1

Expert Report

Hydrogeological Investigation

Bridgeton Landfill

Prepared for

Lathrop & Gage

October, 2015

1. Introduction I am John W. Oneacre, President of Ground Water Solutions, Ltd. (GWS), an

environmental consulting firm located at 12902 Bristol Berry Dive, Cypress, Texas

77429. Information concerning my professional credentials is provided in the attached

resume in Appendix A, and summarized below.

a. I have a Bachelor of Science degree in geology from Kent State University

and a Master of Science degree in geology from Kent State University.

b. I am a Certified Professional Geologist (CPGS No. 6338).

c. I am a Registered Geologist in the State of Texas (No. 4556).

d. I am a Registered Geologist in the State of Indiana (No. IN2314).

e. I am a Registered Geologist in California (No. 6450) and Kentucky (No.

2270).

f. I am a Certified Engineering Geologist in California (No. 2008).

g. I am a Certified Environmental Manager (CEM) in Nevada (EM 2169).

2

h. I have approximately 41 years of professional geological and

hydrogeological experience working for Fortune 500 companies as well as

geotechnical consulting companies.

i. I have owned Ground Water Solutions for approximately sixteen years.

j. In my career as a hydrogeologist/engineering geologist, I have personally

been involved with several hundred projects dealing with ground water

related issues. As part of my responsibilities on these ground water

projects, I have worked on numerous contracts, consent agreements,

work plans, landfill design, and ground water investigations.

k. I have extensive geological experience throughout the United States and

have worked on landfill ground water projects in 13 countries. I was

responsible for the RCRA ground water monitoring of approximately 100

municipal solid waste landfills in the United States and have worked on

dozens of other landfill projects.

l. I have been an invited speaker at several universities, USEPA Region I

and Region IX, several State regulatory agencies including the Texas

Commission on Environmental Quality (TCEQ), and the Australian EPA.

m. For the past thirty-five years, my experience has focused on ground water

concerns including contamination, assessment, and supply. This

experience includes wok on dozens of contaminated ground water

projects including hazardous waste sites. I have managed the

environmental cleanup of several Federal Superfund sites listed on the

National Priority List (NPL).

n. I have personally designed, conducted, and analyzed dozens of pump

tests conducted in various geological settings. Tests were conducted at

3

flow rates as low as a few gallons per minute to wells capable of yielding

over 1,000 gallons per minute.

o. I have worked on many ground water projects in the United States,

including Missouri, that occur in fractured limestones.

p. I have appeared as an expert witness in 9 judicial and administrative

proceedings where the issues focused on potential or existing

contamination of ground water. Several of these proceedings were landfill

cases.

2. Executive Summary

a. I have reviewed the Plaintiff’s report on the groundwater at the Bridgeton

Landfill titled “Bridgeton Sanitary Landfill Groundwater Investigation

Report, St. Louis County, Missouri, August, 2015. In my professional

opinion the report has two serious deficiencies. The first deficiency is the

failure to recognize the industrial setting of the landfill and surrounding

industries that could be alternate sources of impact to groundwater. The

second deficiency of the report is the technical discussion of geochemistry

and groundwater movement. The geochemical discussion failed to

discuss sources of trace VOCs in the groundwater, other than leachate,

such as laboratory artifacts, LUST sources onsite and offsite, and landfill

gas. The groundwater movement discussion failed in several ways; these

included measuring groundwater levels in the MDNR wells after, rather

than before, sampling; uncertainty that the groundwater levels in the

MDNR wells had reached equilibrium prior to taking level measurements,

thus potentially giving an erroneous groundwater flow direction; failure to

use groundwater elevations from four St. Louis Deep/Shallow Salem wells

listed in Table 2 to prepare a potentiometric map that depicts groundwater

flow toward the landfill in that hydrostratigraphic unit; and failure to

4

recognize upward trends in groundwater elevations in Champ Landfill

monitor wells. This report provides my review and professional opinions

of Mr. Price’s report.

