RA-1530_9807_CA_RPTS_19930301

RICHMOND ENVIRONMENTAL SERVICES, INC.
Environmental Consulting Assessment & Remediation Services
CORRECTIVE ACTION PLAN
HOLLAND BP FACILITY
WILSON, NORTH CAROLINA
Prepared For:
Comer Oil Company
1553 South Church Street
Rocky Mount, North Carolina
March 1993
P.O. Box 5336 • Raleigh, North Carolina 27650 • [phone]
RICHMOND ENVIRONMENTAL SERVICES, INC.
Environmental Consulting Assessment & Remediation Services
'^^CEIVEd
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CORRECTIVE ACTION
HOLLAND BP FACILITY
WILSON, NORTH CAROLINA
Prepared For:
Comer Oil Company
1553 South Church Street
Rocky Mount, North Carolina
By:
RICHMOND ENVIRONMENTAL
SERVICES, INC.
GEO-SOLUTIONS, INC.
Martin R. Richmond
Project Manager
Richard E. Bolich, P.O.
Geologist
March 1993
P.O. Box 5336 Raleigh, North Carolina 27650 [phone]
RICHMOND ENVIRONMENTAL SERVICES, INC.
Environmental Consulting Assessment & Remediation Services
CORRECTIVE ACTION PLAN
HOLLAND BP FACILITY
WILSON, NORTH CAROLINA
1.0 INTRODUCTION
This Corrective Action Plan has been prepared by Richmond Environmental Services,
Inc. and Geo-Solutions, Inc. on behalf of Comer Oil Company of Rocky Mount, North
Carolina. This report is submitted in response to a release of petroleum products from
a commercial underground storage tank system as required under Title 15A of the
North Carolina Administrative Code Subchapter 2N Section .0707 Corrective Action
Plan.
It is the purpose of this report to describe and present a system for the restoration of
soil and groundwater at the facility. The intended remediation system for contaminated
soil is designed to prevent further migration of contaminants to the groundwater at the
site. The intended remediation system for contaminated groundwater is designed to
restore the affected areas in accordance with Title 15A of the North Carolina
Administrative Code Subchapter 2L Section .0106 Corrective Action. The information
presented in this report shall be used to specify, construct, install and monitor the
corrective action system.
Included in this report are sections detailing the site description, the extent of
contamination, the site geology and hydrogeology, the corrective action system and the
monitoring and reporting of the system.
P.O. Box 5336 • Raleigh, North Carolina 27650 • [phone]
Corrective Action Plan
Holland BP Facility
March 15, 1993
2.0 SITE DESCRIPTION
2.1 Site Location and Setting
The subject site is a former retail petroleum outlet and automotive service stati<Mi
located at the intersection of NC Highway 301 South and Goldsboro Road in the City
of Wilson, NC in Wilson County. A site location map is presented in Figure 1.
The site is located entirely within the City Limits of Wilson, NC. Water and sewer
utilities are provided to the site by the Wilson County Public Works Department.
Underground utitlites exist along the roadways fronting the property. Overhead utilites
cross the site at various points. No potable water supply wells are located within 1500
feet of the property.
2.2 Source Inventory
Two underground storage tank systems have been used at the facility in the past. The
first system, located on the northwest section of the property consisted of three UST
units of unconfirmed size or product type with an associated dispenser island. This
system was never operated by Comer Oil Company and is believed to have been
abandoned since 1961, when a second system was brought into service. This
abandoned UST system is shown on the Site Diagram in Figure 2.
The first system was permanently closed in place by Comer Oil Company in 1990.
Samples collected during the system closure by UTTS, Inc. of Greenville, NC
indicated no presence of contaminant release. A report detailing this information was
submitted to the NC Division of Environmental Management Raleigh Regional Office
(NCDEM/RRO) in April 1990.
The second UST system, located on the eastern portion of the property, consisted of
one 3000 gallon gasoline unit, three 2000 gallon gasoline units and one 550 gallon
waste oil unit. Also included with the system was one product dispenser island, located
on the southern central portion of the property and associated piping. This system,
owned by Comer Oil Company, was installed in 1961 and remained in use until
permanent closure and removal in 1991. This UST system is shown in the Site
Diagram presented in Figure 2.
