BLACK & VEATCH

b' 40310920

Superfund

6601 College Boulevard

Overland Park, Kansas 66211 USA

Tel: (913) 458-2900

USEPA Region VII Omaha Lead Site Remedial Design

United States Environmental Protection Agency 901 North 5"̂ Street Kansas City, Kansas 66101 Attn: Robert Feild

Black & Veatch Special Projects Corp.

BVSPC Project 044759 BVSPC File C.3

July 21, 2008

RECEWEO

supERfuuD m »

Subject: Quality Control Assessment of Data Collected in 2007

Dear Mr. Feild:

BVSPC performed a quality control assessment of the soil data obtained from the Omaha Lead site in 2007 and we are transmitting the results to you in this letter. The soil data addressed by our assessment includes the results of the confirmation soil samples and the soil samples that were screened with both a 60 mesh sieve and a 10 mesh sieve.

Confirmation soil samples are analyzed for lead in BVSPC's field office using an XRF instrument. The same soil sample analyzed using the XRF is subsequently sent to the EPA laboratory and is analyzed for lead and other metals. Confirmation samples are collected at a rate of 5 percent (one confirmation sample per 20 XRF samples). The lead concentrations from confirmation samples analyzed by the XRF and the EPA laboratory data are compared to determine if the data satisfy the quality control goals specified in our February 1, 2007 Quality Assurance Project Plan (QAPP).

The XRF data and the EPA laboratory data fi-om the confirmation samples are used to calculate the Relative Percent Difference (RPD) between the two sets of data. The RPD was compared to the goal of 80 percent RPD for confirmation samples specified in our February 1, 2007 QAPP. During the 2007 sampling season, we analyzed 160 confirmafion samples. The RPD between the confirmation samples exceeded 80 percent goal in 3.8 percent of the samples (Table 1). For comparison, we also determined the RPD between the confirmation samples collected from 2001 through 2007. The RPD between the samples analyzed with the XRF and the laboratory in this set of samples exceeded the 80 percent goal in 5.7 percent of the samples.

We also determined the coefficient of determination (r^) of the data from the confirmation samples collected during the 2007 sampling season. For the field XRF analyses to have value, the correlation between the offsite analyses and the field analyses must be acceptable. For quality control/quality assurance purposes, r'̂ should be at least

building a WO f i d <>' difference™

Page 2

USEPA BVSPC Project 44759 Bob Feild July 18,2008

0.49. This is the coefficient of determination value that was identified in the Sverdrup QAPP as being acceptable.

As shown in the enclosed Figures 1 and 2, we determined the coefficient of determination for the XRF and laboratory data collected during the 2007 sampling season and for all of the XRF and laboratory data from 2001 through 2007. The coefficient of determinafion for the data collected in 2007 is 0.7673, indicating a very strong correlation. The coefficient of determination for all of the data collected from 2001 through 2007 is 0.5242, which is above the goal specified in the Sverdrup QAPP.

In addition to comparing the XRF data with the laboratory data from the confirmation samples, we also compared the XRF data generated by sieving the soil samples with a 10 mesh sieve and a 60 mesh sieve. On days when soil samples are analyzed in the field office, one sample per day is sieved using both a 10 mesh and a 60 mesh sieve and the soil in both samples is analyzed with an XRF instrument. The data was compared for the 2007 (Table 2) sampling season. As indicated by the enclosed Figure 3, the coefficient of determination for 2007 is 0.9545, indicating that there is a very strong correlation between the results fi-om the two sieve sizes. There were no goals established in the QAPP for the coefficient of determinafion for this data. However, a coefficient of determinafion of 0.49 or higher is generally considered acceptable.

We also determined the RPD of the samples analyzed using a 60 mesh sieve and a 10 mesh sieve for 2007 and compared the results to a RPD of 80 percent. In 2007 there were no sampling results above 80 percent (Table 2).

Based on our analysis, we believe the quality of the data in 2007 was acceptable. If you have any questions, please contact me at (913) 458-6605.

L PROJECTS CORP.

David Sanders Project Manager

Enclosure[s]

Q L i .

