BREAK: Beach, Richard OT1 · 2020-04-28 · BREAK: Beach, Richard . OT1 ilk: From: Beach, Richard ....

BREAK:

Beach, Richard OT1 ilk:

From: Beach, Richard Sent: Monday, April 15, 2002 12:51 PM To: Kevin Russell (E-mail) Subject: Modeling Mtg Followup

Kevin,

As we discussed this morning, please find attached the two presentations that Dick McGrath made last week.

When you get your final presentation files together, please forward them to myself and I will provide them to our team.

By the way, could you also provide Jim Rhea's presentation(s)? We would like to followup on the database inconsistencies, and would like to have a complete accounting for them.

Thanks in advance,

Rick Beach Roy F. Weston, Inc. 610-701-3473 610-701-3125 (fax)

The information contained in this e-mail message is intended only for the personal and confidential use of the recipient(s) named above. This message may be an attorney-client communication and as such is privileged and confidential. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail, and delete the original message.

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Dups, Comps, & Splits: Comparison of EPA and GE

QA Sample Results

Dick McGrath Scott Campbell Sue Stefanosky

Kelly Spittler Roy F. Weston, Inc

April 11, 2002 Draft Confidential - Housatonic River Project

Originals in color.

& Introduction

Principal objective is to present EPA/GE split sample results Will also look at duplicate and "comparability" sample results Total PCB only Three questions of interest: - Magnitude of difference - Variability of difference - Indication of bias

Housatonic River Project pq 2

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Definitions - Soil/Sediment

[Field] Duplicate: Collected for internal QA purposes and analyzed (blind) by same laboratory Comparability Sample: Same procedure as Duplicate. Analyzed by fixed lab as QA check on field lab Split Sample: Aliquot collected following homogenization and provided to GE

Housatonic River Project pg 3

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\ Definitions - Surface Water

[Field] Duplicate: Collected at same time & location. Analyzed (blind) by same laboratory Comparability Sample: Not needed for water Split Sample: Separate container filled at same location and approximately same time and provided to GE (same collection procedure as field dup)

Housatonic River Project pq

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Definitions - Biota (Fish Fillet)

[Field] Duplicate: Second fillet from single specimen removed and analyzed (blind) by same laboratory

Comparability Sample: Not needed for biota

Split Sample: Second fillet from single specimen removed and provided to GE (same procedure as field dup)

Housatonic River

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\ / Sources of Variability

• Small-scale variability in field • Collection procedures • Homogenization effectiveness • Sample handling, storage • Extraction efficiency

• Laboratory instrumentation • Sample quantitation procedures • Error


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Methods

Relative Percent Difference (RPD)

Chi-Square Test for Goodness of Fit

lousatonic River Project pg 7

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VXJ Relationship Between RPD

^PRO^ and Results Ratio 200%

9 11 13 15 17 19

Ratio Between Results Originals in color.


\ / I Duplicates - All Media

Medium

Surface Water

Soils & Sediments

Biota Tissue

Total Samples

29

611

38

Total Mean Detects RPD

6 60.05%

428 34.71%

38 28.67%


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Frequency DistributionSoil & Sediment Dups

140 T

Soils & Sediment Duplicates - RPD 120%

4- 100%

80%

60%

40%

20%

0 01 02 03 04 05 06 07 0.8 09 1 11 12 13 14 15 16 17 18 19 2 More

RPD/100 Housatonic River Project pg 10

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Frequency Distribution Tissue Dups

Tissue Duplicates - RPD

120%

100%

0 0.1 02 0.3 0.4 0.5 06 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 17 1.8 1.9 2 More

RPD/100 Originals in color.


Comparability Samples Soils & Sediments

Sample Grouping

All data with both results "detect"

Grouped by Concentration: STL result < 7 ppm STL result > 7 ppm but <25 ppm STL result > 25 ppm

Grouped by Terrain Type: Bars and Terraces Floodplain Main Channel Banks SCOX

Sample Size

779

255 248 276

140 211 208 128 53

Percent STL>OS

63.03

49.41 67.74 71.38

60.71 59.24 64.42 68.75 71.70

Percent OS>STL

36.84

50.59 31.85 28.62

39.29 40.76 35.58 30.47 28.3

Mean RPD

59.96%

65.10% 49.79% 64.36%

55.87% 49.61% 75.38% 48.88% 73.88%

Chi-square

53.49

0.035 32.07 50.45

6.43 7.21 17.31 18.91 9.98

P

<.0001

ns <.0001 <.0001

0.01 0.007

<.0001 <.0001 0.002

Housatonic Rivei

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> Splits - Surface Water

N GE>EPA (%) EPA>GE (%) Mean RPD Chi-square P Surface Water Splits 190 Surface Water Splits Detects 75 54.67 44.00 87.02% 0.865 ns