Soil samples collected during the permanent closure of the second UST system by
Mangum Oil Spill Resources, Inc. of Wilson, NC indicated the presence of
contaminant release. Further investigation requested by the NC DEM/RRO indicated
the presence of groundwater contamination.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
2.3 Previous Site Investigations
An Initial Site Characterization (ISC) investigation was begun by Richmond
Environmental Services, Inc. of Raleigh, NC in June 1992. Soil and groundwater
samples were collected from around both UST storage areas and dispenser islands.
Results of laboratory analysis confirmed the presence of soil and groundwater
contamination. An ISC Report detailing the findings was submitted to the
NCDEM/RRO in September 1992.
Further investigation was conducted at the site in September and October 1992. In
November 1992, a Comprehensive Site Assessment Report was prepared and submitted
to the NCDEM/RRO. This report contains detailed descriptions of the site
characteristics and contaminant presence.
A Notice of Violation of the North Carolina Groundwater Standards (15A NCAC 2L
Section .0202) was issued to Comer Oil Company on December 8, 1992 requesting a
plan for the restoration of the groundwater in accordance with 15A NCAC 2L .0106.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
3.0 EXTENT OF CONTAMINATION
This section outlines a summary of the extent of contaminant presence as defined in the
Comprehensive Site Assessment Report for the subject facility dated October 30, 1992.
3.1 Extent ofSoil Contamination
A series of soil samples was collected at the site during the Initial Site Characterization
and the Comprehensive Site Assessment. These samples were collected in accordance
with all standard soil sample collection protocol as established by the US
Environmental Protection Agency and the NC Division of Environmental Management
from areas where soil contamination was most likely to be present.
All samples were submitted for laboratory analysis using EPA Method 5030 for Total
Petroleum Hydrocarbons in the volatile product range. Results of laboratory analysis
indicate the presence of petroleum constituents in the area around the south central
dispenser island. All other samples revealed no presence of contamination. Results of
the Eeld screening and laboratory analysis for all soil samples are presented in Table 1.
A diagram showing the location of all soil sample collection points and the estimated
extent of soil contamination is presented in Figure 3.
The soil contamination at the site is generally limited to the area between the central
dispenser island and the former UST storage area on the western portion of the
property. The most probable source of the contamination remaining in place at the site
is leakage from beneath the product dispenser island. Contaminated soil in the UST
storage area was excavated during the UST system closure and the area backfilled with
clean sand. No contamination was detected either during the field screening or in
laboratory analysis of soil samples collected in the area of the abandoned UST system.
3.2 Extent of Groundwater Contamination
Three series of groundwater samples were collected from monitoring wells across the
site. All samples were collected in accordance with all standard groundwater
monitoring protocol as established by the US Environmental Protection Agency and the
NC Division of Environmental Management.
Ground water samples were submitted for laboratory analysis using EPA Method 601
for halogenated volatile hydrocarbons, EPA Method 602 for volatile aromatic
hydrocarbons including Methyl Tertiary-Butyl Ether (MTBE) and EPA 625 for
semivolatile aromatic hydrocarbons.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
Results of the laboratory analysis indicate the presence of petroleum compounds in all
shallow monitoring wells at the site. These compounds detected include benzene,
toluene, ethylbenzene, meta-, ortho-, and para-xylenes, MTBE and naphthalene. No
contamination was detected in the deep cased type HI monitoring well at the site. A
summary of the results of all ground water sample analysis is presented in Table 2.
The extent of the groundwater contamination appears to originate in the area around the
central dispenser island and extends northwest following preferred groundwater
migration pathways. A diagram showing the monitoring well locations and estimated
extent of total BTEX presence (Benzene, Toluene, Ethylbenzene and Xylenes, total) is
included in Figure 4A. A diagram showing the estimated extent of MTBE presence is
included in Figure 4B.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
4.0 SITE GEOLOGY AND HYDROGEOLOGY
4.1 Regional Geology
The Holland BP site lies within the western portion of the Coastal Plain physiographic
province. The western portion of the Coastal Plain physiographic province is
characterized by gently sloping, low amplitude hills with fair to excellent drainage.
This is contrasted with the extensive low elevation marshes and typically poor drainage
found in the eastern portion of the Coastal Plain.
The Coastal Plain was formed by marine and non-marine sediments that were deposited
during the late Mesozoic (Cretaceous) Age to the present. During this period of time,
the sea level oscillated along the eastern portion of North Carolina from a line just east
of Raleigh to the edge of the continental shelf. The sediments that form the Coastal
Plain were deposited in response to the rising and falling sea levels. Coastal Plain
sediments are generally thinnest along the western edge of the province, and thicken
towards the East. Regional groundwater flow is generally from the Northwest to the
Southeast.