3. Plaintiff’s Ground Water Investigation at Bridgeton Sanitary Landfill

a. Peter Price of the Missouri Department of Natural Resources (MDNR)

prepared a report titled “Bridgeton Sanitary Landfill Groundwater

Investigation Report, St. Louis County, Missouri, August, 2015.

b. As part of the investigation, MDNR conducted the following tasks:

i. Installation of monitor wells on private property adjacent to the

Bridgeton Sanitary Landfill (BSLF) to determine if off-site

groundwater has been impacted (Price 0000010);

ii. Review of historic groundwater quality for trends (Price 0000010);

iii. Sampling of monitor wells at BSLF and MDNR wells during the

week of August 17-21, 2015 (Price 0000012);

iv. Review of historic groundwater levels for trends (Price 0000010);

v. Measurement of ground water levels at BSLF on August 17, 2015

and MDNR wells on August 20, 25, and 28, 2015 (0000011);

vi. Comparison of historical Champ Landfill data, applicable to the

Bridgeton investigation (Price 0000010);

vii. Leachate sampling (Price 0000010);

viii. Review of BSLF south pit leachate sump levels.

c. In August, 2015, MDNR installed a total of five (5) monitor wells on

property adjacent to BSLF; three wells, MO-1-SS, MO-1-SDR, and MO-2-

SD were installed adjacent to the southeast side of BSLF whereas MO-3-

SS and MO-3-SDR were installed adjacent to the southwest side of BSLF.

5

d. Wells were screened in the deep St. Louis/shallow Salem

hydrostratigraphic zone (SS designation) and the deep Salem

hydrostratigraphic zone (SD and SDR designations).

e. Appendix G of Mr. Price’s report contains a report by Dr. David J.

Wronkiewicz of Missouri University of Science and Technology. His report

is titled “Report on Redox Reactions Inferred from the Chemical

Composition of Water Collected from the PZ-104-SD and PZ-106-SD

Monitoring Wells at the Bridgeton Sanitary Landfill, St. Louis County,

Missouri.

f. The remainder of my report will discuss the reports of Mr. Price and Dr.

Wronkiewicz.

4. Plaintiff’s Interpretation of Leachate Impact to Ground Water at the Bridgeton Sanitary Landfill

a. Mr. Price concluded, based upon his groundwater investigation of the

BSLF, that: i. Detections of volatile organic compounds are representative of

leachate from the landfill on the southwest side of the south quarry

area and nearby monitoring wells on adjacent property (Price

0000015); ii. Water levels in those wells are consistent with a groundwater flow

direction outward from the landfill (Price 0000015); and, iii. An inward hydraulic gradient has not been consistently maintained

at the Bridgeton Sanitary Landfill (0000015). I have provided my

response to Mr. Price’s conclusions in the following sections of my

report.

b. Response to claim that volatile organic compounds are representative of leachate from the landfill.

i. Mr. Price concluded that the volatile organic compounds (VOCs)

detected in the groundwater in the southwestern side of the landfill

6

are "representative of leachate”; however, Mr. Price apparently did

not consider alternative explanations for the VOCs in the

groundwater. ii. Mr. Price noted that seven VOCs were detected in the leachate

sample (Price 0000014); however, Mr. Price did not discuss

whether the laboratory had to dilute the leachate sample in order to

keep the results within the calibrated scale for the compounds.

Dilution of the sample could introduce common laboratory artifacts

such as acetone and MEK. Once the laboratory has run the

analysis on a diluted sample, the result is multiplied by the amount

of dilution; if a common laboratory artifact is detected in the diluted

sample, the concentration of the artifact is multiplied by the dilution

factor and will indicate a high concentration when, in reality, the

VOC is not actually present but is simply an artifact. Other

compounds such as Hexanone and MIBK could also be artifacts. iii. Mr. Price mentioned three VOCs, benzene, acetone, and 2-

butanone (MEK) in the groundwater. Two of these VOCS, acetone

and MEK are common laboratory artifacts and are poor responders

for calibration (USEPA, 1994). iv. Mr. Price did not indicate in his report whether any control samples

such as Trip Blanks, Field Blanks, Equipment Blanks, etc. showed

these two compounds. v. The USEPA (1994) gives specific guidance on qualifying VOCs

such as acetone and MEK that may be laboratory artifacts. It is not

apparent whether evaluation of laboratory artifacts was conducted. vi. Duplicate samples did show variation of results for acetone and

MEK. For example, acetone results for MO-2-SD were an

estimated “J” value and a non-detect (ND). Similarly, for MO-1-SS,

MEK was reported as an estimated “J” value and a non-detect (ND)