6,000

5,000

4,000

3,000

2,000

1,000

Figure 1

Comparison of XRF Data vs. Lab Data

2007 Data

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000

Lab Data

Figure 2 Comparison of XRF Date vs. Lab Data

2001 - 2007

• 4 - 1

(0

Q Q: X

30,000

25,000

20,000

15,000

10,000

5,000

^^^^P^^^^^^^^ l •

R̂ = 0.5242

^ ^ ^ ^

^ ^ ^ ^

•

li i > » * • — ^ • • "

^ ^

•

•

• • • J

10,000 20,000 30,000

Lab Data

40,000 50,000 60,000

Figure 3 lOIVIesh vs. eOiVlesh Calendar Year 2007 Omaha Lead Site

1,200

y = 0.7394X + 34.447

0.9545

1,000

800

S 600

400

200

200 400 600 800

60 Mesh

1,000 1,200 1,400 1.600

Table 1 Relative Percent Difference

2007 Data Omaha Lead Site

SAID

34595

36747

49354

92431

27264

25553

17700

24989

24396

38269

90857

63239

63007

88004

21005

79306

93345

93003

31283

74154

32996

15611

47163

35042

91234

10046

36679

34560

81398

11343

33372

93342

37756

26084

93419

34985

12457

35517

29795

51960

28423

33744

14449

66791

93434

31823

17461

20922

76891

91335

74047

87941

51011

48923

23742

35384

47293

79703

XRF_DATE

12-Oct-07

20-Sep-07

30-Oct-07

30-Oct-07

11-Oct-07

4-Jan-07

17-Oct-07

10-Dec-07

26-Oct-07

6-Sep-07

28-Sep-07

25-Sep-07

31-Oct-07

18-Sep-07

4-Jan-07

18-Sep-07

23-Oct-07

20-Sep-07

8-Jan-07

4-Jan-07

7-Sep-07

6-Sep-07

13-NOV-07

8-Aug-07

29-Oct-07

25-Oct-07

19-Sep-07

18-Oct-07

11-Sep-07

26-Oct-07

7-Aug-07

23-Oct-07

6-Sep-07

17-Oct-07

24-Oct-07

2-Oct-07

19-Sep-07

28-Sep-07

4-Jan-07

5-Sep-07

18-Sep-07

14-Dec-07

7-Sep-07

2-NOV-07

11-Dec-07

8-Aug-07

18-Dec-07

5-Sep-07

3-Oct-07

11-Oct-07

19-Sep-07

8-NOV-07

20-Sep-07

18-Dec-07

5-Oct-07

25-Sep-07

19-Dec-07

12-Oct-07

XRF_SAMPLE_ID

RYDSCPXA-34595

RD2SCPXA-36747

RYBSCPXA-49354

RYBSCPXA-92431

RYDSCPXA-27264

RDZSCPXA-25553

RYDSCPXA-17700

RDZSCPXA-24989

RYBSCPXA-24396

RYBSCPXA-38269

RDZSCPXA-90857

RYBSCPXA-63239

RYCSCPXA-63007

RYASCPXA-88004

RYDSCPXA-21005

RYCSCPXA-79306

RYBSCPXA-93345

RYBSCPXA-93003

P20SCPXA-31283

RYASCPXA-74154

RYASCPXA-32996

RYASCPXA-15611

RYASCPXA-47163

RYBSCPXA-35042

RYASCPXA-91234

RYDSCPXA-10046

RYBSCPXA-36679

RYBSCPXA-34560

RYDSCPXA-81398

RYDSCPXA-11343

RYCSCPXA-33372

RYDSCPXA-93342

RYASCPXA-37756

RYCSCPXA-26084

RYBSCPXA-93419

RYCSCPXA-34985

RYASCPXA-12457

RYBSCPXA-35517

RYDSCPXA-29795

RYASCPXA-51960

RYASCPXA-28423

RDZSCPXA-33744

RYDSCPXA-14449

RYASCPXA-66791

RYBSCPXA-93434

