.600 524.2 11.000 524.2 11.400 502.2 12.200 524.2 10.000 524.2 10.700 524.2 11.100 524.2 11.500 524.2 12.200

## B-65 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 15.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.800 524.2 13.800 502.2 14.300 524.2 15.090 502.2 15.400 524.2 16.000 524.2 11.900 524.2 13.800 524.2 14.400 524.2 15.100 524.2 15.400 502.2 16.100 524.2 12.000 524.2 13.900 524.2 14.500 524. 2 15.100 other 15.400 502.2 16.200 524.2 12.800 524.2 14.000 502.2 14.700 502.2 15.200 524.2 15.500 524.2 16.800 524.2 13.000 524.2 14.100 502.2 14.800 524.2 15.300 524.2 15.700 524.2 17.000 502.2 13.700 502.2 14.100 502.2 14.800 524.2 15.300 524.2 15.800 524.2 17.300 524.2 13.800 524.2 14.100 524.2 15.000 502.2 15.400 524.2 15.900 502.2 18.100

1,2-Dichloroethane Water Study: 24 True Value: 13.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 7.750 502.2 11.400 524.2 12.140 502.2 12.900 502.2 13.600 524.2 14.200 502.1 9.100 502.2 11.600 502.1 12.200 524.2 12.900 524.2 13.680 502.1 14.300 502.2 9.220 502.2 11.700 524.1 12.200 502.2 13.000 524.2 13.700 502.2 14.700 524.1 9.820 502.2 11.800 524.2 12.200 524.2 13.000 524.2 13.700 502.2 14.700 502.1 10.000 502.2 11.900 502.2 12.300 502. 2 13.200 524.1 13.700 other 15.500 other 10.600 524.2 11.900 524.2 12.500 502.2 13.200 524.2 13.700 502.2 17.000 524.1 10.660 524.2 12.000 524.1 12.600 524.2 13.500 502.1 13.900 524.2 10.700 524.2 12.030 502.2 12.600 502.2 13.500 524.2 14.000 502.2 11.000 524.2 12.100 524.2 12.600 502.2 13.500 524.2 14.000 502.2 11.100 502.2 12.100 502.1 12.900 502.2 13.510 524.2 14.000 Water Study: 25 True Value: 15.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 11.000 524.2 14.260 502.2 15.000 502.1 15.800 524.1 16.600 502.2 18.500 502.2 11.200 502.1 14.500 502.2 15.130 other 15.900 524.2 16.800 other 19.700 524.2 12.610 524.1 14.500 524.2 15.380 502.2 16.300 524.2 16.900 524.2 21.000 502.2 13.350 524.1 14.500 502.2 15.400 502.1 16.400 502.2 17.000 502.2 13.500 524.2 14.530 524.2 15.600 502.2 16.400 524.2 17.000 other 13.910 524.1 14.600 502.2 15.600 502.2 16.400 502.2 17.700 524.2 14.200 502.2 14.900 524.2 15.600 524.2 16.600 502.2 18.100

## B-66 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26 True Value: 10.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.140 502.1 10.400 524.2 11.000 524.2 11.350 502.2 12.000 524.2 12.300 524.2 9.730 502.2 10.400 524.2 11.000 524.2 11.400 524.2 12.000 524.1 12.400 524.1 9.800 502.2 10.500 502.2 11.000 524.2 11.400 502.2 12.000 524.2 12.400 524.2 9.800 502.2 10.500 524.2 11.100 524.2 11.500 524.2 12.000 502.1 12.500 502.2 9.810 other 10.500 524.2 11.100 other 11.600 502.1 12.100 502.1 12.500 524.2 9.960 524.1 10.500 502.2 11.100 502.2 11.600 502.2 12.100 502.2 12.600 524.2 10.100 502.2 10.700 502.2 11.200 502.2 11.700 524.2 12.200 502.2 12.750 502.2 10.200 524.2 10.780 502.2 11.200 502.1 11.700 524.1 12.200 524.2 13.800 502.2 10.200 524.2 10.800 502.2 11.300 524.1 11.900 502.2 12.200 502.2 17.300 524.2 10.400 524.2 11.000 502.1 11.300 524.2 11.900 502.2 12.300 Water Study: 27 True Value: 4.88 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.080 524.2 4.600 524.2 5.000 524.2 5.300 502.2 5.650 524.1 6.610 502.2 4.360 502.2 4.630 524.2 5.090 524. 2 5.310 502.2 5.730 other 6.610 524.2 4.490 524.2 4.740 502.2 5 .100 524.2 5.360 502.2 5.780 502.2 4.500 502.2 4.790 524.1 5. 150 other 5.390 other 5.800 502.2 4.500 502.2 4.800 502.2 5 .160 502.1 5.400 524.2 5.920 524.2 4.510 502.2 4.800 524.2 5 .260 502.2 5.460 502.2 6.230 502.2 4.530 524.2 4.800 524.2 5 .270 524.2 5.560 502.2 6.350 Water Study: 29 True Value: 12.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.360 524.2 12.400 502.2 12.800 524.1 13.300 524.1 14.200 524.2 16.400 502.2 10.650 502.2 12.500 524.2 13.000 524. 2 13.760 other 14.670 524.2 16.500 524.2 11.100 502.2 12.700 502.2 13.100 502.2 13.800 502.2 14.800 502.2 17.700 524.2 12.000 502.2 12.700 502.2 13.170 524. 2 13.800 524.2 15.800 other 17.800 524.2 12.290 502.2 12.700 524.2 13. 200 other 13.800 502.2 16.000 524.2 12.300 502.2 12.700 524.2 13.200 502.2 13.880 524.2 16.100

## B-67 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 7.69 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 6.210 502.2 7.300 524.2 7.600 524.2 7.800 502.2 7.900 502.2 8.610 502.2 6.400 524.2 7.340 524.2 7.610 502.2 7.800 502.2 7.900 524.1 8.650 524.2 6.580 502.2 7.370 502.2 7.700 524.2 7.800 502.2 8.010 502.1 8.740 502.2 6.600 524.2 7.400 524.2 7.700 524.2 7.800 524.2 8.030 502.2 8.770 524.2 6.700 524.2 7.460 502.1 7.710 524. 2 7.800 other 8.130 524.2 8.800 502.2 6.880 524.2 7.500 other 7.725 524.1 7.830 524.2 8.140 502.2 8.870 524.2 6.930 524.2 7.500 502.2 7.740 524.1 7.850 502.2 8.160 502.2 9.330 524.2 6.980 524.2 7.530 502.2 7.753 524.2 7.850 502.2 8.160 524.2 10.030 502.2 7.020 524.2 7.540 524.2 7.770 524. 2 7.860 other 8.390 502.2 19.820 502.2 7.220 502.2 7.600 524.2 7 .790 502.2 7.870 502.2 8.510 Water Study: 31 True Value: 9.25 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.240 524.2 8.610 524.1 9.060 502.2 9.320 502.2 9.720 502.2 10.100 502.1 7.470 502.2 8.620 502.2 9.060 524.2 9.460 524.2 9.730 502.1 10.300 524.2 8.200 502.1 8.850 524.2 9.130 524.2 9.480 502.1 9.890 524.2 10.300 502.2 8.350 502.2 8.876 524.2 9.200 502. 2 9.500 524.2 9.890 other 10.300 524.2 8.380 502.2 8.930 524.2 9.200 502.2 9.590 524.2 9.900 524.2 10.310 524.2 8.510 502.2 8.970 524.2 9.270 502.2 9.660 502.2 9.980 502.2 11.300 Water Study: 32 True Value: 13.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 9.450 524.2 12.300 502.2 12.900 524.2 13.300 524.2 14.100 524.2 14.660 502.1 9.960 502.2 12.400 524.2 12.900 502.2 13.300 502.2 14.100 524.2 15.100 502.2 11.200 502.2 12.500 524.2 13.000 other 13.500 524.2 14.200 524.2 15.300 502.2 11.400 502.1 12.600 502.2 13.000 524.2 13.500 502.2 14.300 502.2 15.400 502.2 11.400 502.1 12.700 524.2 13.000 502.2 13.600 524.2 14.300 524.2 15.600 524.2 11.400 524.2 12.700 502.1 13.000 524.2 13.600 524.2 14.320 524.2 15.600 524.2 11.500 524.2 12.700 502.2 13.200 502. 2 13.700 502.2 14.400 other 16.200 502.2 11.700 502.2 12.700 524.2 13.250 524. 2 13.720 other 14.400 524.2 16.500 524.2 12.100 524.2 12.800 502.2 13.300 524.2 13.800 502.2 14.400 502.2 12.200 502.2 12.800 524.2 13.300 524.2 13.900 502.2 14.500 524.2 12.240 524.2 12.900 524.1 13.300 524.2 14.000 502.2 14.600

## B-68 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 16.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.800 524.2 15.300 524.2 16.400 502.2 17.100 524.2 17.900 502.2 18.900 other 14.270 524.2 15.340 524.2 16.500 502.2 17.100 524.2 18.100 502.1 19.500 502.1 14.600 502.2 15.500 524.2 16.520 502.2 17.200 524.2 18.100 502.2 19.570 524.2 14.700 502.2 15.570 524.1 16.600 524.2 17.230 502.2 18.200 524.2 19.800 502.2 15.200 502.2 16.200 502.2 16.700 502.2 17.700 524.2 18.300 524.2 20.000 524.2 15.300 502.2 16.300 502.2 17.100 524.2 17.800 524.2 18.700 Water Study: 34 True Value: 12.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 9.480 502.2 11.000 502.2 11.700 524.2 12.100 502.2 12.430 524.2 12.900 other 9.700 524.2 11.200 524.2 11.700 502.2 12.100 524.2 12.500 502.2 12.900 502.2 10.000 502.2 11.200 524.2 11.800 502.2 12.150 502.2 12.500 524.2 13.000 524.2 10.200 524.2 11.300 502.2 11.900 524. 2 12.200 524.2 12.600 other 13.100 524.2 10.300 502.2 11.400 524.2 11.900 524.2 12.300 502.2 12.600 524.2 13.200 502.1 10.300 524.2 11.400 502.2 11.900 502.2 12.300 524.2 12.600 502.2 13.200 502.2 10.400 524.2 11.570 502.2 12.000 524.2 12.400 524.2 12.790 524.2 13.400 502.2 10.600 502.2 11.600 502.2 12.000 524.2 12.400 524.2 12.800 502.2 13.500 524.2 10.990 502.2 11.600 524.2 12.000 524.2 12.400 524.2 12.870 524.2 13.500 502.2 11.000 524.2 11.700 524.2 12.100 502.2 12.400 502.2 12.900 502.2 14.400 Water Study: 35 True Value: 14.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.520 502.2 13.400 502.2 13.800 524.2 14.700 502.2 15.300 502.2 15.700 502.2 11.900 524.2 13.500 other 13.860 524.2 14.800 524.2 15.300 502.2 16.400 524.2 13.000 524.2 13.650 524.2 14.100 502.2 15.010 502.2 15.400 524.2 16.400 524.2 13.000 524.2 13.700 502.2 14.100 502.2 15.020 502.2 15.500 524.2 17.700 502.2 13.200 524.2 13.700 524.2 14.200 524.2 15.200 524.2 15.500 502.2 13.380 524.2 13.700 524.2 14. 700 502.2 15.300 other 15.600

## B-69 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 9.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.240 502.2 8.270 524.2 8.600 524.2 8.950 524.2 9.220 502.2 9.870 524.2 7.490 524.2 8.300 524.2 8.640 524.2 9.000 524.2 9.220 502.2 9.880 524.2 7.820 502.2 8.300 524.2 8.680 524.2 9.030 502.2 9.300 524.2 9.900 502.2 7.840 524.2 8.340 524.2 8.690 502. 2 9.040 524.2 9.480 other 10.100 502.2 7.840 524.2 8.350 524.2 8.700 502.2 9.080 524.2 9.670 502.2 10.400 524.2 7.890 524.2 8.350 524.2 8.740 502.2 9.090 502.2 9.700 524.2 10.480 524.2 7.930 524.2 8.450 502.2 8.790 524.2 9.100 502.2 9.710 502.2 11.300 524.2 7.950 502.2 8.460 524.2 8.840 524. 2 9.120 502.2 9.710 other 11.500 524.2 8.130 524.2 8.490 502.2 8.900 502.2 9.120 502.2 9.740 524.2 11.820 502.2 8.240 524.2 8.570 other 8 .930 524.2 9.200 502.2 9.770 Water Study: 37 True Value: 13.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.800 524.2 13.100 524.2 13.400 502.2 14.200 524.2 14.700 524.2 16.900 524.2 11.900 524.2 13.100 502.2 13.400 524.2 14.200 502.2 15.000 524.2 17.000 524.2 11.920 524.2 13.100 502.2 13.500 524.2 14.230 502.2 15.100 524.2 17.150 502.2 12.000 524.2 13.100 524.2 13.600 524.2 14.300 502.2 15.100 524.2 17.600 502.2 12.100 524.2 13.100 524.2 13.700 524.2 14.400 524.2 15.200 502.2 18.800 524.2 12.400 524.2 13.260 524.2 13.700 524.2 14.400 502 15.800 524.2 20.600 524.2 12.500 524.2 13.300 502.2 14.000 502. 2 14.400 other 15.900 524.2 27.500 502.2 12.800 502.2 13.400 502.2 14. 200 502.2 14.700 other 16.600 Water Study: 38 True Value: 15.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.210 524.2 14.900 502.2 15.300 524.2 15.900 502.2 16.100 524.2 16.750 524.2 12.100 524.2 15.000 524.2 15.400 524.2 15.900 502.2 16.100 524.2 16.800 502.2 13.380 524.2 15.000 524.2 15.600 502.2 15.900 524.2 16.200 502.2 17.300 524.2 14.400 524.2 15.000 502.2 15.600 502. 2 16.000 other 16.300 502.2 17.400 502.2 14.400 502.2 15.100 524.2 15.700 502.2 16.000 524.2 16.300 524.2 17.400 524.2 14.500 524.2 15.100 other 15.800 502.2 16.000 524.2 16.500 502.2 17.500 524.2 14.700 524.2 15.200 502.2 15.800 524.2 16.080 524.2 16.500 524.2 17.800 524.2 14.800 524.2 15.200 524.2 15.800 524.2 16.100 502.2 16.700 524.2 18.900 524.2 14.900 524.2 15.300 502.2 15.800 524.2 16.100 524.2 16.700 524.2 21.200

## B-70 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 17.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 12.200 524.2 16.700 524.2 17.100 524.2 17.900 524.2 18.600 524.2 19.700 524.2 13.500 524.2 16.700 524.2 17.100 502.2 18.000 502.2 18.800 524.2 20.100 502.2 15.500 502.2 16.800 524.2 17.300 524.2 18.070 524.2 18.800 524.2 20.700 502.2 15.700 524.2 16.800 524.2 17.400 502.2 18.100 524.2 18.800 524.2 21.200 502.2 15.900 524.2 16.900 502.2 17.500 524.2 18.100 524.2 18.900 524.2 21.400 524.2 15.900 502.2 17.000 524.2 17.500 524.2 18.200 502.2 19.400 524.2 21.600 524.2 16.400 524.2 17.100 502.2 17.800 502.2 18.400 502.2 19.500 524.2 28.500 Water Study: 40 True Value: 15.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 14.000 524.2 16.700 524.2 17.100 524.2 17.600 524.2 18.300 502.2 20.100 524.2 14.700 502.2 16.800 524.2 17.200 502. 2 17.700 other 18.300 524.2 20.300 524.2 14.700 524.2 16.800 524.2 17.260 524.2 17.800 524.2 18.400 524.2 20.500 524.2 15.200 524.2 16.800 524.2 17.300 502.2 17.900 502.2 18.500 524.2 20.600 524.2 15.400 524.2 16.900 524.2 17.300 524.2 17.900 524.2 18.600 524.2 20.600 524.2 16.200 502.2 16.900 524.2 17.400 524.2 18.000 524.2 18.700 524.2 21.200 502.2 16.200 502.2 16.900 502.2 17.400 524.2 18.000 524.2 18.800 524.2 23.300 524.2 16.300 524.2 16.900 502.2 17.500 524.2 18.200 502.2 18.900 524.2 16.300 502.2 17.000 502.2 17.500 524.2 18.300 502.2 19.300 other 16.500 502.2 17.100 524.2 17.500 524.2 18.300 524.2 19.600 Water Study: 41 True Value: 13.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 12.000 524.2 13.100 524.2 13.500 524.2 13.920 524.2 14.230 524.2 15.300 524.2 12.200 524.2 13.300 524.2 13.600 524.2 14.000 524.2 14.300 502.2 15.800 524.2 12.300 524.2 13.300 524.2 13.600 524.2 14.000 502.2 14.500 524.2 16.300 502.2 12.600 502.2 13.400 524.2 13.700 502.2 14.100 502.2 14.600 502.2 16.700 524.2 12.600 524.2 13.500 524.2 13.700 502.2 14.200 524.2 14.700 524.2 17.000 502.2 12.800 524.2 13.500 524.2 13.700 524.2 14.200 502.2 15.100 502.2 18.000 524.2 12.800 524.2 13.500 524.2 13. 800 other 14.200 524.2 15.100

## B-71 Methods Support Document for Six-Year Review Final - March 2003 1,1-Dichloroethylene Water Study: 24 True Value: 5.36ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.000 524.2 4.900 524.2 5.220 502.2 5.430 502.1 5.990 502.2 8.290 524.1 4.060 524.2 4.900 502.1 5.250 502.2 5.500 524.2 6.100 502.2 8.400 524.2 4.250 502.2 4.950 502.2 5.290 502.2 5.550 524.1 6.200 502.2 8.660 502.1 4.290 502.2 4.993 524.2 5.300 524.2 5.600 524.1 6.420 502.1 8.880 502.2 4.420 524.2 5.000 502.2 5.350 other 5.600 502.2 6.500 524.2 9.510 502.2 4.480 524.2 5.030 524.2 5.380 524. 2 5.680 502.2 6.750 other 10.600 524.1 4.520 502.1 5.100 524.1 5.380 502.2 5.710 502.2 6.800 524.2 10.800 502.2 4.880 502.2 5.180 502.2 5 .380 502.2 5.720 524.1 6.810 524.2 4.890 502.1 5.200 524.2 5 .400 524.2 5.742 524.2 7.210 502.2 4.900 other 5.200 524.2 5 .430 524.2 5.820 524.2 7.333 Water Study: 25 True Value: 14.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 10.500 524.2 13.610 524.1 15.100 other 16.500 524.2 17.900 524.1 20.100 524.2 12.100 502.2 13.700 524.2 15.200 524. 2 16.800 502.2 18.300 other 29.700 502.2 12.600 502.2 14.500 502.2 15.700 524.2 17.010 502.2 18.600 524.2 38.200 502.2 12.700 524.2 14.600 502.2 15.800 502.1 17.100 502.2 18.800 502.1 13.400 502.2 14.810 other 15.970 524.2 17.130 524.2 18.800 502.2 13.400 502.1 15.000 524.1 16.300 524.1 17.300 502.2 19.000 502.2 13.610 524.2 15.100 524.2 16.300 502.2 17.400 502.2 19.500 Water Study: 26 True Value: 6.64 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.583 502.2 6.450 524.2 6.740 502.1 7.380 524.1 7.790 524.2 8.420 524.2 5.600 524.2 6.500 502.2 6.790 524.2 7.390 502.2 7.820 524.2 8.590 524.2 5.640 502.2 6.560 502.2 6.850 502.1 7.390 502.1 7.820 524.2 8.600 502.2 5.700 502.2 6.580 524.1 6.980 other 7.390 502.1 7.870 524.2 8.900 502.2 5.730 502.2 6.590 524.2 6.980 524.2 7.400 524.2 7.894 524.1 8.930 502.1 6.030 502.2 6.600 524.2 6.980 502.2 7.550 524.2 7.920 524.2 9.000 524.1 6.050 other 6.700 502.2 7.060 524.2 7.580 502.2 7.960 502.1 9.200 524.2 6.100 524.2 6.710 524.1 7.130 502.2 7.600 524.2 8.000 502.2 9.380 502.2 6.200 502.2 6.730 524.2 7.170 524.2 7.630 524.2 8.300 502.2 9.490 502.2 6.400 502.2 6.730 524.2 7.180 524.2 7.690 502.2 8.300 502.2 15.900

## B-72 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 9.45 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 4.180 524.2 9.050 502.2 9.500 other 10.100 502.2 11.100 524.1 15.700 524.2 6.580 524.2 9.160 524.2 9.500 524.2 10.200 524.1 11.200 502.2 16.400 502.2 7.380 502.2 9.300 524.2 9 .560 524.2 10.200 502.2 11.400 524.2 8.040 502.2 9.400 other 9 .580 502.2 10.300 502.2 11.400 524.2 8.260 524.2 9.430 502.1 9 .780 502.2 10.400 502.2 12.000 524.2 8.300 502.2 9.470 502.2 9 .980 502.2 10.400 524.2 12.110 524.2 8.950 502.2 9.500 502.2 10.000 524.2 10.610 502.2 13.300 Water Study: 29 True Value: 11.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.200 502.2 11.600 502.2 12.100 502.2 12.500 524.2 13.900 502.2 15.800 502.2 10.500 524.1 11.700 502.2 12.100 other 12.500 other 13.960 502.2 16.000 524.2 10.600 other 11.700 524.2 12.200 524.2 12.700 502.2 14.600 524.2 16.500 502.2 10.800 502.2 11.800 524.2 12.200 524.2 12.740 524.1 14.600 502.2 16.900 524.2 11.300 524.2 12.000 524.2 12.400 524.2 12.750 502.2 15.500 502.2 17.390 524.2 11.300 524.2 12.000 524.2 12.400 502.2 13.700 502.2 15.650 Water Study: 30 True Value: 14.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.950 502.2 13.400 524.2 14.000 502.2 14.800 502.2 15.700 502.1 17.100 502.2 11.400 524.2 13.600 502.2 14.100 524.2 15.000 502.2 15.780 502.2 17.200 524.2 11.940 524.2 13.600 524.2 14.100 524.2 15.000 524.2 15.800 502.2 17.300 524.2 12.300 524.2 13.700 524.2 14.200 502. 2 15.300 524.2 15.900 other 17.440 524.2 12.910 524.2 13.800 524.1 14.400 502.2 15.300 502.2 15.900 524.2 17.800 502.2 13.000 502.2 13.810 502.2 14.500 524.1 15.400 524.2 16.000 502.2 17.900 524.2 13.000 other 13.900 524.2 14.520 502.1 15.420 524.2 16.300 502.1 19.330 502.2 13.100 502.2 13.900 524.2 14.600 502.2 15.500 502.2 16.600 524.2 20.300 502.2 13.300 other 13.900 524.2 14.720 524.2 15.500 524.1 16.800 502.1 20.600 502.2 13.400 524.2 14.000 524.2 14.800 502.2 15.600 524.2 16.800

## B-73 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 7.02 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 3.400 502.2 6.812 502.1 7.480 502.2 7.670 502.2 8.470 502.2 9.420 524.2 5.803 524.2 6.820 502.2 7.500 524.2 7.800 502.2 8.480 502.1 9.800 524.2 6.130 524.2 6.830 502.2 7 .560 502.2 7.980 524.2 8.500 502.2 6.410 524.2 6.880 502.2 7 .600 502.2 7.990 524.2 8.500 502.2 6.450 502.1 7.010 524.2 7 .600 502.1 8.000 502.2 8.620 other 6.460 524.2 7.200 524.2 7 .650 524.2 8.120 502.2 8.710 524.2 6.790 524.2 7.420 524.1 7 .670 502.2 8.330 524.2 8.860 Water Study: 32 True Value: 9.13 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.740 other 8.900 502.2 9.280 524.2 9.540 524.2 9.980 502.1 10.800 524.2 7.800 524.2 8.960 502.2 9.290 524.2 9.650 524.2 10.100 502.2 10.800 524.2 8.090 524.2 9.000 502.2 9.350 502.2 9.700 502.2 10.200 524.2 11.000 502.2 8.450 524.2 9.100 524.2 9.380 524.2 9.700 502.2 10.300 524.2 11.500 502.2 8.490 502.2 9.130 524.2 9.380 other 9.700 502.2 10.400 524.2 11.700 502.2 8.510 524.2 9.160 502.1 9.390 524.2 9.800 502.2 10.400 524.2 12.000 502.2 8.550 502.2 9.230 524.2 9.460 524.2 9.920 502.2 10.400 502.2 12.100 502.2 8.620 524.2 9.240 524.2 9.470 524.2 9.930 524.2 10.500 524.1 12.100 524.2 8.730 524.2 9.240 502.1 9 .470 524.2 9.940 524.2 10.500 502.1 8.750 524.2 9.260 524.2 9 .480 502.2 9.940 524.2 10.600 502.2 8.810 524.2 9.260 502.2 9. 530 502.2 9.960 other 10.600 Water Study: 33 True Value: 12.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.670 524.2 12.000 502.2 13.300 502.2 14.100 524.2 15.000 524.2 17.500 502.2 9.950 502.2 12.000 502.2 13.400 502.2 14.400 502.2 15.100 502.2 17.800 502.1 10.500 502.2 12.500 524.2 13.600 524.2 14.500 502.2 15.400 524.2 19.400 502.2 10.800 524.2 12.760 524.2 13.600 524.1 14.800 502.1 15.900 other 11.850 524.2 13.100 524.2 13.790 524.2 14.900 502.2 15.900 524.2 11.900 502.2 13.150 502.2 13.800 524.2 15.000 524.2 16.800

## B-74 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 7.64 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.860 other 7.200 502.2 7.450 524.2 7.950 524.2 8.380 502.2 8.880 502.2 6.260 524.2 7.200 524.2 7.450 524.2 7.950 524.2 8.400 502.2 9.000 524.2 6.400 502.2 7.270 502.1 7.520 502.2 7.960 524.2 8.400 502.2 9.090 524.2 6.580 other 7.300 502.2 7.610 524.2 8.000 502.2 8.420 524.2 9.200 502.2 6.720 524.2 7.300 524.2 7.670 502.2 8.010 524.2 8.450 524.2 9.320 524.2 6.720 502.2 7.303 524.2 7.680 502.2 8.050 502.2 8.450 502.2 9.400 502.2 6.840 502.2 7.340 524.2 7.740 502.2 8.060 524.2 8.500 502.2 9.420 524.2 7.100 524.2 7.380 502.2 7.900 502.2 8.240 524.2 8.610 524.2 9.900 524.2 7.160 502.2 7.390 524.2 7.920 524.2 8.340 524.2 8.620 524.2 10.500 502.2 7.180 524.2 7.440 502.2 7.940 502.2 8.360 524.2 8.670 524.2 12.100 Water Study: 35 True Value: 13.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.320 502.2 13.400 524.2 14.200 502.2 15.100 524.2 15.600 524.2 16.500 502.2 10.000 524.2 13.400 502.2 14.500 502.2 15.200 524.2 15.600 524.2 16.500 502.2 11.600 502.2 13.700 502.2 14.590 502.2 15.200 524.2 15.600 502.2 16.500 other 12.720 524.2 14.000 502.2 14.630 524.2 15.500 524.2 15.650 524.2 16.830 524.2 13.000 524.2 14.100 524.2 14.800 524.2 15.500 502.2 15.700 502.2 16.960 502.2 13.300 524.2 14.200 524.2 15. 100 other 15.600 524.2 15.900 Water Study: 36 True Value: 8.49 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.990 524.2 8.230 524.2 8.580 other 9.100 524.2 9.470 524.2 10.100 524.2 7.510 502.2 8.260 524.2 8.600 502. 2 9.100 524.2 9.500 other 10.200 524.2 7.670 524.2 8.280 524.2 8.780 502.2 9.120 524.2 9.750 502.2 10.200 524.2 7.720 502.2 8.310 502.2 8.820 524.2 9.200 502.2 9.750 524.2 10.300 502.2 7.730 502.2 8.340 524.2 8.860 502. 2 9.220 other 9.760 524.2 10.300 524.2 7.730 524.2 8.420 524.2 8.900 524.2 9.290 524.2 9.760 502.2 10.400 502.2 7.940 502.2 8.450 524.2 8.910 502.2 9.340 524.2 9.860 524.2 10.470 524.2 7.950 502.2 8.470 502.2 8.970 524.2 9.340 524.2 9.910 502.2 11.100 502.2 8.120 524.2 8.480 524.2 8.980 524.2 9.340 524.2 9.990 502.2 11.100 524.2 8.150 524.2 8.540 524.2 8.980 502. 2 9.410 502.2 10.000 other 12.100

## B-75 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 16.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 13.200 502.2 15.500 524.2 16.400 524.2 17.400 502.2 18.300 524.2 20.500 524.2 14.500 524.2 15.500 524.2 16.460 502.2 17.600 502.2 18.500 502.2 20.600 502.2 14.600 502.2 16.100 other 16.600 524.2 17.700 524.2 18.500 other 20.700 502.2 14.700 524.2 16.200 524.2 16.700 524.2 17.800 524.2 18.700 502.2 20.800 524.2 15.100 502.2 16.200 524.2 16.800 524.2 17.900 502.2 18.700 502.2 20.800 524.2 15.300 524.2 16.270 524.2 16.800 524.2 18.000 524.2 18.800 524.2 21.700 502.2 15.400 524.2 16.400 502.2 17.000 524.2 18.000 502.2 19.300 524.2 22.000 502.2 15.400 502.2 16.400 524.2 17.170 524. 2 18.300 other 19.400 524.2 48.200 Water Study: 38 True Value: 11.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.000 524.2 13.800 524.2 14.900 502.2 15.700 524.2 16.400 524.2 17.600 524.2 8.640 524.2 13.800 524.2 15.000 other 15.800 524.2 16.600 502.2 17.800 502.2 12.100 524.2 13.900 524.2 15.100 524.2 15.800 524.2 16.700 502.2 17.900 524.2 13.000 524.2 14.100 502.2 15.100 other 15.900 502.2 16.800 524.2 18.000 502.2 13.000 524.2 14.180 524.2 15.200 524.2 16.000 524.2 17.000 524.2 18.700 502.2 13.100 524.2 14.400 502.2 15.300 524.2 16.100 524.2 17.200 502.2 22.800 502.2 13.100 502.2 14.400 502.2 15.400 524.2 16.200 502.2 17.200 524.2 13.400 524.2 14.500 502.2 15.400 524.2 16.300 502.2 17.300 524.2 13.700 502.2 14.800 502.2 15.410 502.2 16.400 524.2 17.300 other 13.800 524.2 14.900 524.2 15.500 524.2 16.400 524.2 17.490 Water Study: 39 True Value: 12.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.070 524.2 11.400 502.2 12.500 524.2 13.400 502.2 14.400 524.2 22.500 524.2 9.980 502.2 11.900 524.2 12.500 524.2 13.500 524.2 14.400 524.2 23.000 524.2 10.400 524.2 11.900 other 12.600 524.2 13.600 524.2 14.400 524.2 35.240 524.2 10.900 524.2 12.000 502.2 12.800 524.2 13.600 524.2 15.800 524.2 11.200 502.2 12.300 502.2 13.000 524.2 13.800 524.2 16.100 524.2 11.200 502.2 12.400 524.2 13.200 524.2 13.900 524.2 16.800 524.2 11.200 524.2 12.400 502.2 13.300 502.2 14.000 502.2 17.400 502.2 11.300 524.2 12.500 502.2 13.300 524.2 14.000 524.2 18.750

## B-76 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 18.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 12.500 524.2 17.100 502.2 18.100 502.2 19.000 524.2 19.500 524.2 21.900 524.2 13.800 524.2 17.600 524.2 18.100 502.2 19.000 524.2 19.600 524.2 21.900 524.2 14.700 524.2 17.700 502.2 18.200 502.2 19.100 524.2 19.600 524.2 22.600 502.2 15.000 524.2 17.700 502.2 18.400 524. 2 19.200 502.2 19.700 other 22.800 524.2 15.200 524.2 17.700 524.2 18.600 524.2 19.200 502.2 20.200 524.2 22.900 524.2 15.500 524.2 17.800 524.2 18.800 524.2 19.310 524.2 20.200 524.2 23.000 524.2 15.700 524.2 18.000 524.2 18.800 502.2 19.400 524.2 20.500 502.2 23.000 524.2 16.000 524.2 18.000 other 18.800 524.2 19.400 502.2 20.700 502.2 25.000 524.2 16.400 524.2 18.000 502.2 18.800 524.2 19.500 524.2 20.900 other 16.900 524.2 18.000 524.2 18.900 524.2 19.500 502.2 21.800 Water Study: 41 True Value: 5.25 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.670 524.2 5.400 524.2 5.610 524.2 5.800 524.2 5.900 502.2 6.480 502.2 4.720 524.2 5.440 524.2 5.680 524.2 5.810 502.2 6.050 524.2 6.480 502.2 4.760 524.2 5.480 524.2 5.690 524.2 5.830 524.2 6.070 524.2 6.540 502.2 5.010 524.2 5.530 524.2 5.720 524.2 5.860 524.2 6.110 524.2 6.600 524.2 5.020 524.2 5.560 other 5.750 524.2 5.900 502.2 6.210 502.2 7.170 524.2 5.100 502.2 5.570 502.2 5.780 502.2 5.900 524.2 6.260 524.2 9.280 524.2 5.350 524.2 5.600 524.2 5 .790 502.2 5.900 524.2 6.390

Dichloromethane Water Study: 26 True Value: 15.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 9.000 502.2 12.900 524.2 14.500 524.2 15.140 524.2 16.200 524.2 18.300 524.1 9.400 502.2 13.000 524.2 14.600 502.2 15.200 502.1 16.280 502.2 18.400 other 9.900 502.2 13.400 524.2 14.700 524.1 15.200 524.1 16.400 502.2 18.700 524.2 11.100 502.2 13.900 502.2 14.700 502.2 15.200 524.2 16.500 502.1 18.800 524.2 11.100 524.2 13.930 other 14.800 502.2 15.800 502.2 17.070 502.2 19.000 524.2 11.700 524.1 14.200 502.2 14.800 524.2 15.800 502.2 17.200 502.2 22.500 502.2 11.700 502.2 14.200 524.2 14.800 524.2 15.800 502.1 17.600 524.2 11.700 other 14.300 502.1 14.900 524.2 15.800 524.1 17.700 502.2 12.000 502.2 14.400 502.2 14.900 502.2 16.000 502.2 18.100

## B-77 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 14.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 11.800 502.2 14.400 502.2 14.720 524.2 15.360 524.1 15.900 524.2 17.100 502.2 13.230 502.2 14.500 524.2 14.740 524.2 15.400 524.2 16.000 524.2 17.500 524.2 13.280 other 14.540 502.2 14.800 502.2 15.600 502.2 16.100 502.2 21.100 524.2 13.500 524.2 14.600 502.2 14.900 502.2 15.670 524.2 16.700 524.1 14.000 502.2 14.600 524.2 15.200 502.2 15.800 502.2 16.800 524.2 14.300 502.2 14.700 502.2 15. 300 502.2 15.820 other 17.000 Water Study: 32 True Value: 7.77 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 3.260 502.2 6.920 502.2 7.350 502.2 7.840 524.2 8.500 502.2 9.190 524.2 4.430 502.2 7.000 524.2 7.400 other 7.850 502.1 8.600 502.2 9.420 502.2 5.090 502.1 7.050 502.2 7.430 524.2 7.970 502.2 8.660 524.2 9.720 524.2 6.250 other 7.100 524.2 7.480 524.2 8.020 524.1 8.660 524.2 10.400 other 6.340 524.2 7.200 524.2 7.520 524.2 8.070 502.2 8.740 502.2 10.600 502.2 6.370 524.2 7.300 524.2 7.580 524.2 8.200 524.2 8.820 524.2 12.100 524.2 6.450 502.2 7.320 502.2 7 .620 502.2 8.220 524.2 8.950 502.2 6.630 502.2 7.340 502.2 7 .630 524.2 8.300 502.1 9.100 502.2 6.910 524.2 7.340 524.2 7 .840 524.2 8.480 524.2 9.100 Water Study: 33 True Value: 12.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 9.192 502.2 11.500 524.2 12.000 502.2 12.800 502.2 13.700 502.2 15.000 502.2 9.920 other 11.800 524.2 12.300 502.2 12.900 524.2 13.740 502.2 15.280 524.2 10.700 502.2 11.800 524.2 12.500 502.1 13.200 502.2 14.200 502.2 15.500 502.2 11.100 502.2 11.990 524.1 12.500 524.2 13.290 524.2 14.200 524.2 16.400 502.2 11.100 524.2 12.000 524.2 12.700 524.2 13.460 502.2 14.200 502.2 11.400 502.2 12.000 524.2 12.700 524.2 13.500 524.2 14.700

## B-78 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 18.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 14.100 524.2 17.000 502.2 17.900 502.2 19.000 502.2 19.400 524.2 20.600 524.2 14.100 502.2 17.300 524.2 17.900 502.2 19.000 502.2 19.500 524.2 20.700 524.2 14.200 502.2 17.300 502.2 17.900 524.2 19.050 524.2 19.800 524.2 21.200 524.2 14.500 524.2 17.300 502.2 18.000 502.2 19.100 524.2 19.900 502.1 21.600 524.2 15.100 524.2 17.400 524.2 18.100 502.2 19.100 524.2 20.000 524.2 21.710 524.2 15.700 502.2 17.500 524.2 18.100 524. 2 19.200 524.2 20.000 other 22.200 524.2 15.790 524.2 17.600 524.2 18.300 502.2 19.200 502.2 20.000 502.2 22.200 502.2 16.100 502.2 17.600 524.2 18.500 502.2 19.250 524.2 20.000 502.2 25.200 502.2 16.720 502.2 17.700 524.2 18.600 502.2 19.300 524.2 20.270 502.2 33.100 502.2 16.800 524.2 17.900 502.2 18.900 502.2 19.400 524.2 20.500 Water Study: 35 True Value: 5.83 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.510 502.2 5.490 502.2 5.600 524.2 5.990 524.2 6.300 524.2 6.560 524.2 4.570 524.2 5.500 524.2 5.620 524.2 6.100 524.2 6.300 502.2 6.600 502.2 4.690 524.2 5.530 502.2 5.640 502.2 6.157 502.2 6.370 502.2 7.070 524.2 4.960 502.2 5.530 502.2 5.770 502.2 6.180 502.2 6.380 524.2 7.200 other 5.030 524.2 5.550 524.2 5.800 524.2 6.220 502.2 6.380 502.2 13.200 524.2 5.400 502.2 5.580 524.2 5 .970 502.2 6.280 524.2 6.470 Water Study: 36 True Value: 12.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.700 524.2 11.000 524.2 11.400 524.2 12.100 524.2 12.400 524.2 13.200 524.2 7.930 524.2 11.050 524.2 11.500 524.2 12.100 524.2 12.500 502.2 13.200 524.2 8.340 524.2 11.100 524.2 11.580 524.2 12.150 502.2 12.500 502.2 13.400 524.2 9.400 524.2 11.100 502.2 11.600 524. 2 12.160 other 12.600 524.2 13.670 524.2 9.960 502.2 11.200 502.2 11.700 other 12.200 502.2 12.600 502.2 14.300 524.2 9.980 502.2 11.200 524.2 11.700 502.2 12.200 524.2 12.600 502.2 14.400 524.2 10.000 524.2 11.200 502.2 11.900 502.2 12.200 524.2 12.700 502.2 14.500 524.2 10.300 524.2 11.300 502.2 12.000 502.2 12.210 502.2 12.700 524.2 15.100 other 10.900 502.2 11.300 502.2 12.000 524.2 12.300 524.2 12.700 502.2 15.800 524.2 11.000 524.2 11.400 524.2 12.100 502.2 12.400 502.2 13.000

## B-79 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 8.41 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.900 502.2 8.040 502.2 8.420 other 8.610 502.2 9.260 524.2 10.740 502.2 7.210 524.2 8.070 524.2 8.420 524. 2 8.660 502.2 9.360 other 10.800 524.2 7.280 502.2 8.110 524.2 8.420 524.2 8.740 502.2 9.370 524.2 10.800 524.2 7.350 502.2 8.250 524.2 8.450 524.2 8.750 502.2 9.640 502.2 11.900 524.2 7.540 524.2 8.270 524.2 8.500 502.2 9.100 524.2 9.710 524.2 12.300 524.2 7.790 502.2 8.280 524.2 8.520 524.2 9.150 502.2 9.760 524.2 12.700 524.2 7.900 524.2 8.310 524.2 8.590 524.2 9.150 524.2 10.400 502.2 14.200 502.2 8.020 524.2 8.330 502.2 8 .600 524.2 9.170 502.2 10.500 Water Study: 38 True Value: 14.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.970 524.2 13.200 other 13.800 524.2 14.200 524.2 14.900 502.2 15.400 other 12.500 524.2 13.300 502.2 13.800 524.2 14.200 524.2 14.900 502.2 15.500 502.2 12.500 524.2 13.400 524.2 13.800 524.2 14.400 524.2 15.000 502.2 15.600 524.2 12.500 502.2 13.400 524.2 13.800 502.2 14.600 502.2 15.000 524.2 16.000 524.2 12.800 502.2 13.500 524.2 14.000 524.2 14.700 524.2 15.100 502.2 16.120 524.2 13.100 502.2 13.600 524.2 14.000 502.2 14.700 524.2 15.200 524.2 16.200 524.2 13.100 524.2 13.600 524.2 14.000 524.2 14.700 524.2 15.200 502.2 16.400 524.2 13.100 524.2 13.600 502.2 14.100 502.2 14.700 524.2 15.200 502.2 16.600 502.2 13.200 524.2 13.760 524.2 14.200 502.2 14.800 524.2 15.370 524.2 17.400 Water Study: 39 True Value: 7.31 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.750 524.2 7.000 524.2 7.200 524.2 7.550 524.2 8.070 524.2 8.600 502.2 5.500 524.2 7.020 524.2 7.300 524.2 7.620 524.2 8.080 524.2 8.600 524.2 5.970 502.2 7.080 524.2 7.370 524.2 7.700 524.2 8.140 524.2 9.260 524.2 6.030 524.2 7.100 524.2 7.430 502.2 7.750 524.2 8.150 524.2 9.522 502.2 6.300 502.2 7.120 524.2 7.440 502.2 7.940 502.2 8.350 524.2 9.640 524.2 6.420 502.2 7.160 502.2 7.540 524.2 8.040 524.2 8.500 502.2 9.890 524.2 6.950 502.2 7.170 524.2 7.540 524.2 8.060 502.2 8.550 524.2 9.920