(Price 0000026). Other compounds that showed “J” and ND results

7

for duplicate samples include Hexanone, MIBK, Xylene,

Ethylbenzene, and Carbon Disulfide. vii. Mr. Price did not discuss possible sources of VOCs in the

groundwater, unrelated to BSLF. For example, VOC detections at

upgradient well 114-AS appear to be related to contamination from

the upgradient PM Resources, Inc. property (Herst & Associates,

Inc., August, 2014). viii. A report by Environmental Data Resources, Inc. (EDR) identified

numerous sites within a one mile radius of BSLF that have had

known environmental issues. One site, PM Resources, Inc. is

listed as having RCRA Corrective Action Activity. MDNR has

acknowledged that PM Resources, Inc. appears to be the source of

groundwater impact at BSLF’s monitor well 114-AS (MDNR Letter

dated October 23, 2003). ix. EDR identified ten sites with a history of leaking underground

storage tanks within one mile of BSLF; another sixteen sites within

one mile of BSLF are listed as having underground storage tanks.

One site is within one third of a mile from BSLF; this site, the

Hussman Corporation, is listed on the Missouri Voluntary Cleanup

Program. x. A leaking underground storage tank (LUST) area is located on the

Site and is shown in Figures 5-8 through Figure 5-12B of the May,

2008 USEPA Record of Decision (ROD). The onsite LUST could

be a source for benzene, ethylbenzene, toluene, and xylene along

with other components of gasoline or diesel fuel. xi. In the May, 2008 ROD, on Page 8, the USEPA identified other

industrial facilities on Site that include concrete and asphalt batch

plants, and an automotive repair shop. Figure 4-1 of the ROD

shows the locations of these industrial facilities. An active asphalt

facility, Metro Paving, is also in close proximity to BSLF and is

listed as a LUST facility (LUST ID ST0000570.)

8

xii. BSLF is situated in an industrial area and as EDR reported,

numerous sites nearby could potentially be sources of impact to

groundwater beneath BSLF. xiii. Industrial sites listed in 3.b.viii through 3.b.xi are not discussed in

Mr. Price’s “Bridgeton Sanitary Landfill Groundwater Investigation

Report”. xiv. BSLF is currently in Assessment Monitoring; nine monitor wells are

part of the site’s Assessment Monitoring Plan (Herst & Associates,

Inc., June 25, 2015). The Assessment Monitoring Plan is dated

December 17, 2013 with an August 18, 2014 Addendum. Of these

nine wells, only PZ-104-SS and PZ-104-SD were included in Mr.

Price’s report. xv. VOCs detected in the monitor wells could be sources other than the

landfill, laboratory artifacts, landfill gas, or landfill leachate. VOCs

in trace amounts are common in landfill gas (Oneacre and

Figueras, 2004). xvi. Mr. Price included the report by Dr. David J. Wronkiewicz in

Appendix G. Dr. Wronkiewicz’s report is a technical discussion

regarding redox conditions and their relationship to solubility of

metals such as iron and manganese along with sulfur. xvii. Dr. Wronkiewicz noted increases in iron and manganese

concurrent with a decrease in sulfate (Wronkiewicz 0000004). A

possible explanation suggested by Dr. Wronkiewicz is that “…the

inclusion of large amounts of municipal waste with a high organic

content will produce reducing conditions. As fluids in a landfill

migrate, they may also promote reducing conditions in surrounding

areas” (Wronkiewicz 0000003). While I agree with Dr.

Wronkiewicz’s statement, there is another explanation that should

be discussed. xviii. Decomposition of waste in a landfill will produce strongly reduced

(anaerobic) conditions. Part of the decomposition process includes

9

the production of landfill gas, primarily in the form of methane and

carbon dioxide. The presence of methane is indicative of strongly

reduced conditions. Also, if landfill gas migrates away from the

landfill, the presence of carbon dioxide will cause the pH of

groundwater to decrease. In monitor well PZ-104-SD, the pH

decreased from values above 7.0 to 6.44; this is notable because

pH is measured on a logarithmic scale. PZ-106-SD also showed a

decrease of pH to a low of 6.54 in 2014. This could indicate a

landfill gas issue. Dr. Wronkiewicz also mentioned an increase of

TOC; TOC in landfill gas condensate can have very high values

(USEPA, 1988) and can cause increase in TOC of nearby

groundwater. BOD and COD can also be elevated in landfill gas

condensate and cause increased levels of these constituents in

nearby groundwater. Another constituent mentioned by Dr.