The Holland BP site lies on the western fringe exposure of the Yorktown Formation.
The Yorktown Formation is a Pliocene aged (2 to 5 million years ago) predominantly
marine deposit. It is characterized by arenaceous (sandy) clays with occasional shelly
sand lenses. The Yorktown Formation is believed to represent the remains of a shallow
shelf sea that once extended from Maryland to northern Florida (Ward, Bailey, and
Carter, 1991). This deposit is found directly on top of crystalline bedrock in the
vicinity of Wilson. Minor deposits of alluvium may be found on top of the Yorktown
Formation in the vicinity of creeks and streams.
Crystalline bedrock is believed to occur underneath the Yorktown Formation. No
bedrock was observed in any of the monitoring well borings at the site, but bedrock in
nearby areas is part of the Eastern Slate Belt. Therefore, it is believed that bedrock at
this site would be composed of metavolcanic and metasedimentary rocks with
occasional granitic intrusions and batholiths.
No significant faults or fractures are known to exist in the immediate vicinity of
Wilson. Cenozoic tectonism has been documented in the Coastal Plain, but these
occurrences are rare and usually localized.
4,2 Site Geology
A total of eight soil borings, seven shallow and one deep, have been installed at the site
as part of the previous investigations. These borings were created during the
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Corrective Action Plan
Holland BP Facility
March 15, 1993
installation of groundwater monitoring wells and during the air sparging pilot test.
Logs of the subsurface conditions in the four monitoring wells installed by Richmond
Environmental Services, Inc. are included in the Comprehensive Site Assessment
Report. The boring log for the air sparging well is presented in the Air Sparging
Feasibility Study Report in Appendix A. Boring logs for the three monitoring wells
installed by UTTS (MW-1, MW-2, and MW-3) are not available.
The monitoring well borings indicate that the site is underlain by a variable amount of
fill material that was brought to the site from an unknown source. The fill material
was placed on top of the naturally occurring soil, and contains varying amounts of silt,
sand, and clay as well as wood, bricks, glass, and other foreign matter. The fill
material is typically a brown to gray clayey sand, with minor amounts of silt. This
composition is typical for the Yorktown Formation, and may be evidence that the fill
was derived from a nearby source. The thickness of the fill varies across the site fit>m
approximately 10 feet in the vicinity of MW-6 and DW-1 to approximately 5 feet thick
in the vicinity of MW-5.
Yorktown deposits are found directly underneath the fiU material. The Yorktown
deposits are identified by increased clay content and increased density. At the Holland
BP site, the Yorktown deposits are composed of gray sandy and silty clay. The
Yorktown deposits appear to constitute an aquitard throughout the site due to their high
clay content. The actual thickness of the Yorktown sediments at the Holland BP site is
unknown due to the fact that none of the monitoring wells or soil borings at the site
have fully penetrated the Formation.
A stratigr^hic cross-section of the site has been constructed based upon available
boring logs. This cross-section is presented in Figure 5.
4.3 Site Hydrology
A total of seven groundwater monitoring wells were installed at the Holland BP site.
The purpose of the monitoring wells was to define groundwater quality and to provide
data needed to assess the shallow groundwater hydrology at the site. The monitoring
wells were installed in accordance with NC Division of Environmental Management
Well Construction Standards (15A NCAC 2C).
The site was surveyed by Boney & Associates, Inc. of Raleigh, NC to establish a
relative baseline elevation of 100 feet at the site. Monitoring wells were located
relative to the established vertical elevation. The depth to groundwater in the
monitoring wells has been measured at various times using an electronic water level
indicator. The water level probe was decontaminated by a de-ionized water rinse
before use in each well.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
The elevation of the water table was then calculated by subtracting the measured depth
to the water from the established top of casing elevation for each well. Table 3
contains a summary of water table elevations. Figure 6 is a potentiometric map
constructed from the February 4, 1993 water level data.
The shallow groundwater flow direction is towards the Northwest to West across the
site. The horizontal hydraulic gradient was estimated to be 0.05 based on data obtained
from measurements collected February 4, 1993. The vertical hydraulic gradient cannot
be determined directly from the available water level data. However, due to the
significantly lower groundwater elevation in the deep cased monitoring well, it can be
assumed that there is a downward vertical hydraulic gradient.