## B-80 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 6.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.540 524.2 5.900 502.2 6.240 502. 2 6.500 other 6.990 524.2 7.860 524.2 4.910 524.2 5.910 524.2 6.250 524.2 6.530 502.2 7.000 524.2 8.000 524.2 5.350 other 5.940 524.2 6.310 524.2 6.550 524.2 7.010 502.2 8.010 524.2 5.440 524.2 6.000 524.2 6.320 524.2 6.550 524.2 7.060 524.2 8.490 524.2 5.580 524.2 6.010 524.2 6.330 524.2 6.690 502.2 7.100 502.2 8.630 524.2 5.600 502.2 6.070 502.2 6.390 502.2 6.710 524.2 7.120 524.2 9.400 524.2 5.740 524.2 6.080 524.2 6.420 524.2 6.780 524.2 7.170 502.2 10.300 524.2 5.740 502.2 6.100 524.2 6 .440 524.2 6.800 502.2 7.480 524.2 5.780 502.2 6.120 502.2 6 .460 524.2 6.890 524.2 7.570 524.2 5.860 524.2 6.230 524.2 6 .480 502.2 6.920 524.2 7.600 Water Study: 41 True Value: 15.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.380 524.2 14.000 524.2 15.100 524.2 15.400 502.2 16.200 502.2 17.500 524.2 10.000 502.2 14.000 524.2 15.100 524.2 15.500 502.2 16.600 524.2 18.200 524.2 11.500 524.2 14.600 524.2 15.200 502.2 15.600 502.2 16.600 502.2 18.900 524.2 12.500 502.2 14.700 524.2 15.300 524.2 15.760 524.2 16.600 502.2 19.800 524.2 13.400 524.2 14.800 other 15.300 524.2 15.850 524.2 16.800 524.2 19.800 524.2 13.800 502.2 14.900 524.2 15.300 524.2 15.900 524.2 17.300 524.2 13.900 524.2 14.900 524.2 15.400 524.2 16.200 502.2 17.400

1,2-Dichloropropane Water Study: 29 True Value: 15.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.800 524.2 14.500 524.2 15.100 524.2 15.700 524.2 16.500 502.2 18.800 502.2 11.050 524.1 14.700 502.2 15.100 other 15.700 502.2 17.000 524.2 19.600 524.2 12.900 524.2 14.750 502.2 15.300 502.2 15.800 502.2 17.000 502.2 21.080 524.1 13.700 524.2 14.820 other 15.600 524.2 16.000 other 17.080 502.2 13.700 502.2 14.970 502.2 15.600 524.2 16.100 502.2 17.600 502.2 14.400 502.2 15.000 524.2 15.600 502.2 16.300 502.2 18.070

## B-81 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 10.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.690 502.2 9.773 502.2 10.200 502.2 10.600 524.2 10.900 524.2 11.400 524.2 8.780 502.2 9.800 524.2 10.200 502. 2 10.700 524.1 10.900 other 11.400 524.2 8.940 524.2 9.900 524.2 10.290 524.2 10.700 502.2 10.900 524.2 11.400 502.1 9.290 524.2 9.960 524.2 10.300 other 10.710 524.2 10.900 524.2 11.400 502.2 9.490 524.2 10.000 524.2 10.300 502.2 10.800 524.2 11.000 502.2 11.500 502.1 9.590 524.2 10.000 502.2 10.300 502.2 10.800 502.2 11.020 524.2 11.600 524.2 9.600 other 10.000 524.2 10.400 502.2 10.800 524.2 11.100 502.2 11.600 502.2 9.700 524.2 10.100 524.2 10.480 502.2 10.800 502.2 11.100 502.2 11.700 524.2 9.710 502.2 10.100 502.2 10.500 524.2 10.900 524.2 11.200 502.2 9.740 524.1 10.200 524.1 10.600 502.2 10.900 524.2 11.200 Water Study: 32 True Value: 6.46 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.540 502.2 5.690 524.2 5.970 other 6.250 524.2 6.440 524.2 6.910 502.2 4.970 524.2 5.700 502.2 5.980 524.2 6.280 524.2 6.460 524.2 7.070 502.2 4.970 502.1 5.700 524.2 6.000 524. 2 6.280 524.2 6.460 other 7.210 524.2 5.000 502.2 5.760 502.2 6.000 502.2 6.280 524.2 6.480 524.2 7.520 524.2 5.090 502.2 5.760 524.2 6.110 524.2 6.310 524.2 6.600 502.2 7.700 502.2 5.260 502.2 5.880 524.2 6.120 524.2 6.350 524.2 6.630 524.2 8.710 524.2 5.300 502.2 5.900 502.1 6 .130 502.2 6.370 524.1 6.680 502.2 5.410 524.2 5.900 502.2 6 .130 502.2 6.370 502.2 6.720 502.1 5.500 524.2 5.900 502.1 6 .160 524.2 6.380 524.2 6.750 502.2 5.600 524.2 5.920 502.2 6 .160 524.2 6.430 502.2 6.780 502.2 5.640 524.2 5.960 502.2 6 .190 524.2 6.434 524.2 6.900 Water Study: 33 True Value: 14.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.700 524.2 12.900 502.2 13.900 524.2 14.200 502.2 14.800 502.1 15.700 502.2 11.180 524.2 13.200 502.2 13.900 524.2 14.500 524.2 14.900 524.2 16.500 524.1 12.100 524.2 13.300 502.1 14.000 502.2 14.600 524.2 15.100 502.2 12.400 502.2 13.300 502.2 14.000 502.2 14.700 502.2 15.200 other 12.890 502.2 13.500 502.2 14.000 524.2 14.700 524.2 15.500 524.2 12.900 524.2 13.700 502.2 14.030 502.2 14.800 524.2 15.700

## B-82 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 12.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.480 502.2 10.700 502.2 11.600 524.2 11.800 502.2 12.300 524.2 12.900 502.2 9.250 524.2 10.900 524.2 11.600 524.2 11.800 524.2 12.300 524.2 13.000 524.2 10.100 502.2 11.000 524.2 11.600 524.2 11.900 502.2 12.500 502.2 13.100 524.2 10.390 524.2 11.200 502.2 11.600 502.2 11.900 502.2 12.600 524.2 13.100 502.2 10.400 502.2 11.200 524.2 11.600 524.2 12.000 524.2 12.600 502.2 13.100 502.1 10.400 524.2 11.200 502.2 11.600 524.2 12.070 524.2 12.600 502.2 13.200 502.2 10.500 524.2 11.490 other 11.700 524.2 12.100 524.2 12.600 502.2 13.370 502.2 10.500 524.2 11.500 502.2 11.700 524.2 12.100 524.2 12.690 524.2 13.400 502.2 10.600 502.2 11.510 524.2 11.800 502.2 12.100 502.2 12.700 502.2 13.400 524.2 10.600 524.2 11.600 524.2 11.800 502.2 12.200 524.2 12.800 Water Study: 35 True Value: 9.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.140 524.2 8.000 524.2 8.440 524.2 8.820 524.2 9.160 524.2 10.100 502.2 7.346 524.2 8.080 502.2 8.460 524.2 8.830 524.2 9.320 502.2 10.200 other 7.720 502.2 8.300 502.2 8.500 524.2 8.880 524.2 9.390 502.2 10.900 502.2 7.870 524.2 8.320 524.2 8.580 524.2 8.900 524.2 9.700 502.2 12.000 502.2 7.880 524.2 8.360 524.2 8 .700 524.2 9.000 524.2 9.760 502.2 8.000 524.2 8.390 502.2 8 .800 524.2 9.050 502.2 9.790 Water Study: 36 True Value: 16.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.700 524.2 14.600 502.2 15.200 502.2 15.700 502.2 16.100 524.2 16.700 524.2 12.900 502.2 14.600 524.2 15.280 502.2 15.700 502.2 16.100 502.2 16.800 524.2 13.000 502.2 14.600 502.2 15.300 524.2 15.800 502.2 16.200 524.2 17.200 502.2 13.300 524.2 14.700 524.2 15.300 524.2 15.800 524.2 16.200 524.2 17.400 502.2 13.400 502.2 14.700 502.2 15.400 other 15.900 524.2 16.400 524.2 17.450 524.2 14.100 524.2 14.700 524.2 15.500 524. 2 15.900 other 16.400 524.2 18.300 502.2 14.200 524.2 14.700 524.2 15.500 502. 2 15.900 other 16.400 524.2 18.800 502.2 14.320 524.2 14.800 502.2 15.500 524.2 15.960 524.2 16.600 524.2 19.340 524.2 14.400 524.2 15.000 524.2 15.600 502.2 16.000 524.2 16.600 502.2 20.200 524.2 14.500 502.2 15.000 524.2 15.600 524.2 16.000 524.2 16.680

## B-83 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 14.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.000 524.2 13.100 524.2 13.400 502.2 14.000 502.2 14.400 502.2 15.500 502.2 11.600 524.2 13.200 524.2 13.500 502.2 14.100 524.2 14.400 524.2 15.800 502.2 12.400 524.2 13.200 502.2 13.500 524.2 14.200 524.2 14.500 524.2 16.100 524.2 12.700 524.2 13.200 524.2 13.700 524.2 14.300 502.2 14.500 524.2 16.110 524.2 12.800 524.2 13.250 other 13.800 524.2 14.300 502.2 14.900 524.2 18.400 524.2 12.800 524.2 13.300 524.2 13.800 502.2 14.400 502.2 14.900 524.2 18.600 502.2 13.000 502.2 13.300 524.2 13.900 502.2 14.400 502.2 15.100 524.2 19.600 524.2 13.000 502.2 13.400 524.2 13. 930 other 14.400 524.2 15.200 Water Study: 38 True Value: 18.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 13.000 502.2 16.100 502.2 16.900 502.2 17.400 524.2 18.300 502.2 19.500 524.2 15.600 524.2 16.300 524.2 16.900 502.2 17.500 524.2 18.400 524.2 19.600 502.2 15.700 502.2 16.300 other 17.000 524.2 17.500 524.2 18.400 502.2 19.800 524.2 15.700 502.2 16.700 524.2 17.000 524.2 17.600 524.2 18.500 502.2 22.100 502.2 15.700 524.2 16.800 524.2 17.100 other 17.600 524.2 18.700 524.2 24.500 524.2 15.900 524.2 16.800 524.2 17.200 524.2 17.600 524.2 18.750 524.2 15.900 502.2 16.800 524.2 17. 200 524.2 502.2.7 502.2 18.800 524.2 16.000 524.2 16.800 524.2 17.300 524.2 17.800 524.2 18.900 524.2 16.000 502.2 16.800 502.2 17.300 502.2 17.900 524.2 19.000 524.2 16.060 524.2 16.900 524.2 17.300 502.2 18.300 524.2 19.500 Water Study: 39 True Value: 12.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.530 524.2 11.100 502.2 11.800 524.2 12.200 524.2 12.500 524.2 14.300 524.2 10.300 502.2 11.200 524.2 11.800 524.2 12.200 502.2 12.600 524.2 14.990 524.2 10.400 502.2 11.300 524.2 11.800 502.2 12.300 502.2 12.600 524.2 15.800 524.2 10.800 524.2 11.300 524.2 11.800 524.2 12.300 502.2 12.600 502.2 10.800 524.2 11.400 524.2 11.830 524.2 12.300 502.2 12.900 524.2 11.000 524.2 11.400 524.2 11.900 524.2 12.300 524.2 13.300 502.2 11.000 524.2 11.500 524.2 12.000 502.2 12.400 502.2 13.800 524.2 11.100 502.2 11.600 524.2 12.100 502.2 12.400 524.2 14.000

## B-84 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 19.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 11.500 502.2 17.100 502.2 17.800 524.2 18.200 524.2 19.000 524.2 20.300 524.2 11.600 502.2 17.400 524.2 17.800 524.2 18.400 502.2 19.200 524.2 20.500 524.2 15.800 524.2 17.500 524.2 17.900 524.2 18.400 502.2 19.400 524.2 21.700 524.2 15.800 524.2 17.700 502.2 17.900 524.2 18.600 524.2 19.600 524.2 21.800 524.2 16.000 502.2 17.700 524.2 18.000 502. 2 18.600 other 19.600 524.2 21.900 524.2 16.500 524.2 17.700 524.2 18.000 524.2 18.800 502.2 19.800 524.2 22.300 524.2 16.700 524.2 17.700 524.2 18.000 524.2 18.800 524.2 19.900 502.2 23.000 524.2 16.800 524.2 17.700 502.2 18.100 524.2 18.800 502.2 19.900 502.2 16.800 524.2 17.700 502.2 18.100 502.2 18.900 524.2 20.000 other 17.100 524.2 17.800 524.2 18.100 524.2 18.900 524.2 20.300 Water Study: 41 True Value: 15.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 12.900 524.2 14.200 502.2 15.000 524.2 15.400 524.2 15.800 502.2 17.000 502.2 13.400 524.2 14.500 other 15.000 524.2 15.460 502.2 15.900 524.2 17.200 502.2 13.600 524.2 14.600 502.2 15.100 524.2 15.500 524.2 16.000 524.2 18.000 524.2 13.700 524.2 14.600 524.2 15.300 524.2 15.500 524.2 16.200 502.2 18.000 524.2 14.000 524.2 14.600 502.2 15.300 524.2 15.500 502.2 16.200 502.2 18.100 502.2 14.100 524.2 14.700 524.2 15.300 524.2 15.500 502.2 16.300 524.2 14.200 524.2 14.800 524.2 15.400 524.2 15.600 524.2 16.390

Diquat Water Study: 32 True Value: 28.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549 6.300 549 18.000 other 22. 300 549 25.6000 549 40.800 549 101.000 549 18.000 549 19.000 other 24.100 549 38.800 549 43.900 Water Study: 34 True Value: 29.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549 1.000 549 9.590 549 17.600 549 24.100 549 29.900 549 35.600 549 5.820 549 12.500 549 20.200 549 25.600 549 31.100 549 38.100 549 5.950 549 14.200 other 24.100 549 26.150 549 31.700

## B-85 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 37.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549 10.200 549 19.000 549 24.300 549 29.100 other 44.000 549 11.900 549 20.700 549 27.600 549 32.800 549 125.000 549 12.300 549 23.000 549 28.900 549 36.590 549 7230.000 Water Study: 36 True Value: 14.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549.1 7.460 549.1 12.900 other 15.400 549.1 16.400 549.1 20.300 549.1 33.000 549.1 9.600 549.1 13.200 549.1 15.500 549.1 16.700 549.1 20.370 549.1 34.300 549.1 11.600 549.1 14.200 549.1 16.000 other 17.300 549.1 20.700 other 38.600 549.1 11.600 549.1 14.600 549.1 16. 200 549.1 18.800 other 21.300 549.1 11.700 549.1 15.000 549.1 16.300 549.1 19.600 549.1 23.300 Water Study: 37 True Value: 8.41 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549.1 3.890 other 6.100 549.1 6.680 549.1 7.300 549.1 8.290 549.1 17.300 549.1 5.070 549.1 6.180 549.1 6 .720 549.1 7.770 549.1 9.070 549.1 5.080 549.1 6.430 549.1 6 .900 549.1 8.050 549.1 9.160 549.1 5.360 549.1 6.460 549.1 7. 020 other 8.140 549.1 9.500 Water Study: 38 True Value: 23.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549.1 2.090 549.1 13.600 549.1 16.500 549.1 18.200 549.1 20.800 549.1 30.150 other 7.830 549.1 15.000 549.1 17.200 549.1 18.600 other 22.400 549.1 31.900 549.1 8.500 549.1 15.400 549.1 18.200 549.1 19.500 549.1 24.100 549.1 12.700 549.1 16.100 549.1 18.200 549.1 20.500 549.1 26.200 Water Study: 39 True Value: 32.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549.1 8.520 549.1 19.700 549.1 26.500 549.1 29.500 549.1 31.900 549.1 97.700 549.1 11.700 549.1 24.000 549.1 27.100 549.1 30.200 549.1 32.590 549.1 15.000 549.1 24.200 549.1 28.500 549.1 30.200 549.1 35.900 549.1 17.700 549.1 24.500 549.1 29.300 549.1 31.500 549.1 44.800

## B-86 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 14.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549.1 5.300 549.1 8.570 549.1 11.200 549.1 12.800 549.1 14.400 549.1 26.600 549.1 5.400 549.1 9.310 549.1 11.500 549.1 12.900 549.1 15.900 549.1 30.600 549.1 5.740 549.1 9.750 549.1 11.500 549.1 13.300 549.1 16.700 549.1 6.320 549.1 10.100 549.1 12.100 549.1 13.300 549.1 18.000 549.1 7.550 549.1 10.200 549.1 12. 200 other 14.200 549.1 21.300 Water Study: 41 True Value: 44.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 549.1 24.400 549.1 33.800 549.1 35.900 549.1 39.200 549.1 44.100 549.1 45.100 549.1 31.500 549.1 35.000 549.1 37.200 549.1 39.300 549.1 45.000 549.1 46.150 549.1 33.400 549.1 35.350 549.1 39.200 549.1 40.000 549.1 45.100

Ethylene Dibromide Water Study: 24 True Value: 0.480 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.352 504 0.406 504 0.452 other 0.484 504 0.515 504 0.600 504 0.380 other 0.408 504 0.453 502. 1 0.488 504 0.515 other 0.660 504 0.390 504 0.410 504 0.453 504 0.494 504 0.516 other 0.397 502.2 0.420 524. 1 0.470 504 0.505 502.2 0.520 504 0.400 504 0.420 504 0.477 504 0.508 504 0.538 504 0.401 504 0.440 504 0.478 other 0.513 504 0.562 Water Study: 25 True Value: 0.944 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.747 504 0.820 504 0.910 504 0.941 504 0.997 504 1.070 504 0.778 504 0.900 504 0.913 504 0.979 other 1.030 504 1.250 504 0.817 504 0.908 other 0.930 504 0.986 other 1.060 other 1.300

## B-87 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26 True Value: 0.434 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.363 504 0.407 other 0. 449 504 0.462 504 0.491 504 0.582 504 0.365 504 0.410 504 0.450 504 0.464 504 0.491 504 0.590 504 0.365 504 0.423 504 0.452 504 0.465 504 0.522 other 0.710 504 0.370 504 0.427 other 0. 456 504 0.483 504 0.528 504 2.378 504 0.392 504 0.440 504 0.459 504 0. 488 other 0.530 other 3.430 504 0.407 504 0.441 504 0.460 other 0.490 other 0.542 Water Study: 27 True Value: 1.45 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 1.010 504 1.190 504 1.350 other 1.420 504 1.500 504 2.190 other 1.030 504 1.227 504 1.350 504 1.430 other 1.540 504 2.530 504 1.170 504 1.300 504 1.400 other 1.450 504 1.900 Water Study: 29 True Value: 0.850 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.420 504 0.760 504 0.844 504 0.891 other 1.050 504 0.533 other 0.799 other 0 .846 504 0.922 other 1.104 504 0.651 504 0.800 504 0.852 504 0.968 504 1.580 other 0.669 504 0.812 504 0. 860 other 1.000 504 2.180 504 0.751 504 0.820 504 0.874 504 1.010 504 20.200 Water Study: 30 True Value: 1.39 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.989 502.2 1.230 other 1. 300 504 1.340 524.2 1.400 504 1.590 504 1.120 504 1.240 504 1.300 504 1.370 504 1.430 504 2.480 502.2 1.150 504 1.250 504 1.320 504 1.380 504 1.450 504 7.370 504 1.180 504 1.270 504 1.320 504 1.380 other 1.479 504 14.800 other 1.180 504 1.280 504 1.320 504 1.380 504 1.480 504 1.200 502.1 1.290 504 1.320 504 1.380 504 1.530 504 1.210 504 1.300 other 1.330 504 1.400 504 1.570

## B-88 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 0.637 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.368 504 0.564 504 0.619 504 0.647 504 0.737 504 0.528 504 0.580 504 0.620 504 0.653 504 0.750 504 0.534 504 0.592 504 0.628 504 0.655 504 0.998 504 0.549 504 0.600 504 0.628 504 0.660 504 2.900 504 0.560 other 0.604 504 0.638 504 0.670 504 5.860 Water Study: 32 True Value: 2.29 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 0.676 504 1.910 504 2.080 504 2.2000 504 2.330 504 2.560 504 1.440 504 1.910 other 2. 080 504 2.200 504 2.380 504 2.700 other 1.750 504 1.930 504 2. 130 504 2.240 504 2.380 504 2.910 504 1.830 504 1.930 504 2.130 504 2.250 504 2.380 504 3.170 504 1.870 other 1.990 504 2.150 504 2.260 504 2.400 504 1.877 504 2.044 504 2.160 504 2.260 504 2.400 504 1.900 504 2.050 504 2.180 504 2.290 504 2.410 504 1.900 504 2.080 504 2.190 504 2.300 504 2.470 Water Study: 33 True Value: 0.143 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.142 504 0.173 504 0.176 504 0.185 504 0.198 504 0.220 504 0.150 504 0.173 504 0.176 504 0.189 504 0.200 504 0.220 other 0.167 504 0.175 504 0. 177 504 0.190 504 0.204 504 1.000 504 0.169 504 0.175 504 0.177 504 0.195 504 0.210 504 1.090 Water Study: 34 True Value: 0.406 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.091 504 0.371 other 0. 392 504 0.402 504 0.435 504 0.570 504 0.281 504 0.375 504 0.392 504 0.406 504 0.438 504 0.623 504 0.321 504 0.376 504 0.393 504 0.407 504 0.439 504 0.670 504 0.326 504 0.377 504 0.394 504 0.410 504 0.440 other 0.890 504 0.344 504 0.377 504 0.395 504 0.411 504 0.440 504 2.040 504 0.347 504 0.379 504 0.399 504 0.420 504 0.445 504 0.354 other 0.386 other 0.400 504 0.423 504 0.457 504 0.357 other 0.389 504 0.402 504 0.423 504 0.486

Water Study: 35

## B-89 Methods Support Document for Six-Year Review Final - March 2003 True Value: 0.609 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504 0.360 504 0.528 504 0.572 other 0.601 504 0.641 504 0.691 504 0.400 504 0.549 504 0.583 504 0.608 504 0.646 other 0.695 504 0.446 504 0.551 504 0.590 504 0.617 504 0.656 504 0.766 504 0.498 504 0.567 504 0.596 504 0.620 504 0.679 other 3.135 504 0.511 other 0.571 504 0.598 504 0.639 other 0.689 504 7.030 Water Study: 36 True Value: 0.283 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.171 504.1 0.261 504.1 0.274 504.1 0.280 504.1 0.311 other 0.338 504.1 0.216 504.1 0.262 504.1 0.274 504. 1 0.280 504.1 0.312 other 0.360 504.1 0.230 504.1 0.263 504.1 0.274 other 0.282 504.1 0.322 504.1 0.363 504.1 0.231 504.1 0.266 504.1 0.275 504.1 0.285 504.1 0.323 504.1 0.403 551 0.246 504.1 0.268 504.1 0.276 504. 1 0.287 504.1 0.325 504.1 0.473 other 0.251 504.1 0.270 504.1 0.276 524.2 0.300 504.1 0.325 504.1 0.476 504.1 0.251 other 0.270 504.1 0 .278 504.1 0.310 other 0.333 504.1 0.259 504.1 0.271 504.1 0 .280 504.1 0.310 504.1 0.335 504.1 0.260 504.1 0.272 504.1 0 .280 504.1 0.311 504.1 0.336 Water Study: 37 True Value: 0.138 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.123 other 0.133 other 0.139 other 0.146 other 0.157 504.1 0.205 504.1 0.125 other 0.135 504.1 0.141 504.1 0.148 504.1 0.160 504.1 0.233 504.1 0.126 504.1 0.136 504.1 0.141 504.1 0.149 504.1 0.165 551 0.243 504.1 0.130 504.1 0.136 504.1 0.143 504.1 0.149 504.1 0.165 504.1 0.246 504.1 0.131 504.1 0.138 504.1 0.145 504.1 0.149 504.1 0.170 504.1 0.271 504.1 0.133 504.1 0.138 504.1 0.146 504.1 0.150 504.1 0.188 504.1 0.494 504.1 0.133 504.1 0.139 504.1 0.146 524.2 0.150 504.1 0.192 504.1 0.705

## B-90 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 0.336 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.130 504.1 0.300 504.1 0.320 504.1 0.348 504.1 0.359 504.1 0.390 504.1 0.245 504.1 0.301 504.1 0.330 504.1 0.348 504.1 0.361 504.1 0.397 504.1 0.257 504.1 0.303 504.1 0.333 504.1 0.349 504.1 0.361 504.1 0.399 504.1 0.276 504.1 0.304 504.1 0.333 504.1 0.351 524.2 0.364 504.1 0.404 504.1 0.282 504.1 0.304 504.1 0.337 504.1 0.351 504.1 0.367 504.1 0.408 504.1 0.286 504.1 0.313 551 0.338 504. 1 0.354 504.1 0.368 504.1 0.426 other 0.287 other 0.314 other 0 .342 551 0.356 504.1 0.370 504.1 0.438 504.1 0.292 504.1 0.320 504.1 0.343 504.1 0.357 504.1 0.376 504.1 1.890 Water Study: 39 True Value: 0.227 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.137 504.1 0.195 504.1 0.208 504.1 0.223 504.1 0.242 504.1 0.263 504.1 0.174 504.1 0.196 504.1 0.213 504.1 0.228 524.2 0.243 504.1 0.267 504.1 0.185 504.1 0.196 504.1 0.214 504.1 0.231 504.1 0.247 504.1 0.287 504.1 0.185 504.1 0.203 504.1 0.216 504. 1 0.234 504.1 0.250 other 0.302 504.1 0.190 504.1 0.205 504.1 0.216 504.1 0.237 504.1 0.254 504.1 1.950 504.1 0.194 other 0.205 504.1 0.222 504.1 0.239 504.1 0.259 504.1 2.500 Water Study: 40 True Value: 0.638 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.297 504.1 0.571 504.1 0.599 504.1 0.630 504.1 0.658 504.1 0.720 other 0.447 other 0.576 504.1 0. 601 504.1 0.631 504.1 0.668 504.1 0.742 504.1 0.455 504.1 0.581 504.1 0.601 other 0.634 504.1 0.671 504.1 0.759 504.1 0.530 504.1 0.588 504.1 0.608 504.1 0.636 504.1 0.675 504.1 0.762 504.1 0.531 504.1 0.591 504.1 0.612 504.1 0.641 504.1 0.677 504.1 0.826 504.1 0.541 504.1 0.595 504.1 0 .616 551 0.641 other 0.678 504.1 0.543 504.1 0.596 504.1 0 .621 504 0.642 504.1 0.696 504.1 0.548 504.1 0.597 504.1 0 .623 551 0.648 504.1 0.700 504.1 0.569 504.1 0.598 504.1 0 .628 504.1 0.653 551 0.702

## B-91 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 0.344 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 504.1 0.280 504.1 0.308 504.1 0.329 504. 1 0.339 other 0.368 504.1 0.389 504.1 0.290 504.1 0.318 504.1 0.329 504.1 0.342 504.1 0.375 504.1 0.390 504.1 0.297 504.1 0.319 504.1 0.331 504.1 0.345 504.1 0.380 504.1 0.394 504.1 0.299 504.1 0.320 504.1 0.332 504.1 0.349 504.1 0.385 504.1 0.395 504.1 0.307 504.1 0.323 504.1 0. 336 504.1 0.361 other 0.385 504.1 0.307 504.1 0.325 504.1 0 .336 504.1 0.365 504.1 0.389

Fluoride Water Study: 24b True Value: 1.30 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 414B 0.640 340.3 1.260 340.2 1.280 340. 2 1.290 340.2 1.310 340.2 1.330

340.2 1.040 340.2 1.270 340. 2 1.280 340.2 1.296 380- 75WE 1.310 340.2 1.330

340.2 1.190 380- 75WE 1.270 340.2 1.290 380- 75WE 1.299 414B 1.310 other 1.340

340.2 1.200 340.2 1.270 340.2 1.290 340. 2 1.300 other 1.310 340.2 1.350

340.2 1.210 340.2 1.270 129-71W 1.290 340.2 1.300 414B 1.310 340.2 1.350

other 1.220 340.2 1.270 129-71W 1.290 340.2 1.300 other 1.310 340.3 1.360

380- 75WE 1.220 340.2 1.270 340.2 1.290 other 1.300 340.2 1.320 340.2 1.390

340.3 1.220 other 1.280 380- 75WE 1.290 340.2 1.300 340.2 1.320

340.2 1.230 340.2 1.280 340.2 1. 290 other 1.300 340.2 1.330

380- 75WE 1.240 340.2 1.280 340.2 1. 290 340.2 1.300 414B 1.330

340.3 1.240 340.1 1.280 340.2 1 .290 340.2 1.300 340.2 1.330

## B-92 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24a True Value: 1.72 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 414B 0.850 340.2 1.640 340.2 1.700 other 1.720 340.2 1.740 other 1.780

340.2 0.950 340.2 1.650 380- 75WE 1.700 340.2 1.720 340.2 1.750 340.3 1.780

340.2 1.470 380- 75WE 1.660 340.2 1.700 340.2 1. 720 340.2 1.750 340.2 1.800

other 1.580 380- 75WE 1.660 340.2 1.700 340.2 1. 720 129-71W 1.750 340.1 1.800

340.2 1.600 340.2 1.660 other 1.700 340.2 1.724 340.2 1.750 340.2 1.810

340.2 1.600 340.3 1.660 340.2 1.700 340.2 1.730 340.2 1.750 340.2 1.850

380- 75WE 1.610 other 1.680 other 1.700 340.2 1.730 340.2 1.750 129-71W 1.940

340.3 1.620 340.2 1.680 340.2 1 .700 340.2 1.730 340.2 1.760

340.2 1.630 340.2 1.680 340.3 1 .700 414B 1.740 340.2 1.760

414B 1.640 380- 75WE 1.689 340.2 1.710 340.2 1.740 340.2 1.760

340.2 1.640 340.2 1.690 380- 75WE 1.710 other 1.740 414B 1.770

Water Study: 25a True Value: 2.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.2 2.100 129-71W 2.340 340.2 2.440 340.2 2.490 340.2 2.520 340.2 2.550

414B 2.140 other 2.340 380- 75WE 2.450 340.2 2.490 340.2 2.520 340.2 2.590

129-71W 2.160 340.2 2.380 380- 75WE 2.460 340.2 2.500 340.1 2.520 340.2 2.600

340.2 2.190 380- 75WE 2.397 340.2 2.460 340.2 2. 500 340.2 2.520 340.2 2.650

340.3 2.220 340.2 2.400 340.2 2.480 414B 2.500 other 2.530 other 3.500

340.2 2.260 340.2 2.420 340.2 2 .487 340.2 2.500 340.2 2.540

603 2.320 340.2 2.430 other 2 .490 340.2 2.510 340.3 2.550

## B-93 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 25b True Value: 1.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.2 1.300 other 1.440 340.2 1 .480 340.2 1.500 340.2 1.520 380- 75WE 1.550

340.3 1.300 other 1.450 340.2 1.490 340.2 1.500 340.2 1.530 340.2 1.550

340.2 1.310 380- 75WE 1.450 340.2 1.490 340.2 1.500 380- 75WE 1.534 340.2 1.550

414B 1.330 340.2 1.450 340.2 1.490 340. 2 1.500 340.2 1.540 340.3 1.600

129-71W 1.340 340.2 1.460 340.2 1.490 414B 1.510 129-71W 1.540 340.1 1.640

340.2 1.380 340.2 1.460 340.2 1 .500 340.2 1.520 340.2 1.540

603 1.380 other 1.480 340.2 1. 500 other 1.520 340.2 1.550

Water Study: 26b True Value: 3.41 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.210 340.2 3.280 340.2 3.340 129- 71W 3.390 380- 75WE 3.445 340.2 3.550

340.2 2.910 other 3.280 340.2 3.350 340.2 3.390 340.2 3.450 other 3.550

340.2 3.200 340.2 3.290 340.1 3.350 129- 71W 3.390 340.2 3.450 340.2 3.600

380- 75WE 3.200 340.2 3.300 414B 3.350 other 3.390 340.2 3.460 340.2 3.600

340.2 3.200 340.2 3.300 340.2 3.350 414B 3.400 other 3.460 414B 3.760

340.3 3.200 other 3.300 340.2 3.350 340.2 3.400 340.2 3.460 340.3 3.770

340.2 3.229 340.2 3.300 380- 75WE 3.357 340.2 3.420 340.2 3.480 340.2 3.800

340.2 3.260 340.2 3.300 340.2 3.360 340.2 3.420 340.2 3.480 340.2 4.350

380- 75WE 3.260 414B 3.320 340.2 3.380 340.2 3 .420 340.2 3.500 340.2 4.350

340.2 3.270 340.2 3.320 340.2 3.380 129- 71W 3.420 340.3 3.500

340.2 3.270 340.2 3.330 340.2 3. 390 340.2 3.430 other 3.540

## B-94 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26a True Value: 1.25 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.2 1.108 340.2 1.210 340.2 1.240 340.2 1.260 340.2 1.270 340.2 1.340

340.2 1.140 340.2 1.210 340.2 1.240 340.2 1.260 340.2 1.270 340.2 1.350

340.2 1.140 380- 75WE 1.218 340.2 1.240 340.2 1. 260 340.2 1.270 414B 1.360

340.2 1.160 340.2 1.220 340.2 1.240 380- 75WE 1.260 340.2 1.280 340.1 1.370

340.2 1.190 129-71W 1.220 340.2 1.250 340.2 1.260 340.2 1.280 129-71W 1.380

340.2 1.200 340.2 1.220 340. 2 1.250 340.2 1.260 380- 75WE 1.287 340.2 1.420

other 1.200 414B 1.230 other 1.250 129- 71W 1.260 414B 1.300 340.3 1.470

340.2 1.200 340.2 1.230 414B 1.250 other 1.270 340.2 1.300 other 3.480

340.2 1.210 340.2 1.240 340.2 1. 250 other 1.270 340.3 1.300

380- 75WE 1.210 340.2 1.240 340.2 1.260 other 1.270 340.3 1.300

other 1.210 340.2 1.240 340.2 1 .260 340.2 1.270 340.2 1.310

Water Study: 27 True Value: 4.35 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.2 1.100 other 4.100 340.2 4. 300 340.2 4.330 414B 4.440 129-71W 4.650

340.2 2.100 414B 4.190 340.2 4.300 340. 3 4.330 340.2 4.450 340.2 4.720

340.2 2.170 340.2 4.200 340. 2 4.300 other 4.340 380- 75WE 4.450

414B 2.190 340.1 4.250 340.2 4. 310 340.2 4.350 129-71W 4.470

340.2 3.810 D1179- 72B 4.250 340.2 4.320 380- 75WE 4.360 other 4.520

340.2 3.920 340.2 4.250 340.2 4. 330 other 4.378 340.2 4.530

603 4.030 340.2 4.260 340.2 4. 330 340.2 4.400 340.2 4.550

## B-95 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 0.330 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.2 0.266 340.3 0.305 340.3 0.315 129- 71W 0.330 340.2 0.340 380- 75WE 0.360

340.2 0.270 380- 75WE 3.070 340.2 0.320 340.2 0.332 340.2 0.340 other 0.360

340.2 0.290 340.2 3.100 340.2 0.320 413B 0.332 340.2 0.340 340.2 0.393

340.2 0.290 other 0.310 other 0.320 380- 75WE 0.338 129-71W 0.340

380- 75WE 0.302 340.2 0.310 other 0. 330 340.2 0.340 340.2 0.350

340.2 0.303 340.2 0.314 340.2 0 .330 414B 0.340 340.2 0.350

Water Study: 30 True Value: 7.90 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 380- 75WE 1.520 340.2 7.570 340.2 7.780 340. 2 7.850 340.2 8.000 413E 8.170

340.2 5.540 340.2 7.650 340. 2 7.800 340.2 7.860 380- 75WE 8.000 other 8.180

340.2 6.180 340.2 7.650 340.2 7.800 340.2 7.900 340.2 8.000 340.2 8.190

other 7.190 380- 75WE 7.650 340.2 7.800 340.2 7. 900 340.2 8.030 414B 8.225

340.2 7.200 340.2 7.680 340.2 7.810 340.2 7.910 340.2 8.040 340.2 8.550

other 7.500 340.2 7.700 340.2 7.810 380- 75WE 7.930 340.2 8.050 340.2 16.800

other 7.500 340.2 7.720 340.2 7.820 340.2 7.940 380- 75WE 8.060

340.3 7.510 380- 75WE 7.721 340.2 7.830 380- 75WE 7.940 340.2 8.060

414B 7.540 340.2 7.750 340.2 7. 830 340.3 7.950 other 8.080

other 7.540 129-71W 7.760 414B 7.840 380- 75WE 7.980 414B 8.105

340.1 7.550 340.2 7.770 340.2 7 .850 340.2 7.990 340.2 8.125

## B-96 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 5.70 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.1 4.200 340.2 5.440 340.2 5.544 380- 75WE 5.650 340.2 5.700 340.2 5.830

340.2 5.300 340.2 5.440 414B 5.560 340. 2 5.660 other 5.780 340.2 6.000

other 5.340 380- 75WE 5.450 340.2 5.600 340.2 5. 662 414B 5.790 other 6.130

340.3 5.370 340.2 5.500 340.2 5. 640 340.3 5.670 other 5.800

340.2 5.420 129-71W 5.520 340.2 5 .640 340.2 5.690 340.2 5.800

340.2 5.430 340.2 5.540 340.2 5 .650 340.2 5.690 129-71W 5.800

Water Study: 32 True Value: 2.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.340 340.2 1.930 340.2 1.970 340.2 1.990 340.2 2.020 340.2 2.060

340.1 1.640 340.3 1.930 340.2 1.970 414B 2.000 340.2 2.020 340.2 2.070

129-71W 1.790 380- 75WE 1.940 380- 75WE 1.975 340.2 2.000 340.2 2.020 340.2 2.070

340.2 1.800 340.2 1.940 414B 1.975 340. 2 2.000 340.2 2.030 340.2 2.077

340.2 1.800 340.2 1.950 340.2 1.980 380- 75WE 2.000 340.3 2.030 340.2 2.140

340.2 1.860 380- 75WE 1.950 414B 1.980 340.2 2.000 other 2.038 340.2 3.340

380- 75WE 1.860 340.2 1.950 340.2 1.980 340. 2 2.000 340.2 2.040 340.2 4.700

413E 1.880 340.2 1.950 380- 75WE 1.990 340.2 2.009 340.2 2.040

340.2 1.890 380- 75WE 1.960 414B 1.990 340.2 2.010 340.2 2.040

340.2 1.900 340.2 1.960 340.1 1.990 380- 75WE 2.010 other 2.040

340.2 1.930 340.2 1.960 380- 75WE 1.990 340.2 2.020 340.2 2.040

other 1.930 340.2 1.970 340.3 1 .990 340.2 2.020 340.2 2.050

## B-97 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 6.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.2 5.590 340.2 6.240 414B 6.450 340. 2 6.500 129-71W 6.560 340.2 6.670

340.1 5.930 other 6.300 340.2 6.480 414B 6.510 340.2 6.573 other 6.690

340.1 6.340.2 other 6.320 380- 75WE 6.480 340.2 6.530 340.2 6.585 340.2 6.720

340.2 6.170 340.2 6.370 other 6. 490 414B 6.540 340.2 6.610 340.2 6.750

340.2 6.190 340.2 6.400 340.2 6.500 340.2 6.550 340.2 6.610 340.2 6.800

340.3 6.200 340.2 6.440 380- 75WE 6.500 340.2 6.560 340.2 6.643

Water Study: 34 True Value: 1.10 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 340.1 0.870 380- 75WE 1.060 340.2 1.080 340.2 1. 090 340.2 1.120 340.2 1.140

380- 75WE 0.959 340.2 1.060 340.2 1.080 340.2 1 .100 340.2 1.120 other 1.142

300 0.960 340.2 1.060 other 1.080 340.2 1.100 380- 75WE 1.120 340.2 1.150

340.2 1.000 380- 75WE 1.060 340.2 1.080 340.2 1. 100 413E 1.120 340.1 1.160

other 1.020 340.3 1.070 340.2 1. 080 340.3 1.100 340.2 1.120 29 1.160

340.2 1.030 414B 1.070 380- 75WE 1.084 other 1.100 340.2 1.120 340.2 1.180

340.2 1.040 340.1 1.070 340.2 1.090 340. 2 1.100 340.2 1.130 other 1.190

340.2 1.040 414B 1.072 340.2 1.090 340. 2 1.100 340.2 1.130 340.2 1.230

other 1.050 340.2 1.080 340.2 1.090 340.2 1.102 340.2 1.130 340.2 1.620

340.2 1.050 380- 75WE 1.080 340.2 1.090 340.2 1. 110 340.2 1.140 340.2 21.080

other 1.060 340.2 1.080 340.2 1.090 340.2 1.120 380- 75WE 1.140

## B-98 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 3.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 380- 75WE 1.770 340.1 3.610 340.2 3.750 340.2 3 .800 340.2 3.880 other 3.960

340.2 3.450 340.2 3.680 340.1 3.760 340.2 3.800 340.2 3.900 340.2 3.980

other 3.470 413E 3.680 340.2 3.780 340. 2 3.810 340.2 3.900 other 3.980

380- 75WE 3.490 340.1 3.700 414B 3.780 603 3.810 340.2 3.900

340.2 3.520 380- 75WE 3.700 other 3.790 340.2 3.830 340.2 3.900

380- 75WE 3.540 340.2 3.710 other 3. 790 340.2 3.840 340.2 3.920

340.3 3.560 340.2 3.720 340.2 3 .790 340.2 3.840 340.2 3.926

340.2 3.570 340.2 3.740 340.2 3 .790 340.2 3.880 414B 3.930

Water Study: 36 True Value: 7.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.600 Manual Elec. 7.060 Manual Elec. 7.220 Manual Elec. 7.280 300 7.360 Manual Elec. 7.530

413E 6.640 380- 75WE 7.090 300 7.230 340.2 7.280 Manual Elec. 7.370 Manual Elec. 7.600

other 6.660 300 7.110 340.2 7.230 Manual Elec. 7.280 300 7.380 other 7.690

Manual

Elec. 6.680 Manual Elec. 7.130 340.2 7.240 Manual Elec. 7.300 414B 7.380 380- 75WE 7.750