Wronkiewicz is ammonia; he stated that ammonia increased then

decreased in PZ-104-SD. Ammonia is the reduced form of nitrogen

and is a common landfill gas constituent

(http://www.atsdr.cdc.gov/HAC/landfill/html/ch2.html#t2_1). Dr.

Wronkiewicz noted that sulfate decreased; this is due to the

reduced conditions that will result in the production of sulfide, the

reduced form of sulfur. xix. However, increased concentrations of chloride and Total Dissolved

Solids are not considered to be associated with landfill gas and

should be evaluated for the cause of the increases.

c. Response to claim that water levels in those wells are consistent with a groundwater flow direction outward from the landfill

i. Mr. Price stated that “According to Solid Waste Disposal Area

Operating Permit #118912 (MDNR, 1985), BSLF is required to

maintain an inward hydraulic gradient and maintain a liquid

10

leachate level within 30 feet of the base of the landfill” (Price

0000013). This statement is not truly representative of the actual

language of the MDNR, 1985 letter for several reasons.

ii. First, the letter from Director Brunner, dated November 18, 1985

does not use the term “inward hydraulic gradient”.

iii. Second, Items 6.D and 6E actually give two different leachate level

criteria. In Item 6.D, “static leachate levels in the collection sumps

in the unfilled area of the quarry, as shown in the approved permit

documents, will be maintained at a level less than 30 feet above the

base of the sump”. In Item 6.E, “static leachate levels in the

previously filled areas of the quarry, as shown in the approved

permit documents, shall be maintained at a level less than 50 feet

above the base of the sump”.

iv. Third, the language of the MDNR November, 1985 letter required

that the leachate levels be maintained at levels referenced to the

base of the sump, not the base of the landfill.

v. Mr. Price infers from the MDNR November, 1985 letter that the

leachate levels within the landfill waste mass should remain at

elevations lower that the ground water levels in the surrounding

monitoring wells at the BSLF site (Price 0000013). However,

Golder Associates in its report titled “Leachate Head Calculation

Report, prepared for Laidlaw Waste Systems, Inc., July, 1996”,

stated on page 1 that: “Based on a November 18, 1985 letter from

11

Fred Brunner, then director of the Missouri Department of Natural

Resources, the maximum allowable leachate head in the active pit

measured in each of four leachate risers, is 30 feet above the base

of each riser. The technical rationale for the permitted maximum

leachate head of 30 feet is unknown”. Golder Associates did not

use the term “inward hydraulic gradient” when discussing Director

Brunner’s letter and did not seem to know the technical reason for

the 30 feet criteria. The purpose of Golder’s report was given on

page 2 of the report: “This report documents leachate head

calculations made to determine a technically justifiable leachate

head that is sufficient to maintain an inward hydraulic gradient

without excessive pumping into the MSD sewer system.”

vi. Golder’s report concluded on page 14 that current leachate

pumping was “maintaining a leachate level that is lower than

technically justified”. Golder calculated that leachate levels could

increase another 20 to 35 feet (total leachate head of 50 to 65 feet)

and still maintain an inward gradient with a factor of safety

incorporated into the calculations.

vii. Mr. Price stated that water levels were collected from the BSLF

wells on August 17, 2005 and the State of Missouri wells on August

25, 2015.

viii. It would be better technical practice to take measurements on the

same day, if possible. Also, the MDNR used water level

12

measurements for its wells after sampling its new monitor wells.

MDNR should have taken water level measurements prior to

sampling. Also, there is a question as to whether adequate time

was allowed from drilling, well installation, development, and

sampling for the water level in some of the State wells to fully

stabilize.

ix. Questions also arise regarding the selection of monitor wells for

construction of the potentiometric contour maps. In Figure 13, Mr.

Price did not use water level elevations for PZ-105-SS and PZ-107-

SS even though he presented those elevations in Table 2.