The groundwater elevation data indicates that the majority of the site is underlain by a
perched water table. The evidence for a perched water table is the significantly lower
groundwater elevation in the deep cased monitoring well, DW-1. There is a dense clay
layer below the fill that appears to be functioning as an aquitard or aquiclude. This
clay layer corresponds to the approximate top of the Yorktown sediments. Since there
is a saturated zone below the clay layer, it is assumed that the true water table is the
phreatic surface in DW-1. However, due to the fine grained and heterogeneous nature
of the Yorktown Formation, there may be other perched zones below the depth of DW-
1.
In the absence of recharge from rainwater and snow-melt, the perched water table
would eventually disperse. The downward hydraulic gradient suggests that the true
water table is recharged at least in part by the perched water table. The true water
table may also be recharged by up-gradient sources, but since the Holland BP site is
located near the crest of a hill, this contribution is expected to be minor. Groundwater
from both aquifers probably discharges into an unnamed creek located to the Northwest
of the site.
In-situ hydraulic conductivity testing was conducted at this site in October of 1992 by
Environmental Investigations, Inc. of Durham, NC. Rising and falling head tests (slug
tests) were conducted on the seven monitoring wells to determine the average hydraulic
conductivity. The results of the hydraulic conductivity testing indicated that the
average hydraulic conductivity of the aquifer is 0.7 feet per day.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
5.0 CORRECTIVE ACTION SYSTEM DESCRIPTION
5.1 Objectives of Corrective Action System
The goals of the Corrective Action System for the Holland BP site are two-fold;
remediation of the source of subsurface contamination and remediation of the
groundwater contaminant plume (residual contamination). In order to prevent further
spread of the contamination and to assist the natural degradation of the hydrocarbons, a
corrective action system is hereby proposed.
5.1.1 Soil Remediation
One of the primary goals of the corrective action system at the Holland BP site is to
reduce the concentration of hydrocarbons in the unsaturated soil. Analytical data
suggest that the soil in the vicinity of the south pump island is a source of hydrocarbons
within the subsurface environment. Since the site is paved, the direct exposure risk
posed by the contaminated soil is negligible. Groundwater contamination can occur
when precipitation infiltrates the contaminated soil and recharges the perched water
table. Therefore, reducing or eliminating the soil contamination should decrease the
mass of contaminants impacting the groundwater.
Soil remediation will be accomplished by a combination of two remedial technologies;
air stripping and enhanced bioremediation. Air will be forced to circulate through the
soil via an air injection well and a vapor interception system (VIS). Forcing air
through the contaminated soil will cause volatile hydrocarbon compounds adhering to
soil particles to partition into the vapor phase. Compounds that have entered the vapor
phase will be removed from the subsurface environment by the VIS system.
Circulating air through the contaminated soil will also increase the oxygen content of
the soil, allowing for enhanced aerobic microbial growth. Increased microbial activity
will serve to increase the degradation and oxidation of the hydrocarbons present, thus
decreasing contaminant levels.
5.1.2 Groundwater Remediation
A second goal of the remedial action system will be to lower the concentration of
hydrocarbons in the groundwater. Benzene, toluene, ethylbenzene, xylenes, and
MTBE levels should be lowered to concentrations approaching North Carolina 2L
Groundwater Quality Standards for Class GA Waters. The goal of groundwater
remediation will be to reduce the hydrocarbon concentrations in the perched water table
and minimize the threat to the true water table and surface water.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
Groundwater remediation will be accomplished by an air sparging system. The air
sparging system will consist of an air injection well screened below the perched water
table and the VIS system. Air will be forced to circulate through the contaminated
groundwater, resulting in the in-situ stripping of volatile hydrocarbons and an increase
in the dissolved oxygen (DO) concentration.
The primary beneficial effect of the air sparging system will be to increase the DO
level in the groundwater, resulting in a substantial increase in the aerobic microbial
population, thus increasing hydrocarbon degradation. Contaminant removal resulting
from in-situ air stripping is not expected to be as significant as the contaminant
degradation resulting from increased DO levels. Air injection will help to mobilize
adsorbed hydrocarbons in the soil and groundwater, allowing recovery of the
contaminants by the VIS system.