Manual

Elec. 6.800 other 7.150 380- 75WE 7.240 other 7.300 other 7.383 Manual Elec. 7.990

other 6.840 Manual Elec. 7.160 Manual Elec. 7.250 340.2 7.300 300 7.390 Manual Elec. 8.050

Manual

Elec. 6.950 Manual Elec. 7.170 Manual Elec. 7.250 Manual Elec. 7.310 300 7.390

380- 75WE 6.960 300 7.180 380- 75WE 7.260 other 7.320 340.2 7.410

other 6.970 380- 75WE 7.190 Manual Elec. 7.260 380- 75WE 7.340 Manual Elec. 7.420

129-71W 7.010 300 7.190 129-71W 7.260 Manual Elec. 7.350 Manual Elec. 7.450

380- 75WE 7.010 340.1 7.200 380- 75WE 7.270 Manual Elec. 7.350 380- 75WE 7.460

## B-99 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 1.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Manual

Elec. 0.871 Manual Elec. 1.660 Manual Elec. 1.690 Auto Aliza 1.730 Manual Elec. 1.770 Manual Elec. 1.820

300 1.536 300 1.660 Manual Elec. 1.700 Manual Elec. 1.740 Manual Elec. 1.780 other 1.830

300 1.600 380- 75WE 1.660 380- 75WE 1.700 380- 75WE 1.740 Manual Elec. 1.789 Manual Elec. 1.840

Manual

Elec. 1.600 380- 75WE 1.660 300 1.710 Auto Aliza 1.740 Manual Elec. 1.790 other 1.940

Manual

Elec. 1.605 Manual Elec. 1.670 Manual Elec. 1.710 other 1.740 Manual Elec. 1.790 Manual Elec. 2.050

Manual

Elec. 1.610 300 1.670 Manual Elec. 1.710 300 1.740 Manual Elec. 1.790

other 1.630 380- 75WE 1.680 Manual Elec. 1.720 340.2 1.750 other 1.800

340.2 1.640 300 1.680 Manual Elec. 1.730 Manual Elec. 1.750 Manual Elec. 1.800

Manual

Elec. 1.640 300 1.690 129-71W 1.730 380- 75WE 1.750 Manual Elec. 1.802

Manual

Elec. 1.650 Manual Elec. 1.690 380- 75WE 1.730 300 1.760 Manual Elec. 1.810

## B-100 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 4.70 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 4.060 300 4.490 129-71W 4.550 Manual Elec. 4.600 Auto Aliza 4.730 Manual Elec. 4.842

300 4.330 Manual Elec. 4.500 380- 75WE 4.550 Manual Elec. 4.600 Manual Elec. 4.735 340.2 4.850

Manual

Elec. 4.380 129-71W 4.500 other 4.560 380- 75WE 4.600 Manual Elec. 4.740 300 4.860

Manual

Elec. 4.410 Manual Elec. 4.500 380- 75WE 4.580 Manual Elec. 4.610 Manual Elec. 4.740 300 4.870

Manual

Elec. 4.430 Manual Elec. 4.510 Manual Elec. 4.580 Auto Aliza 4.610 Manual Elec. 4.740 Manual Elec. 4.890

other 4.440 Manual Elec. 4.520 Manual Elec. 4.590 other 4.610 Manual Elec. 4.750 Manual Elec. 4.900

Manual

Elec. 4.450 Manual Elec. 4.530 Manual Elec. 4.600 300 4.620 300 4.770 Manual Elec. 4.920

Manual

Elec. 4.460 Manual Elec. 4.530 Manual Elec. 4.600 300 4.650 380- 75WE 4.780 300 4.940

Manual

Elec. 4.480 340.2 4.540 380- 75WE 4.600 other 4.701 Manual Elec. 4.780 300 4.990

Manual

Elec. 4.490 Auto Aliza 4.540 Manual Elec. 4.600 300 4.720 other 4.800 300 5.110

340.2 4.490 Manual Elec. 4.550 Manual Elec. 4.600 Manual Elec. 4.730 Manual Elec. 4.800

Water Study: 39 True Value: 2.90 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 300 2.470 Manual Elec. 2.660 Manual Elec. 2.700 Manual Elec. 2.740 Manual Elec. 2.820 300 2.880

Manual

Elec. 2.580 Manual Elec. 2.660 Manual Elec. 2.700 Manual Elec. 2.740 Auto Aliza 2.820 Manual Elec. 2.890

Manual

Elec. 2.590 300 2.670 Manual Elec. 2.700 other 2.740 Manual Elec. 2.820 Manual Elec. 2.900

other 2.600 Manual Elec. 2.670 Manual Elec. 2.700 other 2.750 Manual Elec. 2.840 Manual Elec. 2.910

300 2.610 380- 75WE 2.670 other 2.720 Manual Elec. 2.760 Manual Elec. 2.850 Manual Elec. 2.920

Manual

Elec. 2.640 380- 75WE 2.670 300 2.730 380- 75WE 2.760 380- 75WE 2.850 Manual Elec. 2.940

Manual

Elec. 2.650 Manual Elec. 2.680 Manual Elec. 2.740 Manual Elec. 2.770 Manual Elec. 2.850 300 2.960

Manual

Elec. 2.650 other 2.680 Manual Elec. 2.740 380- 75WE 2.810 Manual Elec. 2.850 Manual Elec. 3.050

300 2.650 Manual Elec. 2.690 Manual Elec. 2.740 other 2.820 300 2.860 300 3.170

## B-101 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 1.40 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Manual

Elec. 1.140 Manual Elec. 1.230 Manual Elec. 1.250 300 1.270 Manual Elec. 1.300 Manual Elec. 1.310

Manual

Elec. 1.160 Manual Elec. 1.230 Manual Elec. 1.250 Auto Aliza 1.270 Manual Elec. 1.300 Manual Elec. 1.320

Manual

Elec. 1.180 Manual Elec. 1.230 Manual Elec. 1.250 Auto Aliza 1.270 Manual Elec. 1.300 Auto Aliza 1.320

Manual

Elec. 1.180 300 1.240 380- 75WE 1.250 Manual Elec. 1.270 380- 75WE 1.300 380- 75WE 1.330

300 1.200 Manual Elec. 1.240 300 1.260 300 1.280 Manual Elec. 1.300 Manual Elec. 1.350

Manual

Elec. 1.200 other 1.240 Manual Elec. 1.260 300 1.280 Manual Elec. 1.300 other 1.360

380- 75WE 1.200 other 1.240 300 1.260 380- 75WE 1.280 Manual Elec. 1.309 Manual Elec. 1.360

380- 75WE 1.210 300 1.240 300 1.260 380- 75WE 1.280 Manual Elec. 1.310 Manual Elec. 1.380

other 1.210 Manual Elec. 1.240 Manual Elec. 1.260 Manual Elec. 1.290 340.2 1.310 Manual Elec. 1.390

Manual

Elec. 1.210 300 1.250 300 1.260 Manual Elec. 1.290 300 1.310 300 1.400

Manual

Elec. 1.220 380- 75WE 1.250 Manual Elec. 1.270 Manual Elec. 1.297 other 1.310 Manual Elec. 1.440

Water Study: 41 True Value: 6.20 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Manual

Elec. 1.240 Manual Elec. 5.870 Manual Elec. 5.950 Manual Elec. 6.030 380- 75WE 6.200 380- 75WE 6.490

other 5.700 300 5.890 300 5.960 Manual Elec. 6.050 Manual Elec. 6.200 Manual Elec. 6.570

300 5.750 Manual Elec. 5.890 300 5.970 300 6.060 300 6.210 Manual Elec. 6.590

Manual

Elec. 5.800 Manual Elec. 5.902 380- 75WE 5.980 380- 75WE 6.090 380- 75WE 6.240 Manual Elec. 6.670

Manual

Elec. 5.800 Manual Elec. 5.920 Manual Elec. 6.000 300 6.140 other 6.240 300 7.070

Manual

Elec. 5.810 other 5.930 Manual Elec. 6.010 300 6.170 Manual Elec. 6.270 Manual Elec. 8.040

other 5.820 Manual Elec. 5.930 Manual Elec. 6.020 Manual Elec. 6.170 Manual Elec. 6.390

Manual

Elec. 5.850 Auto Aliza 5.950 380- 75WE 6.030 Manual Elec. 6.200 300 6.480

## B-102 Methods Support Document for Six-Year Review Final - March 2003 Glyphosate Water Study: 32 True Value: 447 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 360.000 547 428.000 547 443.000 547 461.000 547 483.000 547 360.000 547 438.300 547 446.000 547 476.000 other 490.000 547 411.000 547 440.000 547 459.000 547 482.000 547 512.000 Water Study: 33 True Value: 308 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 192.000 other 255.000 547 268.000 547 306.000 547 317.000 547 326.3999 547 248.000 547 263.000 547 287.000 547 307.000 547 323.000 Water Study: 34 True Value: 438 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 284.000 547 398.000 547 420.000 547 428.000 547 454.000 547 510.000 547 397.000 547 407.000 547 420.000 547 441.400 547 463.000 547 728.000 547 396.000 547 416.000 547 424.000 547 446.000 547 464.000 other 390.000 547 416.000 547 425.000 547 453.000 547 490.000 Water Study: 35 True Value: 665 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 57.200 547 609.000 547 637.000 547 654.000 547 732.000 547 562.000 547 623.000 547 650.000 547 682.000 547 750.000 547 573.000 547 626.000 547 651.000 547 690.000 other 1515.000 Water Study: 36 True Value: 528 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 356.000 547 490.000 547 513.000 547 525.000 other 559.000 547 579.000 6651 453.000 547 492.000 547 515.000 547 536.000 6651 562.000 547 584.000 other 468.000 other 502.000 547 518.000 547 538.000 547 567.000 547 478.000 547 505.000 547 520.000 547 552.500 other 570.000 547 490.000 547 512.000 547 520.000 547 554.000 547 572.000

## B-103 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 780 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 7.940 547 663.000 547 740.000 547 785.000 547 802.000 547 861.000 547 74.800 other 720.000 547 751. 000 547 785.000 547 808.100 547 1590.000 547 605.000 6651 725.000 547 777.000 547 786.000 547 815.000 547 628.000 547 739.000 547 781.000 547 798.000 547 820.000 Water Study: 38 True Value: 410 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 292.000 547 409.000 547 430.000 547 450.000 547 481.000 other 345.000 547 410.000 547 435.000 547 455.000 547 486.000 547 399.000 547 411.000 547 443.000 547 461.000 547 489.000 547 401.000 other 420.000 547 444. 000 547 473.000 other 535.000 547 406.400 547 420.000 547 445.000 547 473.000 other 580.000 Water Study: 39 True Value: 620 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 450.000 547 599.000 547 631.000 547 639.000 547 658.000 6651 712.000 547 545.000 547 612.000 547 633.000 547 640.000 547 659.000 547 726.000 547 580.000 547 622.000 547 637.000 547 648.000 547 677.000 547 583.000 547 623.000 547 638.000 547 652.000 547 683.000 Water Study: 40 True Value: 375 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 239.500 547 360.600 547 381.000 547 394.000 547 403.000 547 416.000 547 336.000 547 369.000 other 385.000 547 394.000 other 405.000 547 416.000 547 340.000 547 370.000 547 385.000 547 396.000 547 408.000 547 433.000 547 355.000 547 377.000 547 386.000 547 398.000 547 411.000 547 435.000 547 360.000 547 380.000 547 388.000 547 399.000 547 415.000 547 460.000 Water Study: 41 True Value: 560 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 547 487.000 547 519.000 547 561.900 547 571.000 547 604.000 547 607.000 547 512.000 547 538.000 547 564.000 547 572.900 547 606.000 547 644.000 547 515.000 547 538.000 547 567.000 547 576.000 547 606.000

## B-104 Methods Support Document for Six-Year Review Final - March 2003 Heptachlor Water Study: 24b True Value: 3.15 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.953 508 2.560 other 2. 660 505 2.831 505 3.250 505 4.034 508 2.124 505 2.570 other 2. 660 508 2.840 505 3.260 505 4.130 other 2.220 other 2.570 other 2.680 505 2.870 505 3.270 505 6.010 505 2.260 508 2.580 508 2.680 other 2.900 other 3.300 other 2.340 508 2.580 508 2.710 505 3.010 505 3.348 505 2.370 508 2.650 505 2.720 505 3.150 505 3.740 Water Study: 24a True Value: 0.263 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.065 508 0.208 505 0.229 508 0.244 other 0.267 508 0.335 505 0.186 505 0.216 505 0.234 505 0.250 505 0.272 505 0.350 other 0.193 508 0.219 505 0. 238 505 0.251 505 0.280 505 1.777 other 0.196 other 0.220 other 0.240 508 0.260 505 0.290 505 0.198 508 0.224 508 0.241 505 0.262 505 0.294 other 0.206 other 0.225 508 0.242 505 0.265 other 0.310 Water Study: 25b True Value: 0.113 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.071 508 0.079 505 0.086 other 0.096 505 0.114 505 0.117 508 0.074 other 0.0827 505 0.089 other 0.0974 508 0.115 508 0.127 508 0.078 508 0.084 508 0.090 508 0.111 other 0.116 508 0.132 Water Study: 25a True Value: 1.42 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.972 508 1.140 508 1.230 508 1.390 505 1.520 other 1.020 505 1.187 505 1. 260 508 1.400 other 1.530 other 1.050 508 1.190 508 1.291 508 1.430 508.1 1.640 508 1.090 508 1.210 other 1.330 505 1.460

## B-105 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26 True Value: 2.27 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.514 other 1.750 525 2.030 505 2.200 505 2.350 525.1 4.516 505 1.178 508 1.760 505 2.101 505 2.210 505 2.390 other 1.510 508 1.860 other 2 .140 508 2.230 other 2.400 508.1 1.530 505 1.910 508 2.150 505 2.240 508 2.460 other 1.650 508 1.930 other 2.168 508 2.320 505 2.880 505 1.690 508 1.980 505 2.190 525 2.340 505 3.090 Water Study: 27 True Value: 0.642 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.381 525 0.421 508 0.530 505 0.577 508 0.638 508 0.678 508 0.411 505 0.430 508 0.543 508 0.618 508 0.639 505 0.698 508 0.413 508 0.437 508 0.550 505 0.628 508 0.660 508 0.817 other 0.415 508 0.492 505 0.576 508 0.630 other 0.669 505 1.040 Water Study: 29 True Value: 0.370 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.150 508 0.246 508 0.290 508 0.315 other 0.330 508 0.380 other 0.232 508 0.258 508 0.294 other 0.317 other 0.340 508 0.381 508 0.238 508 0.264 other 0. 310 508 0.318 505 0.350 505 0.395 508 0.240 508 0.284 505 0.310 508 0.326 505 0.358 508 0.400 Water Study: 30 True Value: 1.38 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.506 other 0.958 505 1. 100 508 1.200 508 1.260 508 1.420 505 0.663 505 0.988 508 1.100 other 1.202 508 1.270 other 1.480 505 0.720 other 0.990 508 1.110 other 1.210 508 1.287 505 1.500 508 0.847 508 1.000 other 1.130 other 1.210 508 1.320 508 1.520 508 0.875 508 1.030 505 1.160 508 1.230 other 1.330 508 1.520 508 0.933 508 1.030 508 1.170 508 1.230 508 1.330 505 1.530 508 0.940 508 1.070 505 1.180 505 1.240 other 1.350 508 1.530 508 0.949 505 1.090 508 1.190 508 1.260 508 1.390

## B-106 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 1.44 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.514 508 0.890 508 0.985 other 1.220 508 1.340 508 1.680 505 0.523 505 0.924 508 1.040 508 1.224 508 1.390 505 0.531 508 0.948 508 1.120 508 1.252 508 1.430 525.1 0.654 508 0.968 508 1.150 508 1.330 508 1.510 508 0.875 508 0.980 508 1.220 508 1.340 other 1.600 Water Study: 32 True Value: 0.443 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.070 508 0.330 508 0.369 other 0.399 508 0.462 505 0.529 508 0.107 525.1 0.332 508 0.380 508 0.405 505 0.467 505 0.532 508 0.251 508 0.337 505 0.383 508 0.408 508 0.469 525.1 0.590 525.1 0.288 508 0.349 508 0.384 508 0.426 505 0.472 508 0.620 508 0.288 508 0.349 508 0.386 505 0.433 508 0.481 508 0.636 508 0.310 508 0.352 other 0.386 508 0.445 508 0.489 525.1 0.860 508 0.321 other 0.353 508 0.390 508 0.446 505 0.493 505 0.323 505 0.356 525.1 0.394 505 0.450 525.1 0.503 508 0.324 505 0.358 508 0.395 508 0.452 505 0.508 525.1 0.330 508 0.363 525.1 0.395 508 0.460 505 0.510 Water Study: 33 True Value: 1.73 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.020 508 1.200 508 1.280 525.1 1.420 508 1.500 508 1.780 other 0.608 508 1.220 508 1. 290 508 1.430 508 1.550 505 1.980 508 0.810 508 1.250 505 1.300 508 1.450 505 1.560 508 1.060 525.1 1.250 505 1. 314 525.1 1.460 525.1 1.580 508 1.060 508 1.260 508 1.370 525.1 1.490 508 1.700 508 1.190 508 1.280 508 1.402 525.1 1.490 505 1.710

## B-107 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 0.914 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.351 508 0.618 505 0.724 508 0.800 525.1 0.862 508 0.930 505 0.358 other 0.620 508 0.728 525. 1 0.812 525.1 0.871 other 0.970 525.1 0.490 505 0.638 525.1 0. 734 508 0.819 505 0.883 505 1.005 508 0.495 508 0.639 505 0.736 508 0.822 525.1 0.885 525.1 1.090 525.1 0.546 508 0.707 508 0.751 508 0.823 505 0.899 508 1.220 508 0.548 508 0.713 508 0.758 505 0.830 505 0.905 508 1.490 508 0.567 508 0.714 505 0.770 508 0.840 505 0.906 508 0.588 505 0.720 508 0.775 525.1 0.850 505 0.911 508 0.595 505 0.720 508 0.780 508 0.853 508 0.916 Water Study: 35 True Value: 2.54 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 1.080 508 1.820 508 2.100 508 2.310 505 2.470 525.1 2.610 525.1 1.344 508 1.893 508 2.130 508 2.350 505 2.500 other 2.720 508 1.360 508 1.900 505 2.190 525.1 2 .390 508 2.540 other 3.100 508 1.440 505 1.920 508 2.240 508 2.410 508 2.560 508 1.670 508 1.990 525.1 2.270 505 2.420 505 2.570 508 1.700 other 2.050 508 2.310 525.1 2.460 508 2.600 Water Study: 36 True Value: 0.751 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.172 508 0.594 525.2 0.660 508 0.727 508 0.800 505 0.936 508.1 0.440 508 0.622 508 0.660 508 0.730 505 0.801 525.2 0.947 508 0.480 505 0.624 other 0.661 508 0.730 505 0.816 508.1 1.070 508 0.504 508 6.320 508 0.673 525. 2 0.733 525.2 0.825 505 1.310 508 0.530 525.1 0.640 508 0.675 505 0.736 508.1 0.828 525.2 2.200 508 0.562 505 0.640 525.2 0.676 505 0.746 508 0.828 525.2 0.566 508 0.640 508 0.676 505 0.750 505 0.829 508 0.570 525.2 0.650 525.2 0.714 508 0.784 505 0.840 525.2 0.574 508 0.654 other 0.721 508 0.785 505 0.882 other 0.585 508 0.659 508 0.726 525.2 0.791 508 0.896

## B-108 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 0.563 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.010 508 0.412 508 0.450 505 0.501 508 0.559 505 0.675 508 0.322 508 0.422 525.2 0.457 505 0.513 505 0.565 505 0.695 508 0.350 other 0.423 508 0.471 508 0.524 525.2 0.570 505 0.702 508.1 0.355 508 0.425 508 0.472 505 0.529 other 0.602 525.2 0.802 508 0.371 525.2 0.428 508 0.484 508 0.534 505 0.605 508 1.080 508 0.380 508 0.430 505 0.487 505 0.540 525.2 0.612 525.2 0.393 508.1 0.435 508 0.500 other 0.549 other 0.619 508 0.402 525.2 0.435 525.2 0.500 508 0.550 508 0.620 Water Study: 38 True Value: 1.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 0.581 508 0.885 508 1.000 508 1.120 505 1.180 508.1 1.310 508 0.601 525.2 0.900 508 1.040 508 1.120 505 1.200 508 1.430 508 0.707 508 0.901 508 1.040 508 1.130 other 1.200 505 1.430 508.1 0.770 508 0.935 525.2 1.050 505 1.140 525.2 1.220 508 1.430 525.2 0.796 508 0.938 508 1.060 other 1.150 508 1.230 525.2 1.810 508 0.806 508.1 0.953 505 1.080 508 1.160 505 1.230 other 0.850 508 0.965 505 1.090 525.2 1.160 508 1.270 505 0.855 508 0.967 508 1.090 508 1.170 525.2 1.280 525.2 0.883 508 0.992 508 1.100 508 1.170 505 1.310 Water Study: 39 True Value: 0.687 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.280 508 0.497 508 0.551 508 0.610 505 0.670 525.2 0.718 508 0.422 525.2 0.506 other 0.560 525.2 0.620 505 0.674 508.1 0.735 508 0.458 508 0.525 508 0.560 508.1 0.630 508 0.681 508 0.739 525.2 0.460 525.2 0.529 525.2 0.560 other 0.647 508 0.682 525.2 0.740 508 0.467 508 0.535 508 0.560 508 0.650 505 0.697 508 0.749 508 0.470 505 0.542 525.2 0.565 525.2 0.654 505 0.700 508 0.785 other 0.484 525.2 0.549 505 0. 583 505 0.658 525.2 0.710 508 0.919

## B-109 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 2.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.980 other 1.640 508 1.950 525. 2 2.100 508 2.320 other 2.440 508 1.060 508 1.740 525.2 1.960 508 2.140 525.2 2.330 508 2.460 508 1.070 508.1 1.810 525.2 1. 980 505 2.140 508 2.340 505 2.470 525.2 1.140 508 1.810 508 1.980 other 2.142 508 2.360 505 2.520 508 1.140 525.2 1.850 505 1.990 525. 2 2.170 508 2.360 525.2 2.550 508 1.290 525.2 1.850 505 2.010 508 2.190 508.1 2.380 505 2.550 508 1.390 525.2 1.880 508 2.030 525. 2 2.260 508 2.400 525.2 2.810 508 1.550 508 1.900 508.1 2.040 508 2.270 505 2.400 505 2.810 508 1.630 other 1.950 508 2.050 508 2.300 508 2.400 525.2 3.680 Water Study: 41 True Value: 0.83 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 0.165 525.2 0.578 525.2 0. 649 508 0.674 505 0.742 505 0.865 525.2 0.370 525.2 0.579 525.2 0.650 508 0.675 other 0.747 525.2 0.868 505 0.458 508 0.587 508.1 0.658 508 0.690 508 0.760 505 0.898 508 0.548 other 0.590 508 0.659 505 0.690 other 0.770 508.1 0.915 525.2 0.550 508 0.634 other 0. 664 508 0.694 505 0.777 508 1.330 508 0.560 508 0.636 525.2 0.667 508.1 0.730 508 0.812 508 0.561 525.2 0.640 525.2 0.668 505 0.735 505 0.827 508.1 0.567 508 0.647 525.2 0.670 508 0.737 508 0.828

Heptachlor Epoxide Water Study: 24a True Value: 0.161 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.046 505 0.133 other 0. 145 505 0.157 505 0.170 508 0.207 505 0.116 508 0.137 508 0.145 505 0.158 508 0.173 other 0.310 508 0.120 other 0.140 505 0. 149 505 0.161 508 0.174 505 0.514 other 0.124 other 0.141 505 0.155 505 0.163 508 0.180 505 0.130 505 0.142 other 0.155 505 0.164 508 0.188 505 0.130 other 0.143 505 0. 155 505 0.166 other 0.201

## B-110 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24b True Value: 1.61 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.624 505 1.401 505 1.460 other 1.560 505 1.660 508 2.350 505 1.200 505 1.430 505 1.460 505 1.560 505 1.680 other 3.000 508 1.380 508 1.440 505 1.510 508 1.590 505 1.690 505 3.050 505 1.380 508 1.440 other 1.520 505 1.600 505 1.710 other 1.390 508 1.450 508 1. 530 505 1.606 other 1.940 other 1.400 other 1.450 other 1.540 505 1.620 508 2.150 Water Study: 25a True Value: 0.771 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.597 other 0.715 508 0.757 508 0.798 other 0.817 508 0.885 505 0.646 other 0.726 508 0.763 508.1 0.800 505 0.838 508 0.685 505 0.732 508 0.774 508 0.802 other 0.850 508 0.699 other 0.752 508 0.780 505 0.809 508 0.865 Water Study: 25b True Value: 0.094 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.075 508 0.080 other 0. 0843 508 0.098 other 0.110 505 0.076 other 0.0802 505 0.085 505 0.101 505 0.110 508 0.078 505 0.081 508 0.092 508 0.104 508 0.110 508 0.080 508 0.084 508 0.096 other 0.108 508 0.123 Water Study: 26a True Value: 0.198 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.074 508 0.180 other 0 .190 508 0.204 505 0.228 505 1.770 other 0.148 525 0.181 505 0.195 525 0.208 505 0.243 other 0.159 505 0.183 508 0. 195 other 0.220 505 0.254 508 0.171 508 0.184 505 0.195 505 0.223 508 0.285 508 0.172 505 0.184 other 0.197 505 0.223 505 0.356 525 0.179 525.1 0.186 505 0.199 508 0.227 508 0.542

## B-111 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 1.81 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.402 505 1.540 other 1.640 525.1 1.717 505 1.840 505 1.980 other 1.400 525 1.540 508 1. 640 505 1.727 525 1.850 508 2.060 525 1.420 508 1.590 505 1.648 505 1.760 505 1.880 505 2.090 other 1.460 other 1.630 508 1.700 505 1.789 505 1.940 505 2.120 508 1.530 505 1.636 508 1.700 other 1.800 508 1.960 other 2.300 Water Study: 27 True Value: 0.533 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.272 508 0.419 505 0.452 505 0.493 505 0.524 other 0.578 525 0.275 508 0.436 505 0.453 508 0.499 508 0.540 505 0.606 508 0.384 other 0.442 508 0. 459 508 0.500 508 0.548 508 0.650 508 0.393 508 0.450 508 0.469 508 0.521 508 0.568 508 0.878 Water Study: 29 True Value: 0.267 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.110 505 0.200 508 0.226 other 0.250 505 0.266 508 0.133 508 0.204 508 0.234 508 0.250 508 0.286 other 0.157 508 0.205 508 0.236 508 0.252 505 0.298 505 0.194 508 0.218 508 0.246 other 0.254 508 0.310 508 0.199 508 0.220 other 0. 249 other 0.260 505 0.360 Water Study: 30 True Value: 0.85 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.463 508 0.678 other 0. 760 508 0.800 508 0.842 508 0.900 505 0.512 508 0.681 505 0.770 508 0.810 508 0.855 508 0.930 508 0.548 other 0.686 508 0. 780 508 0.812 508 0.858 508 0.950 505 0.550 other 0.714 505 0. 781 508 0.815 508 0.858 508 0.964 508 0.636 508 0.724 other 0. 790 505 0.824 508 0.862 505 1.010 508 0.664 525 0.728 508 0.796 505 0.826 other 0.875 508 1.040 508 0.671 505 0.748 505 0.800 other 0.830 other 0.876 508 1.048 505 0.672 508 0.757 other 0.800 508 0.834 508 0.882

## B-112 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 1.92 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.810 505 1.270 508 1.480 other 1.690 508 1.790 508 2.210 505 0.868 508 1.300 508 1.570 508 1.710 508 1.800 508 2.630 508 0.869 508 1.320 508 1.662 508 1.730 508 1.910 508 0.940 508 1.370 508 1.670 508 1.755 508 2.040 508 0.974 508 1.460 other 1.680 508 1.780 508 2.130 Water Study: 32 True Value: 0.346 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.073 508 0.300 508 0.336 525.1 0.353 508 0.372 508 0.448 508 0.206 508 0.304 508 0.336 508 0.354 505 0.376 508 0.471 508 0.210 508 0.320 505 0.337 508 0.357 505 0.382 525.1 0.480 505 0.272 other 0.321 508 0. 340 508 0.360 505 0.383 505 0.519 other 0.279 505 0.322 508 0. 343 508 0.360 508 0.387 508 0.582 508 0.285 525.1 0.324 508 0.345 508 0.367 505 0.390 508 0.287 525.1 0.325 505 0.345 508 0.369 505 0.394 508 0.292 508 0.327 other 0.347 508 0.370 505 0.400 508 0.297 525.1 0.331 505 0.350 508 0.370 525.1 0.420 508 0.297 508 0.333 508 0.351 505 0.372 525.1 0.440 Water Study: 33 True Value: 0.679 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 0.170 508 0.525 508 0.602 505 0.651 505 0.681 508 0.830 other 0.346 505 0.540 508 0.605 508 0.662 505 0.700 508 0.380 525.1 0.560 525.1 0 .617 508 0.665 525.1 0.705 508 0.436 508 0.583 508 0.625 508 0.670 525.1 0.737 508 0.513 508 0.583 508 0.631 508 0.670 505 0.738 508 0.522 505 0.601 508 0.639 508 0.674 508 0.800

## B-113 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 0.550 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.200 525.1 0.425 525.1 0. 486 505 0.512 505 0.546 508 0.604 505 0.277 other 0.427 508 0. 488 508 0.514 505 0.550 505 0.622 525.1 0.326 508 0.438 508 0.496 508 0.520 505 0.552 508 0.625 508 0.329 508 0.446 508 0.499 505 0.525 508 0.556 505 0.627 508 0.349 508 0.447 508 0.500 508 0.526 525.1 0.560 525.1 0.630 505 0.380 508 0.448 505 0.503 525. 1 0.526 505 0.562 525.1 1.090 505 0.415 other 0.450 508 0.508 508 0.528 508 0.563 508 0.421 508 0.450 508 0.508 508 0.540 508 0.579 525.1 0.424 505 0.458 525.1 0.511 505 0.543 508 0.590 Water Study: 35 True Value: 1.49 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 0.917 508 1.300 508 1.390 508 1.470 505 1.610 508 1.920 508 1.040 508 1.300 508 1.400 505 1.530 525.1 1.650 525.1 1.984 525.1 1.140 508 1.320 508 1.420 other 1.530 other 1.660 508 3.030 508 1.180 505 1.320 508 1.420 508 1.550 525.1 1.670 508 1.250 505 1.330 508 1.460 505 1.560 other 1.700 508 1.280 508 1.370 508 1.460 508 1.594 525.1 1.860 Water Study: 37 True Value: 0.403 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.039 525.2 0.312 525.2 0.350 505 0.369 other 0.380 505 0.406 525.2 0.211 508.1 0.317 508 0. 350 508 0.370 508 0.387 508 0.450 505 0.235 525.2 0.333 508 0.354 525. 2 0.370 508 0.389 other 0.531 508 0.257 505 0.334 508 0.357 525.2 0.372 505 0.390 505 0.536 508 0.262 508 0.336 505 0.360 508 0.375 505 0.391 508 0.952 508.1 0.283 508 0.340 508 0.361 505 0.375 505 0.392 525.2 0.297 525.2 0.340 508 0.363 508 0.375 508 0.400 other 0.311 other 0.346 508 0.365 508 0.380 508 0.401

## B-114 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 0.742 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.400 508.1 0.616 508 0.660 508 0.681 525 0.735 508 0.860 525.2 0.520 508 0.616 508 0.662 508 0.683 508 0.749 508 0.890 508 0.528 508 0.619 508 0.662 505 0.690 505 0.750 508 0.967 525.2 0.534 525.2 0.620 508 0. 663 505 0.693 508 0.751 508 0.996 525.2 0.538 508.1 0.630 505 0.665 505 0.699 525.2 0.753 508 1.110 505 0.542 508 0.631 525.2 0.670 other 0.705 525.2 0.756 525.2 1.130 508 0.563 508 0.633 508 0.675 508 0.719 508 0.758 508 0.584 525.2 0.636 508 0.675 505 0.721 other 0.765 505 0.614 508 0.643 505 0.680 other 0.722 508.1 0.765 Water Study: 39 True Value: 0.340 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 0.148 525.2 0.268 508 0.291 508 0.318 525.2 0.350 508 0.414 508 0.217 505 0.270 505 0.300 508 0.324 508 0.350 508 0.452 508 0.236 525.2 0.270 525.2 0.300 508.1 0.327 508 0.352 508 0.468 505 0.249 508 0.274 508 0.303 505 0.333 525.2 0.355 505 0.250 525.2 0.275 508 0.303 508 0.337 508 0.369 505 0.253 other 0.278 505 0.306 508 0.343 525.2 0.370 508 0.259 525.2 0.278 508.1 0. 309 525.2 0.345 525.2 0.373 508 0.263 other 0.283 505 0.316 525.2 0.350 508 0.384 Water Study: 40 True Value: 1.48 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.770 508 1.200 505 1.320 505 1.390 508.1 1.480 508 1.520 508 0.975 508 1.210 508 1.320 508 1.400 508 1.500 508 1.550 525.2 1.010 525.2 1.240 508 1.320 508 1.400 505 1.500 525.2 1.560 508 1.090 508 1.250 525.2 1.330 525.2 1.400 508 1.500 505 1.560 508 1.100 525.2 1.280 other 1. 340 508 1.420 508 1.500 505 1.570 508 1.100 525.2 1.300 525.2 1.340 508 1.440 525.2 1.500 508.1 1.700 other 1.140 525.2 1.300 508 1. 340 505 1.440 508 1.500 505 1.820 508 1.140 508 1.310 508 1.360 other 1.440 508 1.510 525.2 2.230 508.1 1.160 508 1.320 525.2 1.360 other 1.476 505 1.510 525.2 2.340

## B-115 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 0.630 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 0.179 508.1 0.541 525.2 0.580 other 0.615 505 0.640 505 0.712 525.2 0.310 508.1 0.544 508 0. 585 508 0.623 505 0.655 508 0.719 508.1 0.368 508 0.549 525.2 0. 585 508 0.625 505 0.661 508 0.756 525.2 0.420 508 0.561 other 0.589 508 0.630 508 0.665 505 0.455 other 0.568 508 0.589 508 0.633 505 0.680 505 0.530 other 0.569 525.2 0.593 505 0.633 508 0.684 508 0.530 525.2 0.570 525.2 0 .600 505 0.636 525.2 0.710 508 0.534 525.2 0.573 508.1 0 .608 508 0.640 525.2 0.712

Hexachlorobenzene Water Study: 27 True Value: 0.483 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.235 508 0.380 508 0.410 505 0.479 505 0.542 508 0.303 508 0.383 508 0.413 505 0.483 508 0.554 505 0.366 508 0.393 508 0.450 508 0.503 508 0.593 Water Stdy: 29 True Value: 0.417 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value
505 0.130 508 0.274 508 0.337 508 0.358 505 0.401 508 0.435 508 0.170 other 0.298 508 0. 342 505 0.360 508 0.408 505 0.493 508 0.259 508 0.322 508 0.350 508 0.390 505 0.413 other 0.692 Water Study: 30 True Value: 0.667 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.315 other 0.478 508 0. 531 508 0.585 505 0.700 508 0.880 505 0.329 505 0.490 508 0.538 other 0.590 other 0.716 508 0.966 505 0.360 508 0.496 other 0. 558 508 0.606 505 0.730 508 1.716 508 0.406 505 0.505 508 0.569 508 0.623 508 0.738 other 0.425 508 0.506 505 0.580 508 0.630 508 0.752 508 0.450 508 0.517 505 0.580 508 0.651 508 0.785 508 0.452 505 0.523 other 0.580 505 0.659 508 0.812

## B-116 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 2.40 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.820 508 1.140 508 1.630 505 1.810 508 2.029 508 2.220 505 0.830 508 1.440 508 1.650 508 1.840 508 2.180 508 2.400 505 0.921 508 1.520 508 1.736 508 1.930 508 2.200 508 3.040 508 1.120 508 1.540 other 1.770 508 1.990 508 2.200 Water Study: 32 True Value: 0.857 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.154 other 0.600 508 0.734 508 0.810 525.1 0.880 508 1.010 508 0.155 525.1 0.638 508 0.749 505 0.818 508 0.885 505 1.030 508 0.175 508 0.646 505 0.753 508 0.825 505 0.935 505 1.210 508 0.437 508 0.667 508 0.754 505 0.832 525.1 0.938 508 1.430 508 0.450 508 0.693 508 0.755 525.1 0.853 508 0.943 other 0.538 508 0.696 508 0.760 505 0.860 505 0.962 525.1 0.538 508 0.696 508 0.779 505 0.872 525.1 0.969 525.1 0.570 508 0.722 505 0.809 505 0.880 525.1 0.990 Water Study: 33 True Value: 1.32 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.620 508 0.940 508 1.060 505 1.310 505 1.590 other 0.799 508 0.947 508 1.150 508 1.340 525.1 1.590 505 0.858 508 1.014 525.1 1.190 525.1 1.360 508 1.600 508 0.892 508 1.020 505 1.220 525.1 1.370 505 1.940 508 0.915 505 1.050 508 1.250 525.1 1.390 508 2.850 508 0.929 508 1.060 505 1.290 508 1.500 Water Study: 34 True Value: 3.57 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 2.050 505 2.830 508 2.960 505 3.280 505 3.630 505 4.340 525.1 2.340 508 2.860 525.1 2.970 525.1 3.300 508 3.670 508 4.640 505 2.400 505 2.870 508 2.977 505 3.325 505 3.700 505 5.726 508 2.440 508 2.909 508 2.980 505 3.340 525.1 3.720 508 7.300 508 2.660 508 2.920 508 3.020 525.1 3.380 505 3.860 508 13.400 508 2.670 508 2.930 508 3.070 525.1 3 .380 525.1 3.890 525.1 13.600 525.1 2.710 505 2.930 505 3.080 508 3.430 508 4.000 508 2.740 508 2.960 505 3.080 505 3.460 508 4.310

## B-117 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 0.635 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.346 525.1 0.442 508 0.567 505 0.631 505 0.710 508 1.160 508 0.353 508 0.475 508 0.568 525.1 0.640 525.1 0.728 508 0.360 508 0.480 508 0.577 505 0.685 525.1 0.736 508 0.401 other 0.520 508 0.582 508 0.696 505 0.808 508 0.407 508 0.529 505 0.620 508 0.700 other 0.930 508 0.436 525.1 0.555 505 0.620 525.1 0.706 505 1.050 Water Study: 36 True Value: 0.847 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.261 508 0.630 508 0.739 other 0.790 505 0.901 525.1 1.080 508.1 0.342 508 0.671 525.2 0.739 505 0.804 505 0.914 508.1 1.200 508 0.410 508 0.685 525.2 0.741 525. 2 0.811 508 0.918 508.1 1.700 508 0.456 525.2 0.692 505 0.749 508 0.824 508 0.920 508 3.520 525.2 0.510 505 0.700 508 0.761 525. 2 0.830 525.2 0.925 505 4.960 508 0.556 508 0.708 525.2 0.765 505 0.835 505 0.940 508 0.558 525.2 0.708 508 0.769 505 0.840 505 0.942 508 0.559 525.2 0.725 508 0.778 505 0.854 525.2 0.960 508 0.597 508 0.737 505 0.785 508 0.857 525.2 1.010 Water Study: 37 True Value: 0.806 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 0.023 508 0.579 508 0.722 508 0.756 525.2 0.799 505 0.877 508 0.091 525.2 0.612 508 0.723 508 0.760 505 0.803 505 0.880 508 0.460 508.1 0.643 525.2 0.738 505 0.779 525.2 0.810 505 0.896 508.1 0.528 508 0.650 505 0.739 508 0.786 525.2 0.825 505 0.920 508 0.551 508 0.680 508 0.746 525.2 0 .790 525.2 0.832 525.2 0.958 508 0.562 508 0.686 508 0.746 505 0.791 508 0.837 505 0.964 508 0.570 525.2 0.710 508 0.750 505 0.795 other 0.866 525.2 1.000

## B-118 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 0.538 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.204 505 0.344 508 0.408 525.2 0.480 508 0.523 505 0.600 508 0.264 508 0.350 508 0.422 508 0.480 508 0.525 508.1 0.620 525.2 0.324 508 0.361 525.2 0.442 508 0.489 508 0.531 525.2 0.690 508 0.328 525.2 0.370 525.2 0.445 508 0.498 525.2 0.535 508 0.913 525.2 0.329 508.1 0.370 525.2 0. 452 508 0.504 505 0.539 508 1.110 508 0.332 508 0.370 508 0.453 505 0.507 505 0.547 508 0.337 508.1 0.396 505 0.473 505 0.512 525.2 0.567 508 0.339 other 0.396 525.2 0.479 505 0.520 508 0.570 Water Study: 39 True Value: 1.68 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.970 505 1.230 505 1.440 525. 2 1.610 508.1 1.750 508 2.210 508 0.995 505 1.230 508 1.450 508 1.620 525.2 1.760 525.2 2.290 508 1.090 508 1.240 505 1.470 525.2 1.630 508 1.770 508 1.100 525.2 1.270 508 1.520 525.2 1.660 505 1.770 508.1 1.130 525.2 1.370 525. 2 1.560 505 1.660 505 1.780 508 1.160 525.2 1.390 525.2 1. 560 525.2 1.700 525.2 1.880 508 1.160 525.2 1.425 505 1.590 other 1.750 505 1.900 Water Study: 40 True Value: 2.90 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.910 525.2 2.100 525.2 2.400 525.2 2.670 508 2.880 505 3.100 508 1.030 508.1 2.130 508 2.460 525. 2 2.670 525.2 2.940 508 3.150 508 1.170 508 2.140 508.1 2.460 525. 2 2.680 525.2 2.940 505 3.160 508 1.800 508 2.200 525.2 2.460 525.2 2.710 508 2.970 508 3.200 508 1.850 525.2 2.290 508 2.490 508 2.780 508 2.990 505 3.390 508 1.870 508 2.330 525.2 2.600 505 2.800 505 3.060 505 3.510 508 1.930 505 2.370 525.2 2.620 525. 2 2.800 505 3.080 525.2 3.670 508 1.950 508 2.380 525.2 2.630 508. 1 2.880 other 3.080 505 4.100