Housatonic River

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Frequency Distribution Surface Water Splits

Surface Water Split Samples RPD

T 120%

• 100%

01

More



Soils & Sediments

Sample Grouping

Total N of Soil & Sediment Splits Both results >DL

Grouped by Terrain Type Bars and Terraces Main Channel Floodplains Pond Sediment River banks

Grouped by River Reach Reach 4 Reach 5 Reach 6

N

805 562

53 182 73 52 139

106 179 39

GE>EPA (%)

71.53

64.15 68.68 73.97 80.77 73.38

74.53 75.98 82.05

EPA>GE (%)

28.47

35.85 31.32 26.03 19.23 26.62

25.47 24.02 17.95

Mean RPD

64.29%

53.98% 77.36% 39.60% 67.44% 65.10%

85.81% 54.90% 71.13%

Chi-square

312.30

106.98 10.95 76.93 3.53 0.43

17.49 4.08

401.28

P

<.0001

<.0001 <.001 <.0001 0.06 ns

<.0001 <.043 <.0001


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Frequency Distribution Soil & Sediment Splits

Soils & Sediment Splits - RPD 120%

70 r

100%

80%

60%

40%

20%

More

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Soil & Sediment Splits Fixed Labs Only (both>DL)

Sample Grouping N GE>EPA (%) EPA>GE (%) Mean RPD Chi -square P

Soil/Sed Splits - Fixed Labs Only 127 66.14 33.86 58.33% 13.23 <.001

Soil/Sed Splits - All Results 562 71.53 28.47 64.29% 312.30 <.0001


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Frequency Distribution Soil & Sediment FL Splits

Soils & Sediments Splits (Fixed Labs) 120%

• 100%

- 80%

- 60%

- 40%

20%

04 0.2 0.5 07 08 0.1 0.3 12 06 1 09 1 1 16 13 14 18 19 15 0 17 2 More



v / Magnitude of Differences Soils & Sediments

Geometric Mean of Geometric Mean of GE Concentration EPA Concentration Correlation Percent

Sample Grouping N Percent GE > EPA (ppm) (ppm) Coefficient Difference

Total Soil & Sediment Splits 805 3.26 3.04 0.89 7.01% Both results >DL 562 71.53 10.15 6.92 0.89 46.56%

Grouped by Terrain Bars and Terraces 53 64.15 19.32 15.35 0.31 25.90% Main Channel 182 68.68 7.85 5.56 0.70 41.08% Floodplains 73 73.97 3.32 2.73 0.93 21.37% Pond Sediment 52 80.77 9.03 4.91 0.91 83.98% Rirer banks 139 73.38 17.60 10.63 0.46 65.60%

Grouped by Reach Reach 4 106 74.53 10.12 6.29 0.84 60.72% Reach 5 179 75.98 11.32 7.76 0.53 45.90% Reach 6 39 82.05 21.76 9.64 0.69 125.80%

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Comparison to Other PCB Field Investigations

Tetra Tech PSARA Result Result Difference RPD ABS RPD

2.1 2.7 0.6 -25.00% 25.00% 5.8 5.1 -0.7 12.84% 12.84% 2.7 4.3 1.6 -45.71% 45.71% 8.7 9.1 0.4 -4.49% 4.49% 160 2300 2140 -173.98% 173.98% 60 520 460 -158.62% 158.62%

280 440 160 -44.44% 44.44% 13 12 -1 8.00% 8.00% 2.7 25 22.3 -161.01% 161.01% 11 31 20 -95.24% 95.24% 3 4 1 -28.57% 28.57%

• •• ••• ^ •• ^ ^ •i ^H • ^ •• ••• ••B •••• •••• •••• H

Mean 68.90%

FROM: Indiana Superfund Site(s) 2001 Split Sample Analytical Results Housatonic River Project pg 20

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Splits - Tissue (Fish Fillet)

N GE>EPA (%) EPA>GE {%) Mean RPD Chi -square P

Fish Tissue 18 7 11 41.48% 0.889 ns

Housatonic River

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Frequency Distribution Tissue Splits

Tissue Samples - RPD

120%

5 - 100%

- 80%

O

0)3 3 o£ u.