RYDSCPXA-31823

RYASCPXA-17461

RYBSCPXA-20922

RYCSCPXA-76891

RYCSCPXA-91335

RPZSCPXA-74047

RDZSCPXA-87941

RYCSCPXA-51011

RDZSCPXA-48923

RYASCPXA-23742

RYASCPXA-35384

RYCSCPXA-47293

RYASCPXA-79703

XRF_ND XRF_PB

157

123

31

195

283

49.01

378

3592

352

80

5523

69

318

326

37.17

239

84

257

50.74

253.71

124

145

179

37

115

195

77

172

44

189

502

174

69

433

114

198

117

138

348.23

338

46

651

221

424

79

84

714

551

282

96

239

34

883

64

481

84

54

253

ASR_NUM8eR

3609

3608

3609

3609

3609

3336

3609

3611

3609

3608

3608

3608

3609

3608

3336

3608

3609

3608

3336

3336

3608

3608

3610

3606

3609

3609

3608

3609

3608

3609

3606

3609

3608

3609

3609

3609

3608

3608

3336

3608

3608

3612

3608

3610

3611

3606

3612

3608

3609

3609

3608

3610

3608

3612

3609

3608

3612

3609

LAB_DATE

12-Oct-07

20-Sep-07

30-Oct-07

30-Oct-07

11-Oct-07

4-Jan-07

17-Oct-07

10-Dec-07

26-Oct-07

6-Sep-07

28-Sep-07

25-Sep-07

31-Oct-07

18-Sep-07

4-Jan-07

18-Sep-07

23-Oct-07

20-Sep-07

8-Jan-07

4-Jan-07

7-Sep-07

6-Sep-07

13-NOV-07

8-Aug-07

29-Oct-07

25-Oct-07

19-Sep-07

18-Oct-07

11-Sep-07

26-Oct-07

7-Aug-07

23-Oct-07

6-Sep-07

17-Oct-07

24-Oct-07

2-Oct-07

19-Sep-07

28-Sep-07

4-Jan-07

5-Sep-07

18-Sep-07

13-Dec-07

7-Sep-07

2-NOV-07

11-Dec-07

8-Aug-07

18-Dec-07

5-Sep-07

3-Oct-07

11-Oct-07

19-Sep-07

8-NOV-07

20-Sep-07

18-Dec-07

5-Oct-07

25-Sep-07

19-Dec-07

12-Oct-07

U \B_SAMPLEJD

RYDSCPLA-34595

RDZSCPLA-36747

RYBSCPLA-49354

RYBSCPLA-92431

RYDSCPLA-27264

RDZSCPLA-25553

RYDSCPLA-17700

RDZSCPU\-24989

RYBSCPI7^-24396

RYBSCPI7i,-38269

RDZSCPU\-90857

RYBSCPLA-63239

RYCSCPLA-63007

RYASCPU\-88004

RYDSCPLA-21005

RYCSCPLA-79306

RYBSCPU\-93345

RYBSCPU\-93003

P20SCPLA-31283

RYASCPUii-74154

RYASCPLA-32996

RYASCPLA-15611

RYASCPLA^7163

RYBSCPLA-35042

RYASCPLA-91234

R Y D S C P L J ^ - 1 0 0 4 6

RYBSCPLA-36679

RYBSCPLA-34560

RYDSCPLA-81398

RYDSCPLA-11343

RYCSCPlA-33372

RYDSCPLA-93342

RYASCPU\-37756

RYCSCPU\-26084

RYBSCPLA-93419

RYCSCPLA-34985

RYASCPU\-12457

RYBSCPLA-35517

RYDSCPLA-29795

RYASCPLA-51960

RYASCPLA-28423

RDZSCPLA-33744

RYDSCPU\-14449

RYASCPLA-66791

RYBSCPU\-93434

RYDSCPLA-31823

RYASCPLA-17461

RYBSCPLA-20922

RYCSCPLA-76891

RYCSCPLA-91335

RPZSCPLA-74047

RDZSCPLA-87941

RYCSCPLA-51011

RDZSCPLA-48923

RYASCPLA-23742

RYASCPLA,-35384

RYCSCPLA-47293

RYASCPLA-79703

L^B_PB DETECTION.