## B-119 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 1.03 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.420 508 0.653 508 0.762 505 0.882 505 0.925 525.2 1.100 508 0.530 525.2 0.664 508 0.779 508 0.883 505 0.970 other 1.200 508.1 0.570 508.1 0.709 525.2 0. 800 505 0.885 505 0.984 525.2 1.250 525.2 0.605 525.2 0.721 508 0.830 505 0.900 508 0.985 505 0.617 508.1 0.730 508 0.830 508 0.918 other 0.992 508 0.636 525.2 0.740 525.2 0. 840 525.2 0.920 525.2 1.030 508 0.646 508 0.750 other 0.848 508 0.920 505 1.070

Hexachlorocyclopentadiene Water Study: 24a True Value: 4.42 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.550 505 3.010 other 3 .390 505 3.890 505 4.780 505 14.000 505 1.950 505 3.120 505 3.440 505 4.020 505 5.050 505 2.720 other 3.140 505 3.780 505 4.030 505 5.075 other 2.730 525 3.160 505 3. 870 other 4.310 505 5.680 Water Study: 24b True Value: 0.736 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.159 505 0.503 525 0. 547 505 0.696 505 0.750 505 2.500 505 0.450 505 0.521 other 0.550 505 0.700 505 0.762 505 0.472 other 0.529 other 0.550 505 0.706 505 0.807 505 0.493 505 0.532 505 0.609 505 0.731 other 0.871 Water Study: 25a True Value: 1.87 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.610 508.1 1.040 505 1.125 other 1.690 505 1.870 508.1 2.400 508 0.836 508 1.060 508 1.380 other 1.718 505 2.080 508 3.300 Water Study: 25b True Value: 0.267 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.074 508.1 0.093 508 0.156 508 0.218 505 0.226 508 0.494 508 0.091 505 0.133 other 0. 506 other 0.220 505 0.268

## B-120 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26a True Value: 2.47 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.912 other 1.450 other 1. 900 508.1 2.290 other 2.770 505 5.670 505 0.931 525 1.540 505 1.960 505 2.568 505 3.290 505 1.200 other 1.770 505 2.058 505 2.600 505 3.370 525 1.200 505 1.820 505 2.240 505 2.730 505 3.700 Water Study: 26b True Value: 0.367 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525 0.143 other 0.219 505 0.290 505 0.309 other 0.515 505 1.350 505 0.167 505 0.251 505 0.292 505 0.322 505 0.529 other 0.201 508.1 0.256 525 0.298 505 0.334 505 0.591 505 0.201 other 0.267 505 0. 301 other 0.347 505 0.605 Water Study: 27 True Value: 0.774 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.423 508 0.511 505 0.629 525 0.664 508 0.706 other 0.440 508 0.550 505 0.631 505 0.676 505 0.788 508 0.482 other 0.568 505 0.660 505 0.680 505 0.908 Water Study: 29 True Value: 0.313 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 0.132 508 0.169 other 0 .211 505 0.285 other 0.437 508 0.142 other 0.182 508 0.230 505 0.297 508 0.443 505 0.150 508 0.185 other 0.250 505 0.330 Water Study: 30 True Value: 1.72 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.266 other 0.650 505 0.900 505 1.230 other 1.460 other 1.840 505 0.268 508 0.666 505 0.975 505 1.260 505 1.540 508 1.940 other 0.360 505 0.766 other 1.030 other 1.280 508 1.569 other 1.970 508 0.380 other 0.856 other 1 .100 505 1.360 505 1.700 508 2.270 other 0.400 other 0.866 505 1. 120 other 1.370 508 1.790 505 2.430 508 0.638 505 0.880 other 1. 191 505 1.440 other 1.840

## B-121 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 1.11 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.237 other 0.462 other 0. 701 508 0.736 508 0.842 other 1.840 508 0.310 other 0.496 505 0.702 505 0.740 505 0.970 other 0.362 508 0.696 other 0.710 505 0.749 505 1.000 Water Study: 32 True Value: 0.823 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.066 525.1 0.420 505 0. 592 525.1 0.676 505 0.783 508 1.000 other 0.177 508 0.433 505 0. 597 505 0.700 505 0.830 505 1.120 505 0.282 other 0.489 other 0. 600 505 0.704 508 0.831 other 1.240 525.1 0.297 525.1 0.503 505 0.604 505 0.710 505 0.842 other 1.800 525.1 0.328 525.1 0.510 508 0.636 525.1 0.745 505 0.851 525.1 1.970 508 0.336 other 0.522 505 0.648 other 0.761 505 0.879 505 2.780 other 0.403 other 0.559 505 0.672 other 0.772 505 0.885 Water Study: 33 True Value: 2.92 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.528 525.1 1.290 505 1.580 505 1.740 505 2.610 other 7.700 other 0.860 505 1.320 505 1.590 508 1.970 525.1 2.870 508 1.000 505 1.500 508 1.670 525.1 2.230 505 2.990 other 1.020 505 1.540 other 1.680 505 2.280 525.1 3.040 other 1.170 505 1.570 525.1 1 .690 505 2.420 other 3.160 Water Study: 34 True Value: 2.14 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.377 525.1 1.010 other 1. 350 505 1.650 505 2.040 505 2.850 508 0.555 525.1 1.090 525.1 1.380 other 1.740 505 2.090 505 4.310 525.1 0.626 508 1.170 505 1.390 505 1. 750 other 2.150 other 18.300 other 0.750 other 1.240 505 1.410 525.1 1.760 505 2.240 other 0.823 other 1.270 505 1.420 other 1.780 505 2.247 525.1 0.826 525.1 1.280 505 1.440 505 1.900 525.1 2.580 505 0.961 505 1.330 505 1.450 505 1.980 505 2.610 505 0.970 505 1.350 other 1.602 505 1.990 505 2.780

## B-122 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 1.84 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.380 505 0.820 505 0.932 other 1.330 other 1.790 505 2.460 525.1 0.387 other 0.855 525.1 0. 968 505 1.520 505 1.810 other 3.200 505 0.583 505 0.902 other 1.060 505 1.540 505 2.000 508 0.606 505 0.930 525.1 1.140 508 1.540 505 2.090 525.1 0.728 525.1 0.930 505 1. 210 other 1.750 525.1 2.180 Water Study: 36 True Value: 4.71 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.028 508.1 1.920 505 2.650 525.2 3.520 505 4.020 505 4.600 508 0.726 525.2 1.940 525.2 2.770 508 3.590 525.2 4.090 525.1 4.640 other 0.802 525.2 1.960 508 3. 050 525.2 3.640 505 4.210 505 4.960 508 1.180 508 2.340 525.2 3.070 525.2 3.890 508 4.310 505 5.010 525.2 1.240 508 2.400 508 3.220 505 3.900 505 4.320 508 6.280 508 1.500 525.2 2.460 505 3.260 505 3.900 505 4.530 525.2 7.910 508 1.880 508 2.490 508 3.280 525.2 3.930 505 4.590 505 8.110 508 1.885 other 2.510 505 3.330 508.1 3.940 508 4.600 Water Study: 37 True Value: 2.49 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.004 525.2 0.265 525.2 0.609 525.2 0.935 505 1.600 508 2.160 508 0.116 508 0.320 508 0.705 525.2 0.962 508 1.610 505 2.230 508.1 0.152 other 0.335 508 0.705 525.2 1.060 525.2 1.680 505 3.050 508.1 0.205 525.2 0.374 525. 2 0.750 508 1.090 505 1.910 505 0.230 505 0.443 525.2 0.806 505 1.120 505 2.060 508 0.235 508 0.470 508 0.860 505 1.130 505 2.100 508 0.238 508.1 0.590 508 0.900 508 1.340 508 2.120

## B-123 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 1.47 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.037 525.2 0.725 525.2 0.829 525.2 1.070 505 1.260 505 1.520 508 0.421 508 0.735 525.2 0.870 508. 1 1.090 508 1.280 525.2 2.000 508.1 0.505 other 0.750 508 0. 913 505 1.090 505 1.280 508 2.030 508 0.555 508.1 0.760 505 0.940 508 1.130 505 1.290 508 4.920 525.2 0.676 508 0.780 508 0.999 525.2 1.140 505 1.330 508 0.686 508 0.795 508 1.010 505 1.150 508 1.390 508 0.697 525.2 0.821 505 1.020 525.2 1.180 505 1.430 525.2 0.721 525.2 0.828 505 1. 060 525.2 1.190 525.2 1.440 Water Study: 39 True Value: 3.26 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.145 508 1.360 525.2 1.830 525.2 2.170 505 2.550 505 3.440 508 0.145 508.1 1.540 508.1 1.910 525.2 2.230 525.2 2.670 505 3.720 525.2 0.460 525.2 1.700 505 1.950 525.2 2.260 505 2.750 525.2 3.920 525.2 0.710 505 1.720 525.2 1.960 525.2 2.260 505 3.060 505 4.670 508 0.794 508 1.750 505 2.030 508 2.410 508 3.150 508 6.050 508 1.090 525.2 1.780 525.2 2 .110 525.2 2.474 505 3.160 Water Study: 40 True Value: 1.22 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.163 525.2 0.610 525.2 0.830 508 0.956 508 1.080 525.2 1.320 508 0.300 508 0.615 525.2 0.843 525. 2 0.965 525.2 1.120 505 1.380 505 0.462 508 0.667 508.1 0.856 525. 2 0.982 508 1.130 525.2 1.420 508 0.469 508 0.695 508.1 0.865 508 0.983 505 1.170 508 1.460 508 0.488 525.2 0.748 525.2 0. 875 505 1.020 505 1.180 505 1.590 508 0.510 525.2 0.750 525.2 0.912 525. 2 1.030 other 1.180 505 1.660 525.2 0.540 525.2 0.770 505 0.932 508 1.080 508.1 1.180 505 1.700 508 0.543 508 0.826 508 0.940 525.2 1.080 525.2 1.290

## B-124 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 1.93 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 0.190 525.2 0.933 508 1.110 525. 2 1.360 505 1.670 other 2.110 508 0.677 525.2 0.950 508.1 1.130 525. 2 1.490 other 1.680 505 2.120 508.1 0.786 508 0.951 525.2 1.150 508 1.510 508 1.730 other 2.140 508 0.828 508 1.020 525.2 1.260 505 1.560 505 1.730 505 2.240 508 0.857 525.2 1.040 508 1.290 505 1.610 505 1.770 505 2.560 508.1 0.919 525.2 1.070 505 1.300 508 1.620 525.2 1.990

Mercury Water Study: 24a True Value: 5.76 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 3.800 245.1 5.230 245.1 5.510 245.1 5.700 245.1 5.910 245.1 6.210 245.1 4.200 245.2 5.260 245.1 5.560 245. 1 5.710 other 5.960 245.1 6.340 245.1 4.500 245.1 5.280 other 5.580 245.1 5.740 245.1 5.980 245.1 6.400 245.1 4.780 245.1 5.350 245.1 5.600 245. 1 5.780 245.1 6.000 other 6.460 245.2 4.970 245.2 5.400 245.1 5.600 245.1 5.790 245.1 6.000 245.1 6.480 245.1 5.070 245.1 5.400 245.1 5.620 245. 1 5.800 245.1 6.030 other 6.800 245.1 5.110 245.2 5.410 245.1 5.650 245.2 5.900 245.1 6.100 245.1 7.050 245.1 5.120 245.1 5.430 245.1 5.690 245. 1 5.900 other 6.100 245.1 7.100 245.1 5.120 245.1 5.500 245.1 5.700 245. 1 5.900 245.1 6.130 other 8.510 245.1 5.200 245.1 5.500 245.1 5 .700 245.1 5.900 245.1 6.190 Water Study: 24b True Value: 2.16ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 1.400 245.1 1.780 245.1 2.000 245.1 2.040 245.1 2.190 245.1 2.400 245.1 1.500 245.1 1.850 245.1 2.000 245.1 2.050 245.2 2.200 245.1 2.400 245.1 1.520 245.1 1.890 245.2 2.000 245.1 2.090 245.1 2.230 245.1 2.410 245.1 1.540 245.2 1.900 245.1 2.000 other 2.100 245.1 2.270 245.1 2.500 245.1 1.580 245.1 1.900 245.1 2.000 245. 1 2.100 245.1 2.280 other 2.610 245.1 1.600 245.1 1.920 245.2 2.005 245.1 2.110 245.1 2.300 245.1 2.700 other 1.700 245.1 1.960 245.1 2.010 other 2.130 245.1 2.300 245.1 2.800 245.1 1.700 245.1 1.960 245.2 2.020 other 2.160 245.1 2.340 245.1 2.950 245.1 1.740 245.1 2.000 245.1 2.040 245. 1 2.170 245.1 2.350 other 3.430 245.1 1.750 245.1 2.000 245.1 2 .040 245.1 2.190 245.1 2.360

## B-125 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 25a True Value: 0.72 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.320 245.1 0.545 245.1 0.646 245.1 0.710 245.1 0.800 245.1 1.000 245.1 0.360 245.1 0.580 245.1 0.670 245.1 0.716 245.1 0.800 245.1 1.300 245.1 0.400 245.2 0.580 245.1 0 .670 245.1 0.728 245.1 0.800 301A-VI 0.400 245.1 0.597 245.1 0 .670 245.1 0.730 245.1 0.900

245.1 0.470 245.1 0.600 245.1 0 .690 245.1 0.750 245.2 0.900 245.1 0.480 other 0.600 245.1 0 .690 245.1 0.785 other 0.940 245.1 0.500 245.1 0.600 245.1 0. 700 other 0.790 245.1 0.950 Water Study: 25b True Value: 4.32 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 2.540 245.1 3.770 other 4.130 245.1 4.420 245.1 4.610 245.1 5.200 245.1 2.700 245.1 3.970 245.1 4.180 245.1 4.430 245.1 4.720 245.1 5.750 245.1 3.300 245.1 3.990 245.1 4 .270 245.1 4.450 245.2 4.720 245.1 3.530 245.1 4.050 301A-VI 4 .280 245.1 4.540 245.1 4.750 245.1 3.630 245.1 4.060 245.2 4 .300 245.1 4.550 245.1 5.035 other 3.700 245.1 4.100 other 4.300 245.1 4.600 245.1 5.100 245.1 3.700 245.1 4.120 245.1 4. 420 245.1 4.600 other 5.130 Water Study: 26a True Value: 4.56 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.2 2.200 245.1 4.060 245.1 4.300 245.2 4.510 245.2 4.720 245.1 5.100 245.1 3.280 245.1 4.080 245.1 4.330 245.1 4.520 245.1 4.800 245.1 5.170 245.1 3.425 245.1 4.100 245.1 4.350 245.1 4.600 245.1 4.840 245.1 5.170 245.1 3.500 245.1 4.200 245.1 4.400 245.1 4.600 245.1 4.870 245.1 5.350 245.1 3.510 245.1 4.200 245.1 4.400 245.1 4.600 245.1 4.900 245.1 5.600 245.1 3.770 245.1 4.200 245.1 4.400 245.1 4.600 245.1 4.930 245.1 7.100 245.1 3.800 245.2 4.240 245.1 4 .400 245.1 4.630 245.1 4.940 245.1 3.800 245.1 4.240 245.1 4 .420 245.1 4.690 245.1 4.960 245.1 3.950 245.1 4.280 245.1 4 .490 245.2 4.700 245.1 4.990 245.1 4.000 245.1 4.300 245.1 4 .500 245.1 4.700 245.1 5.000 245.1 4.010 other 4.300 other 4.500 245.1 4.710 245.1 5.100

## B-126 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 2.47 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.2 1.000 245.1 2.100 245.1 2.290 245. 2 2.440 other 2.580 245.1 2.740 245.1 1.500 245.1 2.130 245.1 2.300 245.1 2.480 245.1 2.600 245.1 2.800 245.1 1.565 245.1 2.170 245.1 2.300 245.2 2.480 245.1 2.600 245.1 2.800 245.1 1.800 245.1 2.170 245.1 2.340 245.2 2.480 245.1 2.600 245.1 2.950 245.1 1.900 245.1 2.200 245.1 2.340 245.1 2.480 245.1 2.600 245.1 3.050 245.1 2.000 245.2 2.200 245.1 2.340 245.1 2.500 245.1 2.600 245.1 3.270 245.1 2.000 245.1 2.200 245.2 2 .350 245.1 2.510 245.1 2.600 245.1 2.000 245.1 2.200 245.1 2 .400 245.1 2.510 245.1 2.630 245.1 2.010 245.1 2.200 other 2 .400 245.1 2.550 245.1 2.640 245.1 2.070 245.1 2.240 245.1 2 .400 245.1 2.550 245.1 2.700 245.1 2.070 245.1 2.250 245.1 2 .420 245.1 2.550 245.1 2.700 Water Study: 27 True Value: 1.29 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 0.970 245.1 1.200 245.1 1.260 245.1 1.330 245.2 1.460 245.1 1.600 245.2 1.000 245.1 1.200 245.1 1.290 245.1 1.350 245.1 1.490 245.1 1.660 245.1 1.000 245.2 1.230 245.1 1.310 other 1.370 245.1 1.500 245.1 2.250 245.1 1.090 245.1 1.250 245.1 1. 310 245.1 1.370 301A-VI 1.530 245.1 1.110 245.1 1.260 245.1 1 .310 245.1 1.400 245.1 1.560 245.1 1.130 245.1 1.260 245.2 1 .320 245.1 1.400 245.1 1.580 Water Study: 29 True Value: 0.506 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 0.300 245.2 0.420 245.1 0.478 245.2 0.500 245.1 0.544 245.1 0.721 245.1 0.352 245.1 0.422 245.1 0 .481 245.1 0.500 245.1 0.550 245.1 0.380 245.2 0.440 245.1 0 .485 245.1 0.500 245.1 0.550 245.1 0.395 other 0.450 245.1 0 .486 245.1 0.518 245.1 0.629 245.1 0.397 245.1 0.450 245.2 0 .488 245.1 0.530 245.1 0.640 other 0.400 245.2 0.467 245.2 0 .500 245.1 0.540 245.1 0.700

## B-127 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 3.46 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.720 303F 3.120 245.1 3.260 245.1 3.436 245.1 3.570 245.1 3.760 245.1 2.800 245.1 3.126 245.1 3.290 245.1 3.450 245.1 3.570 245.2 3.784 245.1 2.820 245.1 3.130 245.1 3.300 245.1 3.490 245.1 3.600 245.2 3.790 245.1 2.820 245.1 3.130 245.1 3.320 245.1 3.500 245.1 3.600 245.1 3.797 245.2 2.880 245.1 3.160 245.1 3.350 245.1 3.500 245.1 3.610 245.2 3.800 245.1 2.920 245.1 3.180 245.1 3.350 245. 1 3.500 245.1 3.619 other 3.920 245.1 3.030 245.1 3.180 245.1 3.370 245.2 3.500 245.2 3.640 245.2 4.100 245.2 3.070 245.2 3.200 245.1 3 .385 245.1 3.500 245.1 3.700 245.1 3.080 245.1 3.200 245.2 3 .400 245.1 3.530 245.1 3.700 245.1 3.100 245.1 3.220 245.1 3 .400 245.1 3.540 245.1 3.700 245.1 3.100 245.1 3.250 245.1 3 .410 245.1 3.550 245.1 3.700 Water Study: 31 True Value: 0.908 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 0.471 245.1 0.872 245.1 0.890 245.1 0.940 245.1 0.969 245.1 1.200 245.1 0.700 245.1 0.874 245.1 0 .895 245.1 0.946 245.1 1.000 other 0.780 245.1 0.877 245.2 0 .900 245.1 0.950 245.1 1.020 245.1 0.800 245.2 0.880 245.2 0 .906 245.1 0.950 245.1 1.080 245.1 0.800 245.2 0.880 245.1 0 .930 245.1 0.950 245.2 1.190 245.1 0.860 245.1 0.890 245.1 0 .940 245.1 0.953 245.1 1.200 Water Study: 32 True Value: 6.23 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 0.574 245.2 5.800 245.2 6.100 245.1 6.270 245.1 6.500 245.1 6.800 245.1 4.300 245.2 5.800 245.1 6.110 245.2 6.280 245.1 6.530 245.2 6.920 245.1 4.940 245.1 5.880 245.1 6.120 245.1 6.300 245.2 6.540 245.1 6.969 245.2 5.100 245.1 5.890 245.1 6.120 245.1 6.300 245.1 6.540 245.1 7.000 245.1 5.380 3112B 5.900 245.2 6.140 245. 1 6.300 245.1 6.540 245.1 7.050 245.1 5.400 245.2 6.000 other 6.150 245.2 6.400 245.1 6.570 245.2 7.100 245.1 5.490 3112B 6.050 245.1 6.160 245. 1 6.410 245.1 6.580 245.1 7.140 245.2 5.500 245.1 6.056 245.1 6.200 245.1 6.460 245.2 6.600 245.1 7.500 245.1 5.600 245.1 6.060 245.1 6.200 245.1 6.480 245.1 6.610 245.1 7.800 245.1 5.620 245.1 6.090 245.1 6 .200 245.1 6.480 245.1 6.660 245.1 5.730 245.1 6.100 245.1 6 .210 245.1 6.500 245.1 6.710

## B-128 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 1.77 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 1.560 245.1 1.670 245.1 1.780 245.1 1.830 245.1 1.930 245.1 2.070 245.1 1.608 245.1 1.680 245.1 1.800 245.1 1.857 3112B 1.950 245.1 2.240 245.2 1.620 245.2 1.700 245.1 1.800 245. 2 1.860 other 1.970 245.1 3.350 245.1 1.630 245.1 1.730 245.1 1.800 245.1 1.870 245.1 2.000 245.2 1958.000 245.1 1.640 245.1 1.740 245.1 1 .810 other 1.880 3112B 2.010 245.2 1.660 245.1 1.750 245.1 1 .830 245.1 1.900 245.2 2.030 Water Study: 34 True Value: 5.09 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 3.850 245.1 4.740 245.1 4.900 245.1 5.060 245.1 5.310 245.1 5.800 245.1 4.160 245.2 4.790 245.1 4.900 245.2 5.070 3112B 5.350 245.1 5.810 245.1 4.180 245.1 4.800 245.2 4.900 245.1 5.070 245.1 5.370 245.2 5.970 3112B 4.400 245.1 4.800 245.1 4.910 245. 2 5.100 245.1 5.400 245.1 5.980 245.1 4.490 245.2 4.810 245.2 4.930 245.1 5.130 245.1 5.410 245.1 6.230 245.2 4.580 245.1 4.840 245.1 4.950 245.1 5.150 245.1 5.417 245.1 6.400 245.1 4.600 245.1 4.850 245.2 4 .980 245.1 5.180 245.2 5.460 245.1 4.620 245.2 4.850 245.1 5 .000 245.1 5.200 245.1 5.600 245.1 4.697 245.2 4.860 245.1 5 .000 245.1 5.220 245.1 5.640 245.1 4.700 245.1 4.870 245.1 5 .020 245.1 5.230 245.1 5.650 245.1 4.700 245.1 4.900 245.1 5 .030 245.1 5.270 245.1 5.700 Water Study: 35 True Value: 0.897 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.500 245.1 0.800 245.1 0.860 245.2 0.930 245.1 0.986 245.1 1.100 245.1 0.700 245.1 0.820 3112B 0.863 245. 1 0.940 245.1 1.000 245.1 1.440 245.2 0.750 245.2 0.840 245.2 0 .865 245.1 0.956 245.1 1.010 245.1 0.766 245.1 0.845 245.1 0 .897 245.1 0.960 245.1 1.030 245.1 0.781 245.1 0.850 245.2 0 .900 245.1 0.963 245.1 1.040 245.1 0.800 245.1 0.860 245.1 0 .900 245.1 0.975 245.1 1.040 245.1 0.800 245.1 0.860 3112B 0. 900 245.1 0.979 245.1 1.060

## B-129 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 3.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 1.924 3112B 2.640 245.2 2.820 245. 2 2.910 245.1 3.070 other 3.300 245.1 2.300 245.2 2.700 245.2 2.820 245.1 2.920 245.1 3.100 245.1 3.420 245.1 2.400 200.8 2.740 245.1 2.840 245. 2 2.950 245.1 3.120 other 3.490 245.2 2.440 245.1 2.770 245.2 2.840 245.1 2.960 245.1 3.120 245.2 3.900 245.1 2.500 other 2.790 3112B 2.840 3112B 3.000 245.1 3.150 245.1 3.940 245.1 2.560 245.1 2.800 245.1 2.850 245.1 3.000 245.1 3.150 3112B 4.240 245.2 2.580 245.1 2.800 245.1 2 .850 245.2 3.000 245.2 3.180 3112B 2.590 245.1 2.800 245.2 2. 860 245.1 3.000 245.1 3.200 245.2 2.600 245.1 2.800 3112B 2. 880 245.1 3.020 245.2 3.200 245.2 2.620 245.1 2.800 245.1 2 .900 245.2 3.030 245.2 3.220 245.1 2.640 245.1 2.820 other 2.900 3112B 3.060 245.2 3.240 Water Study: 37 True Value: 8.16 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.2 5.300 3112B 7.340 245.1 7.700 245. 2 7.900 245.1 8.140 245.2 8.660 245.1 5.600 245.1 7.440 245.1 7.720 245.1 7.920 245.1 8.150 245.1 8.660 245.1 6.360 245.1 7.500 245.1 7.730 245.1 7.950 3112B 8.170 245.1 8.680 3112B 6.490 245.1 7.570 245.1 7.730 245. 1 7.980 245.2 8.180 245.1 8.743 245.2 7.100 245.1 7.590 245.2 7.760 245.2 8.000 245.1 8.200 245.2 8.820 245.2 7.270 245.2 7.640 245.1 7.800 245.1 8.040 245.2 8.600 245.1 13.400 245.2 7.300 245.1 7.650 245.1 7.820 3112B 8.080 245.1 8.600 245.1 80.400 245.1 7.300 245.2 7.660 3112B 7. 900 245.1 8.100 245.2 8.620 Water Study: 38 True Value: 6.39 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 3.280 245.1 5.430 245.1 5.750 245. 1 5.900 other 6.040 245.2 6.470 200.8 4.200 245.2 5.510 245.2 5.750 245.2 5.920 245.1 6.100 245.1 6.500 245.2 4.260 245.2 5.530 3112B 5.760 245. 2 5.930 245.1 6.150 245.1 6.500 other 5.020 245.1 5.540 245.2 5. 760 245.1 5.980 245.1 6.210 3112B 6.530 245.1 5.040 245.2 5.550 245.1 5.780 245.2 5.990 245.2 6.240 245.2 6.530 245.1 5.150 245.1 5.570 245.1 5.800 245.1 6.000 245.2 6.330 245.1 6.600 245.1 5.200 200.8 5.630 3112B 5.800 245.1 6.000 3112B 6.340 245.2 6.800 245.1 5.250 245.1 5.640 245.1 5.860 245.1 6.020 245.1 6.340 245.1 6.980 245.1 5.309 245.2 5.680 245.2 5.870 245.2 6.020 245.2 6.400 245.2 7.520 245.2 5.400 245.1 5.690 245.2 5.900 245. 1 6.030 245.1 6.420 other 8.020

## B-130 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 3.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 1.400 245.1 2.960 3112B 3.200 245.1 3.400 3112B 3.520 245.1 3.840 245.1 1.690 245.2 2.980 3112B 3.230 245. 2 3.430 245.2 3.600 200.8 3.840 245.2 1.820 245.1 3.000 245.2 3.300 245.1 3.450 245.2 3.620 245.1 3.890 245.2 1.890 245.1 3.000 245.1 3.350 245.1 3.460 245.2 3.630 245.2 3.900 245.1 2.140 245.1 3.000 245.2 3.390 245.2 3.470 245.1 3.650 245.1 3.940 245.1 2.280 3112B 3.080 245.1 3.390 245. 1 3.480 245.1 3.700 245.1 4.010 245.1 2.570 245.1 3.170 245.2 3.390 245.2 3.500 245.1 3.790 245.2 4.030 245.2 2.620 3112B 3.180 245.2 3. 400 245.1 3.500 245.1 3.810 Water Study: 40 True Value: 1.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.2 0.833 3112B 1.250 other 1.330 245.1 1.380 245.1 1.420 245.1 1.490 245.1 0.900 245.2 1.250 245.2 1.340 245.2 1.390 245.2 1.440 245.1 1.510 245.2 1.100 245.2 1.260 245.1 1.340 245.1 1.390 3112B 1.440 245.1 1.580 245.1 1.100 245.2 1.260 245.1 1.340 245. 1 1.400 245.2 1.450 other 1.600 245.2 1.120 245.2 1.290 245.2 1.350 245.1 1.400 245.1 1.460 245.2 1.700 200.8 1.140 245.2 1.290 245.1 1.350 245.1 1.400 245.1 1.460 245.1 1.700 other 1.160 245.1 1.300 245.2 1. 360 3112B 1.400 245.2 1.470 245.2 1.790 245.2 1.180 245.2 1.310 3112B 1.360 245. 1 1.400 245.1 1.470 245.1 1.900 200.8 1.210 245.2 1.320 245.2 1.360 245.1 1.410 3112B 1.480 245.2 2.070 245.1 1.240 245.1 1.320 other 1.370 245.1 1.420 245.1 1.490 245.1 14.500 Water Study: 41 True Value: 5.82 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 245.1 4.450 245.2 5.160 245.2 5.400 245.1 5.690 245.2 5.820 245.1 6.180 3112B 4.510 245.1 5.200 245.2 5.420 245. 2 5.700 245.2 5.860 245.1 6.240 245.2 4.870 245.2 5.300 245.2 5.500 245.1 5.700 3112B 5.910 245.1 6.460 245.1 4.900 245.1 5.320 245.1 5.530 245.2 5.740 245.2 5.950 245.1 6.570 245.1 4.950 200.8 5.350 3112B 5. 550 245.1 5.780 245.2 6.100 245.1 5.010 245.1 5.350 245.1 5 .610 245.1 5.780 245.2 6.120 245.1 5.030 245.2 5.360 245.2 5 .620 245.2 5.800 200.8 6.120 3112B 5.140 245.2 5.400 245.2 5. 620 245.1 5.800 245.1 6.150

## B-131 Methods Support Document for Six-Year Review Final - March 2003 Methoxychlor Water Study: 24a True Value: 73.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 4.190 509A 52.700 p. 1 59.000 509A 63.900 p. 1 69.020 other 77.700 p. 1 4.780 p. 1 53.800 p. 1 59.500 p. 1 64.000 p. 1 69.200 p. 1 77.800 other 30.000 509A 54.200 other 60.000 p. 1 64.400 509A 69.300 other 78.000 509A 40.200 other 55.000 p. 1 60.600 p. 1 65.300 other 72.900 other 83.000 p. 1 40.900 p. 1 56.100 p. 1 61.000 other 65.700 525.1 73.300 p. 1 101.000 525.1 41.500 p. 1 56.450 p. 1 61.450 other 66.700 p. 1 73.500 509A 105.000 D3086-79 42.000 525.1 56.850 525.1 62.150 p. 1 67.400 p. 1 74.400 509A 1930.000 p. 1 44.800 p. 1 57.300 p. 1 62.400 p. 1 67.900 p. 1 74.700 p. 1 47.000 509A 58.500 p. 1 62. 500 other 68.300 p. 1 74.850 509A 47.110 p. 1 58.500 p. 1 63. 560 p. 1 68.300 p. 1 76.300 p. 1 52.600 other 58.800 p. 1 63.570 other 68.990 p. 1 77.500 Water Study: 24b True Value: 5.37 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.362 p. 1 4.300 p. 1 4.490 p. 1 4.890 p. 1 5.350 p. 1 5.770 p. 1 3.360 p. 1 4.310 other 4.500 p. 1 4.970 p. 1 5.360 other 5.780
p. 1 3.480 p. 1 4.320 other 4 .500 509A 4.990 509A 5.380 other 7.100
p. 1 3.550 p. 1 4.390 other 4.500 p. 1 5.050 other 5.388 p. 1 10.100

525.1 3.700 p. 1 4.400 p. 1 4.520 p. 1 5.060 525.1 5.456 other 61.000

509A 3.790 p. 1 4.410 509A 4.590 p. 1 5.100 p. 1 5.460 509A 6660.000
p. 1 3.990 p. 1 4.410 509A 4.640 525.1 5.120 p. 1 5.470

509A 4.000 other 4.430 509A 4.670 D3086- 79 5.140 509A 5.550
p. 1 4.030 p. 1 4.440 p. 1 4.790 525.1 5.171 p. 1 5.700
p. 1 4.080 other 4.450 other 4 .820 p. 1 5.190 p. 1 5.706
p. 1 4.250 p. 1 4.460 other 4 .850 p. 1 5.194 other 5.710

## B-132 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 25a True Value: 3.17 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value p. 1 0.117 509A 2.570 505 2.710 505 2.810 D3086- 79 3.090 p. 1 3.990 SPE-500 1.600 other 2.600 p. 1 2. 720 p. 1 2.860 509A 3.160 other 4.000

509A 2.020 509A 2.607 p. 1 2.730 other 2.920 p. 1 3.200

D3086-79 2.060 p. 1 2.640 SPE-500 2.754 508 3.000 509A 3.200

other 2.060 p. 1 2.680 p. 1 2 .800 p. 1 3.007 other 3.200
509A 2.310 p. 1 2.687 other 2.800 509A 3.010 D3086- 79 3.240
p. 1 2.380 p. 1 2.690 p. 1 2.800 509A 3.080 p. 1 3.270

Water Study: 25b True Value: 48.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value p. 1 2.360 505 36.900 other 40.800 509A 43.300 other 46.000 p. 1 51.420
509A 23.800 other 37.000 other 42.100 p. 1 43.500 p. 1 46.000 other 62.200

p. 1 28.020 p. 1 37.400 509A 42.200 509A 43.800 p. 1 46.300
SPE-500 30.000 509A 39.100 p. 1 42.260 D3086- 79 45.000 p. 1 47.800
SPE-500 34.720 D3086-79 39.100 p. 1 42.300 509A 45.600 509A 48.200

p. 1 35.000 other 39.900 p. 1 42.700 p. 1 45.600 p. 1 48.210
D3086-79 35.100 505 40.300 508 43.000 509A 45.800 p. 1 48.400

## B-133 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26a True Value: 92.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 509A 9.130 other 72.300 p. 1 82.400 509A 87.400 p. 1 94.600 D3086-79 101.000 other 20.900 p. 1 72.800 other 83.500 p. 1 87.500 p. 1 95.000 p. 1 102.000
D3086-79 44.500 p. 1 73.100 p. 1 83.900 p. 1 89.300 other 95.000 p. 1 104.000
p. 1 46.100 p. 1 79.200 other 84. 000 p. 1 89.500 509A 95.140 p. 1 104.000

SPE-500 55.000 509A 79.300 SPE-500 84.440 p. 1 91.600 SPE-500 96.360 509A 105.000

other 59.600 p. 1 80.500 p. 1 84.870 p. 1 91.900 p. 1 96.600 p. 1 106.000
SPE-500 60.320 other 80.600 509A 85.500 p. 1 91.990 p. 1 96.700 other 106.800

other 60.900 p. 1 82.000 p. 1 86.100 508 92.800 p. 1 98.100 509A 124.000
p. 1 64.000 p. 1 82.100 other 86. 200 505 92.900 p. 1 99.100 525.1 130.100
other 68.900 p. 1 82.300 other 86.900 p. 1 93.300 other 100.000

Water Study: 26b True Value: 2.18 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value SPE-500 0.242 p. 1 1.850 other 2.030 other 2.180 p. 1 2.290 other 2.590
SPE-500 1.200 p. 1 1.930 p. 1 2.040 p. 1 2.183 p. 1 2.300 p. 1 2.600

509A 1.220 p. 1 1.970 D3086-79 2.040 other 2.200 SPE-500 2.309 p. 1 2.610
509A 1.560 other 1.970 p. 1 2.092 p. 1 2.220 p. 1 2.350 509A 2.700
505 1.590 p. 1 1.980 other 2.100 other 2.250 p. 1 2.380 other 2.700
p. 1 1.690 p. 1 1.980 other 2.150 p. 1 2.250 p. 1 2.400 p. 1 2.920
p. 1 1.690 p. 1 2.000 SPE-500 2.159 D3086- 79 2.260 p. 1 2.480 other 3.040
other 1.700 p. 1 2.010 p. 1 2. 160 509A 2.280 525.1 2.483 p. 1 3.720
other 1.730 509A 2.030 p. 1 2.170 p. 1 2.280 509A 2.540 p. 1 3.970
509A 1.820 p. 1 2.030 other 2.180 p. 1 2.290 508 2.560

## B-134 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 16.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 509A 2.620 508 14.000 509A 15.500 p. 1 16.500 other 17.400 D3086-79 19.300
p. 1 4.040 p. 1 14.500 p. 1 15. 700 other 16.600 509A 17.700 other 19.530
other 8.540 p. 1 14.900 p. 1 15.810 509A 16.700 509A 17.800 p. 1 23.100
p. 1 9.230 other 14.900 p. 1 15.840 p. 1 16.800 p. 1 18.070 p. 1 75.090
505 9.400 p. 1 15.000 other 16.000 509A 17.000 p. 1 18.100

508 12.500 508 15.500 other 16.200 p. 1 17.110 p. 1 18.610
p. 1 13.000 other 15.500 p. 1 16.400 505 17.400 p. 1 19.000

Water Study: 29 True Value: 5.21 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 2.830 508 4.080 D3086-79 4.560 508 4.820 508 5.600 508 6.020 p. 1 3.280 other 4.087 other 4 .700 508 4.870 508 5.700 p. 1 6.130
p. 1 3.570 p. 1 4.300 505 4.760 508 4.930 508 5.800 508 6.300
508 3.620 p. 1 4.331 508 4.780 508 5.270 509A 5.808
508 3.910 508 4.400 other 4.800 p. 1 5.400 505 5.920
p. 1 4.080 SPE-500 4.403 other 4 .811 other 5.530 p. 1 5.960

## B-135 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 34.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.839 other 24.700 508 29.810 505 32.400 other 35.000 other 37.200

other 3.691 other 25.200 other 29. 900 p. 1 32.800 505 35.100 p. 1 37.500

505 13.720 508 26.700 508 30.100 505 33.200 508 35.500 508 38.500
505 14.300 505 27.000 p. 1 30.200 508 33.500 other 35.600 508 39.100

508 15.800 508 27.200 508 31.100 D3086- 79 34.300 508 35.900 508 39.600
508 20.400 508 28.800 p. 1 31.200 other 34.300 other 36.400 508 40.700

p. 1 21.560 508 29.100 p. 1 31. 500 p. 1 34.600 505 36.500 508 41.700

505 22.600 508 29.440 508 31.700 508 34.700 508 36.700 508 42.670
505 24.000 508 29.500 505 32.300 508 35.000 p. 1 37.000 508 55.100

Water Study: 31 True Value: 12.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.962 508 7.780 508 11.400 508 11. 600 other 12.600 p. 1 14.120 508 4.860 508 9.420 508 11.500 508 11.700 other 12.700 508 16.400 508 5.170 505 10.100 508 11.500 508 11.900 508 12.800 508 5.300 508 10.560 508 11.500 508 12.300 508 12.800 505 6.440 other 11.000 508 11.500 508 12.400 p. 1 13.100 508 6.690 other 11.200 505 11. 600 508 12.500 other 13.400

## B-136 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 17.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 1.700 508 13.300 525.1 14.900 508 16.000 508 16.800 508 19.700 508 5.350 other 14.100 508 15. 000 508 16.100 508 17.200 508 19.900 508 7.320 508 14.200 508 15.100 525. 1 16.200 508 17.200 508 20.300 525.1 8.610 505 14.240 508 15.300 505 16.200 505 17.200 other 20.400 other 9.600 508 14.400 508 15.400 other 16.300 505 17.600 505 21.100 505 10.800 508 14.400 525.1 15.450 other 16.500 508 17.900 505 21.400 525.1 10.900 505 14.500 508 15.500 508 16.600 508 17.940 505 29.800 505 11.100 525.1 14.600 525.1 15.500 508 16.620 508 18.200 525.1 30.080 508 13.000 508 14.700 508 15.700 other 16.700 508 18.900 508 31.490 508 13.200 508 14.770 508 16.000 505 16.790 508 19.600 Water Study: 33 True Value: 42.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 27.200 525.1 33.100 508 37. 900 508 41.100 505 44.100 505 48.800 508 27.700 508 34.800 other 38.900 other 41.300 other 44.200 508 50.200 508 28.600 505 35.800 508 39.080 508 41.300 508 44.800 508 51.600 508 29.700 525.1 37.100 505 39.500 508 42.100 508 44.900 525.1 52.830 508 29.900 525.1 37.500 508 39.900 525. 1 42.300 505 44.900 525.1 100.000 508 32.000 508 37.600 508 40.200 505 42.300 508 45.300 Water Study: 34 True Value: 14.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 1.540 505 11.200 508 12.200 508 13.900 505 14.800 other 16.800 508 6.470 508 11.300 525.1 12.700 505 14.020 508 14.900 508 16.850 525.1 9.380 505 11.350 other 13. 000 508 14.400 505 15.100 508 17.100 525.1 9.980 508 11.500 525.1 13. 000 508 14.400 505 15.200 508 18.500 508 10.900 508 11.600 508 13.100 508 14.500 525.1 15.500 508 19.100 525.1 10.900 505 11.700 525.1 13. 100 508 14.600 508 15.700 508 19.600 505 10.970 505 11.900 505 13.200 505 14.600 508 15.840 508 22.300 other 11.200 525.1 12.000 508 13. 200 508 14.600 505 16.200 508 24.500 other 11.200 525.1 12.200 508 13.500 505 14.600 508 16.600