Additionally, PZ-204-SS is in close proximity to MO-3-SS but was

not listed in Table 2 and was not used in the construction of the

potentiometric contour map of Figure 13.

x. Utilizing the groundwater elevations of PZ-105-SS and PZ-107-SS

may result in a potentiometric map with different groundwater flow

direction. It is recommended that groundwater elevations from

these wells be used for constructing the potentiometric map.

xi. Mr. Price constructed potentiometric maps for both the Deep St.

Louis/Shallow Salem wells and the Deep Salem wells in Figures 13

and 14. However, only Deep Salem wells were used by Mr. Price

for construction of the potentiometric map along the southeast

corner of the South Quarry Pit, despite the fact that four Deep St.

Louis/Shallow Salem wells exist with the four Deep Salem wells.

13

These four Deep St. Louis/Shallow Salem wells are PZ-209-SS,

PZ-211-SS, PZ-104-SS, and PZ-210-SS. Groundwater elevations

for these four Deep St. Louis/Shallow Salem wells are provided by

Mr. Price in Table 2 of his report but he did not produce a

potentiometric map using those four groundwater elevations.

Highest groundwater elevation of 468.15 feet was in PZ-209-SS,

located the greatest distance from the landfill. Conversely, the

lowest groundwater elevations of 464.73 feet and 460.66 feet were

in PZ-104-SS and PZ-210-SS, located the shortest distance from

the landfill. In my opinion, a potentiometric map using these four

wells would show an inward hydraulic gradient.

d. Response to claim that an inward hydraulic gradient has not been

consistently maintained at the Bridgeton Sanitary Landfill

i. Plaintiff’s groundwater expert, Mr. Price stated in the MDNR

August, 2015 report that a comparison of water levels between

BSLF and the IESI MO Champ Landfill showed that:

ii. “Between 2005 and approximately 2010 the water levels in the

BSLF wells ranged in elevation from approximately 360 to 450 feet

amsl for both the SS and SD monitoring wells. From approximately

2010 to the present groundwater levels have increased in all but

five of the BSLF wells, including the period of 2012 and into 2013

when Missouri experienced a severe drought. The groundwater

14

elevations in several of the SS and SD wells, particularly those on

the east side of the landfill, are currently at elevations 10 to 15 feet

higher than groundwater elevations prior to 2010.”

iii. Mr. Price continues by stating: “In contrast, water levels graphed

over the same 10 year time period at the IESI MO Champ Landfill

have remained relatively unchanged or have receded. Water levels

in many of the monitoring wells near the south pit quarry area of

IESI MO Champ Landfill are at elevations lower than they have

been for several years” (Price 0000013).

iv. Mr. Price constructed three potentiometric maps, Figures 13

through 15 as a means to illustrate that inward hydraulic

e. Response to Plaintiff’s claim of ground water levels at BSLF

i. Mr. Price’s claim that water levels at the IESI MO Champ Landfill

have remained relatively unchanged or have receded is not correct.

Mr. Price did not show any type of trend for the water levels in the

monitor wells. I have plotted hydrographs of monitor wells at the

IESI MO Champ Landfills that clearly demonstrate that the water

levels in several wells have not remained relativey unchanged or

receded. For example, the hydrograph for SL 1 (Figure 1) covers

the time period used by Mr. Price. I have added a simple linear

trend line to this hydrograph; the trend line clearly shows that the

trend in water levels in SL 1 from 2005 to 2015 is upward. This

15

upward trend is due to the fact that over the ten year period, the

water levels have increased from approximately 377 feet to as

much as 425 feet with an ending water level of approximately 407.

The water level increased by nearly 50 feet just prior to 2012 and,

as of 2015, was still approximately 30 feet higher than the level in

2005. SL 1 is screened in the St. Louis limestone.

ii. The hydrograph for SL 4 (Figure 2), another St. Louis limestone

well, also shows a significant increase in water level over the ten

year period used by Mr. Price. The trend line clearly demonstrates

an upward trend over the ten year period; the water level in 2015

was approximately 40 feet higher than the level in 2005.

iii. The hydrograph for S 10 (Figure 3) shows a significant increase in

water level over the ten year period used by Mr. Price. The trend

line clearly demonstrates an upward trend over the ten year period;

the water level in 2015 was approximately 30 feet higher than the

level in 2005. Monitor well S 10 is screened in the Salem

limestone.

iv. The hydrograph for S 7 (Figure 4), another Salem limestone well,

shows a significant increase in water level over the ten year period

used by Mr. Price. The trend line clearly demonstrates an upward

trend over the ten year period; the water level in 2015 was

approximately 45 feet higher than the level in 2005.