5570

2170

277

884

702

20.9

848

6530

638

143

9390

115

522

533

23.5

375

126

385

33.9

171

180

210

257

52.6

162

268

105

232

58.6

247

656

227

89.2

558

146

253

149

175

275

423

57.4

811

178

526

97.9

104

579

451

344

117

291

28.1

1060

53.6

573

100

45.5

300

J

J

J

J

J

J

JC RPD

1.8903440

1.7854339

1.5974026

1.2771084

0.8507614

0.8041768

0.7667210

0.5805177

0.5777778

0.5650224

0.5186079

0.5000000

0.4857143

0.4819558

0.4506346

0.4429967

0.4000000

0.3987539

0.3979206

0.3894893

0.3684211

0.3661972

0.3577982

0.3482143

0.3393502

0.3153348

0.3076923

0.2970297

0.2846004

0.2660550

0.2659758

0.2643392

0.2553729

0.2522704

0.2461538

0.2439024

0.2406015

0.2364217

0.2350015

0.2233903

0.2205029

0.2188782

0.2155388

0.2147368

0.2136800

0.2127660

0.2088167

0.1996008

0.1980831

0.1971831

0.1962264

0.1900161

0.1821925

0.1768707

0.1745731

0.1739130

0.1708543

0.1699819

1 of 3

Table 1 Relative Percent Difference

2007 Data Omaha Lead Site

SAID

90427

35637

77146

55636

27402

34377

32049

29155

17374

25918

74664

87763

11982

49319

27446

93364

74149

47681

46673

2355

91195

33468

33043

35964

33477

89377

30422

16006

93381

27461

92501

93358

21815

88031

37031

78989

32092

90107

27756

93120

29844

19988

93337

34396

30995

34219

89893

68667

93474

90601

87989

17417

29942

32914

17418

38007

93114

32284

XRF_DATE

17-Oct-07

l-Nov-07

25-Sep-07

27-Sep-07

25-Sep-07

15-Aug-07

17-Sep-07

15-Aug-07

19-Sep-07

26-Sep-07

25-Sep-07

10-Sep-07

21-Sep-07

1-Oct-07

14-Aug-07

27-NOV-07

23-Oct-07

17-Sep-07

5-Sep-07

29-NOV-07

14-NOV-07

1-Aug-07

15-Oct-07

1-Aug-07

30-Oct-07

9-NOV-07

7-Sep-07

29-Aug-07

5-NOV-07

15-NOV-07

23-Oct-07

18-Dec-07

17-Dec-07

21-Sep-07

9-Aug-07

28-Sep-07

9-Aug-07

25-Sep-07

13-Dec-07

17-Dec-07

1-Aug-07

20-NOV-07

18-Oct-07

2-Oct-07

27-Sep-07

27-Sep-07

26-Oct-07

20-Sep-07

20-NOV-07

12-NOV-07

6-NOV-07

12-Dec-07

10-Oct-07

14-Aug-07

5-Sep-07

15-Aug-07

20-Sep-07

10-Oct-07

XRF_SAMPLE_ID

RPZSCPXA-90427

RYDSCPXA-35637

RYDSCPXA-77146

RYBSCPXA-55636

RYASCPXA-27402

RYCSCPXA-34377

RYBSCPXA-32049

RYDSCPXA-29155

RYBSCPXA-17374

RYDSCPXA-25918

RYBSCPXA-74664

RYCSCPXA-87763

RYBSCPXA-11982

RYDSCPXA-49319

RYASCPXA-27446

RYDSCPXA-93364

RYDSCPXA-74149

RYCSCPXA-47681

RYCSCPXA-46673

RYBSCPXA-2355

RYASCPXA-91195

RYDSCPXA-33468

RYBSCPXA-33043

RYASCPXA-35964

RYASCPXA-33477

RYASCPXA-89377

RYBSCPXA-30422

RYCSCPXA-16006

RYBSCPXA-93381

RYDSCPXA-27461

RYASCPXA-92501

RYASCPXA-93358

RYDSCPXA-21815