## B-137 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 62.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 34.900 508 44.200 525.1 51.400 508 55.700 525.1 60.700 525.1 63.200 508 39.900 505 47.100 508 52.000 508 57.600 505 60.800 508 69.700 525.1 40.300 505 47.580 508 52.600 508 59.400 508 61.060 508 70.400 other 41.000 508 49.800 508 52. 900 508 59.500 508 61.200 508 72.600 508 44.000 525.1 50.500 505 53.650 505 59. 800 other 63.100 other 90.800 Water Study: 36 True Value: 28.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 12.700 508 22.400 525.2 26.040 508 27.600 508 29.600 525.2 33.100 508 15.680 508.1 22.600 525.2 26.100 505 27.600 505 29.600 525.2 33.400 505 17.110 525.2 23.100 525.2 26.300 505 27.700 508 30.000 508.1 39.300 508.1 19.200 508.1 23.200 508 26.300 other 28.000 525.2 30.000 508 40.900 508 19.200 508 23.700 508 26.400 508 28.000 508 30.650 505 42.500 525.2 20.800 508 24.400 508 26.800 505 28.200 508 30.900 505 84.900 525.2 20.800 505 25.180 other 26.900 508 28.600 525.2 31.600 508 20.900 525.2 25.300 525.1 27. 000 other 28.800 508 32.100 508 21.900 508 25.400 508 27.300 508 29.200 508 32.500 other 22.140 505 26.000 508 27.500 505 29.400 505 32.900 Water Study: 37 True Value: 18.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.754 525.2 14.800 other 16.400 505 18.700 505 20.100 other 23.600 508 7.880 508 15.100 505 16.800 508 19.100 508 20.200 525.2 23.800 508 10.200 525.2 15.700 505 17.000 505 19.100 505 20.400 508 25.600 508 12.100 508 15.800 525.2 17.600 505 19.200 508.1 20.400 505 26.150 508 12.800 508 15.900 508 17.900 508 19.300 508.1 21.100 525.2 27.300 508 13.000 508 16.000 525.2 17. 900 505 19.400 other 22.100 508 13.500 525.2 16.000 525.2 18.350 508 19.700 508 22.700 508 13.900 525.2 16.000 508 18.400 505 19.800 525 23.500

## B-138 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 34.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 14.000 other 24.260 505 30.800 508.1 32.700 508 35.000 508 40.350 508 16.400 508 25.400 508 31.100 505 33.000 525.2 35.390 505 40.700 508 17.700 508.1 27.000 508 31.200 525. 2 33.100 525.2 35.400 508 42.900 525.2 17.900 508 28.500 508 31.500 505 33.700 508 35.700 508 43.600 525.2 18.000 508 29.300 508 31.800 508 34.000 505 36.100 525.2 48.400 508 19.600 508 29.400 508 31.900 508 34.050 525.2 37.400 525.2 51.800 508 22.500 525.2 30.100 505 32.000 508 34.100 508 37.420 505 23.400 508.1 30.200 505 32. 100 other 34.500 505 38.600 525.2 23.400 508 30.500 508 32.600 508 34.600 525.2 40.100 Water Study: 39 True Value: 53.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 16.100 508 45.000 525.2 49.600 505 52.600 508 56.300 525.2 71.800 508 28.000 525.2 45.100 505 49.900 other 53.200 505 56.800 508.1 76.400 525.2 35.300 505 45.800 525.2 51.000 525.2 53.200 508 57.000 525.2 79.800 508 36.800 508 45.960 other 51. 300 other 53.500 525.2 57.900 508 40.200 508 47.000 508 51.500 508 53.600 525.2 59.300 505 41.050 505 47.100 508 51.500 525.2 54.100 505 61.200 508 41.500 508 47.400 508 51.800 525.2 54.100 505 63.000 508 44.600 525.2 47.600 525.2 51.820 508.1 54.300 508 67.800 Water Study: 40 True Value: 42.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 4.420 508 34.700 508 38.100 508 40.100 505 43.400 other 47.600 508 22.900 505 35.800 505 38.400 525. 2 42.000 508 43.500 508 48.800 508 23.700 508 36.700 508 38.600 505 42.000 508 43.500 508 49.100 other 26.800 525.2 36.800 525.2 39. 100 508 42.000 other 43.690 505 49.800 508 28.000 508.1 37.000 508 39.300 508 42.100 525.2 44.100 525.2 50.100 508 28.800 525.2 37.200 508 39.400 508 42.200 508.1 44.900 508 50.800 525.2 32.000 525.2 37.400 525.2 39. 540 508 43.000 508 45.600 525.2 51.500 508 33.300 508.1 37.700 other 39. 800 508 43.000 508 46.200 525.2 51.800 505 33.900 525.2 37.800 525.2 40.100 505 43.200 505 46.500 525.2 54.600

## B-139 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 26.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508.1 5.060 505 22.200 508 26.000 508 27.400 505 28.400 508 37.000 508.1 9.950 508 22.500 508 26.100 525. 2 27.600 525.2 29.500 508.1 39.100 508 18.700 508 22.500 508 26.300 505 27.900 525.2 30.300 508 39.200 525.2 18.900 other 23.300 505 26. 300 other 28.000 525.2 30.500 508 19.000 508 24.400 505 26.500 525.2 28.000 508.1 31.800 505 20.900 508 24.400 other 26.800 525.2 28.100 505 32.200 525.2 21.200 508.1 24.600 505 26.800 508 28.400 505 34.200 508 22.200 525.2 25.280 other 27.400 508 28.400 525.2 36.000

Oxamyl Water Study: 24a True Value: 12.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 10.000 531.1 12.300 531. 1 12.800 other 13.150 531.1 12.000 531.1 12.500 531.1 12.900 531.1 14.300 Water Study: 24b True Value: 31.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 22.800 531.1 29.100 531.1 32.000 531.1 32.600 531.1 24.700 other 30.500 531.1 32.100 531.1 33.100 Water Study: 25a True Value: 17.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 4.770 531.1 16.900 531.1 17.970 531.1 18.140 531.1 26.900 Water Study: 25b True Value: 53.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 50.700 531.1 52.700 531.1 56.730 531.1 58.300 531.1 92.600

## B-140 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26a True Value: 22.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 9.270 531.1 18.700 other 21.500 531.1 23.000 531.1 25.530 531.1 16.800 other 20.100 531.1 22.000 531.1 23.100 531.1 16.900 531.1 21.500 531.1 22.400 531.1 23.800 Water Study: 26b True Value: 46.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 25.500 other 41.400 531.1 44.600 531.1 46.800 531.1 52.640 531.1 31.900 531.1 42.500 other 44.800 531.1 47.500 531.1 33.000 531.1 43.300 531.1 46.600 531.1 48.000 Water Study: 27 True Value: 12.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 3.330 531.1 11.500 531.1 16.600 531.1 19.400 531.1 10.500 531.1 13.000 531.1 17.900 531.1 34.700 Water Study: 29 True Value: 4.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 3.180 531.1 4.340 531.1 4. 400 other 5.260 531.1 5.620 531.1 4.050 531.1 4.390 531.1 4 .800 531.1 5.280 531.1 8.650 Water Study: 30 True Value: 6.47 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 4.600 531.1 5.980 531.1 6 .570 531.1 6.840 531.1 7.570 531.1 5.080 531.1 6.060 531.1 6 .660 531.1 6.920 531.1 7.680 531.1 5.240 531.1 6.260 531.1 6 .660 531.1 7.210 531.1 7.840 531.1 5.390 531.1 6.260 531.1 6 .720 531.1 7.320 531.1 9.150 531.1 5.450 531.1 6.460 531.1 6 .740 531.1 7.530 531.1 9.490 Water Study: 31 True Value: 5.72 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 2.000 531.1 4.840 531.1 5 .070 531.1 6.070 531.1 9.140 531.1 2.740 531.1 4.900 531.1 5 .300 531.1 7.150 531.1 11.200 531.1 3.010 531.1 4.960 531.1 5.900 531.1 7.370

## B-141 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 12.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 0.897 531.1 8.800 531.1 9.400 531.1 10.100 531.1 10.590 531.1 11.600 531.1 7.370 531.1 8.850 531.1 9.480 other 10.290 531.1 10.600 531.1 11.660 531.1 8.194 531.1 9.080 531.1 9.540 531.1 10.370 531.1 10.600 531.1 12.300 531.1 8.500 531.1 9.340 531.1 9.660 531.1 10.400 531.1 11.000 531.1 12.500 531.1 8.530 531.1 9.380 531.1 9.790 531.1 10.500 531.1 11.340 531.1 13.600 531.1 8.650 531.1 9.390 531.1 9.910 531.1 10.500 531.1 11.500 531.1 14.400 Water Study: 33 True Value: 26.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 2.690 531.1 22.800 531.1 25.800 531.1 26.200 531.1 27.200 531.1 34.220 531.1 8.450 531.1 24.100 531.1 25.800 531.1 26.200 531.1 27.300 531.1 40.300 531.1 19.500 531.1 24.290 531.1 25.900 531.1 26.300 531.1 27.600 531.1 41.800 531.1 22.150 531.1 25.400 531.1 25.900 531.1 26.600 531.1 28.000 531.1 22.300 531.1 25.400 531.1 26.100 531.1 26.800 531.1 28.100 531.1 22.700 531.1 25.600 other 26.100 531.1 26.900 531.1 32.000 Water Study: 34 True Value: 22.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 0.021 531.1 21.300 531.1 22.000 531.1 23.500 531.1 24.300 531.1 30.400 531.1 17.800 531.1 21.450 531.1 22.300 531.1 23.500 531.1 24.400 531.1 34.300 531.1 18.100 531.1 21.600 531.1 22.500 531.1 23.600 531.1 24.400 531.1 45.900 531.1 19.100 531.1 21.700 531.1 22.700 531.1 23.700 531.1 26.700 531.1 20.100 531.1 21.720 531.1 22.900 531.1 23.900 531.1 26.800 531.1 20.400 531.1 21.900 531.1 23.000 531.1 24.000 531.1 28.400 531.1 20.800 531.1 22.000 531.1 23.000 531.1 24.300 531.1 28.900 531.1 21.300 531.1 22.000 531.1 23.100 531.1 24.300 531.1 30.400 Water Study: 35 True Value: 47.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 24.700 531.1 39.200 531.1 43.670 531. 1 44.700 other 46.400 531.1 52.400 531.1 28.100 531.1 39.900 531.1 44.300 531.1 45.200 531.1 47.400 531.1 53.100 531.1 34.300 531.1 41.700 531.1 44.400 531.1 45.800 531.1 47.600 531.1 53.400 531.1 34.900 531.1 42.020 531.1 44.400 531.1 46.200 531.1 50.000 531.1 53.500 531.1 39.010 531.1 42.300 531.1 44.700 531.1 46.300 531.1 51.300 531.1 58.400

Water Study: 36

## B-142 Methods Support Document for Six-Year Review Final - March 2003 True Value: 34.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 20.000 531.1 29.400 531.1 32.500 531.1 33.500 531.1 35.700 531.1 38.400 531.1 22.500 531.1 29.700 531.1 32.500 531. 1 33.800 531.1 36.000 other 38.700 531.1 24.300 other 31.400 531.1 32.600 531.1 33.900 531.1 36.400 531.1 39.100 531.1 24.700 531.1 31.400 531.1 32.600 531.1 34.000 531.1 36.400 531.1 39.600 531.1 24.900 531.1 31.600 531.1 32.800 531.1 34.500 531.1 36.600 531.1 44.700 531.1 24.900 531.1 31.900 531.1 33.100 531.1 34.500 531.1 37.500 531.1 45.400 531.1 28.000 531.1 32.100 531.1 33.100 531.1 35.000 531.1 38.000 531.1 397.000 531.1 29.200 531.1 32.400 531.1 33.400 531.1 35.600 531.1 38.100 Water Study: 37 True Value: 46.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 9.750 531.1 39.800 531.1 42.700 531.1 44.800 531.1 46.180 531.1 48.400 531.1 10.600 531.1 40.800 531.1 42.800 531.1 45.200 531.1 46.200 531.1 48.730 531.1 10.600 531.1 41.000 531.1 43.100 531. 1 45.300 other 46.300 531.1 49.100 531.1 31.200 531.1 41.600 531.1 43.300 531.1 45.500 531.1 47.600 531.1 55.300 531.1 38.900 531.1 41.900 531.1 43.800 531.1 45.700 531.1 48.300 531.1 66.700 531.1 39.200 531.1 42.300 531.1 43.900 531.1 46.100 531.1 48.400 531.1 71.100 Water Study: 38 True Value: 58.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 6.050 531.1 53.500 531.1 59.000 531.1 60.600 531.1 62.500 531.1 65.900 531.1 48.400 531.1 55.600 531.1 59.200 531.1 61.300 531.1 62.700 531.1 67.400 531.1 49.400 531.1 55.800 531.1 59.500 531.1 61.500 531.1 63.200 531.1 67.500 other 51.600 531.1 56.000 531.1 59.600 531.1 62.000 531.1 63.400 531.1 68.800 531.1 52.000 531.1 57.900 531.1 60.100 531.1 62.000 531.1 64.000 531.1 74.200 531.1 52.100 531.1 58.200 531.1 60.100 531.1 62.300 531.1 64.980 531.1 79.000 531.1 53.400 531.1 58.300 531.1 60.100 531.1 62.300 531.1 65.300 531.1 84.500

## B-143 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 78.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 36.000 531.1 72.020 531.1 77.900 531.1 80.000 531.1 87.400 531.1 97.900 531.1 60.400 531.1 72.500 531.1 78.000 531.1 80.400 531.1 88.400 531.1 109.000 531.1 63.000 531.1 72.500 531.1 78.200 531.1 80.500 531.1 88.900 531.1 68.100 531.1 73.000 531.1 79.000 531.1 81.840 531.1 89.500 531.1 68.700 531.1 74.800 531.1 79.000 531.1 83.600 531.1 89.700 531.1 70.800 531.1 76.100 531.1 79.900 531.1 85.400 531.1 93.000 Water Study: 40 True Value: 42.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 28.700 531.1 37.100 531.1 39.000 531.1 40.000 531.1 42.700 531.1 44.200 6610 32.100 531.1 37.600 531.1 39.200 531. 1 40.100 531.1 43.300 531.1 44.600 531.1 32.700 531.1 37.900 531.1 39.300 531.1 40.400 531.1 43.510 531.1 45.300 531.1 33.600 531.1 38.200 531.1 39.400 531.1 40.500 531.1 43.700 531.1 45.400 531.1 35.800 531.1 38.500 531.1 39.700 531.1 41.000 531.1 43.800 531.1 46.800 531.1 36.500 531.1 38.800 531.1 39.900 531.1 42.300 531.1 43.900 531.1 48.900 531.1 36.800 531.1 38.900 531.1 40.000 531.1 42.600 531.1 44.100 531.1 49.000 Water Study: 41 True Value: 33.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 531.1 17.800 531.1 30.000 531.1 31.700 531.1 32.700 531.1 33.900 531.1 24.700 531.1 30.900 531.1 31.700 531.1 33.100 531.1 34.000 531.1 25.200 531.1 31.000 531.1 31.800 531.1 33.600 531.1 34.400 531.1 27.600 531.1 31.200 531.1 32.000 531.1 33.690 531.1 36.700 531.1 27.800 531.1 31.200 531.1 32.200 531.1 33.700 531.1 522.00 531.1 28.800 531.1 31.600 531.1 32.600 531.1 33.900

PCBs Water Study: 31 True Value: 0.445 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508A 0.220 other 0.421 508A 0.509 508A 0.900 508A 3.900 508A 0.290 508A 0.430 508A 0.600 508A 0.935 508A 0.360 other 0.496 other 0.615 508A 1.220

## B-144 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 0.959 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508A 0.294 508A 0.814 other 0.968 other 1.080 508A 1.120 508A 1.480 508A 0.406 508A 0.835 508A 0.980 508A 1.080 508A 1.180 508A 6.820 508A 0.495 508A 0.882 508A 1.000 508A 1.095 508A 1.281 508A 0.797 508A 0.901 508A 1.000 other 1.100 508A 1.380 Water Study: 33 True Value: 0.807 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508A 0.407 508A 0.574 508A 1.030 other 1.160 other 1.320 other 0.511 other 0.690 508A 1.052 508A 1.220 other 2.430 508A 0.532 508A 1.010 508A 1.110 508A 1.220 Water Study: 34 True Value: 1.08 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508A 0.113 other 0.688 508A 0. 860 508A 0.939 508A 1.060 508A 13.200 508A 0.417 508A 0.723 508A 0.865 508A 0.941 508A 1.104 508A 0.460 508A 0.786 other 0. 900 other 1.010 508A 1.110 508A 0.596 508A 0.843 other 0.911 other 1.020 other 1.230 508A 0.670 other 0.850 508A 0.935 508A 1.030 508A 1.290 Water Study: 35 True Value: 0.596 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.025 508A 0.271 508A 0.537 508A 0.706 508A 1.250 508A 0.088 other 0.333 508A 0. 550 508A 0.720 other 1.313 508A 0.164 508A 0.394 508A 0.666 other 1.070 508A 3.560 Water Study: 36 True Value: 1.13 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.380 508A 0.637 508A 0. 748 508A 0.958 508A 1.140 508A 1.620 other 0.474 508A 0.690 508A 0. 774 508A 0.986 508A 1.140 508A 1.640 508A 0.502 508A 0.700 other 0.873 other 1.090 508A 1.150 508A 1.860 other 0.548 508A 0.705 508A 0.912 508A 1.100 508A 1.270 other 3.960 508A 0.589 508A 0.720 508A 0.944 other 1 .100 other 1.440 other 6.400

## B-145 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 0.527 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.249 508A 0.372 508A 0.456 508A 0.563 508A 0.853 other 2.020 other 0.249 508A 0.404 508A 0. 457 508A 0.566 508A 0.866 508A 9.610 508A 0.310 other 0.413 508A 0.480 508A 0.664 508A 1.030 508A 0.318 508A 0.422 508A 0.508 508A 0.686 508A 1.060 508A 0.360 508A 0.451 508A 0.554 508A 0.690 other 1.550 Water Study: 38 True Value: 0.733 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.100 other 0.541 other 0.650 508A 0.720 508A 0.951 508A 1.660 508A 0.436 other 0.558 508A 0.659 508A 0.787 508A 1.120 other 14.900 508A 0.480 508A 0.590 508A 0.668 508A 0.860 508A 1.200 508A 0.523 508A 0.593 508A 0.671 508A 0.874 508A 1.340 508A 0.531 508A 0.611 508A 0.674 508A 0.909 508A 1.400 Water Study: 39 True Value: 0.667 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.197 other 0.507 508A 0. 592 508A 0.739 other 0.809 508A 3.720 508A 0.310 508A 0.513 508A 0.606 508A 0.746 508A 0.815 508A 0.392 508A 0.526 508A 0.664 other 0.756 508A 0.860 508A 0.432 508A 0.533 508A 0.700 508A 0.765 508A 0.945 other 0.504 508A 0.580 508A 0.715 508A 0.770 508A 0.992 Water Study: 40 True Value: 1.23 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508A 0.100 other 0.703 other 0. 854 508A 0.905 508A 1.080 other 1.400 508A 0.506 508A 0.730 other 0.883 other 0.985 508A 1.090 508A 1.570 other 0.520 508A 0.760 other 0. 885 other 1.000 other 1.120 508A 0.555 508A 0.774 other 0.877 508A 1.020 508A 1.190 508A 0.646 508A 0.788 508A 0.901 508A 1.030 508A 1.210

## B-146 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 1.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508A 0.149 508A 0.837 508A 1.140 508A 1.460 508A 1.970 508A 2.240 508A 0.240 other 0.906 508A 1.140 508A 1.590 508A 1.980 508A 0.710 other 0.987 508A 1. 240 other 1.690 508A 2.100 508A 0.712 508A 1.050 other 1.400 508A 1.790 508A 2.110

Pentachlorophenol Water Study: 24a True Value: 0.924 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.067 515.1 0.649 525 0. 693 other 0.770 515.1 0.898 other 0.428 515.1 0.672 515.1 0.735 other 0.860 other 0.468 525 0.685 515.1 0.760 other 0.895 Water Study: 24b True Value: 16.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.596 other 8.750 515. 1 11.300 525 14.200 515.1 17.200 515.1 7.120 515.1 10.200 515. 1 11.400 other 14.500 other 7.770 525 10.800 other 14.000 other 14.900 Water Study: 26a True Value: 3.75 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.214 515.1 2.100 other 2.440 515.1 3.190 515.1 3.940 515.1 5.050 515.1 1.730 525 2.100 515.1 2. 820 515.1 3.470 515.1 3.980 515.1 1.950 515.1 2.410 other 3 .140 515.1 3.670 other 4.400 Water Study: 26b True Value: 38.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 11.500 515.1 18.490 other 24.400 other 31.000 515.1 34.500 515.1 41.320 515.1 12.700 515.1 21.800 515.1 24.500 515.1 33.400 515.1 37.000 515.1 18.300 525 23.700 515.1 29. 700 515.1 34.400 other 37.300

## B-147 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 6.73 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.150 other 3.190 515.1 4.620 515.1 6.310 515.1 7.000 other 7.840 other 2.162 other 4.500 515.1 5 .820 other 6.990 515.1 7.030 Water Study: 31 True Value: 11.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 1.300 515.1 4.460 other 6.360 515.1 8.830 other 10.340 515.1 16.100 515.1 3.000 515.1 4.500 515.1 7 .430 515.1 9.280 525 10.500 515.1 4.320 515.1 4.870 515.1 8. 690 other 9.990 515.1 10.800 Water Study: 32 True Value: 10.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 1.240 515.1 6.140 other 7.440 515.1 9.720 515.1 10.300 515.1 12.300 other 1.650 515.1 6.600 515.1 7.920 515.1 9.810 515.1 10.400 515.1 13.400 515.1 3.120 515.1 6.980 515.1 8.260 515. 1 9.875 other 10.400 515.1 20.000 other 3.780 515.1 7.360 515.1 8.500 515.1 10.200 515.1 10.500 515.1 20.700 515.1 4.950 515.1 7.361 other 8.720 515.1 10.200 other 10.720 515.1 23.400 515.1 5.820 515.1 7.390 515.1 8. 970 515.1 10.300 other 11.700 Water Study: 33 True Value: 2.72 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 1.020 515.1 2.340 515.1 2.520 515. 1 2.730 515.1 3.010 other 5.350 515.1 1.400 515.1 2.380 515.1 2.540 515. 1 2.760 515.1 3.010 other 6.000 515.1 1.400 other 2.400 515.1 2.600 515.1 2.811 515.1 3.110 515.1 8.500 other 1.810 515.1 2.490 515.1 2 .640 other 2.840 515.1 4.140 515.1 2.280 515.1 2.520 515.1 2. 710 515.1 3.000 other 4.370

## B-148 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 22.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 1.010 515.1 8.860 515.1 14.700 515. 1 18.700 other 21.900 other 25.700 515.1 3.140 515.1 8.910 515.2 15.800 515.1 18.800 515.1 22.500 515.1 27.600 515.1 3.170 515.1 8.950 other 17.100 other 19.100 515.1 22.600 515.1 30.500 515.1 3.320 515.1 10.600 515.1 17.400 515.1 19.500 515.2 22.600 515.1 61.100 515.1 3.360 515.1 11.100 515.1 17.400 other 19.750 other 22.950 515.1 80.000 515.1 5.650 other 11.200 other 17.500 515.1 19.900 515.1 24.600 other 6.603 515.1 11.500 515.1 18.020 515.1 20.100 515.1 24.800 515.1 7.800 other 12.500 515.1 18.400 515.1 21.000 other 25.300 Water Study: 35 True Value: 8.91 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.860 515.1 5.810 515.1 7.000 515. 1 7.900 other 9.760 other 12.000 515.1 3.190 515.1 5.970 515.1 7.370 other 7.910 515.1 10.100 515.1 17.500 515.1 3.230 515.1 6.290 515.1 7.430 515.1 7.979 515.1 10.500 515.1 32.800 515.1 3.770 515.1 6.710 515.1 7.600 other 8.220 515.1 10.800 515.1 36.800 515.1 4.420 515.1 6.920 other 7.730 515.1 8.850 other 10.850 515.1 73.500 515.1 5.580 other 6.940 515.1 7. 894 other 9.440 other 11.200 Water Study: 36 True Value: 14.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 1.650 515.1 9.940 515.1 11.500 515.1 12.500 515 14.200 515.1 18.600 515.1 3.850 other 9.960 515.1 11. 500 525.2 12.700 515.2 14.300 555 20.500 515.1 4.420 other 10.000 555 11.500 515.2 12.800 515 14.370 525.2 21.000 other 5.390 515.1 10.400 515.1 11. 800 515.1 12.800 555 14.800 515.2 21.400 515.2 7.750 515.1 10.400 555 12.000 515.2 12.900 555 14.900 515.1 22.000 515.1 8.540 515.2 10.500 515.1 12.000 515. 1 13.500 other 15.100 515.1 28.500 other 8.620 515.1 10.500 515.1 12.000 515.2 13.600 515.1 15.700 515.1 8.890 515.1 10.600 515.1 12.200 515.2 13.900 515.2 18.000

## B-149 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 6.59 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.203 515.1 2.630 515.2 4.650 515.2 5.070 555 6.110 515.1 8.950 515.2 1.090 other 3.600 515.1 4. 660 555 5.080 555 6.390 other 9.070 515.1 1.200 515.2 3.860 515.2 4.770 515.1 5.100 555 6.540 other 9.540 other 1.270 other 3.940 515.2 4. 870 515.1 5.370 other 6.680 555 16.900 515.1 1.380 515.1 3.950 515.1 4.910 515.1 5.750 515.1 6.750 515.1 22.000 515.1 1.490 515.1 4.020 515.1 4 .930 515.2 5.930 515.2 7.440 515.1 1.840 515.1 4.170 515.1 4 .970 other 6.070 555 8.140 Water Study: 38 True Value: 14.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.2 2.730 515.1 10.300 515.2 13.300 515.1 14.500 515.1 16.000 525.2 18.000 515.1 5.150 other 11.200 515.1 13. 300 515.2 15.000 555 16.200 525.2 18.800 515.1 6.110 515.1 11.700 515.1 13.400 515.1 15.100 555 16.200 515.2 19.300 other 9.530 515.1 12.200 515.1 13.400 515.2 15.100 515.1 16.500 515.2 19.500 other 9.600 515.1 12.600 515.1 13.400 other 15.200 515.1 16.500 515.1 19.800 515.2 10.100 other 12.700 555 13.600 515.1 15.400 515.1 16.700 515.1 23.200 515.1 10.100 515.1 12.700 515.1 14.200 other 15.700 515.2 17.000 515.1 27.800 515.1 10.300 515.1 12.800 515.2 14.340 515.2 15.900 515.1 17.400 515.1 46.800 Water Study: 39 True Value: 43.7ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.030 515.1 25.120 515.1 32.400 515.1 38.000 555 40.800 other 44.300 515.1 15.100 515.1 26.300 515.2 32.700 515.1 39.000 555 41.500 other 44.400 515.1 15.500 other 28.400 515.1 33.400 515.1 39.000 other 41.600 515.1 45.600 515.1 15.500 515.2 29.000 515.2 35.810 515.1 39.300 525.2 42.200 515.1 48.900 515.1 17.200 515.2 29.700 515.1 37.100 515. 1 39.500 other 42.300 515.2 51.600 515.1 19.400 other 30.100 515.1 37. 100 555 39.600 515.1 42.500 555 53.700 515.1 24.600 515.2 30.500 515.2 38. 000 other 39.900 515.2 43.260

## B-150 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 22.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 555 10.200 515.1 16.000 515.1 17.600 515. 1 20.100 515.2 22.500 other 27.100 515.1 12.700 other 16.200 515.2 17.800 other 20.100 515.1 22.900 515.2 27.390 515.1 14.400 515.1 16.500 515.1 17.800 555 20.500 515.1 22.900 515.1 28.200 515.1 14.500 515.1 17.000 515.2 18.100 515. 2 20.600 other 23.100 515.1 28.900 515.1 14.900 515.1 17.200 515.1 18.800 other 21.200 525.2 23.400 525.2 31.300 515.2 15.000 other 17.400 515.1 18.900 515.1 21.300 515.1 23.600 515.2 32.900 515.1 15.900 515.1 17.500 515.1 19.600 515.2 21.400 515.1 23.800 515.2 40.300 515.2 15.900 555 17.600 515.1 19. 600 515.1 22.300 515.1 24.200 Water Study: 41 True Value: 34.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 3.110 515.1 21.800 515.1 27.900 515.2 30.890 515.1 32.400 other 38.600 515.1 10.800 555 21.800 515.1 29.700 other 31.100 other 33.000 525.2 39.300 515.1 18.000 515.2 24.600 515.2 30.000 other 31.400 555 33.000 515.2 41.900 515.1 19.300 515.2 25.300 515.1 30.100 555 31.500 515.1 33.000 515.1 46.100 515.2 20.900 other 27.000 515.1 30.300 515.2 32.000 other 33.200 515.1 48.400 515.1 20.900 515.1 27.800 515.1 30.600 555 32.270 515.1 34.000 other 57.600

Picloram Water Study: 24a True Value: 17.5ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 1.480 other 9.590 other 10.900 515.1 12.100 other 14.400 515.1 25.600 515.1 6.500 other 10.900 515.1 11.800 other 13.300 515.1 19.000 Water Study: 24b True Value: 2.63 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.360 other 1.550 other 1.950 other 2.410 515.1 3.650 515.1 4.460 515.1 1.500 other 1.790 other 2.400 515.1 3.120 515.1 3.960 Water Study: 26a True Value: 31.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.433 515.1 15.900 515.1 16.800 515. 1 21.700 515.1 26.500 other 30.270 other 1.130 515.1 16.200 other 20. 000 515.1 23.300 515.1 28.400 515.1 50.840

## B-151 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26b True Value: 1.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.023 515.1 0.688 other 0. 996 515.1 1.220 515.1 1.290 515.1 2.190 515.1 0.270 515.1 0.790 other 1 .140 515.1 1.270 515.1 1.380 Water Study: 30 True Value: 22.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.0412 515.1 11.000 515.1 16.200 other 18.650 other 25.690 515.1 40.800 515.1 5.600 515.1 12.000 515.1 16. 500 515.1 21.200 other 25.700 515.1 7.470 other 13.100 515.1 17.200 515.1 21.220 515.1 27.600 515.1 9.930 515.1 13.400 other 17.600 515.1 21.900 other 29.600 515.1 10.700 other 15.590 515.1 18. 200 other 25.500 other 35.100 Water Study: 31 True Value: 26.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 5.320 515.1 9.960 515.1 11.400 515.1 15.000 515.1 18.600 515.1 32.750 515.1 9.600 515.1 10.200 515.1 11.800 other 17.730 other 19.900 515.1 69.200 Water Study: 32 True Value: 10.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.889 515.1 6.690 515.1 8.110 515.1 10.200 515.1 12.900 515.1 20.300 515.1 2.100 515.1 7.040 515.1 8.250 515.1 11.000 515.1 13.100 515.1 21.400 515.1 2.880 515.1 7.150 515.1 8 .652 515.1 11.200 515.1 13.400 515.1 2.910 515.1 7.760 515.1 8. 730 515.1 11.300 other 15.200 515.1 3.070 515.1 7.810 515.1 8 .900 515.1 11.400 515.1 15.700 515.1 6.530 515.1 7.900 515.1 9. 820 515.1 11.900 other 16.260 Water Study: 33 True Value: 17.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 7.730 515.1 9.350 515.1 12.000 515.1 13.900 515.1 14.900 515.1 23.700 other 8.000 515.1 9.360 other 12. 100 515.1 14.500 515.1 17.700 515.1 32.400 515.1 8.070 515.1 10.100 515.1 12.400 515.1 14.800 515.1 18.200 515.1 46.300 515.1 9.170 515.1 11.400 515.1 13.060 515. 1 14.900 other 20.000 515.1 149.000

## B-152 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 13.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.1 0.542 515.1 6.190 515.1 8.700 515.1 10.200 515.1 12.400 515.2 15.950 515.2 0.577 515.1 6.830 515.1 9.310 515. 1 10.800 other 12.700 515.1 16.800 515.1 3.060 other 6.860 other 9.390 other 10.800 515.1 13.100 515.2 28.800 other 3.340 515.1 6.990 515.2 9 .450 515.1 11.300 515.1 13.700 515.1 4.410 515.1 7.000 515.1 9 .940 515.1 11.500 515.1 13.700 515.1 5.220 515.1 7.320 515.1 9. 980 other 11.930 515.1 14.970 515.1 5.470 515.1 7.540 515.1 9 .990 515.2 12.100 515.1 15.280 515.1 5.640 515.1 7.980 515.1 10. 150 515.1 12.100 other 15.400 Water Study: 35 True Value: 62.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.2 3.760 515.1 19.700 515.1 44.700 515.1 51.600 515.1 60.500 515.1 83.900 515.1 11.920 515.1 28.000 515.1 44.900 515. 1 52.500 other 64.100 515.1 85.000 515.1 13.400 515.1 36.060 515.1 47.300 515. 1 54.800 515.2 67.860 other 132.000 515.1 14.990 515.1 44.600 515.1 50.100 515.1 57.000 515.1 83.000 515.2 149.600 Water Study: 36 True Value: 42.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.2 1.500 515.1 15.000 515.1 22.200 515.1 30.700 515 34.800 515.1 41.400 515.1 3.440 515.1 16.500 515.1 22.400 515.1 31.400 555 35.700 515.1 44.000 515.2 4.830 515.1 16.700 515.1 25.200 515.1 32.000 515.1 36.900 515.2 53.000 515.2 7.630 other 17.100 515.1 25.920 515.1 32.400 515.2 37.400 515.2 54.100 515.2 8.250 515.2 19.100 555 27.500 515. 1 32.900 515.1 37.700 other 63.000 515.1 9.280 515.1 19.500 515.1 28.800 515.1 33.600 515.1 39.000 515.1 13.100 515.1 20.100 515.1 29.000 515.1 33.800 555 39.300 515.1 13.900 515.2 22.000 other 29.900 515.1 34.200 555 39.800

## B-153 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 23.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.2 0.907 other 8.750 other 16.800 515.2 19.100 555 22.000 555 25.900 other 1.630 515.2 13.600 515.2 17.200 other 19.300 other 22.300 other 26.700 515.2 2.880 other 13.900 555 17.700 other 19.800 other 22.300 other 32.900 other 4.120 other 13.900 other 17.700 other 20.000 555 23.300 515.2 5.500 other 14.200 555 18. 100 other 20.200 other 23.600 other 8.360 other 14.300 515.2 18.500 other 20.700 other 24.500 555 8.540 other 14.500 other 18. 600 other 20.900 other 25.400 Water Study: 38 True Value: 56.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 6.070 other 22.200 555 35.000 other 41.600 other 49.600 515.2 79.100 other 10.400 other 26.900 other 35. 800 515.2 41.600 515.2 49.700 515.2 108.800 other 12.100 other 28.800 other 36.200 other 44.800 other 51.900 515.2 256.000 515.2 15.400 other 30.600 other 38.400 515.2 45.360 other 53.100 555 16.000 other 32.400 other 38.400 515.2 46.700 other 53.100 515.2 17.500 other 33.000 other 39.600 other 47.300 other 61.300 555 19.000 other 33.500 other 40. 200 other 47.800 other 71.300 other 20.800 other 34.000 other 41.400 other 49.000 515.2 72.100 Water Study: 39 True Value: 74.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 515.2 1.830 515.2 18.500 555 41.900 other 51.000 other 63.200 other 73.400 515.2 2.010 other 27.800 other 42.230 other 51.300 555 64.300 other 78.500 other 2.320 other 29.700 515.2 43.040 other 51.400 other 69.400 555 7.250 515.2 30.200 other 45. 900 other 52.300 515.2 70.250 other 12.200 515.2 35.400 other 45.900 555 56.100 other 70.700 515.2 12.900 other 37.400 other 46.200 other 59.800 555 70.800 other 17.900 other 41.200 other 46.300 other 60.900 other 72.800

## B-154 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 44.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 555 1.080 other 21.400 other 27.400 555 31.800 other 36.300 515.2 53.000 515.2 8.780 515.2 22.000 other 27.600 other 32.300 555 37.900 other 78.700 other 10.900 other 22.200 other 29.100 other 33.400 515.2 38.500 other 97.700 515.2 12.900 other 22.400 other 29.500 515.2 33.700 other 38.700 515.2 13.600 other 23.300 other 30.800 other 34.900 515.2 40.800 other 13.700 other 24.200 515.2 31.200 other 35.200 other 42.200 515.2 17.700 other 24.500 other 31.300 other 35.500 other 43.800 other 18.200 other 27.200 other 31.600 other 35.900 other 48.200 Water Study: 41 True Value: 62.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 0.852 515.2 25.100 other 35. 000 515.2 41.900 other 50.800 555 58.080 515.2 4.040 other 26.000 other 37.700 other 43.300 other 51.800 other 59.800 other 8.720 515.2 29.000 other 39.500 other 44.100 other 52.600 other 63.700 other 21.100 other 32.500 other 41. 000 555 48.800 other 52.900 other 75.000 515.2 21.400 other 33.300 515.2 41.100 515. 2 50.160 other 53.200 other 96.400 555 23.100 other 34.000 other 41. 700 other 50.200 other 54.100

Tetrachloroethylene Water Study: 27 True Value: 7.76 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 5.870 502.2 6.800 524.2 6.900 502.2 7.590 502.2 8.030 524.2 9.030 other 6.000 524.2 6.820 524.2 7.040 524.1 7.600 502.2 8.380 502.2 9.080 502.2 6.400 502.2 6.860 502.2 7.090 502.2 7.700 502.2 8.500 524.2 9.150 502.2 6.660 524.2 6.860 524.2 7.140 524.2 7.700 524.1 8.580 524.1 10.600 502.2 6.660 502.2 6.890 524.2 7.400 524.2 7.810 502.2 8.610 502.2 10.770 502.1 6.710 502.2 6.900 502.2 7. 490 502.2 8.020 other 8.630

## B-155 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 15.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.250 524.1 14.000 524.2 14.850 502. 2 15.700 502.2 16.600 other 18.800 502.2 12.800 502.2 14.100 502.2 15.200 524.2 16.000 502.2 16.700 502.2 19.000 524.2 13.300 524.2 14.200 502.2 15.200 502.2 16.190 524.2 16.800 524.2 19.500 502.2 13.600 524.2 14.600 502.2 15.400 524. 2 16.200 other 16.820 502.2 21.100 502.2 13.900 524.2 14.680 524.2 15.600 502.2 16.300 524.2 16.900 524.2 13.900 524.2 14.800 other 15.600 502.2 16.300 524.1 17.000 Water Study: 30 True Value: 9.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 5.690 524.2 7.880 other 8.430 502.2 8.810 502.2 9.040 524.2 9.580 502.2 6.381 502.2 7.920 524.2 8.580 502.2 8.820 502.2 9.070 524.2 9.700 524.2 6.800 524.2 8.010 524.2 8.580 524.1 8.880 524.2 9.170 524.2 9.710 other 6.850 524.2 8.230 524.2 8.590 524.2 8.900 502.2 9.240 524.2 9.800 524.2 7.110 524.2 8.250 524.2 8.600 502. 2 8.900 502.2 9.250 other 10.020 524.2 7.200 502.2 8.270 524.1 8.610 524. 2 8.900 other 9.270 524.2 10.200 502.2 7.330 502.2 8.340 502.2 8.610 524.2 8.900 524.2 9.400 502.2 10.200 502.2 7.330 502.2 8.370 524.2 8.640 502.2 8.920 502.2 9.420 524.2 10.300 524.2 7.620 502.2 8.420 other 8.720 524.2 8.940 524.2 9.490 502.2 10.400 524.2 7.770 502.2 8.430 502.2 8.800 524. 1 8.990 other 9.520 502.2 11.900 Water Study: 31 True Value: 11.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.305 502.2 10.600 502.1 11.300 502.2 11.600 502.2 12.000 502.1 12.600 502.2 9.410 other 10.600 524.2 11.360 502.2 11.700 524.2 12.200 524.2 13.100 524.2 9.900 524.2 10.900 502.2 11.400 524.2 11.800 524.2 12.300 502.2 14.800 502.2 10.400 524.2 10.900 502.2 11.500 524.2 11.800 524.2 12.300 524.2 10.500 502.2 11.000 502.1 11.500 502.2 11.900 524.2 12.400 524.2 10.500 524.1 11.200 other 11.600 524.2 11.910 524.2 12.540

## B-156 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 7.43 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.590 524.2 6.700 524.2 7.010 502.2 7.390 524.2 7.670 524.2 8.060 502.2 5.260 524.2 6.800 524.2 7.010 502.2 7.440 502.2 7.700 502.2 8.300 502.2 5.690 502.2 6.840 502.2 7.020 524.2 7.450 524.2 7.700 524.2 8.500 524.2 6.000 502.2 6.850 502.2 7.040 502.1 7.460 524.2 7.700 502.1 8.800 502.2 6.010 524.2 6.860 502.1 7.100 502.2 7.490 524.2 7.720 524.2 8.970 other 6.280 other 6.900 502.2 7. 180 524.2 7.500 502.1 7.740 524.2 9.040 524.2 6.410 502.2 6.930 524.2 7.258 524.1 7.570 524.2 7.770 524.2 9.200 502.2 6.450 524.2 6.980 524.2 7.310 524.2 7.620 502.2 7.770 502.2 10.400 502.2 6.530 524.2 7.000 524.2 7 .310 502.2 7.620 524.2 7.840 524.2 6.560 502.2 7.000 524.2 7 .350 502.2 7.620 502.2 7.870 524.2 6.700 other 7.000 502.2 7 .370 502.2 7.650 524.2 7.900 Water Study: 33 True Value: 12.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.540 502.2 11.610 524.2 12.400 524. 2 13.000 502.2 13.600 other 14.300 502.2 9.970 502.2 11.700 502.2 12.500 502.2 13.100 524.2 13.800 524.2 14.400 524.2 10.670 524.2 11.800 other 12.500 502.2 13.400 524.2 13.800 524.2 15.400 524.1 11.100 524.2 11.900 502.1 12.700 502.2 13.400 502.2 13.800 502.2 17.600 other 11.150 524.2 12.000 502.2 12.800 502.2 13.400 524.2 13.900 524.2 11.510 502.2 12.300 524.2 12.900 502.2 13.400 502.2 14.000 Water Study: 34 True Value: 16.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 12.500 502.1 14.600 524.2 15.400 524.2 16.000 524.2 16.500 524.2 17.100 524.2 12.700 524.2 14.600 524.2 15.400 524.2 16.100 502.2 16.500 524.2 17.200 502.2 13.300 524.2 14.900 502.2 15.600 502.2 16.100 524.2 16.600 524.2 17.300 524.2 14.100 502.2 15.000 502.2 15.600 524.2 16.100 524.2 16.620 502.2 17.400 502.2 14.100 502.2 15.000 other 15.800 524.2 16.100 502.2 16.700 524.2 17.400 502.2 14.100 other 15.100 502.2 15.800 502.2 16.200 502.2 16.700 524.2 17.500 524.2 14.100 524.2 15.100 502.2 15.800 524.2 16.300 524.2 16.770 502.2 17.540 524.2 14.200 502.2 15.200 524.2 15.900 502.2 16.300 502.2 16.900 524.2 17.870 524.2 14.400 524.2 15.200 502.2 15.900 524.2 16.400 502.2 17.100 524.2 17.900 502.2 14.520 502.2 15.300 524.2 15.900 524.2 16.480 502.2 17.100 502.2 19.000