2

• 60%

- 40%

1 - 20%

0 02 04 06 08 1 12 14 16 18 2 More 0%

RPD/100 f Originals in color.l


Summary of Split Sample Analysis

Numerous sources of variability expected to produce different results Values reported appear to be reasonable and within expected ranges GE reported concentrations often higher than EPA results - difference is statistically significant for soils/seds


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Review of Changes to Soil and Sediment TOC Data

Scott Campbell Dick McGrath

Roy F. Weston, Inc. April 11, 2002

Housatonic River Project

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v Initial Discovery

Routine database audit: - Out-of-range data

- Suspect data points

- Follow-up action

TOC values greater than 30% - Review of hardcopy reports - Laboratory contacted

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A..;/,

TOO Methods

Initial instrumentation and method - Fall of 1998 to late April 1999 - Ol analytical 1010 NDIR TOO Detection System

- 500 mg sample output as mg of TOC - Concentrations converted to dry-wt TOC -Dilutions of 2X and 5X

- Approximately 1630 samples analyzed - Pre-drying step initiated

Housatonic River

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^ TOC Methods (Concluded) • New Method

- Late April 1999 to August 2000

- CE instruments NC 2500 elemental GC- TCD analyzer

- 25 mg of sample output as %Carbon

- Pre-dried sample analyzed - Approximately 2400 samples analyzed


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^ Incorporating a Dilution Factor to Initial Method

Correct formula - TOCS = (1000 * TOG, / 0.5) / S / D

- Dilution Factor of 0.5 or 0.2 (fractional) - Some sample batches had integer DFs

incorrectly entered in the denominator - Dividing by the integer value had the effect of

decreasing the TOC value


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j Incorporating a DF to New Method

Correct Formula -TOCS =(1000*TOCC/(0.025*S))*D

- DF calculated in the numerator

- Effectively increases the TOC result

- DF as an integer is appropriate - Incorrect Formula -TOCS =(1000*TOCC/(0.025*S))*D

• Parenthesis preceding 0.025 omitted

• Expression evaluated from left to right


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., Effects on Results from Calculation Modification

Dry weight of 100% introduces no error Dry weight decrease introduces a induced error that becomes larger in a non-linear fashion A 95% solids values induces a 10.8% decrease in reported TOC content At 80% solids the calculated TOC is less than 75% of the true value

Housatonic River Project pg

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, Calculation Effects by Method

Initial Method - Two different calculations

- Results potentially have either calculation error

New Method - Results can only have error involving percent

solids calculation


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J

Corrective Actions

Identification of all TOC Sample Delivery Groups (SDG) TOC formula reviewed for each SDG SDG separated into three groups

Unaffected Percent solid miscalculation Dilution factor miscalculation


color.

I

Summary TOC Changes

4,185 potentially effected TOC results - 340 required no change

- Approximately 2,000 required < 5% change

- 500 results more than doubled

-Approximately 250 required 5X change or greater


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, Database TOG Changes by Reach

Reach 1 and 2 Combined - Nearly 30% of results with less than 5% change - Approximately 18% of results changed by a

factor of 2X or more

Reach 3 - No samples analyzed for TOC by these

methods


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, Database TOC Changes by Reach (Continued)

Reach 4 - Nearly 80% of results less than 5% increase - Approximately 8% of results with 2X or greater

corrections Reach 5 - Nearly 67% of results less than 50% increase - Approximately 8% of results with 5X or greater

corrections Reach 6 - Similar to overall pattern with corrections

greater than 5% but less than 2X


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, Database TOC Changes by Reach (Concluded)

Reach 7 (including Rising Pond) - Nearly 90% increased by less than 5%

Reach 9 - No sample requiring greater than a 10%

increase

Reference Locations - Majority of samples increased by more than 5%

- Nearly a third of samples more than tripled in value


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, Database TOC Changes by Selected Terrain

Floodplain Samples - Nearly 25% increased by a factor of 5X - More than half of the samples more than

doubling - One third of results increased by 5% or less

Main Channel Samples - Nearly half of the samples changing by less

than 5% - Approximately 30% of sample increased by a

factor of 2X or more


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j Database TOC Changes by Selected Terrain (concluded)

SCOX Samples (Reach 5) - Greatest changes observed - Less than 25% of results increased by 5% - Nearly 60% of results increased by 2X or more - One third of results increase by a factor of 5X or more

Woods Pond Samples - More than 20% of samples had no change - Approximately one-third of samples doubling - Nearly 20% of samples increased by a factor of 5X or

more


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BREAK: Beach, Richard OT1 · 2020-04-28 · BREAK: Beach, Richard . OT1 ilk: From: Beach, Richard ....

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