RYASCPXA-88031

RYASCPXA-37031

RYDSCPXA-78989

RYBSCPXA-32092

RYASCPXA-90107

RYBSCPXA-27756

RYDSCPXA-93120

RYCSCPXA-29844

RYASCPXA-19988

RYBSCPXA-93337

RYBSCPXA-34396

RYBSCPXA-30995

RYDSCPXA-34219

RYBSCPXA-89893

RYBSCPXA-68667

RDZSCPXA-93474

RYCSCPXA-90601

RYDSCPXA-87989

RYCSCPXA-17417

RYDSCPXA-29942

RYDSCPXA-32914

RYCSCPXA-17418

RYASCPXA-38007

RYASCPXA-93114

RYCSCPXA-32284

XRF_ND XRF_PB

93

104

230

146 68

144

100 107

266 46

226

73

142 404

364

48

328 264

76

262

49 97

54

123

100

52

458

180

53

107

83

39

676 303

72

75

428

76

283

62 197

958

95

111

66

69

140

38

546

76

949

466

377

120

268

78

560

291

ASR_NUMBER

3609

3609

3608

3608

3608

3607

3608

3607

3608

3608

3608

3608

3608

3608

3607

3611

3609

3608

3608

3611

3610

3606

3609

3606

3609

3610

3608

3607

3610

3610

3609

"3612

3612

3608

3606

3608

3606

3609

3611

3612

3606

3611

3609

3609

3608

3608

3609

3608

3611

3610

3610

3611

3609

3607

3608

3607

3608

3609

U\B_DATE

17-Oct-07

l-Nov-07

25-Sep-07

27-Sep-07

25-Sep-07

15-Aug-07

17-Sep-07

15-Aug-07

19-Sep-07

26-Sep-07

25-Sep-07

10-Sep-07

21-Sep-07

1-Oct-07

14-Aug-07

27-NOV-07

23-Oct-07

17-Sep-07

5-Sep-07

29-NOV-07

14-NOV-07

1-Aug-07

15-Oct-07

1-Aug-07

30-Oct-07

9-NOV-07

7-Sep-07

29-Aug-07

5-NOV-07

15-NOV-07

23-Oct-07

18-Dec-07

17-Dec-07

21-Sep-07

9-Aug-07

28-Sep-07

9-Aug-07

25-Sep-07

13-Dec-07

17-Dec-07

1-Aug-07

20-NOV-07

18-Oct-07

2-Oct-07

27-Sep-07

27-Sep-07

26-Oct-07

20-Sep-07

20-NOV-07

12-NOV-07

6-NOV-07

12-Dec-07

10-Oct-07

14-Aug-07

5-Sep-07

15-Aug-07

20-Sep-07

10-Oct-07

LAB_SAMPLE_ID

RPZSCPLA-90427

RYDSCPLA-35637

RYDSCPLA-77146

RYBSCPLA-55636

RYASCPLA-27402

RYCSCPLA-34377

RYBSCPLA-32049

RYDSCPLA-29155

RYBSCPLA-17374

RYDSCPLA-25918

RYBSCPLA-74664

RYCSCPLA-87763

RYBSCPLA-11982

RYDSCPLA-49319

RYASCPLA-27446

RYDSCPI-A-93364

RYDSCPI-A-74149

RYCSCPLA-47681

RYCSCPLA-46673

RYBSCPLA-2355

RYASCPLA-91195

RYDSCPLA-33468

RYBSCPLA-33043

RYASCPLA-35964

RYASCPLA-33477

RYASCPLA-89377

RYBSCPLA-30422

RYCSCPU\-16006

RYBSCPLA-93381

RYDSCPLA-27461

RYASCPLA-92501

RYASCPLA-93358

RYDSCPLA-21815

RYASCPLA-88031

RYASCPLA-37031

RYDSCPLA-78989

RYBSCPLA-32092

RYASCPLA-90107

RYBSCPLA-27756

RYDSCPLA-93120

RYCSCPLA-29844

RYASCPLA-19988

RYBSCPLA-93337

RYBSCPLA-34396

RYBSCPLA-30995

RYDSCPLA-34219

RYBSCPlA-89893

RYBSCPLA-68667

RDZSCPLA-93474

RYCSCPLA-90601

RYDSCPLA-87989

RYCSCPLA-17417

RYDSCPLA-29942

RYDSCPLA-32914

RYCSCPLA-17418

RYASCPLA-38007

RYASCPLA-93114

RYCSCPLA-32284

LAB_PB DETECTION.