5.2 System Selection Rationale
On the basis of the results of the CSA, it was determined that the subsurface condititms
at the Holland BP site were potentially conducive to the use of air sparging as a
remedial option. Air sparging is an effective and inexpensive in-situ technique which
can be used to remediate soil and groundwater contaminated with petroleum
hydrocarbons. Based on this information, a pilot test was conducted in January 1993 to
evaluate the feasibility of air sparging at the site.
The results of the pilot test indicate that air sparging is a feasible technology for site
remediation. This is based on the following effects observed during the air sparging
pilot test:
• Increased DO concentration in the groundwater.
• Increased organic vapor concentrations in soil vapor monitoring wells.
• Noticeable effect on static water table elevation.
• Noticeable effect on contaminant concentration.
A copy of the Air Sparging Feasibility Study Report containing the results and
conclusions of the air sparging pilot test is included in Appendix A.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
5.3 Description of Air Injection System
A galvanized steel well point was used to inject air into the groundwater during the air
sparging pilot test. The location of this well is shown in Figure 7, and the construction
of the well is shown on Figure 8. Since this well is located in the approximate center
of the soil and groundwater contamination, and the well is screened at the appropriate
level, the existing air injection well will be utilized for the corrective action system.
The data from the air sparging pilot test indicate that the existing air injection well has
a radius of influence of at least 50 feet. This well is therefore appropriate for use in
the final corrective action system.
An oil-less compressor will be utilized as the injection air source. A coalescing filter, a
pressure gauge capable of measuring air pressure from 0 to 30 pounds per square inch
(psi), a flow meter capable of measuring air flow rates between 0 and 10 cubic feet per
minute (cfm), and a flow regulating valve will be part of the air delivery
instrumentation and controls. Figure 9 shows a schematic diagram of the air injection
controls and instrumentation. A pressure sensor attached to a low pressure alarm will
also be placed in the air injection line to warn of system shut-down or malfunction.
In order to minimize the mounding effect caused by the air injection, the injection rate
will be regulated during system start-up. The air injection rate will be adjusted
manually to achieve the highest injection rate that does not cause an increase in the
static water level in MW-6.
5.4 Description of Vapor Interception System
Due to the high organic vapor concentrations measured in the vapor monitoring wells
during the air sparging pilot test and to improve the overall efficiency of the remedial
action system, a vapor interception system (VIS) will be installed. A trench system
was selected for vapor removal due to the shallow depth to water (less than six feet)
and to minimize the groundwater upwelling.
The VIS trench will be similar in design to a dry French drain. Figure 10 shows a
cross-sectional view of the VIS trench. The soil excavated during trench installation
will be used to backfill the excavation. The top of the trench will be paved in order to
minimize the amount of surface water and external air infiltration into the trench. The
asphalt cap on the trench will also be sloped to provide for rainwater run-off control.
The layout of the VIS will be a rectangular-shaped shallow trench manifolded to a
vacuum pump system. The VIS trench will be installed at the approximate edge of the
estimated contaminated soil zone and in a location that will intercept mobilized volatile
hydrocarbons. Figure 11 shows a plan view of the VIS design.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
6.0 CORRECTIVE ACTION SYSTEM OPERATION
6.1 Permits
The proposed corrective action system will have minimal permitting requirements. A
well construction permit will be required for the air injection well and may be required
for the vapor interception trench. Due to the fact the system will discharge
hydrocarbon vapors to the air, it will be registered with the DEM Air Quality Section.
Under present regulations, an air permit would only be required if the mass of
contaminants discharged to the air exceeds 40 pounds per day.
A non-discharge permit may be required from the DEM Water Quality Section. Due to
the fact that air sparging is a relatively new technology, the present regulations are
unclear whether or not a non-discharge permit would be required. A non-discharge
permit application would require a set of plans and specifications for the system to be
prepared and sealed by a North Carolina licensed Professional Engineer.
Since there is no discharge to storm drains or surface water, a NPDES permit is not
required. A pretreatment permit will not be required since there will be no discharge
to a wastewater treatment plant. At present, an Authorization to Construct permit is
required if the treatment system discharges to surface waters and is issued after a
NPDES permit. Therefore, an Authorization to Construct permit may not be required
for this system.
6.2 System Initiation
After the necessary permits have been obtained, the air compressor and conveyance
system will be assembled and rendered operational. The air injection system will then
be tested for leaks and malfunctions. Leaks and malfunctions will be repaired and
corrected as necessary.