## B-157 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 11.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.070 524.2 10.380 502.2 10.900 524.2 11.400 502.2 11.600 524.2 12.400 524.2 9.510 502.2 10.400 524.2 11.000 502.2 11.400 524.2 11.600 502.2 12.500 524.2 10.000 524.2 10.600 524.2 11.000 524. 2 11.400 other 11.620 other 12.800 502.2 10.100 524.2 10.700 524.2 11.100 502.2 11.500 524.2 11.800 524.2 12.900 524.2 10.200 502.2 10.710 524.2 11.200 524.2 11.500 524.2 12.000 524.2 14.930 502.2 10.200 502.2 10.800 524.2 11.300 502.2 11.510 524.2 12.200 502.2 20.800 Water Study: 36 True Value: 18.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.510 524.2 16.500 502.2 17.000 502. 2 17.800 other 18.400 524.2 19.900 524.2 14.200 524.2 16.700 502.2 17.100 502.2 17.900 524.2 18.500 524.2 20.380 524.2 14.600 502.2 16.780 524.2 17.200 524.2 18.000 524.2 18.500 524.2 20.500 524.2 14.800 524.2 16.800 524.2 17.200 502. 2 18.000 other 18.600 524.2 21.100 524.2 15.100 524.2 16.800 524.2 17.300 502.2 18.100 524.2 18.600 502.2 22.500 502.2 15.200 502.2 16.800 524.2 17.350 502.2 18.100 502.2 18.600 524.2 22.800 502.2 15.300 524.2 16.920 524.2 17.400 502.2 18.200 502.2 18.600 502.2 15.800 524.2 16.970 524.2 17.600 524.2 18.300 524.2 18.800 502.2 15.800 other 17.000 502.2 17.700 524.2 18.300 524.2 18.980 524.2 16.260 502.2 17.000 524.2 17.700 524.2 18.300 524.2 19.100 502.2 16.400 524.2 17.000 524.2 17. 800 other 18.400 502.2 19.300 Water Study: 37 True Value: 9.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.820 524.2 8.690 524.2 9.060 other 9.340 524.2 9.560 524.2 9.930 502.2 8.060 502.2 8.700 502.2 9.100 524.2 9.350 524.2 9.560 524.2 9.990 524.2 8.060 524.2 8.820 524.2 9.210 502.2 9.390 502.2 9.620 502.2 10.500 other 8.100 502.2 8.860 524.2 9.220 524.2 9.390 524.2 9.620 502.2 11.000 502.2 8.170 524.2 8.900 524.2 9.24 502.2 9.390 502.2 9.660 524.2 11.100 524.2 8.230 524.2 8.910 524.2 9.300 502. 2 9.420 other 9.780 524.2 11.900 502.2 8.290 524.2 8.960 524.2 9.330 502.2 9.450 502.2 9.890 524.2 12.400 524.2 8.620 524.2 9.020 502.2 9.330 502.2 9.510 524.2 9.920 524.2 13.300

## B-158 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 14.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.720 524.2 12.700 502.2 13.200 524.2 13.600 524.2 14.270 524.2 15.000 524.2 11.200 524.2 12.800 524.2 13.200 other 13.800 502.2 14.300 524.2 15.500 524.2 11.300 502.2 12.800 524.2 13.200 524.2 13.800 524.2 14.300 524.2 15.600 524.2 11.300 524.2 12.900 524.2 13.300 524.2 13.900 524.2 14.660 524.2 16.000 524.2 11.600 502.2 12.900 524.2 13.300 524.2 13.900 502.2 14.700 524.2 16.400 502.2 11.700 524.2 13.000 other 13.400 502.2 13.980 524.2 14.800 502.2 19.700 502.2 11.800 502.2 13.000 524.2 13.500 524.2 14.000 502.2 14.800 524.2 12.700 524.2 13.000 524.2 13.600 524.2 14.100 502.2 14.900 524.2 12.700 502.2 13.200 other 13.600 524.2 14.100 502.2 14.900 502.2 12.700 524.2 13.200 502.2 13.600 502.2 14.200 502.2 15.000 Water Study: 39 True Value: 7.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.400 524.2 6.610 524.2 7.200 524.2 7.480 524.2 7.900 524.2 8.400 524.2 5.680 524.2 6.840 502.2 7.240 524.2 7.500 524.2 7.980 524.2 8.560 524.2 5.770 502.2 6.900 524.2 7.350 524.2 7.510 524.2 8.000 502.2 8.560 502.2 5.950 524.2 6.920 524.2 7.350 502.2 7.580 524.2 8.020 502.2 8.770 524.2 6.510 524.2 6.930 524.2 7.400 524.2 7.600 524.2 8.050 524.2 31.770 524.2 6.520 524.2 6.960 524.2 7 .400 502.2 7.790 502.2 8.090 524.2 6.570 524.2 7.100 524.2 7 .420 502.2 7.820 524.2 8.150 502.2 6.590 other 7.170 502.2 7 .480 502.2 7.870 524.2 8.250 Water Study: 40 True Value: 14.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.000 524.2 12.900 524.2 13.800 524.2 14.500 502.2 15.000 524.2 15.800 502.2 11.200 524.2 13.100 524.2 13.800 502.2 14.500 502.2 15.000 502.2 15.900 524.2 11.800 524.2 13.100 other 14.000 502.2 14.500 524.2 15.000 502.2 16.000 524.2 12.000 other 13.200 524.2 14.100 524.2 14.500 502.2 15.100 502.2 16.200 524.2 12.100 524.2 13.200 524.2 14.100 502.2 14.800 502.2 15.200 524.2 16.700 524.2 12.600 524.2 13.300 524.2 14.300 other 14.800 502.2 15.200 524.2 17.600 524.2 12.620 524.2 13.500 524.2 14.300 502.2 14.900 524.2 15.300 502.2 17.800 524.2 12.800 524.2 13.600 524.2 14.400 524.2 14.900 524.2 15.300 524.2 18.000 524.2 12.900 524.2 13.700 524.2 14.400 524.2 14.900 524.2 15.400 524.2 12.900 502.2 13.700 524.2 14.500 524.2 15.000 524.2 15.700

## B-159 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 11.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.720 502.2 10.200 524.2 10.900 other 11.200 524.2 11.600 524.2 12.200 524.2 9.490 524.2 10.200 502.2 10.900 524.2 11.200 502.2 11.700 502.2 12.300 502.2 9.680 502.2 10.300 524.2 10.900 524.2 11.230 502.2 11.700 524.2 13.000 524.2 9.730 524.2 10.600 524.2 11.000 524.2 11.300 524.2 11.740 502.2 13.100 524.2 9.850 524.2 10.800 524.2 11.100 524.2 11.300 524.2 11.800 524.2 14.000 524.2 9.970 524.2 10.800 502.2 11.200 502.2 11.400 524.2 11.800 502.2 14.500 524.2 10.000 524.2 10.900 524.2 11.200 502.2 11.600 524.2 12.000

Thallium Water Study: 24a True Value: 2.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 1.100 279.2 1.770 279.2 1.900 279.2 2.030 279.2 2.300 279.2 2.610 279.2 1.530 279.2 1.800 200.7A 1.900 279.1 2.100 279.1 2.400 279.2 3.000 279.2 1.730 279.2 1.800 279.2 1.920 279. 2 2.140 200.7A 2.400 other 4.000 279.2 1.740 279.2 1.830 279.2 2.000 200. 7A 2.160 279.2 2.570 other 6.150 279.2 1.760 279.2 1.870 279.2 2.000 279.2 2.200 279.2 2.600 279.2 16.500 Water Study: 24b True Value: 18.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 2.000 279.2 15.700 200.7A 17.400 279.2 18.000 279.2 18.600 279.2 19.900 279.2 9.600 279.1 16.000 other 17.500 279.2 18.200 279.2 18.600 other 20.700 279.2 12.000 279.2 16.600 279.2 18.000 279.1 18.300 279.2 18.600 279.1 20.700 279.2 14.500 279.2 16.600 279.2 18.000 200.7A 18.500 279.2 18.900 279.2 21.900 279.2 14.800 279.2 16.900 279.2 18.000 200.7A 18.500 279.2 19.000 279.2 24.700 200.7A 15.600 279.2 17.000 279.2 18.000 279.2 18.600 279.2 19.100 Water Study: 25a True Value: 36.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 3.700 279.2 33.000 279.2 34.900 279.1 36.000 279.2 36.600 279.2 41.600 279.2 28.000 279.2 33.000 279.2 35.000 279.2 36.000 279.2 36.900 279.2 31.000 279.2 33.900 279.2 35.000 279.2 36.000 279.2 37.000 279.1 31.200 279.2 34.700 279.2 35.000 279.1 36.100 279.2 37.000 279.2 32.000 279.2 34.800 279.2 35. 200 279.2 36.500 other 37.800

## B-160 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 25b True Value: 3.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 2.000 279.2 2.590 279.2 3.000 279.2 3.100 279.2 3.470 279.2 37.000 279.2 2.040 279.2 2.780 279.2 3 .000 279.1 3.210 279.2 3.600 279.2 2.400 279.2 2.800 279.2 3 .000 279.2 3.280 279.2 3.900 other 2.550 279.2 2.900 279.2 3 .020 279.2 3.320 279.2 4.000 Water Study: 26 True Value: 4.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 1.900 279.2 3.300 279.2 3.600 279.2 4.200 279.2 4.390 279.2 6.300 279.2 1.960 279.2 3.450 279.2 3.620 200.7A 4.200 200.7A 4.400 279.2 7.300 279.2 2.670 279.2 3.470 279.2 3. 670 279.2 4.200 other 4.500 279.2 3.040 279.2 3.480 279.2 3 .840 279.2 4.240 279.2 4.500 279.2 3.200 279.2 3.500 279.2 3 .950 279.2 4.250 279.2 4.560 279.2 3.200 279.2 3.500 279.2 4 .000 279.2 4.260 200.7A 4.610 279.2 3.250 279.2 3.510 279.2 4 .110 279.2 4.370 279.2 5.040 Water Study: 27 True Value: 26.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 7.200 279.2 24.900 279.2 25.700 279.2 27.000 279.2 27.600 279.2 29.000 279.2 13.500 279.2 25.200 279.2 25.800 279.2 27.000 279.2 28.200 279.2 29.000 other 20.600 279.2 25.300 279.2 25.900 279.2 27.200 other 28.800 279.2 32.100 279.2 24.700 279.2 25.300 279.2 26.200 279.2 27.500 279.2 29.000 Water Study: 29 True Value: 9.74 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 5.400 279.2 8.700 279.2 9.500 279.2 9.700 279.2 10.200 279.2 11.000 279.2 7.100 279.2 8.820 279.2 9 .570 279.2 9.700 279.2 10.200 other 7.300 279.2 9.100 279.2 9 .600 279.2 9.900 279.2 10.300 279.2 8.300 other 9.380 other 9.600 200.9 9.900 279.2 10.700

## B-161 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 5.30 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.7 4.100 279.2 4.980 279.2 5.150 279.2 5.320 279.2 5.600 279.2 7.000 279.2 4.580 200.9 4.980 279.2 5.200 279.2 5.350 279.2 5.600 279.2 7.140 200.9 4.590 279.2 5.000 279.2 5.200 279.2 5.370 200.9 5.750 279.2 7.500 279.2 4.640 279.2 5.010 279.2 5 .200 279.2 5.400 279.2 5.800 279.2 4.650 279.2 5.070 279.2 5 .200 279.2 5.458 279.2 5.820 200.9 4.780 279.2 5.070 279.2 5 .230 279.2 5.500 200.9 5.900 279.2 4.830 200.9 5.080 279.2 5 .260 279.2 5.500 200.9 6.200 279.2 4.880 279.2 5.100 279.2 5 .300 279.2 5.500 200.9 6.300 279.2 4.920 279.2 5.110 200.7 5 .300 200.9 5.500 279.2 7.000 Water Study: 31 True Value: 1.48 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 279.2 1.010 279.2 1.340 279.2 1.480 200.9 1.600 279.2 1.700 279.2 2.300 279.2 1.050 200.9 1.400 279.2 1.500 200.9 1.600 279.2 1.760 200.9 3.000 279.2 1.100 279.2 1.400 200.9 1. 530 279.2 1.635 other 2.000 279.2 1.200 200.9 1.400 279.2 1 .590 200.9 1.650 200.9 2.040 279.2 1.280 279.2 1.450 279.2 1 .600 200.9 1.690 200.9 2.100 Water Study: 32 True Value: 2.56 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 1.000 200.9 2.100 279.2 2.350 200.9 2.460 279.2 2.600 279.2 2.960 200.9 1.260 279.2 2.200 279.2 2.370 279.2 2.460 279.2 2.628 279.2 2.978 200.9 1.700 279.2 2.230 279.2 2.400 200.9 2.460 279.2 2.650 200.9 2.980 200.8 1.750 200.9 2.300 279.2 2.400 200.9 2.470 200.9 2.650 200.9 3.000 200.9 1.780 279.2 2.300 279.2 2.400 200.9 2.470 200.9 2.700 200.9 3.000 279.2 1.800 279.2 2.300 279.2 2.400 200.8 2.480 200.9 2.700 279.2 3.100 279.2 1.900 279.2 2.310 279.2 2.410 279. 2 2.540 200.9 2.720 other 3.100 279.2 1.900 279.2 2.310 279.2 2.430 279.2 2.550 200.9 2.780 200.9 3.300 200.8 1.960 279.2 2.340 279.2 2.450 200.9 2.600 200.9 2.880 279.2 4.400 279.2 2.060 279.2 2.350 279.2 2.460 279.2 2.600 200.9 2.900 279.2 5.000

## B-162 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 9.56 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 3113 5.230 279.2 7.660 200.9 9.000 279. 2 9.530 279.2 10.000 279.2 10.900 279.2 6.000 279.2 8.400 200.9 9.000 279.2 9.538 200.9 10.300 200.8 10.900 3113 6.400 279.2 8.700 279.2 9. 100 279.2 9.610 279.2 10.300 279.2 6.880 279.2 8.940 279.2 9 .160 279.2 9.700 200.9 10.300 279.2 7.400 other 8.980 200.9 9 .500 279.2 10.000 279.2 10.400 279.2 7.580 200.9 9.000 279.2 9 .510 279.2 10.000 200.9 10.700 Water Study: 34 True Value: 6.19 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value
200.9 3.800 200.9 5.330 200.9 5.940 200.9 6.200 200.9 6.500 200.9 6.700 279.2 4.580 200.9 5.470 279.2 6.000 279.2 6.200 279.2 6.500 200.9 6.760 200.8 4.760 279.2 5.520 279.2 6.000 279.2 6.240 279.2 6.500 279.2 6.800 3113 4.800 200.9 5.600 200.9 6.000 279. 2 6.260 279.2 6.520 279.2 6.840 279.2 4.860 279.2 5.650 200.9 6.000 279.2 6.270 200.9 6.610 279.2 7.100 279.2 4.890 279.2 5.700 200.8 6.060 279.2 6.300 200.8 6.620 200.9 7.340 279.2 5.130 200.9 5.700 279.2 6.100 279.2 6.320 279.2 6.630 200.9 8.000 279.2 5.300 200.9 5.780 200.8 6.117 279.2 6.340 200.9 6.640 200.8 9.950 200.9 5.300 279.2 5.800 279.2 6 .160 200.9 6.400 200.9 6.680 279.2 5.300 279.2 5.860 279.2 6. 170 200.9 6.440 other 6.700 Water Study: 35 True Value: 8.00 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 5.200 279.2 7.210 200.8 7.600 279.2 7.900 279.2 8.130 279.2 8.780 279.2 5.430 200.9 7.300 200.8 7.600 200.9 7.900 200.9 8.190 279.2 8.810 other 5.760 200.9 7.390 279.2 7.600 200.9 7.920 200.9 8.200 279.2 9.000 3113 6.000 200.9 7.400 200.8 7.670 279. 2 7.950 200.9 8.230 279.2 9.100 200.9 6.000 other 7.400 3113 7.770 279.2 8.030 200.8 8.250 200.9 10.100 279.2 6.020 279.2 7.500 279.2 7.800 279.2 8.100 279.2 8.500 200.9 10.700 200.9 6.300 200.9 7.600 200.9 7 .800 200.9 8.120 279.2 8.600

## B-163 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 4.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 3.440 200.9 4.310 200.9 4.580 200.8 4.730 200.9 4.940 200.9 5.300 3113 3.600 279.2 4.330 200.8 4.580 200. 9 4.740 other 4.980 200.9 5.300 200.9 3.700 200.9 4.400 200.9 4.590 200.9 4.740 200.9 5.000 200.9 5.320 200.9 4.000 200.9 4.430 200.9 4.600 200.8 4.750 200.9 5.000 200.8 5.420 200.8 4.040 200.9 4.440 other 4.600 200.8 4.770 200.8 5.000 200.9 5.620 other 4.100 200.9 4.450 other 4.600 other 4.780 200.9 5.000 200.9 33.100 200.9 4.200 279.2 4.460 200.9 4 .650 200.9 4.800 200.8 5.120 279.2 4.200 200.9 4.500 200.9 4 .670 200.9 4.800 279.2 5.120 200.9 4.230 200.9 4.550 other 4 .680 200.9 4.810 200.9 5.150 200.8 4.280 other 4.560 200.8 4 .700 200.9 4.870 other 5.200 200.8 4.290 other 4.580 200.9 4 .720 200.9 4.900 200.9 5.250 Water Study: 37 True Value: 2.38 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value
200.9 0.816 200.9 2.000 200.9 2.260 200.9 2.440 200.9 2.540 200.9 2.690 3113 1.000 other 2.100 200.9 2.270 200.8 2.440 200.9 2.550 200.9 2.810 200.9 1.120 200.9 2.130 200.9 2.280 200.9 2.450 200.8 2.560 200.9 2.930 279.2 1.200 200.9 2.200 200.9 2 .290 200.8 2.460 200.8 2.570 200.9 1.900 200.9 2.200 200.9 2 .300 200.9 2.470 200.8 2.570 200.9 1.920 200.9 2.200 200.9 2 .300 200.9 2.500 200.9 2.600 200.9 2.000 200.9 2.220 200.9 2 .350 200.8 2.500 200.8 2.600 200.9 2.000 200.9 2.230 200.9 2 .390 200.9 2.540 200.9 2.670 Water Study: 38 True Value: 8.91 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 1.060 200.9 7.800 200.9 8.260 200.8 8.580 200.9 8.900 200.8 9.110 200.9 3.370 200.9 7.890 200.8 8.300 other 8.600 200.8 8.900 200.8 9.130 200.9 4.350 200.9 7.920 200.9 8.300 200.9 8.650 200.9 8.990 200.8 9.210 200.9 6.200 200.9 8.080 200.8 8.300 200.9 8.650 200.9 9.000 200.9 9.520 200.9 6.600 200.9 8.100 200.8 8.350 200.9 8.650 200.9 9.000 200.9 9.570 200.9 7.000 200.8 8.100 200.9 8.460 200.8 8.700 200.8 9.000 200.9 9.600 other 7.190 200.8 8.110 200.9 8.490 200.8 8.700 200.8 9.010 other 9.660 200.9 7.490 200.9 8.130 200.9 8.490 other 8.720 200.8 9.050 200.9 10.000 200.9 7.550 200.9 8.200 200.9 8.520 200.9 8.790 200.9 9.080 279.2 10.100 200.9 7.630 other 8.250 200.9 8 .530 200.8 8.880 200.9 9.100

## B-164 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 5.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 4.060 200.9 5.220 200.9 5.400 200.9 5.560 200.8 5.900 200.9 6.100 200.9 4.690 200.9 5.260 200.9 5.400 200. 9 5.580 200.8 5.900 other 6.100 200.9 4.850 200.9 5.280 200.8 5.400 200.9 5.590 200.9 5.930 200.9 6.180 200.9 4.900 200.9 5.300 200.9 5.440 200.9 5.600 200.9 5.940 200.9 6.500 200.9 4.900 200.9 5.320 200.9 5.440 200. 9 5.680 other 5.970 200.9 6.950 200.9 5.000 200.8 5.320 200.8 5.470 200.9 5.800 200.9 5.980 200.9 7.000 200.9 5.120 200.9 5.350 200.9 5.500 200.9 5.800 200.9 6.000 200.8 7.600 200.9 5.160 200.9 5.390 200.9 5 .560 200.8 5.800 200.8 6.050 Water Study: 40 True Value: 10.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 7.170 200.9 9.650 200.8 9.940 200. 8 10.300 200.8 10.600 other 10.900 200.9 9.040 200.9 9.670 200.8 9.950 200.9 10.400 200.9 10.600 200.9 11.000 200.9 9.300 200.8 9.760 200.8 9.960 200.9 10.400 200.9 10.700 200.9 11.000 200.9 9.370 200.8 9.770 200.8 9.980 200.9 10.400 200.9 10.700 200.8 11.000 200.9 9.380 200.9 9.800 200.9 10.000 200.8 10.400 200.8 10.700 200.9 11.000 200.9 9.420 200.9 9.800 200.8 10.000 200.8 10.500 200.9 10.800 200.9 11.300 200.9 9.490 200.9 9.900 200.9 10.200 279.2 10.500 200.8 10.800 200.9 11.600 200.8 9.500 200.9 9.920 other 10.200 200.9 10.600 200.9 10.800 200.9 12.300 other 9.540 200.9 9.930 200.8 10.200 other 10.600 200.9 10.900 other 18.100 200.8 9.620 200.9 9.930 200.8 10. 280 200.9 10.600 other 10.900 Water Study: 41 True Value: 3.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 200.9 2.700 200.9 3.000 200.8 3.160 200. 9 3.260 200.9 3.340 other 3.590 200.9 2.720 200.9 3.000 279.2 3.170 200.9 3.270 200.9 3.350 200.8 3.610 200.8 2.820 200.9 3.070 200.9 3.180 200.9 3.280 200.8 3.410 200.9 5.800 200.9 2.900 200.9 3.070 200.9 3.200 200. 9 3.300 200.9 3.440 other 408.000 200.9 2.930 200.9 3.090 200.9 3 .230 200.9 3.300 200.9 3.470 200.8 2.960 200.9 3.100 200.9 3 .240 200.8 3.310 200.9 3.500 200.8 2.990 200.8 3.120 200.8 3 .250 200.8 3.310 200.9 3.500 200.9 3.000 200.9 3.140 200.8 3 .250 200.8 3.340 200.9 3.500

## B-165 Methods Support Document for Six-Year Review Final - March 2003 Toluene Water Study: 29 True Value: 11.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.640 502.2 10.680 502.2 11.400 502.2 11.400 502.2 12.100 524.2 12.800 524.2 9.820 502.2 10.900 524.2 11.400 524.2 11.400 524.1 12.100 524.2 13.200 524.2 10.200 524.2 10.900 502.2 11.400 524.2 11.500 502.2 12.300 524.2 13.400 524.1 10.400 502.2 11.000 502.2 11.400 524.2 11.600 502.2 12.500 502.2 13.500 524.2 10.500 502.2 11.100 other 11.400 other 11.640 other 12.600 524.2 14.700 524.2 10.600 524.2 11.160 502.2 11.400 502.2 11.740 502.2 12.640 Water Study: 30 True Value: 8.02 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.190 502.2 7.450 524.2 7.700 524.2 8.000 524.1 8.300 502.2 8.540 502.2 6.420 524.2 7.500 524.2 7.730 502.2 8.010 524.2 8.300 524.2 8.570 524.2 6.430 524.2 7.500 524.2 7.740 502.2 8.010 502.2 8.320 524.2 8.600 524.2 6.500 502.2 7.540 other 7.760 524.2 8.020 502.2 8.330 524.2 8.640 502.2 7.030 524.2 7.540 other 7.780 524.1 8.070 524.2 8.330 524.2 8.670 524.2 7.150 502.2 7.550 524.2 7.780 502.2 8.110 524.2 8.400 502.2 8.800 524.2 7.210 524.2 7.630 502.2 7.860 502. 2 8.200 other 8.420 502.2 9.050 other 7.386 502.2 7.630 503.1 7.890 524.2 8.200 524.2 8.420 524.2 9.100 524.2 7.400 502.2 7.630 502.2 7.930 502. 2 8.200 503.1 8.440 other 23.800 502.2 7.401 524.1 7.680 502.2 7 .960 502.2 8.250 502.2 8.510 Water Study: 31 True Value: 15.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 12.330 524.2 14.100 502.2 14.400 524.2 14.800 524.2 15.200 524.2 16.000 502.2 12.600 524.2 14.200 524.2 14.400 502.2 14.900 502.2 15.400 502.2 16.000 other 13.200 502.2 14.200 524.2 14.400 other 15.000 502.2 15.700 502.2 16.100 524.2 13.500 524.2 14.200 502.2 14.400 502.1 15.000 502.2 15.700 502.2 16.500 524.2 13.700 524.1 14.300 503.1 14.600 524.2 15.060 524.2 15.800 502.2 16.600 503.1 14.000 524.2 14.300 502.2 14.700 524.2 15.200 524.2 15.920

## B-166 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 6.54 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.000 502.2 5.840 502.2 6.160 524.2 6.380 524.2 6.680 502.2 7.000 503.1 5.340 524.2 5.900 502.2 6.170 502.2 6.400 524.2 6.730 502.2 7.070 502.2 5.410 other 5.900 524.2 6.190 524.2 6.420 524.2 6.730 524.2 7.300 524.2 5.500 524.2 5.910 503.1 6.190 524.2 6.440 524.2 6.750 502.2 7.370 524.2 5.610 524.2 5.970 524.2 6.200 524.2 6.460 502.2 6.800 524.2 7.530 502.2 5.620 502.2 6.010 524.2 6.220 524.2 6.500 502.2 6.800 502.2 7.760 524.2 5.710 502.2 6.010 502.2 6.230 524.2 6.500 524.2 6.840 524.2 8.000 524.2 5.800 other 6.020 other 6.300 524.2 6.530 524.2 6.860 other 8.700 502.2 5.820 524.2 6.030 502.2 6 .300 524.2 6.600 502.2 6.890 502.2 5.830 other 6.060 502.2 6 .320 524.1 6.650 524.2 6.890 502.2 5.830 524.2 6.130 502.2 6 .360 524.2 6.670 502.2 6.930 Water Study: 33 True Value: 12.3 ug/L Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.170 502.2 11.100 other 11.900 502.2 12.300 524.2 12.800 502.1 14.100 other 9.890 524.2 11.300 524.2 12.000 502.2 12.300 524.2 12.900 502.2 15.200 524.2 10.930 524.2 11.500 502.2 12.100 524. 2 12.300 502.2 13.000 other 15.200 524.2 10.940 524.2 11.600 502.2 12.200 502.2 12.500 502.2 13.160 524.2 11.000 524.2 11.800 502.2 12.200 502.2 12.500 524.2 13.600 502.2 11.010 502.2 11.800 502.1 12.300 502.2 12.600 524.2 13.800 Water Study: 34 True Value: 15.6 ug/L Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.100 502.2 14.500 other 15.100 502.2 15.600 524.2 15.900 503.1 16.200 524.2 12.700 524.2 14.600 502.2 15.120 524.2 15.600 502.2 15.900 524.2 16.300 524.2 12.800 502.2 14.700 502.2 15.200 524.2 15.650 524.2 15.900 502.2 16.400 502.2 13.300 524.2 14.800 524.2 15.300 502.2 15.700 524.2 16.000 524.2 16.400 524.2 13.900 502.2 14.900 524.2 15.310 502.2 15.700 502.2 16.000 502.2 16.500 524.2 14.000 502.2 14.900 524.2 15.350 502.2 15.800 524.2 16.000 524.2 16.500 524.2 14.000 524.2 14.900 502.2 15.400 524.2 15.800 502.2 16.000 524.2 16.700 502.2 14.100 524.2 14.900 502.2 15.400 502.2 15.800 502.2 16.080 502.2 16.800 other 14.200 524.2 14.900 524.2 15.400 524.2 15.800 524.2 16.100 502.2 17.200 524.2 14.500 524.2 15.000 524.2 15.500 502. 2 15.800 524.2 16.200 other 17.400

## B-167 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 9.92 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.160 524.2 9.150 502.2 9.580 502.2 9.810 524.2 10.100 524.2 10.500 502.2 8.660 524.2 9.190 524.2 9.590 502.2 9.840 524.2 10.100 524.2 10.800 524.2 8.940 524.2 9.300 502.2 9.600 524.2 9.960 524.2 10.200 524.2 11.200 524.2 8.950 524.2 9.300 other 9.622 524.2 10.000 other 10.300 502.2 11.500 524.2 9.090 524.2 9.500 524.2 9.660 502.2 10.090 524.2 10.410 502.2 12.700 502.2 9.120 502.2 9.580 524.2 9 .750 502.2 10.090 502.2 10.500 Water Study: 36 True Value: 13.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 11.200 502.2 12.500 524.2 13.100 524.2 13.300 524.2 13.700 524.2 14.300 502.2 11.400 524.2 12.600 502.2 13.200 524.2 13.300 524.2 13.700 524.2 14.600 502.2 11.600 524.2 12.700 502.2 13.200 502.2 13.400 502.2 13.700 502.2 14.700 502.2 11.900 502.2 12.800 524.2 13.200 502.2 13.400 502.2 13.900 524.2 15.050 524.2 12.000 502.2 12.800 502.2 13.240 502. 2 13.400 other 14.000 524.2 15.100 524.2 12.040 524.2 12.850 524.2 13.300 524.2 13.490 524.2 14.000 524.2 15.150 502.2 12.200 524.2 12.900 other 13.300 524.2 13.500 502.2 14.000 524.2 15.200 other 12.300 524.2 12.900 502.2 13.300 524.2 13.600 524.2 14.100 524.2 15.300 502.2 12.300 502.2 13.000 524.2 13.300 524.2 13.700 502.2 14.200 524.2 16.500 524.2 12.350 524.2 13.000 524.2 13.300 524. 2 13.700 other 14.200 502.2 16.600 Water Study: 37 True Value: 5.70 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.750 524.2 5.230 524.2 5.400 502.2 5.620 524.2 5.840 524.2 6.120 502.2 5.050 524.2 5.230 524.2 5.400 524.2 5.620 502.2 5.870 502.2 6.200 524.2 5.080 524.2 5.240 524.2 5.450 524. 2 5.670 524.2 5.900 other 6.360 502.2 5.100 524.2 5.240 524.2 5.480 502.2 5.670 502.2 5.910 524.2 6.460 502.2 5.160 502.2 5.270 524.2 5.500 524.2 5.680 524.2 5.980 502.2 6.540 502.2 5.160 524.2 5.340 502.2 5.510 other 5.700 502.2 6.010 524.2 7.050 524.2 5.190 502.2 5.380 502.2 5.530 502.2 5.780 524.2 6.060 524.2 7.450 502.2 5.200 524.2 5.390 524.2 5.580 524. 2 5.830 other 6.100 524.2 7.600

## B-168 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 22.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 14.000 524.2 15.500 502.2 16.200 other 16.700 502.2 17.100 502.2 17.800 524.2 14.700 524.2 15.600 524.2 16.200 524.2 16.700 502.2 17.300 502.2 18.000 502.2 14.800 502.2 15.700 524.2 16.300 502.2 16.700 524.2 17.300 524.2 18.200 524.2 14.900 other 15.800 other 16. 300 502.2 16.800 502.2 17.400 524.2 18.300 524.2 15.000 524.2 15.800 502.2 16.300 524.2 16.800 502.2 17.600 502.2 20.600 524.2 15.000 524.2 15.800 524.2 16.340 524.2 16.800 524.2 17.600 524.2 21.100 524.2 15.100 524.2 15.900 502.2 16.400 524.2 16.800 502.2 17.700 502.2 15.200 524.2 16.000 524.2 16.400 524.2 16.900 524.2 17.700 524.2 15.400 502.2 16.030 524.2 16.500 524.2 17.000 524.2 17.800 524.2 15.400 524.2 16.100 502.2 16.600 524.2 17.100 524.2 17.800 Water Study: 39 True Value: 7.31 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 5.520 502.2 6.860 524.2 7.150 524.2 7.360 524.2 7.610 524.2 8.550 524.2 6.190 524.2 6.860 524.2 7.190 524.2 7.400 502.2 7.700 524.2 8.920 524.2 6.270 524.2 6.950 524.2 7.270 524.2 7.430 524.2 7.950 524.2 17.390 524.2 6.330 other 7.050 502.2 7 .290 524.2 7.500 524.2 8.000 502.2 6.400 524.2 7.050 524.2 7 .300 524.2 7.540 502.2 8.060 524.2 6.740 502.2 7.100 524.2 7 .300 502.2 7.590 502.2 8.090 502.2 6.790 502.2 7.140 502.2 7 .310 524.2 7.600 524.2 8.290 524.2 6.830 502.2 7.150 502.2 7 .340 524.2 7.600 524.2 8.300 Water Study: 40 True Value: 14.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 5.800 other 13.300 524.2 14.100 502.2 14.500 502.2 14.900 524.2 15.200 502.2 11.800 524.2 13.400 524.2 14.100 other 14.500 524.2 14.900 524.2 15.300 524.2 12.000 524.2 13.500 524.2 14.200 524.2 14.600 524.2 14.900 502.2 15.500 524.2 12.300 524.2 13.600 524.2 14.300 524.2 14.600 524.2 14.900 502.2 15.700 524.2 12.890 524.2 13.600 502.2 14.300 502.2 14.600 502.2 15.000 524.2 15.900 524.2 12.900 524.2 13.700 524.2 14.300 524.2 14.600 524.2 15.000 502.2 16.000 524.2 13.000 524.2 13.800 502.2 14.300 502.2 14.700 502.2 15.000 524.2 17.400 524.2 13.000 502.2 13.800 524.2 14.400 524 14.700 502.2 15.000 524.2 17.700 524.2 13.100 other 14.100 524.2 14.400 524.2 14.800 502.2 15.100 524.2 13.200 524.2 14.100 524.2 14.500 524.2 14.800 524.2 15.100

## B-169 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 18.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 15.300 524.2 17.300 524.2 17.900 502. 2 18.500 524.2 18.800 other 19.400 524.2 16.400 524.2 17.500 502.2 18.000 524.2 18.600 524.2 18.900 524.2 19.600 524.2 16.500 524.2 17.540 502.2 18.100 502.2 18.700 524.2 18.900 502.2 19.700 502.2 16.700 524.2 17.600 524.2 18.200 524.2 18.700 524.2 19.000 502.2 19.800 524.2 16.700 524.2 17.600 524.2 18.200 502.2 18.700 524.2 19.130 502.2 20.900 502.2 17.100 524.2 17.600 other 18.300 524.2 18.700 524.2 19.200 524.2 22.500 524.2 17.200 502.2 17.600 524.2 18.300 502.2 18.700 524.2 19.300 524.2 23.000

Toxaphene Water Study: 24a True Value: 7.58 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.800 p. 1 6.100 other 6.970 p. 1 7.270 other 7.700 D3086-79 8.500

p. 1 2.340 P. 24 6.110 other 7.010 other 7.326 p. 1 7.810 p. 1 8.510

p. 1 2.390 p. 1 6.110 p. 1 7.100 SPE-500 7.400 p. 1 7.820 p. 1 8.550
p. 1 4.160 p. 1 6.440 p. 1 7.130 p. 1 7.480 other 7.840 p. 1 8.600

p. 1 4.360 p. 1 6.510 SPE-500 7.130 p. 1 7.490 p. 1 8.000 other 8.945

p. 1 5.880 p. 1 6.658 p. 1 7. 166 p. 1 7.580 other 8.000 509A 9.420

D3086-79 5.970 509A 6.710 p. 1 7.180 p. 1 7.600 p. 1 8.000 other 9.500

other 6.000 p. 1 6.800 other 7.200 p. 1 7.680 other 8.180 p. 1 10.600

509A 6.010 p. 1 6.860 509A 7.220 p. 1 7.680 p. 1 8.320 509A 10.800
SPE-500 6.098 p. 1 6.930 SPE-500 7.264 p. 1 7.700 other 8.500 p. 1 18.200

## B-170 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 24b True Value: 2.33 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value p. 1 0.213 509A 2.040 p. 1 2.260 p. 1 2.460 p. 1 2.630 p. 1 3.020 509A 1.530 SPE-500 2.080 p. 1 2.280 p. 1 2.460 509A 2.710 p. 1 3.090 D3086-79 1.600 p. 1 2.090 other 2.300 p. 1 2.500 p. 1 2.720 other 3.180 SPE-500 1.780 p. 1 2.110 other 2.300 p. 1 2.500 other 2.730 p. 1 3.224

p. 1 1.800 p. 1 2.110 p. 1 2.300 other 2.500 p. 1 2.730 p. 1 3.300 p. 1 1.880 p. 1 2.140 p. 1 2. 320 D3086- 2.580 other 2.759 509A 3.520 p. 1 1.920 p. 1 2.150 other 2.320 p. 1 2.600 P. 24 2.800 other 5.700 p. 1 2.000 p. 1 2.170 other 2.379 SPE-500 2.600 p. 1 2.820 p. 1 6.230 other 2.010 p. 1 2.240 p. 1 2.400 other 2.610 other 2.880 p. 1 7.020 p. 1 2.020 509A 2.250 SPE-500 2. 411 p. 1 2.610 other 2.900 Water Study: 25a True Value: 4.22 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 509A 0.310 P. 24 3.610 509A 3.960 other 4.120 p. 1 4.200 p. 1 4.500 p. 1 1.740 p. 1 3.610 505 3.990 p. 1 4.150 p. 1 4.260 p. 1 4.790 p. 1 2.400 508 3.670 509A 4.010 509A 4.160 other 4.300 p. 1 4.891 p. 1 2.690 other 3.840 509A 4.040 p. 1 4.170 other 4.330 p. 1 5.220 p. 1 3.500 other 3.900 SPE-500 4. 040 509A 4.200 p. 1 4.340 other 5.660 p. 1 3.600 p. 1 3.940 P. 24 4.050 509A 4.200 p. 1 4.440 Water Study: 25b True Value: 1.41 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 509A 0.130 p. 1 1.130 other 1.280 p. 1 1.390 p. 1 1.540 509A 1.660 other 0.922 other 1.190 p. 1 1.300 p. 1 1.423 p. 1 1.550 P. 24 1.720 p. 1 1.020 p. 1 1.220 505 1. 320 509A 1.430 509A 1.560 p. 1 1.940 p. 1 1.040 509A 1.240 508 1.320 p. 1 1.435 other 1.600 other 1.940 509A 1.070 other 1.260 P. 24 1.350 509A 1.440 p. 1 1.620 p. 1 1.980 p. 1 1.110 p. 1 1.260 p. 1 1 .370 p. 1 1.520 SPE-500 1.635

## B-171 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26a True Value: 10.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value p. 1 6.950 p. 1 8.910 p. 1 9.865 p. 1 10.500 other 11.100 p. 1 13.100 p. 1 8.180 other 8.980 other 9. 980 p. 1 10.600 p. 1 11.100 509A 13.100 p. 1 8.210 other 9.010 other 10. 000 p. 1 10.600 509A 11.200 p. 1 13.400 p. 1 8.390 other 9.220 p. 1 10. 100 508 10.660 525.1 11.240 p. 1 13.590 p. 1 8.680 p. 1 9.470 other 10.100 p. 1 10.800 p. 1 11.900 p. 1 15.100 p. 1 8.700 SPE-500 9.551 p. 1 10.200 p. 1 10.900 p. 1 12.100 p. 1 15.300 other 8.710 p. 1 9.580 other 10. 300 509A 10.900 SPE-500 12.200 p. 1 16.500 509A 8.750 P. 24 9.600 p. 1 10.300 other 10.900 other 12.300 p. 1 17.400 p. 1 8.880 SPE-500 9.660 p. 1 10.400 SPE-500 10.940 505 12.700 509A 8.890 509A 9.700 509A 10.400 p. 1 11.000 other 13.000 Water Study: 26b True Value: 3.68 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.340 509A 2.930 p. 1 3.350 p. 1 3.620 p. 1 3.820 other 4.350 509A 2.360 other 2.960 p. 1 3.400 p. 1 3.637 p. 1 3.820 p. 1 4.619 other 2.490 509A 2.960 other 3.430 509A 3.650 other 3.820 P. 24 4.750 p. 1 2.540 p. 1 3.010 other 3.480 SPE-500 3.670 p. 1 3.850 p. 1 4.770 other 2.720 p. 1 3.110 other 3. 490 p. 1 3.680 508 3.860 p. 1 4.870 p. 1 2.730 p. 1 3.170 SPE-500 3.507 509A 3.690 505 3.893 p. 1 5.740 p. 1 2.770 other 3.180 p. 1 3.520 SPE-500 3.700 p. 1 3.990 p. 1 5.820 other 2.800 p. 1 3.230 p. 1 3.560 other 3.780 525.1 4.018 p. 1 6.740 p. 1 2.900 p. 1 3.270 p. 1 3.590 509A 3.790 p. 1 4.030 SPE-500 2.920 p. 1 3.280 509A 3. 610 p. 1 3.800 p. 1 4.280 Water Study: 27 True Value: 6.39 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value p. 1 4.240 509A 5.160 P. 24 5. 600 508 5.900 p. 1 6.660 505 7.850 p. 1 4.310 p. 1 5.190 other 5.660 p. 1 5.960 p. 1 6.820 p. 1 10.600 other 4.820 other 5.200 508 5.700 509A 5.990 other 7.000 p. 1 10.900 p. 1 4.950 p. 1 5.210 other 5.800 p. 1 6.050 p. 1 7.175 p. 1 16.500 509A 5.040 509A 5.380 p. 1 5.810 509A 6.220 p. 1 7.190 p. 1 5.050 other 5.550 p. 1 5.820 508 6.240 other 7.230