110

123

271

172

79.7

123

117

91.6

310

53.1

260

83.9

163

353

416

54.8

373

300

86

232

43.4

109

60.6

138

112

58.2

410

201

59

119

74.7

35.1

750

336

79.8

82.8

472 J

83.7

257

56.4

216

875

104

121

71.8

75

129

41.2

591 J

82.2

880

502

406

129

288

72.8

597

310 J

ID RPD

0.1674877

0.1674009

0.1636727

0.1635220

0.1584292

0.1573034

0.1566820

0.1550856

0.1527778

0.1432896

0.1399177

0.1389420

0.1377049

0.1347424

0.1333333

0.1322957

0.1283880

0.1276596

0.1234568

0.1214575

0.1212121

0.1165049

0.1151832

0.1149425

0.1132075

0.1125227

0.1105991

0.1102362

0.1071429

0.1061947

0.1052632

0.1052632

0.1037868

0.1032864

0.1027668

0.0988593

0.0977778

0.0964308

0.0962963

0.0945946

0.0920097

0.0905619

0.0904523

0.0862069

0.0841800

0.0833333

0.0817844

0.0808081

0.0791557

0.0783818

0.0754511

0.0743802

0.0740741

0.0722892

0.0719424

0.0689655

0.0639585

0.0632280

2 of 3

Table 1 Relative Percent Difference

2007 Data Omaha Lead Site

SAID

30189

89842

93344

89408

25780

27315

31283

18718

38142

81400

87991

34224

28157

29165

93338

90908

30939

21730

27269

91239

73077

90101

91926

30978

93354

63751

79377

93413

29274

44636

29753

37226

43843

91449

73862

23433

37036

92675

27038

68686

89514

29063

36574

37434

XRF_DATE

4-Oct-07

9-NOV-07

18-Oct-07

l -Nov-07

7-Sep-07

9-Aug-07

8-Jan-07

7-Sep-07

1-Aug-07

3-Oct-07

18-Oct-07

16-NOV-07

14-Aug-07

8-Aug-07

25-Oct-07

6-NOV-07

26-Sep-07

19-Dec-07

8-Aug-07

27-NOV-07

15-Oct-07

13-Dec-07

29-Oct-07

10-0ct-07

11-Dec-07

14-NOV-07

4-Oct-07

24-Oct-07

30-Oct-07

29-Aug-07

5-Sep-07

26-Sep-07

20-Dec-07

6-NOV-07

12-Oct-07

1-Oct-07

6-Sep-07

5-Oct-07

14-Aug-07

3-Oct-07

5-NOV-07

6-Sep-07

18-Sep-07

31-Jul-07

XRF_SAMPLE_ID

RYCSCPXA-30189

RYBSCPXA-89842

RYASCPXA-93344

RYCSCPXA-89408

RYBSCPXA-25780

RYCSCPXA-27315

P40SCPXA-31283

RYASCPXA-18718

RDZSCPXA-38142

RYCSCPXA-81400

RYCSCPXA-87991

RYASCPXA-34224

RYDSCPXA-28157

RYASCPXA-29165

RYCSCPXA-93338

RYBSCPXA-90908

RYDSCPXA-30939

RYBSCPXA-21730

RYDSCPXA-27269

RYASCPXA-91239

RYBSCPXA-73077

RYBSCPXA-90101

RYASCPXA-91926

RYBSCPXA-30978

RYASCPXA-93354

RYDSCPXA-63751

RYBSCPXA-79377

RYCSCPXA-93413

RYCSCPXA-29274

RYCSCPXA-44636

RYBSCPXA-29753

RYASCPXA-37226

RYASCPXA-43843

RYCSCPXA-91449

RYCSCPXA-73862

RYCSCPXA-23433

RYCSCPXA-37036

RYDSCPXA-92675

RYCSCPXA-27038

RYASCPXA-68686

RYASCPXA-89514

RYBSCPXA-29063

RYDSCPXA-36574

RYDSCPXA-37434

XRF_ND XRF_PB

232

421

71

136

127

849

90.94

167

484

43

76

356

42

153

84

447

18

120

729

55

62

54

35

27

46

60

186

47

71

196

254

246

76

293

55

247

69

43

317

83

189

420

44

299

ASR_NUMBER

3609

3610

3609

3609

3608

3606

3336

3608

3606

3609

3609

3611

3607

3606

3609

3610

3608

3612

3606

3611

3609

3611

3609

3609

3611

3610

3609

3609

3609

3607

3608

3608

3613

3610

3609

3608

3608

3609

3607

3609

3610

3608

3608

3606

LAB_DATE

4-Oct-07

9-NOV-07

18-Oct-07

l-Nov-07

7-Sep-07

9-Aug-07

8-Jan-07

7-Sep-07

1-Aug-07

3-Oct-07

18-Oct-07

26-NOV-07

14-Aug-07

8-Aug-07

25-Oct-07

6-NOV-07

26-Sep-07

19-Dec-07

8-Aug-07

27-NOV-07

15-Oct-07

13-Dec-07

29-Oct-07

10-Oct-07

11-Det>07

14-NOV-07

4-Oct-07

24-Oct-07

30-Oct-07

29-Aug-07

5-Sep-07

26-Sep-07

20-Dec-07

6-NOV-07

12-Oct-07

10-0ct-07

6-Sep-07

5-Oct-07

14-Aug-07

3-Oct-07

5-NOV-07

6-Sep-07

18-Sep-07

31-Jul-07

LAB_SAMPLE_ID

RYCSCPLA-30189

RYBSCPLA-89842

RYASCPLA-93344

RYCSCPLA-89408

RYBSCPLA-25780

RYCSCPLA-27315

P40SCPLA-31283

RYASCPLA-18718

RDZSCPLA-38142

RYCSCPLA-81400

RYCSCPLA-87991

RYASCPLA-34224

RYDSCPLA-28157

RYASCPLA.-29165

RYCSCPLA-93338

RYBSCPLA-90908

RYDSCPLA-30939

RYBSCPLA-21730

RYDSCPLA-27269

RYASCPLA-91239

RYBSCPLA-73077

RYBSCPLA-90101

RYASCPLA-91926

RYBSCPLj^-30978

RYASCPLA-93354

RYDSCPLA-63751

RYBSCPLA-79377

RYCSCPLA-93413

RYCSCPLA-29274

RYCSCPLA-44636

RYBSCPLA-29753

RYASCPLA-37226

RYASCPLA-43843

RYCSCPLA-91449

RYCSCPLA-73862

RYCSCPLA-23433

RYCSCPLA-37036

RYDSCPLA-92675

RYCSCPLA-27038

RYASCPLA-68686

RYASCPLA-89514

RYBSCPLA-29063

RYDSCPLA-36574

RYDSCPLA-37434

LAB_PB DETECTION.