16

f. Although Mr. Price noted that there are several similar geologic and

hydrologic characteristics (Price 0000010), there are other

considerations when making comparisons:

i. The BSLF is a closed landfill; the north pit ceased taking waste in

1985 and the south pit ceased taking waste in 2004 (Price

0000006).

ii. The IESI Champ landfill is an active landfill and portions of the

quarry are still producing limestone.

iii. The production of limestone may affect the ground water elevations

as a result of dewatering for ground water control.

iv. Operations of the active landfill and quarry could affect the ground

water elevations at the IESI Champ landfill.

v. Geologic and hydrogeologic conditions could be variable over the

distance between the two landfill sites; the distance between the

two landfill sites is approximately 1.25 miles.

vi. Water level data for some IESI Champ landfill wells do not exist

prior to 2010; for example, deep Salem wells S 29, S 30 and S 31

do not have data from the time period of 2005 to 2010. Likewise,

St. Louis monitor well SL 29 does not have ground water elevation

data prior to 2010. Therefore, water level trends cannot be

analyzed over the ten year time period for these wells.

17

g. Response to Mr. Price’s claim that groundwater level trends at BSLF

have increased over the past 10 years whereas groundwater levels at

Champ Landfill have remained relatively unchanged or have receded.

i. Mr. Price stated that, regarding the water levels at BSLF, “The

groundwater elevations in several of the SS and SD wells,

particularly those on the east side of the landfill, are currently at

elevations 10 to 15 feet higher than groundwater elevations prior to

2010 (Price 0000013).

ii. Mr. Price’s Section 3.1.1 is titled “Groundwater Elevation Trend

Analysis”; however, Mr. Price does not show any trend lines for any

of the monitor well hydrographs.

iii. Mr. Price’s groundwater elevation scale on Figures 8 through 12

tends to mask the upward trend in several monitor wells, including

the Champ Landfill wells.

iv. Conversely, 2015 water levels at several of the IESI Champ landfill

monitor wells are as much as 45 feet higher than the groundwater

levels prior to 2010 as stated in Section 3 of this report.

v. Water levels in the BSLF monitor wells do show increasing trends;

however, some of these increases over the period of 2005 to 2015

are small compared to the water level increases at several IESI

wells. For example, well 114 AS showed nearly identical beginning

and ending water levels of approximately Elevation 430. Over the

10 year period, the water level increase was limited to

18

approximately 5 feet; therefore, the overall upward trend was

nominal.

vi. Overall, the beginning and ending water levels in the BSLF monitor

wells ranged from virtually no change to a maximum change of 30

feet in 201A SS; most changes ranged from 3 feet to 25 feet. Half

of the BSLF wells used by Mr. Price showed changes of 10 feet or

less.

vii. Conversely, the greatest increase of water levels over the ten year

period actually occurred at the IESI Champ landfill; water level

increases of 45 feet occurred at the IESI Champ landfill in S 7.

viii. Therefore, increases in water levels alone may not be indicative of

a hydraulic gradient problem at the BSLF.

ix. Mr. Price correctly noted that from 2010 to the present water levels

at BSLF have increased in all but five wells (Price 0000013);

however, Mr. Price did not discuss the fact that between 2005 and

2010 many wells showed a decreasing trend in water levels. I

prepared a graph for 106 SD (Figure 5) that clearly shows this initial

downward trend from 2005 through 2010. I placed a polynomial

trend on the graph that shows the downward trend followed by an

upward trend. This gives a clearer picture of the actual fluctuation

in water levels over the ten year time period. The water level

increased by about 30 feet from the lowest level to the present level

in 2015. However, looking at the entire ten year interval, the water

19

level increased by only about 10 feet from November, 2005 to the

present.