After the air injection system is rendered operational, the air delivery pressure and flow
rate will be adjusted by gradually increasing these levels until the first rise in the static
water level measured in MW-6 is noted. The air injection pressure and flow rate will
be set to the highest level possible without effecting the water level in MW-6. On the
basis of the results of the air sparging pilot test, it is anticipated that the air injection
pressure will be approximately 4 psi with an approximate flow rate of 2 cfm.
The vapor interception system will be constructed after the air injection system has
been completed and tested. The location of known underground utilities will be
identified in the VIS trench plans. The plans and specifications for construction of the
VIS trench will include the relocation of underground utilities, if necessary.
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Corrective Action Plan
Holland BP Facility
March 15, 1993
After the VIS trench has been installed, it will be connected to the vapor removal
vacuum blower. The estimated operational vacuum pressure will be determined by the
design engineer. During start-up of the vapor removal system, static water levels will
be monitored, with the VIS vacuum rate adjusted to avoid creating a rise in the static
water table.
The level of organic vapors will be monitored at the air discharge point of the VIS to
estimate the contaminant mass discharge rate. The pounds per day of hydrocarbons
discharged to the atmosphere will be calculated from readings obtained by a portable
organic vapor analyzer. The VIS discharge rate will be adjusted, if necessary, to
prevent the contaminant mass discharge rate from exceeding 40 pounds per day.
6.3 System Operation
The air sparging system will operate continuously under the parameters determined
from the engineering report and system initiation. Sensors will monitor injection air
pressure and/or flow rate, vacuum pressure and/or flow rate of the VIS, the presence of
water in the VIS, and power supply. The corrective action system will be equipped
with a programmable logic control circuit that will shut the entire system down and an
alarm will be issued if one or more of the following conditions are detected:
• Air injection pressure and/or flow drops to zero or exceeds maximum
designed operating parameters.
• Vacuum pressure and/or flow drops to zero or exceeds maximum designed
operating parameters.
• Excess water is present in the VIS caused by stormwater or an excessive rise
in the static water table.
• Power supply is interrupted due to ground fault or electrical service
interruption for more than one hour.
The system logic controller will be connected to a telephone line that will allow the
alarm to be communicated to a remote sensor such as a FAX machine or computer. In
the event of an alarm, a manual inspection of the system will be conducted to assess the
problem and correct it. If power is interrupted for less than one hour, the system shall
be equipped to re-start automatically.
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6.4 Monitoring & Reporting
A system for groundwater and vapor discharge monitoring will be implemented under
the following schedule:
Prior to System Installation:
Groundwater Samples
Static Water Levels
During System Installation:
Vapor Discharge Levels
Static Water Levels
*ost System Installation (7 Days Following):
Groundwater Samples
Vapor Discharge Levels
Static Water Levels
Monthly (First Three Months ofSystem Operation):
Groundwater Samples
Vapor Discharge Levels
Static Water Levels
Monthly (Remainder ofSystem Operation):
Vapor Discharge Levels
Static Water Levels
Qjarterly (Remainder of System Operation):
• Groundwater Samples
Data obtained from the system monitoring will be submitted to the NO Division of
Environmental Management Raleigh Regional Office on a quarterly basis in the form of
Quarterly Monitoring Reports. All groundwater samples will be analyzed using EPA
Method 602 + MTBE 4- DIPE and EPA Method 625. Quarterly Monitoring Reports
will include summary tables of results of laboratory analysis, static water levels and
vapor discharge levels. In addition, copies of laboratory analysis reports, groundwater
elevation contour diagrams and contaminant presence isopleths will be included.
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March 15, 1993
7.0 SYSTEM CLOSURE
Contaminant levels in groundwater samples will be statistically analyzed throughout the
quarterly monitoring process. A such a time that groundwater contaminant levels have
appeared to stabilize at a minimal presence over a period covering three quarterly
reports, a request shall be submitted to the NC Division of Environmental Management
for site closure or reclassification.