247

448

66.8

144

120

803

96 J

176

461

45.1

79.5

372

40.2

159

87

432

17.4

116

754

53.4

60.2

55.6

36

26.3

47.1

58.7

182

48

72.5

192

249

242

77.1

289

55.7

249

68.5

42.7

319

83.5

188

422 J

44.2

298

1C RPD

0.0626305

0.0621404

0.0609579

0.0571429

0.0566802

0.0556901

0.0541350

0.0524781

0.0486772

0.0476731

0.0450161

0.0439560

0.0437956

0.0384615

0.0350877

0.0341297

0.0338983

0.0338983

0.0337154

0.0295203

0.0294599

0.0291971

0.0281690

0.0262664

0.0236305

0.0219040

0.0217391

0.0210526

0.0209059

0.0206186

0.0198807

0:0163934

0.0143697

0.0137457

0.0126468

0.0080645

0.0072727

0.0070012

0.0062893

0.0060060

0.0053050

0.0047506

0.0045351

0.0033501

3 of 3

Table 2 Comparison of 60 Mesh vs 10 Mesh Sieve

2007 Data Onnaha Lead Site

SAID

32650

91239

66791

90599

91158

30293

19869

52385

87462

87989

38186

83038

22871

90316

90373

73891

93381

90601

89408

46747

93358

87941

35517

29155

2355

93435

26226

29848

34651

35365

36416

48854

20926

30139

22070

64027

30186

15046

32388

26159

21005

47365

63751

21854

SAMPLE_DATE_60

25-Sep-07

27-NOV-07

2-NOV-07

20-NOV-07

29-OC1-07

18-Oct-07

19-Sep-07

26-Oct-07

17-Oct-07

6-NOV-07

1-Aug-07

3-Oct-07

17-Sep-07

13-NOV-07

16-NOV-07

27-Sep-07

5-NOV-07

12-NOV-07

l-Nov-07

14-Dec-07

18-Dec-07

8-NOV-07

28-Sep-07

15-Aug-07

29-NOV-07

11-Dec-07

13-Dec-07

23-Oct-07

20-Sep-07

5-Sep-07

8-Aug-07

9-NOV-07

17-Jan-07

15-NOV-07

19-Dec-07

31-Oct-07

4-Oct-07

25-Oct-07

9-Aug-07

11-Oct-07

4-Jan-07

7-Sep-07

14-NOV-07

20-Dec-07

SAIVIPLE_ID_60

RYBSCMXA-32650

RYDSCMXA-91239

RYDSCMXA-66791

RYDSCMXA-90599

RYBSCMXA-91158

RYBSCMXA-30293

RYCSCMXA-19869

RYCSCMXA-52385

RYDSCMXA-87462

RYCSCMXA-87989

RYCSCMXA-38186

RYCSCMXA-83038

RYCSCMXA-22871

RYASCMXA-90316

RYDSCMXA-90373

RYASCMXA-73891

RYBSCMXA-93381

RYASCMXA-90601

RYBSCMXA-89408

RYDSCMXA-46747

RYASCMXA-93358

RYASCMXA-87941

RYDSCMXA-35517

RYDSCMXA-29155

RYBSCMXA-2355

RYBSCMXA-93435

RYASCMXA-26226

RYASCMXA-29848

RYASCMXA-34651

RYCSCMXA-35365

RYASCMXA-36416

RYASCMXA-48854

RYASCMXA-20926

RYASCMXA-30139

RYASCMXA-22070

RYBSCMXA-64027

RYCSCMXA-30186

RYASCMXA-15046