## B-172 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 7.60 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 3.850 505 6.500 other 7. 115 505 7.560 505 7.690 508 8.950 508 5.790 508 6.700 other 7.160 508 7.560 other 7.700 505 9.300 508 5.800 508 6.760 p. 1 7.170 508 7.580 other 7.941 508 9.710 508 5.950 508 6.940 509A 7.197 p. 1 7.590 508 8.020 508 6.220 other 6.940 p. 1 7.300 505 7.650 508 8.100 p. 1 6.370 p. 24 6.990 SPE- 500 7.385 508 7.670 p. 1 8.300 Water Study: 30 True Value: 2.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 0.871 508 2.090 other 2.400 505 2.550 p. 1 2.700 508 2.970 508 1.490 p. 1 2.100 508 2.420 505 2.550 other 2.720 508 3.020 508 1.520 505 2.130 508 2.450 other 2.600 508 2.740 508 3.040 508 1.590 SPE-500 2.250 508 2. 450 505 2.630 508 2.740 508 3.040 505 1.690 other 2.280 p. 1 2.460 p. 1 2.630 508 2.790 other 3.060 p. 24 1.730 508 2.280 508 2.480 508 2.630 508 2.810 508 3.190 other 1.860 508 2.330 p. 1 2.490 other 2.659 other 2.840 p. 1 3.200 508 1.880 505 2.340 508 2.520 508 2.680 508 2.940 other 3.960 508 1.935 other 2.390 p. 1 2. 540 p. 1 2.700 508 2.970 505 12.600 Water Study: 31 True Value: 3.31 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 1.570 505 2.400 other 3.060 p. 1 3.330 508 3.500 505 16.500 508 1.910 508 2.750 other 3. 120 508 3.340 other 3.530 508 1.960 505 2.810 508 3.120 508 3.420 508 3.710 508 2.070 508 2.830 508 3.130 p. 1 3.440 508 3.850 508 2.130 508 2.900 508 3.200 508 3.440 508 4.030 508 2.300 505 2.930 508 3.220 508 3.490 p. 1 4.100

## B-173 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 3.71 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.230 508 2.820 508 3.290 other 3.6900 SPE-500 3.900 505 4.370 other 2.350 525.1 2.830 508 3.429 508 3.700 other 3.900 508 5.130 508 2.410 SPE-500 2.920 508 3. 490 505 3.700 505 3.956 505 5.770 508 2.490 508 2.980 508 3.500 508 3.720 508 3.960 508 6.110 508 2.590 505 3.010 508 3.550 508 3.740 508 3.970 525.1 6.200 508 2.600 508 3.060 508 3.580 508 3.750 505 3.970 505 7.360 508 2.640 508 3.120 508 3.590 508 3.800 505 4.000 508 2.640 other 3.200 508 3.590 508 3.800 508 4.000 508 2.700 508 3.230 508 3.620 other 3.830 505 4.180 other 2.810 508 3.240 508 3.680 505 3.830 525.1 4.270 Water Study: 33 True Value: 9.23 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 4.960 505 7.610 other 8.640 508 9.020 508 10.000 other 12.400 508 5.760 505 7.690 508 8.690 508 9.030 508 10.500 525.1 13.600 508 6.840 508 7.920 508 8.750 508 9.240 505 10.800 other 26.300 505 7.110 508 8.050 508 8.780 508 9.630 505 10.900 508 7.120 508 8.380 other 8.900 508 9.840 508 11.300 other 7.500 508 8.520 508 9.000 508 9.880 508 11.960 Water Study: 34 True Value: 5.37 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.1 2.850 508 4.460 508 5.070 508 5.340 505 5.795 525.1 6.420 505 3.290 508 4.480 505 5.100 508 5.480 508 5.800 508 6.670 other 3.430 505 4.650 508 5. 140 508 5.480 508 5.810 505 6.790 505 3.520 508 4.750 508 5.170 508 5.490 508 5.960 508 6.985 508 3.590 508 4.860 508 5.210 508 5.550 508 6.090 508 7.030 508 3.830 508 4.900 508 5.230 508 5.560 508 6.150 other 7.070 505 4.170 508 4.930 other 5. 280 505 5.560 508 6.180 508 7.230 525.1 4.280 508 4.950 505 5.280 other 5.570 508 6.230 508 10.400 508 4.340 525.1 5.000 505 5.330 508 5.630 505 6.320 505 23.890

## B-174 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 18.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 1.810 508 14.380 508 16.000 508 17.100 505 18.200 505 22.300 508 11.300 505 14.400 505 16.200 508 17.100 508 19.400 508 22.500 508 11.400 505 14.700 508 16.400 508 17.780 508 19.800 other 23.200 508 13.100 505 14.900 525.1 16.700 508 17.900 508 20.000 508 26.100 508 13.300 508 14.900 505 16.800 508 17.900 508 20.400 508 13.490 508 15.750 508 17.000 525.1 18.100 508 21.300 Water Study: 36 True Value: 14.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 5.570 508 11.000 other 13.200 525.2 13.900 508 14.700 505 16.000 508 8.050 other 11.030 other 13.250 508 14.000 508 14.800 505 17.300 508 8.900 505 11.300 508 13.400 505 14.000 505 14.800 508 19.370 508 9.570 508 11.800 508 13.400 505 14.000 505 14.800 525.2 20.600 505 10.180 508 11.900 508 13.500 508 14.000 525.2 14.900 505 22.600 508 10.500 508 12.000 508 13.600 508 14.200 508 15.300 508 28.000 other 10.700 505 12.100 505 13.800 508 14.200 525.2 15.500 508 28.700 505 10.700 other 12.300 508 13.800 508 14.300 508 15.600 508 10.800 508 12.900 505 13.800 508 14.700 508 15.800 Water Study: 37 True Value: 8.81 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 505 1.470 other 6.770 508 8. 130 508 8.930 508 9.890 508 11.400 508 4.010 508 7.150 505 8.210 525.2 8.940 508 10.050 508 11.500 525.2 4.800 525.2 7.510 other 8 .240 505 9.000 508 10.100 508 11.800 505 5.630 508 7.560 505 8.300 508 9.140 508 10.110 525 13.100 508 6.520 508 7.570 508 8.330 505 9.140 508 10.200 508 14.000 508 6.700 508 7.760 508 8.560 other 9.480 505 10.300 508 14.000 other 6.700 508 7.800 505 8.740 508 9.730 505 10.660 508 6.740 505 7.860 508 8.800 505 9.740 505 11.000

## B-175 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 12.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 0.970 508 9.700 508 11.600 505 12.500 505 13.200 525.2 16.200 505 6.210 508 10.360 508 11.700 508 12.500 508 13.500 other 16.300 525.2 6.220 505 10.400 508 11.800 508 12.600 508 13.500 508 16.600 508 7.510 508 10.600 508 11.800 508 12.900 505 13.600 508 18.400 508 7.570 505 10.600 508 11.800 508 12.900 505 13.700 508 32.300 505 7.860 508 10.700 505 11.900 508 12.900 508 13.960 508 8.080 other 11.160 508 12.000 505 12.900 525.2 14.000 12 8.400 508 11.400 508 12.300 505 13.100 505 14.250 508 9.620 508 11.400 505 12.400 508 13.200 508 14.300 Water Study: 39 True Value: 3.65 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 2.140 508 3.540 508 3.860 508 3.990 508 4.140 525.2 4.930 505 2.600 508 3.550 508 3.860 508 4.010 508 4.140 508 4.960 508 2.700 508 3.580 505 3.880 508 4.030 505 4.300 508 5.280 508 2.890 other 3.740 505 3.880 508 4.038 505 4.320 525.2 5.500 505 3.010 508 3.810 505 3.890 508 4.070 505 4.650 525.2 5.690 508 3.180 508 3.820 508 3.950 525.2 4.120 508 4.740 508 7.300 508 3.420 525.2 3.860 508 3.960 505 4.130 508 4.780 Water Study: 40 True Value: 16.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 508 10.000 other 13.700 508 15.400 525.2 16.500 505 17.600 508 19.200 525.2 10.700 508 13.800 508 15.400 508 16.600 505 17.600 505 19.500 508 10.600 508 13.900 505 15.600 508 16.600 508 17.700 508 19.600 508 11.000 508 14.300 508 15.600 525.2 16.700 other 17.800 505 20.700 508 11.800 505 14.310 508 16.000 508 16. 800 other 17.930 other 27.400 505 11.800 525.2 14.400 505 16.100 508 17.000 508 18.000 508 29.500 508 11.900 508 14.500 508 16.100 other 17.300 508 18.000 508 13.500 508 14.600 508 16.400 508 17.300 505 18.800 505 13.600 508 14.800 508 16.400 508 17.560 508 18.900 508 13.700 525.2 15.000 508 16.500 505 17.600 508 19.100

## B-176 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 6.90 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 525.2 2.890 508 4.930 508 5.520 508 6.430 505 7.090 505 8.160 other 3.460 508 5.024 508 5.530 505 6.650 525.2 7.190 508 8.490 505 4.080 other 5.050 508 5. 550 508 6.660 508 7.270 508 10.000 505 4.520 508 5.190 508 5.730 508 6. 700 525.2 7.630 other 10.200 other 4.740 508 5.290 525.2 5.770 505 6.950 508 7.850 505 4.880 505 5.310 508 5.850 505 7.010 508 7.900 508 4.920 other 5.410 508 6.010 508 7.020 508 8.070

1,1,1-Trichloroethane Water Study: 24 True Value: 3.21 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 1.960 524.2 2.830 524.2 2.990 502.2 3.130 502.2 3.320 502.1 3.730 502.2 2.050 524.1 2.850 524.2 3.000 524.2 3.150 524.2 3.390 502.2 3.800 502.2 2.410 524.2 2.860 524.2 3.010 524.1 3.150 502.2 3.420 502.2 3.880 524.1 2.430 502.2 2.890 502.2 3.020 524. 2 3.200 524.2 3.490 other 4.000 502.2 2.600 524.2 2.900 524.2 3.070 502.2 3.210 502.1 3.490 502.2 4.100 524.2 2.630 other 2.900 524.2 3.090 502.2 3.210 502.2 3.500 502.2 4.100 502.1 2.690 502.2 2.915 524.2 3.100 502.2 3.220 524.2 3.607 524.2 7.040 524.2 2.700 502.1 2.920 502.1 3 .100 502.2 3.300 524.2 3.620 502.2 2.760 502.2 2.960 other 3 .100 502.1 3.300 524.1 3.660 524.1 2.820 524.2 2.990 502.2 3 .100 502.2 3.300 524.2 3.710 Water Study: 25 True Value: 11.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 6.400 502.2 10.400 502.2 10.800 524. 2 11.100 502.2 12.200 other 21.900 502.2 9.000 524.1 10.500 other 10.830 502.2 11.110 502.2 12.600 524.2 71.600 502.2 9.000 502.2 10.500 524.2 10.900 524.1 11.300 502.2 12.800 524.2 9.730 524.2 10.600 502.2 10.900 524.2 11.360 524.2 12.800 502.2 9.760 524.2 10.630 524.1 10.900 524.2 11.400 502.2 13.000 other 10.100 502.2 10.700 502.1 11.100 502.1 11.600 524.1 13.100 524.2 10.150 524.2 10.800 502.2 11.100 502.2 11.800 524.2 14.000

## B-177 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 26 True Value: 13.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.160 502.2 12.000 524.2 12.700 502.1 13.500 524.2 14.000 524.2 15.000 502.2 9.620 502.2 12.000 524.1 12.800 524.2 13.500 524.2 14.080 502.2 15.300 502.2 10.000 524.2 12.100 524.2 13.100 502.1 13.500 524.2 14.100 502.2 15.500 524.2 10.700 other 12.100 524.1 13.100 524.2 13.500 502.2 14.100 502.1 15.600 502.2 11.100 524.2 12.100 502.2 13.200 502.1 13.700 524.2 14.200 524.2 16.200 524.2 11.200 502.2 12.200 524.2 13.200 502.2 13.800 502.2 14.300 502.2 16.800 502.2 11.570 524.2 12.310 524.2 13.200 502.2 13.800 524.2 14.300 502.2 17.490 524.1 11.800 502.2 12.400 524.1 13.400 524.2 13.960 502.1 14.400 524.2 18.900 502.2 11.800 524.1 12.400 502.2 13.400 502.2 14.000 524.2 14.700 524.2 21.400 other 11.900 502.1 12.630 502.2 13.500 524.2 14.000 524.2 14.800 Water Study: 27 True Value: 7.38 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 3.140 502.2 6.200 502.2 6.730 502.2 7.160 502.2 7.460 502.2 9.630 502.2 5.300 502.2 6.330 524.2 6.880 524.1 7.200 524.2 7.620 524.1 9.730 other 5.450 524.2 6.420 other 6 .900 524.2 7.200 other 8.230 502.2 5.470 524.2 6.590 502.2 6 .980 524.2 7.210 524.2 8.460 524.2 5.570 502.1 6.600 524.2 7 .010 524.2 7.350 502.2 8.470 502.2 5.730 502.2 6.600 524.2 7 .130 524.2 7.400 502.2 8.860 524.2 6.200 502.2 6.650 502.2 7 .150 502.2 7.450 502.2 9.450 Water Study: 29 True Value: 8.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.560 502.2 7.660 524.2 8.110 524.2 8.700 502.2 9.270 502.2 9.450 524.2 6.600 other 7.800 other 8. 310 524.2 8.960 524.1 9.320 524.2 9.700 502.2 7.076 502.2 7.879 502.2 8.390 524.2 9.000 502.2 9.330 524.2 9.780 524.2 7.130 524.2 7.900 502.2 8.610 502. 2 9.040 other 9.389 502.2 9.930 other 7.300 524.2 7.920 524.2 8.630 502.2 9.080 524.1 9.420 524.2 10.500 502.2 7.650 524.2 8.080 524.2 8 .700 502.2 9.210 502.2 9.420

## B-178 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 30 True Value: 7.13 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 5.200 502.2 6.350 502.2 6.720 524.2 7.080 502.2 7.250 502.2 7.600 502.2 5.310 524.2 6.380 502.2 6.730 524.2 7.100 524.2 7.280 502.2 7.670 524.2 5.780 502.2 6.380 502.2 6.750 524.2 7.100 524.2 7.360 524.2 7.800 502.1 5.780 524.2 6.400 524.2 6.790 other 7.120 502.2 7.400 502.2 8.000 524.2 5.790 502.2 6.420 502.1 6.820 524. 1 7.150 other 7.407 524.2 8.190 502.2 5.840 524.2 6.450 other 6.840 524.2 7.170 502.2 7.420 502.2 8.300 502.2 6.000 524.2 6.600 524.2 6.930 502.2 7.180 524.1 7.500 502.1 8.660 524.2 6.100 524.2 6.650 524.2 6.940 524.2 7.200 524.2 7.500 502.2 8.740 524.2 6.300 524.1 6.670 524.2 6.950 502.2 7.200 524.2 7.540 502.2 10.620 502.2 6.310 502.2 6.700 502.2 6 .990 524.2 7.240 502.2 7.548 Water Study: 31 True Value: 13.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.230 524.2 11.300 502.2 11.900 524.2 12.300 502.2 13.200 524.2 13.400 502.2 9.896 524.2 11.400 502.2 12.000 502.2 12.400 524.2 132.000 502.1 13.500 502.1 10.300 524.2 11.600 502.2 12.100 502.2 12.400 524.2 13.300 502.2 13.600 524.2 10.670 502.2 11.600 524.1 12.100 524.2 12.700 502.1 13.300 524.2 13.770 502.2 11.100 524.2 11.700 other 12.100 524.2 12.900 502.2 13.400 524.2 14.600 502.2 11.100 524.2 11.800 502.1 12.200 524.2 12.900 502.2 13.400 502.2 14.600 Water Study: 32 True Value: 10.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 7.310 524.2 8.900 502.1 9.450 502.2 9.884 502.2 10.400 524.1 11.000 502.2 7.760 502.2 8.950 524.2 9.500 502.1 9.880 524.2 10.410 502.2 11.200 502.2 8.200 502.2 9.020 502.2 9.530 524.2 9.910 502.2 10.500 524.2 11.500 502.2 8.280 502.2 9.040 502.2 9.590 524. 2 9.910 524.2 10.500 other 11.600 502.2 8.300 524.2 9.090 524.2 9.690 524.2 9.950 502.2 10.600 524.2 11.700 502.2 8.370 502.2 9.220 502.2 9.690 524. 2 9.970 other 10.600 502.2 11.700 502.1 8.400 524.2 9.250 524.2 9.750 other 10.000 502.2 10.600 524.2 12.500 524.2 8.450 502.2 9.300 524.2 9 .780 524.2 10.000 502.2 10.600 502.2 8.500 502.2 9.350 524.2 9 .780 524.2 10.200 524.2 10.600 524.2 8.640 524.2 9.360 524.2 9 .810 524.2 10.200 524.2 10.700 524.2 8.800 524.2 9.440 524.2 9 .820 524.2 10.400 524.2 10.900

## B-179 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 14.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.680 524.2 13.100 502.2 13.800 502.2 14.660 502.2 15.000 524.2 17.100 other 11.660 502.2 13.300 502.2 14.200 524.2 14.800 502.2 15.200 524.2 19.600 502.2 11.700 502.2 13.400 502.2 14.300 524.2 14.900 502.2 15.600 524.2 20.000 502.2 12.000 502.2 13.500 524.2 14.400 524.2 14.900 524.2 15.700 502.1 12.300 524.2 13.540 524.2 14.500 524.1 14.900 502.1 15.800 524.2 12.950 524.2 13.600 502.2 14.600 524.2 15.000 502.2 15.900 Water Study: 34 True Value: 5.73 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.100 other 4.800 502.2 5.270 502.2 5.510 524.2 5.790 502.2 5.890 502.2 4.370 502.2 4.840 524.2 5.280 502.2 5.510 524.2 5.790 502.2 5.900 524.2 4.580 502.2 4.850 524.2 5.330 502.2 5.550 502.2 5.800 502.2 6.010 524.2 4.610 502.2 4.860 524.2 5.340 524.2 5.570 524.2 5.800 524.2 6.080 502.1 4.650 524.2 4.950 524.2 5.360 502.2 5.580 524.2 5.810 524.2 6.100 502.2 4.700 502.2 4.986 502.2 5.380 524.2 5.600 524.2 5.810 502.2 6.130 524.2 4.700 524.2 5.080 502.2 5.400 524.2 5.640 502.2 5.810 524.2 6.200 502.2 4.720 524.2 5.100 502.2 5.420 502.2 5.700 502.2 5.850 524.2 6.300 502.2 4.740 524.2 5.150 502.2 5.480 524.2 5.720 524.2 5.870 524.2 6.920 502.2 4.780 524.2 5.170 524.2 5 .490 524.2 5.730 524.2 5.870 Water Study: 35 True Value: 8.78 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.900 502.2 7.850 502.2 8.210 524.2 8.500 502.2 8.700 524.2 9.280 502.2 6.580 524.2 7.880 524.2 8.280 524.2 8.500 502.2 8.900 524.2 9.550 502.2 6.610 524.2 7.900 524.2 8.300 502. 2 8.590 other 9.000 502.2 9.570 502.2 6.896 502.2 7.910 502.2 8.300 524.2 8.600 502.2 9.020 524.2 9.570 524.2 7.510 524.2 8.110 524.2 8 .320 524.2 8.630 524.2 9.100 502.2 7.741 other 8.126 524.2 8 .350 524.2 8.680 502.2 9.120

## B-180 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 14.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 11.200 524.2 13.080 524.2 13.600 502.2 13.890 524.2 14.600 502.2 15.200 502.2 11.500 502.2 13.100 524.2 13.600 524.2 14.100 524.2 14.600 524.2 15.200 524.2 12.300 502.2 13.200 502.2 13.600 524.2 14.200 502.2 14.700 502.2 15.400 524.2 12.400 524.2 13.200 524.2 13.610 524.2 14.300 502.2 14.800 524.2 15.400 524.2 12.500 502.2 13.200 502.2 13.700 524.2 14.400 502.2 15.000 502.2 15.400 524.2 12.600 502.2 13.200 502.2 13.700 524.2 14.400 524.2 15.000 524.2 15.500 524.2 12.800 524.2 13.500 502.2 13.700 524.2 14.420 524.2 15.100 524.2 15.720 524.2 12.900 524.2 13.500 502.2 13.800 524. 2 14.500 other 15.200 524.2 16.570 502.2 12.900 524.2 13.530 502.2 13.800 524. 2 14.500 other 15.200 other 16.600 524.2 12.900 524.2 13.600 524.2 13.800 502.2 14.600 502.2 15.200 Water Study: 37 True Value: 10.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.280 502.2 9.600 524.2 10.100 524.2 10.600 524 10.900 524.2 12.100 502.2 8.710 524.2 9.760 502.2 10.100 524. 2 10.600 other 11.100 524.2 12.900 524.2 8.720 524.2 9.840 524.2 10.110 524.2 10.700 502.2 11.100 502.2 13.400 524.2 8.920 502.2 9.860 524.2 10.200 524.2 10.700 502.2 11.200 524.2 13.900 502.2 9.350 524.2 9.890 502.2 10.200 524.2 10.700 524.2 11.360 524.2 14.600 524.2 9.420 502.2 9.960 524.2 10.280 502. 2 10.800 other 11.800 502.2 16.600 524.2 9.460 524.2 10.100 502.2 10.400 524.2 10.800 502.2 11.900 524.2 21.800 524.2 9.550 524.2 10.100 502.2 10.400 502.2 10.900 524 11.900 Water Study: 38 True Value: 17.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.600 other 15.500 524.2 16. 100 524.2 16.700 524 17.300 524.2 18.000 524.2 13.500 502.2 15.500 502.2 16.100 502.2 16.800 502.2 17.300 502.2 18.000 502.2 13.900 524.2 15.500 524.2 16.100 502.2 16.800 524.2 17.300 524.2 18.200 502.2 14.100 524.2 15.500 524.2 16.300 524.2 16.800 524.2 17.400 524.2 18.400 502.2 14.400 524.2 15.600 502.2 16.400 524.2 16.900 524.2 17.400 502.2 18.500 524.2 14.500 524.2 15.800 502.2 16.500 524.2 16.930 502.2 17.500 524.2 19.000 524.2 14.600 502.2 15.800 502.2 16.500 524.2 17.000 524.2 17.700 524.2 19.140 524.2 15.000 524.2 15.900 502.2 16.600 502.2 17.200 524.2 17.800 524.2 19.400 other 15.300 524.2 15.900 502.2 16.700 524.2 17.200 524.2 17.800 524.2 19.400

## B-181 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 11.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.440 524.2 10.100 502.2 11.000 502.2 11.500 502.2 12.100 524.2 12.800 524.2 8.610 524.2 10.200 524.2 11.000 524.2 11.500 524.2 12.100 524.2 19.900 524.2 8.960 524.2 10.300 524.2 11.100 502.2 11.500 524.2 12.100 524.2 27.900 524.2 9.070 524.2 10.700 524.2 11.100 502.2 11.500 524.2 12.100 524.2 9.560 524.2 10.800 502.2 11.200 524.2 11.600 524.2 12.200 502.2 9.700 502.2 10.800 524.2 11.200 502.2 11.900 524.2 12.620 524.2 9.830 524.2 10.800 524.2 11.200 502.2 11.900 524.2 12.700 502.2 10.000 524.2 10.900 524.2 11.500 502.2 12.000 524.2 12.800 Water Study: 40 True Value: 7.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.730 524.2 6.320 524.2 6.770 524.2 7.020 502.2 7.360 502.2 8.250 524.2 5.790 524.2 6.400 524.2 6.800 524.2 7.020 524.2 7.370 502.2 8.260 524.2 5.790 502.2 6.400 524.2 6.800 524.2 7.040 524.2 7.400 502.2 8.280 524.2 5.810 524.2 6.470 524.2 6.800 524.2 7.110 524.2 7.460 524.2 8.390 524.2 5.860 524.2 6.500 502.2 6.840 502.2 7.110 524.2 7.530 502.2 8.900 524.2 6.090 524.2 6.640 524.2 6.840 other 7.110 502.2 7.550 524.2 9.100 524.2 6.200 524.2 6.650 524.2 6.880 524.2 7.140 524.2 7.590 524.2 12.100 502.2 6.230 524.2 6.650 524.2 6 .890 524.2 7.160 502.2 7.780 524.2 6.280 524.1 6.660 502.2 6 .930 502.2 7.310 524.2 7.900 other 6.300 524.1 6.680 524.2 6 .970 524.2 7.320 502.2 8.100 Water Study: 41 True Value: 12.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.500 502.2 11.400 524.2 11.600 524.2 12.000 524.2 12.500 524.2 13.500 502.2 10.500 524.2 11.400 524.2 11.600 524.2 12.000 524.2 12.520 502.2 13.700 524.2 10.500 524.2 11.400 524.2 11.600 524.2 12.000 524.2 12.700 524.2 14.000 524.2 10.900 502.2 11.400 524.2 11.700 524.2 12.000 524.2 12.800 502.2 14.500 524.2 11.100 524.2 11.500 502.2 11.900 524.2 12.100 502.2 12.900 502.2 14.700 524.2 11.200 524.2 11.600 other 11.900 524.2 12.300 502.2 13.200 502.2 15.000 524.2 11.300 524.2 11.600 502.2 11.900 524.2 12.330 524.2 13.200

## B-182 Methods Support Document for Six-Year Review Final - March 2003 1,1,2-Trichloroethane Water Study: 26 True Value: 26.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 19.100 524.2 24.500 502.1 25.200 502.2 26.200 502.1 28.200 502.2 29.600 502.2 20.100 524.1 24.600 524.2 25.400 502.1 26.380 502.2 28.300 524.1 29.900 502.1 20.700 524.2 24.600 524.2 25.580 502.2 26.500 502.1 28.400 524.2 30.100 524.2 21.800 502.2 24.700 524.2 25.730 502.2 26.800 502.2 28.400 502.2 30.200 502.2 21.960 524.2 24.760 502.2 25.730 524.2 26.900 524.2 28.600 524.2 30.400 502.2 22.600 502.2 24.800 524.2 25.800 502.2 27.100 524.1 28.600 524.1 30.600 524.2 23.200 502.2 24.900 524.2 25.800 524.2 27.700 524.1 28.800 524.2 31.100 502.2 23.300 502.2 25.000 524.2 25.900 524. 2 27.800 502.2 29.200 other 32.400 other 23.500 502.2 25.000 524.2 26.000 502.2 27.900 502.2 29.400 502.2 32.900 Water Study: 30 True Value: 11.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 8.360 502.2 10.500 524.2 11.020 524. 2 11.300 524.2 11.600 other 12.500 502.2 8.550 other 10.580 524.2 11.160 524.2 11.300 524.2 11.600 502.2 12.700 524.2 9.850 524.2 10.600 524.2 11.200 502. 2 11.400 other 11.600 524.2 13.100 502.2 10.200 502.2 10.600 524.2 11.200 524.1 11.400 502.1 11.840 502.2 13.100 524.2 10.200 502.2 10.700 524.2 11.200 502.2 11.400 502.2 12.000 502.2 14.200 524.2 10.290 524.2 10.700 502.2 11.200 502.2 11.500 502.2 12.000 502.2 10.370 502.2 10.900 524.2 11.300 524.2 11.500 502.2 12.200 502.2 10.400 other 10.900 524.2 11.300 502.2 11.500 other 12.300 502.2 10.500 524.2 11.000 502.2 11.300 524.2 11.500 524.2 12.400 Water Study: 32 True Value: 13.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.510 502.2 11.400 524.2 11.900 524.2 12.900 524.2 13.100 524.2 14.360 524.2 10.300 524.2 11.400 502.2 12.000 502.2 12.900 524.2 13.200 524.2 14.600 524.2 10.300 502.2 11.500 502.2 12.200 524.2 12.900 524.2 13.200 502.2 14.800 502.2 10.400 524.1 11.600 524.2 12.220 524. 2 12.900 other 13.500 524.2 14.900 502.2 10.700 524.2 11.600 524.2 12.470 other 13.000 502.2 13.500 524.2 15.000 502.2 10.800 524.2 11.700 524.2 12.500 502.2 13.000 502.2 13.600 502.1 15.300 502.2 11.200 502.2 11.700 other 12.520 524.2 13.040 524.2 13.600 502.2 15.500 502.1 11.300 502.2 11.800 502.2 12.600 502.2 13.100 502.2 13.900 524.2 16.600 502.1 11.300 524.2 11.900 524.2 12.600 502.1 13.100 524.2 14.000

## B-183 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 33 True Value: 15.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 10.980 524.2 14.200 524.2 14.900 524.2 15.560 524.2 16.100 524.2 17.100 524.1 11.800 524.2 14.400 524.2 14.930 502.2 15.600 502.1 16.100 524.2 17.200 502.1 12.900 502.2 14.400 524.2 14.980 524.2 15.700 524.2 16.500 502.2 17.600 502.2 13.000 502.2 14.600 502.2 15.000 524.2 15.900 502.2 16.500 524.2 18.300 other 13.100 502.2 14.680 502.2 15.200 502.2 15.900 524.2 16.600 502.2 21.230 502.2 13.400 502.2 14.700 502.2 15. 200 502.2 16.000 other 17.000 Water Study: 34 True Value: 8.50 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.480 524.2 7.720 524.2 8.020 524.2 8.200 524.2 8.480 524.2 8.760 502.2 6.510 524.2 7.750 502.2 8.050 502.2 8.230 524.2 8.500 502.2 8.880 524.2 6.760 524.2 7.800 502.2 8.060 502.2 8.260 502.2 8.510 524.2 8.950 502.2 6.770 502.2 7.800 502.2 8.080 524.2 8.300 524.2 8.520 524.2 9.160 502.2 7.410 524.2 7.800 524.2 8.080 524.2 8.300 502.2 8.530 524.2 9.180 502.2 7.510 502.2 7.880 502.2 8.100 524. 2 8.320 502.2 8.560 other 9.420 502.2 7.560 524.2 7.950 502.2 8.104 502.2 8.330 524.2 8.630 524.2 9.510 524.2 7.600 524.2 7.960 524.2 8.110 524.2 8.360 502.2 8.670 524.2 9.900 524.2 7.620 502.2 7.970 502.2 8.130 524. 2 8.360 other 8.700 502.2 10.300 524.2 7.650 502.2 7.990 524.2 8 .180 502.2 8.370 524.2 8.700 Water Study: 35 True Value: 12.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 8.170 524.2 12.000 502.2 12.700 524.2 13.000 502.2 13.300 524.2 14.600 502.2 10.800 other 12.160 502.2 12.700 524.2 13.100 524.2 13.300 502.2 15.800 524.2 10.900 502.2 12.180 524.2 12.700 524.2 13.100 524.2 13.500 524.2 17.000 502.2 10.900 502.2 12.200 524.2 12.700 502.2 13.200 502.2 13.770 502.2 11.200 524.2 12.400 524.2 12.800 502.2 13.200 502.2 13.900 524.2 11.200 524.2 12.600 502.2 12.800 524.2 13.200 524.2 14.000

## B-184 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 36 True Value: 6.46 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.930 524.2 5.680 524.2 5.900 524.2 6.120 502.2 6.420 502.2 6.700 524.2 5.100 524.2 5.700 524.2 5.910 524.2 6.150 524.2 6.430 524.2 6.740 524.2 5.160 502.2 5.700 524.2 5.940 524.2 6.190 524.2 6.450 502.2 6.760 524.2 5.180 502.2 5.700 524.2 5.940 502.2 6.210 524.2 6.490 524.2 6.830 502.2 5.370 524.2 5.720 502.2 5.980 524. 2 6.260 other 6.530 524.2 7.130 502.2 5.500 524.2 5.720 502.2 5.980 502. 2 6.320 502.2 6.540 other 7.300 524.2 5.550 524.2 5.770 502.2 6.000 502.2 6.340 524.2 6.570 524.2 7.400 502.2 5.580 524.2 5.830 524.2 6.010 524. 2 6.340 other 6.600 502.2 7.940 524.2 5.600 524.2 5.840 502.2 6.030 502.2 6.340 502.2 6.610 502.2 8.000 502.2 5.600 524.2 5.900 524.2 6.050 502.2 6.380 524.2 6.620 524.2 9.490 Water Study: 37 True Value: 10.7 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 9.090 502.2 10.400 524.2 10.900 524.2 11.300 502.2 12.000 524.2 15.700 524.2 9.510 524.2 10.500 524.2 10.900 524.2 11.380 502.2 12.100 524.2 21.200 524.2 9.560 524.2 10.600 524.2 11. 000 502.2 11.400 other 12.200 524.2 9.590 524.2 10.600 524.2 11.100 502.2 11.500 524.2 12.400 524.2 10.100 502.2 10.600 524.2 11.180 502.2 11.600 524.2 12.600 502.2 10.100 524.2 10.700 524.2 11. 190 502.2 11.600 other 12.700 524.2 10.100 524.2 10.800 502.2 11.200 524.2 11.700 524.2 12.900 502.2 10.300 524.2 10.800 524.2 11.200 502.2 11.900 524.2 13.100 502.2 10.400 502.2 10.900 502.2 11.300 502.2 11.900 524.2 13.800 Water Study: 38 True Value: 16.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 13.900 524.2 14.700 502.2 15.300 other 15.800 502.2 16.300 524.2 17.000 524.2 14.000 524.2 14.700 524.2 15.300 524.2 15.800 502.2 16.400 524.2 17.100 524.2 14.300 524.2 14.800 524.2 15.400 502.2 15.900 524.2 16.400 502.2 17.200 502.2 14.300 502.2 14.900 524.2 15.600 524.2 15.970 502.2 16.400 524.2 17.200 502.2 14.400 524.2 14.900 502.2 15.600 524.2 16.000 524.2 16.400 502.2 17.300 502.2 14.500 524.2 14.900 524.2 15.650 other 16.100 524.2 16.400 524.2 17.300 502.2 14.500 502.2 15.000 524.2 15.700 524.2 16.100 524.2 16.500 524.2 17.700 502.2 14.540 524.2 15.000 502.2 15.700 502.2 16.200 524.2 16.700 524.2 18.600 524.2 14.600 502.2 15.100 524.2 15.800 524.2 16.300 524.2 17.000 524.2 20.900

## B-185 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 39 True Value: 12.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.070 502.2 10.500 502.2 11.300 524.2 11.700 524.2 12.200 524.2 12.400 524.2 9.850 524.2 10.600 524.2 11.300 502.2 11.800 524.2 12.200 502.2 12.500 502.2 10.100 502.2 11.000 502.2 11.400 524.2 11.800 524.2 12.270 524.2 13.400 524.2 10.250 524.2 11.000 502.2 11.400 502.2 11.900 524.2 12.300 502.2 13.500 524.2 10.300 502.2 11.000 524.2 11.400 502.2 11.900 524.2 12.300 524.2 13.600 502.2 10.400 524.2 11.300 524.2 11.500 524.2 12.100 524.2 12.300 524.2 13.800 524.2 10.400 524.2 11.300 524.2 11.500 524.2 12.200 524.2 12.400 524.2 14.300 Water Study: 40 True Value: 17.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 11.200 502.2 15.500 524.2 16.400 502.2 16.600 502.2 17.300 502.2 18.300 524.2 13.900 502.2 15.600 502.2 16.400 524.2 16.600 502.2 17.400 502.2 18.400 524.2 14.000 other 15.700 524.2 16.400 524.2 16.600 502.2 17.400 524.2 18.800 524.2 14.300 524.2 15.700 524.2 16.400 524.2 17.000 524.2 17.400 502.2 19.000 524.2 14.300 524.2 15.800 502.2 16.400 524. 2 17.000 other 17.400 524.2 19.500 524.2 14.500 524.2 16.000 524.2 16.400 524.2 17.000 524.2 17.500 524.2 20.100 524.2 15.000 524.2 16.000 524.2 16.400 524.2 17.100 502.2 17.600 524.2 20.200 524.2 15.100 502.2 16.200 524.2 16.400 524.2 17.100 524.2 17.800 502.2 15.100 524.2 16.300 524.2 16.500 502.2 17.200 524.2 17.900 524.2 15.210 524.2 16.400 524.2 16.600 524.2 17.200 524.2 18.000 Water Study: 41 True Value: 13.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.500 524.2 12.300 524.2 12.900 524.2 13.400 524.2 13.800 502.2 14.600 524.2 11.200 524.2 12.400 502.2 13.000 524.2 13.500 502.2 13.800 502.2 14.900 502.2 12.000 524.2 12.400 524.2 13.100 524.2 13.500 502.2 13.900 524.2 15.000 502.2 12.200 524.2 12.500 524.2 13.100 524.2 13.500 524.2 14.000 524.2 15.000 524.2 12.200 524.2 12.700 524.2 13.200 524.2 13.500 502.2 14.100 524.2 15.000 524.2 12.200 524.2 12.800 524.2 13.300 502.2 13.700 524.2 14.100 502.2 16.500 502.2 12.300 502.2 12.900 other 13.400 524.2 13.790 524.2 14.300

## B-186 Methods Support Document for Six-Year Review Final - March 2003 Trichloroethylene Water Study: 24 True Value: 7.36 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 4.640 502.2 6.740 502.2 7.130 524.2 7.340 502.1 7.600 524.2 8.180 502.2 5.650 524.2 6.840 524.2 7.130 502.2 7.340 524.2 7.600 502.2 8.210 524.1 5.680 502.2 6.900 524.2 7.170 524.2 7.360 524.2 7.610 502.2 8.550 502.1 5.830 502.1 6.930 524.1 7.260 502.2 7.398 524.2 7.750 502.2 9.100 502.1 6.100 524.2 6.938 524.2 7.270 other 7.400 502.2 7.800 524.2 9.190 502.2 6.330 502.2 6.960 524.2 7.280 502.2 7.430 502.1 7.850 502.2 9.550 502.1 6.360 524.2 6.980 524.2 7.300 502. 2 7.460 other 7.900 524.2 9.850 524.1 6.500 502.2 7.000 other 7 .300 524.1 7.560 502.2 7.970 524.2 6.590 524.2 7.042 502.2 7 .300 502.2 7.580 502.2 8.000 524.1 6.637 502.2 7.100 524.2 7 .300 502.2 7.580 524.2 8.100 Water Study: 25 True Value: 10.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.1 6.700 502.2 9.700 502.2 10.200 502.2 10.500 524.2 11.200 502.2 13.000 502.2 7.890 524.2 9.730 524.2 10.200 502. 2 10.500 502.2 11.200 other 13.100 524.2 9.069 502.2 9.800 524.2 10.400 502.1 10.600 502.2 11.300 524.1 9.240 524.2 9.850 524.2 10.400 502.2 10.850 524.1 11.900 524.2 9.320 other 10.100 502.2 10.400 524.1 11.000 524.2 12.400 524.2 9.480 524.2 10.110 502.2 10.400 524.2 11.000 524.1 12.500 502.2 9.650 other 10.150 502.2 10.410 502.1 11.100 502.2 12.700 Water Study: 26 True Value: 6.63 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.1 5.000 524.1 5.990 524.2 6.500 502.2 6.730 502.2 7.100 502.1 7.390 502.2 5.230 524.2 6.022 502.2 6.500 524.2 6.740 502.1 7.110 524.2 7.400 524.2 5.610 524.1 6.080 524.2 6.520 524.2 6.780 524.2 7.140 524.2 7.400 524.2 5.680 524.2 6.160 502.1 6.540 524.1 6.910 502.2 7.180 524.2 7.490 502.2 5.760 other 6.200 524.2 6.550 502.2 6.930 502.2 7.190 524.1 7.550 524.2 5.860 524.2 6.300 524.2 6.650 502.2 7.000 502.1 7.210 502.2 7.590 524.2 5.880 524.2 6.310 502.2 6.660 502.2 7.000 524.1 7.230 524.2 7.700 502.2 5.900 502.2 6.310 524.2 6.700 other 7.030 502.2 7.270 524.2 7.800 502.2 5.910 524.2 6.480 524.2 6.700 502.2 7.030 502.2 7.310 502.2 8.409 502.2 5.950 502.1 6.500 502.2 6 .700 524.2 7.090 502.2 7.360

## B-187 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 14.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 10.000 502.2 13.000 524.2 13.690 502.2 14.100 502.2 14.600 502.2 16.300 524.2 11.100 502.2 13.000 524.2 13.800 502.2 14.100 502.2 14.700 524.1 21.600 502.2 11.600 524.2 13.100 502.2 13.900 524.2 14.200 524.2 15.200 524.2 12.000 524.2 13.240 502.2 13. 900 524.1 14.200 other 15.360 502.2 12.100 502.2 13.300 524.2 13.900 502.2 14.300 502.2 15.900 other 12.300 524.2 13.300 502.2 14.000 502.1 14.400 502.2 15.900 524.2 12.500 524.2 13.620 other 14.000 502.2 14.600 524.2 16.070 Water Study: 29 True Value: 15.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 11.100 524.2 14.600 524.2 15.900 other 16.800 524.2 17.900 524.2 20.000 502.2 12.790 502.2 14.700 502.2 16.000 502.2 17.100 502.2 18.100 524.2 20.000 502.2 13.100 524.2 14.800 524.1 16.200 other 17.100 other 18.390 502.2 20.500 502.2 13.800 524.2 14.970 524.2 16.200 502.2 17.400 502.2 18.540 502.2 22.600 502.2 14.220 524.2 15.660 524.2 16.500 524.2 17.600 502.2 18.690 524.2 14.500 502.2 15.900 524.2 16.800 524.1 17.800 502.2 18.700 Water Study: 30 True Value: 9.45 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.430 524.2 8.190 524.2 9.000 502.2 9.425 524.2 9.700 502.2 10.300 502.1 7.290 502.2 8.220 524.2 9.140 524. 2 9.450 other 9.797 502.2 10.300 524.2 7.440 524.1 8.530 524.2 9.170 other 9.490 502.2 9.800 502.2 10.400 524.2 7.470 524.2 8.600 502.2 9.170 524.2 9.510 524.2 9.860 524.2 10.400 502.2 7.600 502.2 8.660 502.2 9.180 502.2 9.550 502.2 9.910 524.2 10.400 524.2 7.880 502.2 8.680 502.2 9.200 524.2 9.580 524.2 10.060 502.2 10.400 524.2 7.900 502.1 8.710 524.2 9.230 other 9.590 502.2 10.100 502.2 10.400 502.2 7.920 524.2 8.810 524.2 9.250 524.2 9.600 524.1 10.100 502.2 10.430 524.2 8.000 524.2 8.900 502.2 9.310 502.2 9.620 524.2 10.200 502.2 10.700 502.1 8.160 502.2 8.950 524.1 9 .370 502.2 9.700 524.2 10.200