5. Conclusions

a. Having reviewed multiple documents, I have made the following

conclusions.

i. Multiple sources of benzene can be a source or sources of

groundwater impact. The LUST that exists onsite is just one

example of a potential source of benzene that could be impacting

groundwater. Other potential benzene sources include nearby

LUST sites such as PM Resources.

ii. Some of the VOCs listed in Table 4 of Mr. Price’s report may simply

be laboratory artifacts; these artifacts include acetone, MEK, MIBK,

Carbon Disulfide, Chloroform, and Hexanone. A thorough QA/QC

study of these VOCs.

iii. A review of the leachate sample would determine if the sample

were diluted by the laboratory and help explain high concentrations

of suspected laboratory artifacts.

iv. Some groundwater elevations in the MDNR wells may not be truly

representative if the levels had not fully stabilized. This could

change the potentiometric maps and ground water flow direction.

v. Groundwater level measurements should be taken on the same

day, if possible, in wells with stable water levels.

20

vi. Deep St. Louis/Shallow Salem potentiometric map in the southeast

corner of the South Quarry Pit should be constructed to determine

groundwater flow direction. It is my professional opinion that

construction of a potentiometric map using the groundwater

elevations from Table 2 of Mr. Price’s report would show

groundwater flow toward the landfill, indicating an inward hydraulic

gradient.

vii. Drawing trend lines on several Champ Landfill monitor well

hydrographs clearly shows upward trend; some of the Champ wells

have groundwater level increases greater than monitor wells at

BSLF. This fact is contrary to Mr. Price’s statement that the Champ

Landfill monitor well levels remained relatively unchanged or have

receded.

21

REFERENCES

Environmental Data Resources, Inc., 2015. Bridgeton Landfill, 12976 St. Charles

Rock Road, Bridgeton, MO 63044, Inquiry Number 4422106.2s, September 25,

2015. 788pp.

Golder Associates, Inc. 1996. Leachate Head Calculation Report, prepared for

Laidlaw Waste Systems, Inc. 16 pp.

Herst & Associates, Inc. 2014. Detection Monitoring Program Groundwater

Statistical Analysis, Semi-Annual Report, May 2014 Sampling Event. Bridgeton

Landfill, LLC. Bridgeton Landfill, Bridgeton, Missouri. MO DNR Permit #MO-

118912. 684 pp.

Herst & Associates, 2015. Second Quarter 2015 Assessment Monitoring Event

Summary Report, Bridgeton Landfill, LLC-Bridgeton Landfill, Bridgeton, Missouri,

Missouri Department of Natural Resources Permit #MO-118912. 14 pp.

Missouri Department of Natural Resources, 1985. Letter from Director Frederick

A. Brunner to Mr. William McCullough, President, West Lake Landfill, Inc. RE:

Solid Waste Disposal Area Operating Permit #118912. 8 pp.

Missouri Department of Natural Resources, 2003. Letter RE: Groundwater

impact to monitor well 114-AS from PM Resources.

22

Oneacre, John, and Figueras, Deborah, 1996. Innovative Ground Water

Monitoring at Municipal Solid Waste Landfills. Proceedings: Texas Solid Waste

Management Conference, Austin, TX. 13 pp.

Price, Peter, 2015. Bridgeton Sanitary Landfill Groundwater Investigation

Report, St. Louis County, Missouri. August, 2015. 58 pp.

USEPA, 1988. Project Summary: Municipal Landfill Gas Condensate,

Hazardous Waste Engineering Research Laboratory, Cincinnati, OH 45268,

EPA/600/S2-87/090. 4 pp.

USEPA, 1994. Laboratory Data Validation Functional Guidelines for Evaluating

Organics Analyses, Office of Solid Waste and Emergency Response,

EPA/540/R/94/082. 47 pp.

USEPA, 1994. USEPA Contract Laboratory Program National Functional

Guidelines for Organic Data Review, Office of Solid Waste and Emergency

Response, EPA/540/R-94/012. 129 pp.

USEPA, 2008. Record of decision, West Lake Landfill Site, Bridgeton, Missouri,

Operable Unit 1, May, 2008. Prepared by US EPA, Region 7, Kansas City,

Missouri. 112 pp.

23

Wronkiewicz, Dr. David J., 2015. Report on Redox Reactions from the Chemical

Composition of Water Collected from the PZ-104-SD and PZ-106-SD Monitoring

Wells at the Bridgeton Sanitary Landfill, St. Louis, County, Missouri. 7 pp.

ONEACRE_0000024