RYDSCMXA-32388

RYBSCMXA-26159

RDZSCMXA-21005

RYCSCMXA-47365

RYASCMXA-63751

RYBSCMXA-21854

PB_60

1479

205

169

173

212

67

167

147

42

454

101

243

40

81

59

217

61

67

60

264

44

56

618

97

288

79

352

78

99

171

203

91

389.04

118

182

56

640

262

48

176

67.38

272

105

100

SAMPLE_DATE_10

25-Sep-07

27-NOV-07

2-NOV-07

20-NOV-07

29-Oct-07

18-Oct-07

19-Sep-07

26-Oct-07

17-Oct-07

6-NOV-07

1-Aug-07

3-Oct-07

17-Sep-07

13-NOV-07

16-NOV-07

27-Sep-07

5-NOV-07

12-NOV-07

l-Nov-07

14-Dec-07

18-Dec-07

8-NOV-07

28-Sep-07

15-Aug-07

29-NOV-07

11-Dec-07

13-Dec-07

23-Oct-07

20-Sep-07

5-Sep-07

8-Aug-07

9-NOV-07

17-Jan-07

15-NOV-07

19-Dec-07

31-Oct-07

4-Oct-07

25-Oct-07

9-Aug-07

11-Oct-07

4-Jan-07

7-Sep-07

14-NOV-07

20-Dec-07

SAMPLE_ID_10

RYBSCPXA-32650

RYDSCPXA-91239

RYDSCPXA-66791

RYDSCPXA-90599

RYBSCPXA-91158

RYBSCPXA-30293

RYCSCPXA-19869

RYCSCPXA-52385

RYDSCPXA-87462

RYCSCPXA-87989

RYCSCPXA-38186

RYCSCPXA-83038

RYCSCPXA-22871 .

RYASCPXA-90316

RYDSCPXA-90373

RYASCPXA-73891

RYBSCPXA-93381

RYASCPXA-90601

RYBSCPXA-89408

RYDSCPXA-46747

RYASCPXA-93358

RYASCPXA-87941

RYDSCPXA-35517

RYDSCPXA-29155

RYBSCPXA-2355

RYBSCPXA-93435

RYASCPXA-26226

RYASCPXA-29848

RYASCPXA-34651

RYCSCPXA-35365

RYASCPXA-36416

RYASCPXA-48854

RYASCPXA-20926

RYASCPXA-30139

RYASCPXA-22070

RYBSCPXA-64027

RYCSCPXA-30186

RYASCPXA-15046

RYDSCPXA-32388

RYBSCPXA-26159

RDZSCPXA-21005

RYCSCPXA-47365

RYASCPXA-63751

RYBSCPXA-21854

PB_10

1012

142

125

133

163

87

129

183

34

369

122

204

34

70

51

250

53

77

68

299

39

50

554

107

262

72

323

85

92

184

218

85

415.55

125

172

53

609

274

50

183

64.97

265

107

101

RPD

0.3749498

0.3631124

0.2993197

0.2614379

0.2613333

0.2597403

0.2567568

0.2181818

0.2105263

0.2065614

0.1883408

0.1744966

0.1621622

0.1456954

0.1454545

0.1413276

0.1403509

0.1388889

0.1250000

0.1243339

0.1204819

0.1132075

0.1092150

0.0980392

0.0945455

0.0927152

0.0859259

0.0858896

0.0732984

0.0732394

0.0712589

0.0681818

0.0658969

0.0576132

0.0564972

0.0550459

0.0496397

0.0447761

0.0408163

0.0389972

0.0364186

0.0260708

0.0188679

0.0099502

1 of 1