## B-188 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 7.46 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.280 524.2 6.800 502.1 7.300 524.2 7.470 524.2 7.600 524.2 7.800 524.2 6.400 502.2 6.830 502.2 7.330 524.2 7.470 524.2 7.600 524.2 7.954 502.2 6.477 other 7.010 502.2 7.350 524.2 7.480 502.2 7.640 524.2 7.990 524.2 6.500 502.2 7.060 524.1 7.370 524.2 7.480 502.2 7.670 502.2 8.430 524.2 6.720 502.2 7.070 502.2 7.400 502.2 7.540 502.1 7.700 502.1 8.480 502.1 6.730 502.2 7.200 524.2 7.460 502.2 7.550 524.2 7.720 502.2 8.550 Water Study: 32 True Value: 11.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.300 502.2 10.300 524.2 10.800 502.2 11.300 502.2 11.700 502.2 12.300 502.2 8.800 502.2 10.400 524.2 11.000 502.2 11.300 502.2 11.700 502.2 12.300 502.2 9.230 524.2 10.500 524.2 11.070 502.2 11.300 524.2 11.800 524.2 12.400 524.2 9.350 524.2 10.600 502.1 11.100 524.2 11.300 502.1 11.800 524.2 12.500 502.1 9.400 524.2 10.600 502.2 11.100 other 11.300 524.2 11.800 502.2 12.600 524.2 9.460 502.2 10.600 524.2 11.100 524.2 11.400 524.1 11.900 502.2 12.800 524.2 9.500 524.2 10.600 502.2 11.100 524.2 11.400 524.2 12.000 524.2 13.100 524.2 9.850 524.2 10.640 524.2 11.100 524.2 11.400 502.2 12.000 502.2 13.700 524.2 9.930 524.2 10.700 502.2 11.200 524.2 11.470 502.2 12.000 524.2 10.100 502.1 10.700 other 11.200 524.2 11.600 524.2 12.000 502.2 10.100 502.2 10.800 502.2 11. 200 524.2 11.630 other 12.200 Water Study: 33 True Value: 14.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.770 502.2 13.600 502.2 14.500 524.2 15.000 524.2 15.500 524.2 16.600 502.2 11.200 502.2 13.750 524.2 14.500 502.2 15.100 502.2 15.600 502.2 17.000 502.2 12.300 524.2 14.000 502.2 14.600 502.2 15.100 524.2 16.000 502.2 17.000 other 12.570 524.1 14.100 524.2 14.900 502.2 15.360 502.2 16.000 502.1 17.200 502.1 13.200 524.2 14.130 502.2 14.900 502.2 15.400 524.2 16.000 524.2 13.380 502.2 14.300 other 14.900 524.2 15.400 524.2 16.400

## B-189 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 8.89 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 6.600 502.2 8.210 502.2 8.510 502.2 8.730 524.2 9.070 524.2 9.490 524.2 6.930 524.2 8.330 502.2 8.540 524.2 8.750 524.2 9.100 524.2 9.670 524.2 7.060 502.2 8.330 502.2 8.550 502.2 8.860 524.2 9.120 502.2 9.700 other 7.200 524.2 8.330 502.2 8.550 524.2 8.900 502.2 9.120 502.2 9.750 502.2 7.200 502.1 8.400 524.2 8.590 524.2 8.900 502.2 9.150 502.2 9.780 524.2 7.700 524.2 8.440 524.2 8.620 502.2 8.930 502.2 9.160 502.2 9.970 524.2 7.700 502.2 8.450 502.2 8.640 502.2 8.990 524.2 9.260 524.2 10.130 502.2 7.710 524.2 8.470 524.2 8.660 524.2 9.000 502.2 9.300 502.2 10.300 524.2 7.850 502.2 8.490 524.2 8.700 524.2 9.000 524.2 9.320 524.2 10.400 524.2 8.010 524.2 8.500 524.2 8.700 502.2 9.020 524.2 9.320 502.2 10.690 Water Study: 35 True Value: 6.13 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.950 502.2 5.710 502.2 5.900 524.2 6.180 524.2 6.370 524.2 6.710 502.2 5.330 502.2 5.740 502.2 6.010 524.2 6.200 524.2 6.510 502.2 6.910 502.2 5.460 524.2 5.800 524.2 6.050 524.2 6.210 524.2 6.530 502.2 7.260 502.2 5.465 502.2 5.830 502.2 6.070 524. 2 6.240 other 6.600 502.2 8.730 524.2 5.700 524.2 5.860 524.2 6 .090 524.2 6.270 502.2 6.640 502.2 5.700 other 5.896 524.2 6 .150 524.2 6.300 524.2 6.700 Water Study: 36 True Value: 17.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 9.260 524.2 15.500 524.2 16.040 524. 2 16.700 502.2 17.400 other 17.900 524.2 13.900 524.2 15.700 524.2 16.100 502. 2 16.800 other 17.400 502.2 18.100 502.2 14.500 524.2 15.700 524.2 16.200 502.2 16.800 524.2 17.400 502.2 18.200 524.2 14.700 502.2 15.700 502.2 16.200 524.2 16.800 502.2 17.600 524.2 19.010 524.2 14.700 524.2 15.800 502.2 16.300 524. 2 16.900 524.2 17.600 other 19.100 524.2 14.900 524.2 15.800 524.2 16.480 502.2 16.900 524.2 17.600 502.2 19.100 524.2 14.900 524.2 15.900 502.2 16.500 502.2 17.200 524.2 17.700 524.2 15.200 502.2 15.900 524.2 16.500 524.2 17.200 524.2 17.700 524.2 15.200 502.2 15.900 502.2 16.600 502.2 17.200 524.2 17.700 524.2 15.240 502.2 15.970 524.2 16. 660 524.2 17.220 other 17.800 502.2 15.500 524.2 16.000 502.2 16.700 502.2 17.300 524.2 17.800

## B-190 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 8.70 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 7.220 502.2 8.070 524.2 8.440 524.2 8.630 524.2 9.000 502.2 9.540 524.2 7.290 524.2 8.240 524.2 8.440 524.2 8.650 502.2 9.110 524.2 9.800 524.2 7.290 502.2 8.250 524.2 8.480 524.2 8.700 502.2 9.150 524.2 10.300 502.2 7.620 other 8.280 524.2 8.480 502.2 8.740 502.2 9.370 other 10.400 524.2 7.780 524.2 8.290 524.2 8.480 524.2 8.780 524.2 9.370 524.2 10.700 524.2 7.840 502.2 8.300 other 8.500 502.2 8.900 502.2 9.400 502.2 11.100 524.2 7.850 524.2 8.330 524.2 8.510 502.2 8.910 524.2 9.460 524.2 11.700 502.2 7.870 524.2 8.430 502.2 8.580 502.2 8.960 502.2 9.530 524.2 16.600 Water Study: 38 True Value: 12.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 9.130 502.2 11.000 524.2 11.600 524.2 12.000 502.2 12.400 524.2 13.000 524.2 9.790 524.2 11.000 502.2 11.600 524.2 12.100 502.2 12.500 524.2 13.000 524.2 10.400 502.2 11.050 other 11.700 524.2 12.160 502.2 12.500 502.2 13.200 502.2 10.500 502.2 11.200 502.2 11.800 524.2 12.200 524.2 12.600 524.2 13.600 502.2 10.500 524.2 11.300 524.2 11.900 502.2 12.200 502.2 12.600 524.2 15.600 other 10.700 524.2 11.400 524.2 11.900 524.2 12.250 524.2 12.600 524.2 10.700 524.2 11.400 524.2 11.900 524.2 12.300 502.2 12.800 524.2 10.700 524.2 11.500 524.2 11.900 502.2 12.300 502.2 12.900 524.2 10.800 524.2 11.500 524.2 11.900 524.2 12.300 524.2 12.900 502.2 10.800 524.2 11.600 other 12.000 502.2 12.400 524.2 12.900 Water Study: 39 True Value: 16.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 13.400 524.2 14.700 524.2 15.500 502.2 16.000 524.2 16.900 524.2 18.600 502.2 13.900 524.2 14.900 524.2 15.530 524.2 16.100 524.2 17.200 524.2 18.800 524.2 13.900 524.2 14.900 other 15.600 524.2 16.200 502.2 17.200 524.2 29.600 524.2 14.000 50.2 15.100 524.2 15.600 524.2 16.200 502.2 17.300 524.2 42.560 524.2 14.000 502.2 15.200 524.2 15.800 502.2 16.300 502.2 17.300 524.2 14.400 502.2 15.200 524.2 15.800 502.2 16.300 524.2 17.400 524.2 14.500 524.2 15.400 524.2 15.800 502.2 16.400 502.2 18.100 524.2 14.600 524.2 15.400 524.2 15.900 524.2 16.400 524.2 18.200

## B-191 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 5.80 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.200 524.2 5.200 524.2 5.520 524.2 5.700 524.2 5.880 502.2 6.150 524.2 4.410 524.2 5.220 524.2 5.530 524.2 5.720 502.2 5.920 502.2 6.400 502.2 4.660 524.2 5.290 524.2 5.600 502.2 5.720 524.2 5.940 502.2 6.510 524.2 4.850 524.2 5.300 other 5.620 524.2 5.720 502.2 6.000 524.2 6.830 524.2 4.860 524.2 5.300 524.2 5.660 524.2 5.730 502.2 6.000 502.2 7.160 524.2 4.980 524.2 5.300 524.2 5.660 502.2 5.750 502.2 6.010 524.2 7.310 524.2 5.060 524.2 5.320 524.2 5.670 524.2 5.750 502.2 6.040 502.2 7.700 524.2 5.140 524.2 5.360 other 5.670 524.2 5.810 524.2 6.060 524.2 16.500 524.2 5.150 524.2 5.410 524.2 5 .670 524 5.840 524.2 6.100 other 5.180 524.2 5.450 502.2 5 .680 524.2 5.860 502.2 6.110 Water Study: 41 True Value: 6.87 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 5.390 502.2 6.330 524.2 6.500 524.2 6.710 524.2 7.060 502.2 7.270 524.2 5.660 524.2 6.340 502.2 6.500 502.2 6.760 524.2 7.080 502.2 7.300 524.2 5.720 524.2 6.350 524.2 6.550 524.2 6.810 502.2 7.180 502.2 7.410 524.2 5.910 524.2 6.400 524.2 6.600 524.2 6.890 524.2 7.200 502.2 7.430 524.2 6.000 524.2 6.440 524.2 6.600 other 6.910 502.2 7.210 524.2 7.600 524.2 6.060 524.2 6.460 524.2 6.660 502.2 7.040 524.2 7.210 502.2 7.800 502.2 6.250 524.2 6.500 524.2 6 .700 524.2 7.060 524.2 7.220

Vinyl Chloride Water Study: 24 True Value: 4.35 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 1.540 502.2 3.480 502.2 3.850 502.1 4.300 502.2 4.940 524.2 6.390 524.2 1.720 502.2 3.545 502.1 3.890 502.1 4.300 524.2 5.040 524.2 6.800 other 2.000 502.2 3.670 524.2 3.900 502.1 4.400 502.2 5.100 502.2 6.900 other 2.500 524.2 3.700 524.2 3.930 524.2 4.433 other 5.140 502.2 7.800 502.2 3.070 524.2 3.700 502.2 3.950 524. 2 4.480 502.2 5.240 other 8.400 502.2 3.210 502.1 3.700 524.2 4.010 524.1 4.480 524.2 5.360 524.2 9.052 524.1 3.320 524.1 3.800 502.2 4.090 502.2 4.500 524.1 5.470 524.1 10.300 502.2 3.370 502.2 3.800 502.2 4 .200 502.2 4.500 502.2 5.480 524.2 3.400 502.2 3.820 524.2 4 .200 524.1 4.560 524.2 5.610 524.2 3.460 502.1 3.850 524.1 4 .200 502.2 4.710 524.2 5.880

## B-192 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 25 True Value: 12.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.580 other 10.300 524.2 11.240 524.2 12.940 524.2 14.600 524.1 21.300 502.2 6.480 524.2 10.400 502.1 11.400 524.2 13.000 502.2 15.000 524.1 21.800 502.2 8.400 other 10.750 502.2 11.500 524.2 13.100 524.1 15.900 other 41.700 other 8.540 502.2 10.800 524.2 11.900 502.2 13.300 502.2 16.000 524.1 9.200 502.2 11.000 524.2 12.500 524.2 13.390 502.1 16.100 502.2 9.950 524.2 11.200 524.2 12.620 524.1 13.600 502.2 16.100 502.2 10.000 502.2 11.200 524.2 12.900 502.2 14.000 502.2 16.640 Water Study: 26 True Value: 8.70 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.600 524.2 7.850 502.1 8.540 524.2 9.150 502.1 10.100 524.2 11.700 502.2 5.640 524.2 7.930 524.1 8.600 502.2 9.200 524.2 10.100 524.2 12.200 502.2 6.350 524.2 8.070 502.2 8.700 502.2 9.200 524.2 10.160 524.2 12.420 502.2 6.480 502.2 8.100 502.2 8.810 524.1 9.440 524.2 10.200 524.2 12.520 524.2 6.520 502.2 8.180 502.2 8.860 524.2 9.640 524.2 10.500 502.2 12.600 524.2 6.540 524.2 8.200 524.1 9.000 502.1 9.680 524.2 10.600 524.2 13.500 502.1 6.570 524.2 8.230 502.2 9.000 502.2 9.690 502.2 10.700 502.2 15.700 524.2 7.240 502.1 8.370 502.2 9.020 502.2 9.740 502.2 10.900 524.2 22.000 502.2 7.580 524.1 8.420 524.2 9.040 524.1 10.000 524.2 11.300 502.2 30.030 502.1 7.750 other 8.500 other 9.120 524.2 10.000 502.2 11.500 Water Study: 27 True Value: 3.57 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 1.740 524.2 3.290 other 3. 700 524.2 4.200 524.2 4.660 524.2 6.200 524.2 1.850 524.2 3.300 524.2 3.700 502.2 4.310 524.2 4.700 502.2 6.210 other 2.280 502.2 3.390 502.2 3.730 524.1 4.430 502.2 4.840 524.1 10.100 502.2 2.970 502.2 3.420 524.2 3.750 502.2 4.510 502.2 4.890 502.2 11.000 502.2 3.020 524.2 3.450 524.2 3 .960 524.2 4.580 524.2 4.950 502.2 3.160 502.1 3.450 502.2 4 .080 502.2 4.620 502.2 5.400 502.2 3.250 502.2 3.700 502.2 4. 130 524.2 4.640 other 5.730

## B-193 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 29 True Value: 14.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 3.920 502.2 12.400 524.2 14.400 524.1 15.500 502.2 17.700 502.2 22.100 524.2 7.400 502.2 13.060 502.2 14.600 524.2 15.900 524.2 18.400 502.2 22.800 502.2 8.130 524.2 13.200 524.2 14.600 502. 2 16.400 502.2 20.300 other 26.700 502.2 11.800 524.2 13.600 524.2 14.700 524.2 16.800 524.2 20.400 502.2 12.070 524.2 13.700 524.2 14.710 524.2 16.900 502.2 20.400 502.2 12.100 502.2 13.790 524.2 15.030 524.2 17.200 524.1 20.900 502.2 12.400 502.2 14.200 502.2 15. 200 502.2 17.400 other 21.160 Water Study: 30 True Value: 5.48 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 3.200 502.2 4.880 502.2 5.480 524.2 5.950 524.2 6.440 524.2 7.800 502.2 4.000 524.2 4.980 502.2 5.490 502.2 5.950 524.2 6.480 524.2 7.850 524.2 4.250 502.2 5.040 524.2 5.500 524. 2 6.000 other 6.498 524.2 7.990 502.1 4.300 502.2 5.050 502.2 5.530 524.2 6.010 524.2 6.630 524.1 9.350 other 4.390 502.2 5.077 502.2 5.600 502.2 6.090 502.2 6.700 502.2 12.900 502.1 4.460 502.2 5.100 524.1 5.730 502.2 6.160 502.2 6.710 524.1 13.400 524.2 4.500 502.2 5.190 502.1 5.780 524.2 6.230 524.2 6.790 502.2 16.890 524.2 4.640 524.2 5.200 524.2 5.800 524.2 6.300 502.2 7.160 524.2 20.300 502.2 4.700 524.2 5.400 502.2 5. 850 other 6.350 502.2 7.280 524.2 4.710 524.2 5.410 524.2 5 .950 502.2 6.400 524.2 7.700 Water Study: 31 True Value: 11.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 0.500 502.2 10.300 524.2 11.800 524.2 12.310 524.2 14.000 524.2 16.900 502.2 3.100 524.2 10.490 502.2 12.100 502.2 12.400 524.2 14.000 502.2 20.100 502.2 6.528 502.2 10.500 524.2 12.100 524.2 12.600 524.2 14.200 502.2 26.100 other 6.600 502.2 10.700 502.2 12.200 502.2 12.700 502.1 14.500 502.2 27.000 502.1 9.410 524.2 10.790 502.2 12.200 524.2 12.900 502.1 14.600 502.1 9.720 502.2 11.400 524.2 12.300 524.1 13.100 502.1 15.700 502.2 10.200 524.2 11.700 524.2 12.300 502.2 13.400 524.2 16.300

## B-194 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 32 True Value: 2.57 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 1.770 524.2 2.440 524.2 2.680 502.2 2.780 524.2 3.130 524.2 3.660 502.2 1.900 502.2 2.440 524.2 2.690 524.2 2.810 524.2 3.200 524.2 3.730 502.2 1.900 524.2 2.460 502.2 2.690 524.2 2.820 524.2 3.200 502.2 3.930 502.2 1.910 502.2 2.500 502.1 2.700 524.2 2.860 502.2 3.220 524.2 4.350 502.2 1.910 502.2 2.520 other 2.700 524.2 2.863 other 3.230 524.1 4.500 502.2 1.950 502.2 2.570 524.2 2.710 524.2 2.890 502.2 3.250 502.1 5.400 502.1 2.080 524.2 2.600 502.2 2.730 524.2 2.940 524.2 3.400 502.2 6.020 502.2 2.100 other 2.630 524.2 2.730 524.2 2.940 524.2 3.400 502.1 6.940 524.2 2.200 524.2 2.640 502.2 2 .750 524.2 3.000 524.2 3.460 524.2 2.200 524.2 2.650 524.2 2 .760 502.2 3.020 502.2 3.600 524.2 2.430 502.2 2.670 502.2 2 .780 502.2 3.080 524.2 3.650 Water Study: 33 True Value: 7.35 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.590 502.2 7.400 502.2 8.410 524.2 8.940 502.2 9.780 524.2 11.900 502.2 4.960 502.2 7.520 502.2 8.460 502. 2 8.940 524.2 10.200 other 12.210 502.2 6.100 524.2 7.680 524.2 8.500 524.2 9.050 502.2 10.200 502.2 13.300 502.1 6.140 524.2 7.780 524.2 8.500 502.2 9.240 524.1 10.300 502.1 29.800 502.2 7.100 524.2 7.900 502.2 8 .580 524.2 9.380 524.2 10.600 524.2 7.260 524.2 8.320 524.2 8 .790 524.2 9.700 502.2 11.200 Water Study: 34 True Value: 14.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.000 502.2 14.010 502.2 14.800 524.2 15.500 524.2 16.900 502.2 18.500 524.2 10.800 524.2 14.100 524.2 15.000 524.2 15.500 502.2 16.900 524.2 18.500 502.2 11.000 524.2 14.200 524.2 15.000 502.2 15.500 524.2 17.500 524.2 19.000 502.2 11.100 502.1 14.200 524.2 15.000 524.2 16.000 502.2 17.500 502.2 19.100 502.2 11.100 524.2 14.400 502.2 15.000 502.2 16.170 524.2 17.600 502.2 19.300 502.2 11.700 524.2 14.400 502.2 15.100 524.2 16.300 502.2 17.600 524.2 20.020 other 12.400 524.2 14.600 524.2 15.300 524.2 16.500 502.2 17.600 524.2 20.500 524.2 12.670 524.2 14.620 502.2 15.300 502.2 16.600 502.2 17.700 524.2 20.670 524.2 13.000 502.2 14.700 other 15.400 524.2 16.700 502.2 18.100 524.2 22.200 502.2 13.400 524.2 14.700 502.2 15.500 524.2 16.700 524.2 18.400

## B-195 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 35 True Value: 4.91 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 3.470 524.2 4.450 524.2 5.000 524.2 5.600 502.2 6.010 524.2 6.300 502.2 3.780 other 4.490 502.2 5.000 524.2 5.690 502.2 6.060 524.2 6.340 502.2 4.254 502.2 4.510 524.2 5.350 524.2 5.710 524.2 6.110 502.2 6.350 524.2 4.260 524.2 4.700 524.2 5.400 524.2 5.720 502.2 6.160 524.2 3.390 502.2 4.310 524.2 4.700 502.2 5.410 524.2 5.750 524.2 6.230 524.2 6.800 502.2 4.360 other 4.800 502.2 5.480 524.2 5.910 502.2 6.260 502.2 6.870 Water Study: 36 True Value: 9.47 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 6.430 524.2 8.560 524.2 9.700 524. 2 10.370 524.2 11.000 other 11.900 502.2 6.960 502.2 8.600 524.2 9.700 524.2 10.580 502.2 11.100 524.2 11.960 502.2 7.560 502.2 8.720 524.2 9.720 502.2 10.600 524.2 11.100 524.2 13.200 524.2 7.600 502.2 8.790 502.2 9.770 524.2 10.600 524.2 11.300 502.2 13.900 524.2 7.900 524.2 8.880 502.2 9.850 524.2 10.700 524.2 11.300 524.2 14.000 524.2 8.140 524.2 8.900 524.2 9.890 502.2 10.700 502.2 11.500 502.2 14.000 502.2 8.140 524.2 8.990 other 10.000 502.2 10.700 502.2 11.600 524.2 14.000 502.2 8.340 502.2 9.030 524.2 10.000 other 10.900 524.2 11.600 524.2 14.300 524.2 8.400 524.2 9.130 other 10.100 524.2 10.900 502.2 11.800 524.2 14.500 502.2 8.560 502.2 9.660 524.2 10.320 524.2 11.000 524.2 11.800 524.2 17.140 Water Study: 37 True Value: 14.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 10.100 502.2 13.600 other 15. 100 524.2 16.300 524 17.910 502.2 22.100 524.2 11.000 502.2 13.700 524.2 15.200 524.2 16.470 524.2 18.000 502.2 26.600 502.2 11.300 524.2 14.080 524.2 15.400 502.2 16.500 524.2 18.600 524.2 26.900 502.2 11.300 524.2 14.200 502.2 15.400 524.2 16.500 502.2 18.700 502.2 29.700 524.2 11.900 524.2 14.400 524.2 15.500 524.2 17.000 524.2 18.900 524.2 47.700 524.2 12.000 524.2 14.500 502.2 15.600 524.2 17.000 524.2 19.400 502.2 12.400 524.2 14.530 524.2 15.700 502.2 17.700 524.2 20.200 502.2 12.400 524.2 14.700 other 16.000 524.2 17.800 524.2 20.200 502.2 12.700 other 15.100 502.2 16.100 other 17.800 524.2 21.000

## B-196 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 38 True Value: 17.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 11.800 502.2 15.700 524.2 16.900 524.2 18.200 524.2 19.500 502.2 21.400 502.2 13.900 524.2 15.800 502.2 16.900 524.2 18.200 524.2 19.560 502.2 21.400 502.2 13.900 524.2 16.400 524.2 17.200 other 18.300 524.2 19.770 524.2 21.600 502.2 14.000 524.2 16.400 524.2 17.600 524.2 18.500 502.2 20.000 524.2 22.400 502.2 14.300 502.2 16.400 other 17.700 502.2 18.600 502.2 20.100 524.2 22.900 other 14.600 524.2 16.500 502.2 17.770 524.2 18.900 524.2 20.200 524.2 24.100 502.2 15.100 524.2 16.500 524.2 18.100 524.2 19.000 502.2 20.700 524.2 24.200 524.2 15.200 524.2 16.600 524.2 18.100 502.2 19.500 502.2 20.700 524.2 26.900 524.2 15.600 502.2 16.700 524.2 18.200 524.2 19.500 524.2 21.100 524.2 28.300 Water Study: 39 True Value: 6.19 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 4.720 524.2 5.690 524.2 6.410 524.2 6.780 524.2 7.200 524.2 8.040 502.2 4.740 502.2 5.790 524.2 6.600 524.2 6.800 502.2 7.240 502.2 9.820 502.2 4.800 524.2 5.890 524.2 6.610 502.2 6.810 524.2 7.300 524.2 9.830 524.2 5.020 524.2 6.070 502.2 6.680 502.2 6.820 502.2 7.330 524.2 16.500 524.2 5.140 524.2 6.090 524.2 6.730 524.2 6.900 524.2 7.460 524.2 16.540 524.2 5.320 524.2 6.200 524.2 6 .730 524.2 7.090 524.2 7.500 502.2 5.390 524.2 6.260 524.2 6 .750 502.2 7.100 524.2 7.530 other 5.620 502.2 6.400 524.2 6 .770 502.2 7.180 524.2 7.670 Water Study: 40 True Value: 27.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.280 524.2 24.040 524.2 26.100 524.2 27.100 502.2 29.000 524.2 31.300 524.2 19.200 524.2 24.200 524.2 26.100 502.2 27.300 524.2 29.200 524.2 32.800 524.2 19.400 524.2 24.400 other 26.100 524.2 27.400 502.2 29.200 502.2 33.200 524.2 21.300 524.2 24.800 524.2 26.300 502.2 27.500 524.2 29.200 524.2 34.900 502.2 22.200 502.2 25.000 524.2 26.400 524.2 27.500 524.2 30.200 524.2 35.000 502.2 22.300 other 25.300 524.2 26.900 502.2 28.000 502.2 30.400 524.2 36.300 502.2 23.000 524.2 25.400 524.2 26.900 524.2 28.300 502.2 30.400 524.2 46.200 524.2 23.200 524.2 25.900 502.2 27.000 524.2 28.400 524.2 30.700 502.2 47.100 524.2 23.200 524.2 25.900 524.2 27.000 524.2 28.500 524.2 31.000 524.2 24.000 502.2 26.100 524.2 27. 000 other 28.900 524.2 31.100

## B-197 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 41 True Value: 22.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 15.700 524.2 21.120 524.2 23.000 524.2 23.900 524.2 25.990 524.2 29.000 524.2 16.000 other 21.300 524.2 23.300 502.2 24.000 502.2 26.200 502.2 29.500 502.2 17.400 524.2 21.300 524.2 23.300 502.2 24.200 524.2 26.500 524.2 29.800 524.2 18.200 502.2 21.800 524.2 23.400 524.2 24.900 524.2 26.800 524.2 33.600 524.2 19.100 502.2 22.900 524.2 23.600 524.2 25.000 524.2 27.000 502.2 35.700 502.2 19.600 524.2 22.900 502.2 23.800 524.2 25.100 524.2 27.400 524.2 45.100 524.2 20.100 502.2 23.000 524.2 23.800 524.2 25.900 524.2 28.000

Total Xylenes Water Study: 24 True Value: 14.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.600 524.2 12.400 524.1 13.060 524.2 13.600 503.1 14.700 524.2 16.000 524.2 6.330 524.1 12.500 524.2 13.230 524.2 13.600 524.1 14.750 524.2 16.700 524.2 8.350 502.2 12.500 502.2 13.300 524.2 13.800 502.2 14.900 524.2 17.700 other 9.900 524.1 12.700 524.2 13.400 502.2 14.000 524.2 15.000 503.1 20.200 503.1 10.200 502.2 12.800 502.2 13.400 502. 2 14.400 502.2 15.000 other 24.400 524.2 10.500 524.2 12.900 502.2 13.400 524.2 14.400 502.2 15.100 524.2 11.400 502.2 12.910 524.2 13.400 524.2 14.500 503.1 15.500 502.2 12.200 524.2 13.010 502.2 13. 500 other 14.530 502.2 15.800 Water Study: 25 True Value: 12.5 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 9.520 502.2 11.300 502.2 11.750 524.1 12.400 524.2 13.400 502.2 14.300 other 9.700 502.2 11.300 502.2 11.900 524.1 12.600 524.2 13.570 other 17.000 524.2 10.800 502.2 11.500 502.2 12.000 502. 2 12.800 524.1 13.600 other 18.200 524.2 11.150 502.2 11.500 524.2 12.100 502.2 13.000 524.2 13.990 502.2 11.200 other 11.510 524.2 12.200 other 13.100 502.2 14.000 503.1 11.200 502.2 11.520 524.2 12.330 503.1 13.200 502.2 14.100

## B-198 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 27 True Value: 8.45 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 6.700 502.2 7.780 502.2 8.000 524.2 8.600 502.2 8.960 524.2 10.610 524.2 6.800 502.2 7.790 502.2 8.040 524.1 8.610 524.2 8.990 502.2 24.840 other 7.410 502.2 7.890 524.2 8 .170 524.2 8.630 524.1 9.240 503.1 7.510 502.2 7.940 524.1 8 .210 524.2 8.880 502.2 9.490 524.2 7.530 502.2 7.980 502.2 8 .270 524.2 8.900 502.2 9.600 502.2 7.600 502.2 8.000 other 8 .530 502.2 8.940 524.2 9.800 Water Study: 29 True Value: 12.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 2.890 502.2 10.900 502.2 11.520 502.2 12.000 524.2 12.600 502.2 14.100 524.2 9.220 524.2 10.990 502.2 11.600 524.2 12.000 502.2 12.800 502.2 14.400 502.2 9.691 524.1 11.000 524.2 11.900 524.2 12.100 524.2 12.800 524.2 16.400 502.2 10.100 524.1 11.100 502.2 11.900 503.1 12.100 502.2 13.190 524.2 18.280 524.2 10.800 other 11.300 502.2 12.000 502.2 12.400 524.2 13.900 other 10.800 524.2 11.500 524.2 12.000 502.2 12.400 other 14.040 Water Study: 30 True Value: 15.0 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.740 524.2 13.400 502.2 14.100 503.1 14.600 524.2 15.600 502.2 16.200 524.2 9.760 502.2 13.470 502.2 14.100 524. 2 14.600 other 15.600 524.2 16.800 524.2 11.200 502.2 13.600 502.2 14.200 502.2 14.800 502.2 15.600 502.2 17.000 524.2 11.800 503.1 13.600 502.2 14.200 502.2 14.900 524.2 15.600 524.2 18.100 524.2 12.600 524.2 13.600 502.2 14.200 524.2 15.000 524.2 15.600 524.2 18.200 other 12.600 524.2 13.800 524.2 14.300 502.2 15.100 524.2 15.700 524.2 20.600 524.2 12.800 524.2 13.840 524.2 14.390 other 15.150 524.1 15.700 502.2 27.400 502.2 13.200 502.2 13.900 524.2 14.600 502.2 15.300 502.2 15.700 524.2 35.300 502.2 13.300 502.2 13.900 524.2 14.600 524. 1 15.400 524.2 15.800 other 37.000 524.1 13.350 524.2 14.000 524.1 14.600 524.2 15.470 524.2 16.200

## B-199 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 31 True Value: 13.2 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value other 6.570 502.2 11.900 503.1 12.400 502.2 12.700 524.2 13.700 524.2 16.990 524.2 10.000 502.2 12.000 524.2 12.400 524.2 12.800 524.2 13.840 524.2 25.800 524.2 11.000 502.2 12.100 502.2 12.500 524.2 12.900 502.2 14.300 502.2 28.600 502.2 11.010 524.2 12.200 524.2 12.500 502.2 13.000 524.2 14.700 524.1 11.500 524.2 12.300 524.2 12.700 502.1 13.000 502.2 14.700 524.2 11.600 524.2 12.350 503.1 12.700 524.2 13.200 502.2 15.200 524.2 11.600 503.1 12.400 524.2 12.700 502.2 13.300 502.2 16.100 Water Study: 32 True Value: 7.54 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 3.400 524.2 6.660 524.2 7.090 502.2 7.440 524.2 7.700 524.2 9.250 502.2 5.950 other 6.800 524.2 7.100 502.2 7.450 502.2 7.850 502.2 9.260 502.2 6.260 502.2 6.840 502.2 7.130 503.1 7.500 524.2 7.850 502.2 9.300 503.1 6.370 502.2 6.880 other 7.160 524.2 7.500 524.2 7.880 524.2 9.950 502.2 6.500 524.2 6.890 524.1 7.200 524.2 7.510 524.2 7.976 524.2 17.200 502.2 6.540 502.2 6.930 502.1 7.200 524.2 7.580 502.2 8.070 524.2 18.600 502.2 6.560 524.2 6.970 524.2 7 .260 524.2 7.580 524.2 8.110 524.2 6.580 502.2 6.990 502.2 7 .290 524.2 7.600 524.2 8.180 524.2 6.600 502.2 7.000 502.2 7 .330 502.2 7.600 524.2 8.220 524.2 6.620 other 7.000 502.2 7 .330 524.2 7.600 524.2 8.620 502.2 6.620 524.2 7.000 524.2 7 .400 524.2 7.670 524.2 8.980 Water Study: 33 True Value: 11.6 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 3.900 524.2 10.300 502.2 10.700 502.2 11.300 524.2 12.400 502.2 13.300 502.2 9.310 524.2 10.380 502.2 10.800 502.2 11.600 502.2 12.500 502.2 13.800 524.2 9.600 502.2 10.590 502.2 10.900 502.1 11.700 502.2 12.600 502.1 14.200 524.1 9.670 524.2 10.600 502.2 11.080 524.2 11.700 524.2 12.630 502.2 26.900 502.2 10.100 other 10.600 524.2 11.200 524.2 11.800 524.2 12.700 524.2 10.110 other 10.670 502.2 11.300 524.2 11.900 524.2 12.800

## B-200 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 34 True Value: 13.1 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 4.730 524.2 11.800 502.2 12.500 524.2 12.800 524.2 13.200 502.2 13.700 524.2 6.580 502.2 11.800 524.2 12.600 524.2 12.900 524.2 13.200 502.2 13.800 524.2 8.620 524.2 11.900 502.2 12.600 502.2 12.900 502.2 13.200 524.2 13.800 524.2 10.600 502.2 11.900 524.2 12.600 502.2 12.900 524.2 13.200 524.2 13.900 524.1 10.900 other 12.000 524.2 12.600 502.2 12.900 524.2 13.300 524.2 13.960 502.2 11.300 524.2 12.100 502.2 12.700 524.2 13.050 502.2 13.300 502.2 14.100 502.2 11.400 524.2 12.100 other 12.700 524.2 13.100 503.1 13.400 502.2 14.500 524.1 11.500 502.2 12.200 524.2 12.740 524.2 13.200 524.2 13.700 502.2 16.300 502.2 11.500 524.2 12.400 524.2 12.800 524.2 13.200 502.2 13.700 524.2 17.080 524.2 11.700 502.2 12.500 502.2 12.800 502.2 13.200 524.2 13.700 502.2 27.200 Water Study: 35 True Value: 17.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 7.930 524.2 16.000 524.2 17.000 other 18.000 524.2 18.400 524.2 20.810 524.2 8.530 502.2 16.500 other 17.010 524.2 18.000 524.2 18.400 502.2 23.000 524.2 14.100 524.2 16.700 524.2 17.200 524.2 18.000 524.2 18.800 502.2 14.600 524.2 16.700 524.2 17.300 524.2 18.000 502.2 18.870 524.2 15.070 524.2 16.800 502.2 17.300 502.2 18.200 502.2 19.900 524.2 15.200 502.2 16.800 524.2 17.500 502.2 18.300 502.2 20.400 502.2 15.300 502.2 16.900 502.2 17.840 524.2 18.300 524.2 20.600 Water Study: 36 True Value: 10.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 8.280 524.2 9.800 524.2 10.200 524. 2 10.500 other 11.000 524.2 11.900 502.2 8.790 524.2 9.800 502.2 10.300 502.2 10.600 502.2 11.100 502.2 12.000 524.2 8.840 524.2 9.810 502.2 10.300 524. 2 10.600 other 11.100 524.2 12.100 502.2 8.970 524.2 9.860 502.2 10.300 502.2 10.600 524.2 11.100 524.2 12.420 other 9.300 524.2 9.870 524.2 10.300 502.2 10.600 502.2 11.200 502.2 13.300 502.2 9.440 524.2 9.890 524.2 10.400 524.2 10.760 502.2 11.300 524.2 14.500 524.2 9.580 502.2 9.910 524.2 10.400 502.2 10.800 502.2 11.300 502.2 9.610 524.2 9.940 other 10.500 524.2 10.800 524.2 11.300 524.2 9.700 502.2 9.990 524.2 10.500 524.2 10.840 524.2 11.300 524.2 9.700 502.2 10.100 524.2 10.500 524.2 10.900 524.2 11.400 524.2 9.730 524.2 10.100 524.2 10.500 502.2 11.000 524.2 11.530

## B-201 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 37 True Value: 12.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 502.2 5.300 502.2 12.100 524.2 12.800 502.2 13.200 502.2 13.700 524.2 16.300 524.2 9.720 502.2 12.100 502.2 12.800 502.2 13.300 524.2 13.800 524.2 16.600 524.2 11.100 502.2 12.200 502.2 12.900 524.2 13.400 524.2 13.800 524.2 17.300 524.2 11.200 524.2 12.200 502.2 12.900 524.2 13.460 524.2 13.880 524.2 17.400 other 11.400 502.2 12.400 502.2 13.000 524.2 13.500 524.2 14.000 524.2 11.400 524.2 12.600 other 13.000 524.2 13.600 502.2 14.400 524.2 11.600 502.2 12.600 524.2 13.000 502.2 13.600 502 14.500 524.2 11.900 524.2 12.600 502.2 13. 100 other 13.600 524.2 14.700 502.2 12.000 524.2 12.690 524.2 13.100 524.2 13.600 524 14.740 Water Study: 38 True Value: 22.9 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 18.100 524.2 20.600 524.2 22.600 502.2 23.200 502 24.300 524.2 25.200 524.2 18.300 524.2 20.900 524.2 22.630 524.2 23.200 524.2 24.300 524.2 25.200 524.2 18.500 524.2 21.000 502.2 22.900 524.2 23.300 524.2 24.400 502.2 26.600 524.2 19.400 502.2 21.200 524.2 22.900 524.2 23.300 502.2 24.500 524.2 26.800 524.2 19.500 524.2 21.500 524.2 22.960 524.2 23.300 502.2 24.600 524.2 28.100 502.2 19.520 other 21.700 524.2 23.000 502.2 23.500 502.2 24.800 524.2 29.700 524.2 19.700 other 21.800 524.2 23.000 502.2 23.500 502.2 24.800 502.2 20.100 other 22.300 502.2 23.000 502.2 23.700 524.2 24.800 524.2 20.400 524.2 22.300 502.2 23.000 524.2 23.800 502.2 24.900 524.2 20.600 524.2 22.400 524.2 23.100 524.2 24.000 502.2 24.900 Water Study: 39 True Value: 24.4 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 13.800 524.2 22.500 524.2 23.700 502.2 24.500 524.2 25.600 524.2 28.200 502.2 14.200 502.2 22.500 524.2 23.700 524.2 24.500 524.2 25.700 502.2 28.300 524.2 19.300 524.2 22.700 502.2 23.900 524.2 24.620 502.2 25.700 502.2 30.200 524.2 20.200 other 22.800 502.2 23.900 524.2 24.700 524.2 26.200 524.2 45.760 524.2 20.900 524.2 22.900 524.2 24.000 524.2 24.800 524.2 26.400 524.2 21.600 502.2 23.200 502.2 24.200 524.2 25.100 524.2 26.800 524.2 22.200 524.2 23.300 524.2 24.400 524.2 25.200 524.2 27.500 502.2 22.300 524.2 23.300 502.2 24.500 502.2 25.300 524.2 28.000

## B-202 Methods Support Document for Six-Year Review Final - March 2003 Water Study: 40 True Value: 30.3 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 16.100 other 27.800 524.2 29.100 524.2 30.000 502.2 31.100 502.2 32.800 524.2 23.400 524.2 28.000 524.2 29.200 524.2 30.100 524.2 31.200 524.2 33.400 524.2 24.000 524.2 28.200 502.2 29.400 other 30.100 502.2 31.400 502.2 33.600 502.2 24.800 524.2 28.500 524.2 29.500 502.2 30.100 524.2 31.700 524.2 33.600 524.2 24.800 other 28.500 502.2 29.500 502.2 30.200 524.2 31.800 524.2 33.700 524.2 25.800 502.2 28.600 524.2 29.700 524 30.200 524.2 32.100 502.2 34.500 502.2 26.800 524.2 28.700 502.2 29.800 524.2 30.300 502.2 32.300 524.2 37.000 524.2 26.800 524.2 28.800 524.2 29.800 524.2 30.300 502.2 32.400 524.2 38.100 524.2 27.000 524.2 28.950 524.2 29.800 524.2 30.600 524.2 32.600 524.2 27.400 524.2 29.000 524.2 29.900 524.2 30.900 524.2 32.700 Water Study: 41 True Value: 30.8 ug/L

Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value Method Reported Value 524.2 25.900 524.2 28.500 502.2 30.600 524.2 31.000 524.2 31.760 524.2 34.000 524.2 26.600 524.2 28.800 524.2 30.600 524. 2 31.130 other 31.800 502.2 34.900 524.2 26.700 502.2 28.900 524.2 30.700 502.2 31.200 502.2 31.800 524.2 44.300 524.2 27.600 502.2 30.000 other 30.700 502.2 31.200 524.2 32.200 524.2 27.700 524.2 30.100 524.2 30.800 524.2 31.300 524.2 32.500 502.2 27.800 524.2 30.100 524.2 30.800 524.2 31.600 502.2 33.000 502.2 28.300 524.2 30.100 524.2 30.900 524.2 31.700 524.2 33.600 524.2 28.400 502.2 30.300 524.2 31.000 502.2 31.700 524.2 34.000

## EPA

_815-R-03-003 Analytical

_Feasibility

_Support

_Document for

_the

_Six-Year

_Review

_of

_Existing

_ National

_Primary

_Drinking

_Water

_Regulations (Reassessment

_of

_Feasibility

_for

_Chemical

_Contaminants)