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TABLES
HOLLAND BP FACILITY
Wilson, North Carolina
RESULTS OF LABORATORY ANALYSIS
Table 2
Date:3/l8/93
Date Sampled:7/6/92 9/24/92 1/27/93 2/5/93
Monltortno Well: MW-1
EPA Method 602
Benzene
Toluene
Ethyl benzene
Xylenes, Total
Total BTEX
MTBE
EPA Method 626
Naphthalene
2200.00 310.00 250.00 130.00
960.00
100.00 <10
400.00 39.00
21.00 <50
<50
n/r
9.10
3.40
n/r
3660.00 370.00 250.00 142.50
140.00 190.00 <100 58.00
• •• • n/s
NC 2L Standards
1.00
1000.00
29.00
400.00
200.00
n/d
Monitoring Well: MW-2
EPA Method 602
NC 2L Standards
Benzene 4.40 •«n/s 1.00
Toluene 3.60 •n/s 1000.00
Ethyi benzene 0.69 «•n/s 29.00
Xyienes, Total 2.60 •n/r n/s 400.00
Total^BTEX 11.29 0.00 0.00 n/s
MTBE 1.40 3.40 * *n/s 200.00
EPA Method 625
Naphthalene •• ••n/s n/d
NOTES:All Results Reported in Parts Per Billion (ug/l)
• = Below Detection Limit of 1.00 ppb; •• = Below Detection Limit of 2.00 ppb
n/s = Not Sampled; n/r ■= Not Reported; n/d = No Detection;
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HOLLAND BP FACILITY
Wilson, North Carolina
Pate Sampled:
Monltortng Welh MW-3
EPA Method 602
Benzene 2.30
Toluene 1-30
Ethyl benzene •
Xylenes, Total 1.10
Total BTEX 4.70
MTBE 120.00
EPA Method 625
Naphthalene •
7/6/92
RESULTS OF LABORATORY ANALYSIS
Table 2
Date:3/18/93
9/24/92 1/27/93 2/5/93
0.00
77.00
n/r
0.00
30 00
n/s
n/s
n/s
n/s
n/s
n/s
n/s
NC 2L Standards
1.00
1000.00
29.00
400.00
200.00
n/d
Monltorlna Well: MW-4
EPA Method 602
NC Standards
Benzene 1.50 •••1.00
Toluene 1.10 •••1000.00
Ethyl benzene **••29.00
Xylenes, Total 2.50 •n/r n/r 400.00
Tata! BTEX 5.10 0.00 0.00 #
MTBE 5.30 42.00 2.80 6 80 200.00
EPA Method 625
Naphthalene • ••n/s n/d
NOTES:All Results Reported In Parts Per Billion (ug/I)
• =n Below Detection Umlt of 1.00 ppb; •* = Below Detection Limit of 2.00 ppb
n/s = Not Sampled; n/r = Not Reported; n/d = No Detection;
Page 2
HOLLAND BP FACILITY
Wilson, North Carolina
RESULTS OF LABORATORY ANALYSIS
Table 2
Date:;5/l8/93
Date Sampled:7/6/92 9/24/92 1/27/93 2/5/93
Monitoring Well: MW-5 NC Standards
EPA Method 602
Benzene 0 ••n/s 1.00
Toluene *tt •n/s 1000.00
Ethylbenzene t »•n/s 29.00
Xylenes, Total «»n/r n/s 400.00
Total BTEX 0.00 0.00 0.00 n/s
MTBE 11.00 42.00 6.00 n/s 200.00
EPA Method 625
Naphthalene «• »*n/s n/d
Monitoring Well: MW-6 NC Standards
EPA Method 602
Benzene n/a 480.00 980.00 1300.00 1.00
Toluene n/a 200.00 540.00 1300.00 1000.00
Ethylbenzene n/a 66.00 83.00 150.00 29.00
Xylenes, Total n/a 217.00 n/r n/r 400.00
Total BTEX n/a 963.00 1603.00 2750.00
MTBE n/a 690.00 400.00 780.00 200.00
EPA Method 625
Naphthalene n/a 12.00 20.00 n/s n/d
NOTES:All Results Reported In Parts Per Billion (ug^)
• = Below Detection Limi1:of1.00ppb; = Below Detection Limit of 2.00 ppb
n/s = Not Sampled; n/r = Not Reported; n/d = No Detection;
Page 3
HOLLAND BP FACILSTY
Wi!son, MobIISti CaroSSjua
RESULTS OF LABO^TORY
TabSa 2
Oat9:3/18/93
Date Sam^ed:7/6/92 9/24/92 1/27/93 2/5/93
Monitorinfl Weil: DW-1 NC Standards
EPA Method 602
Benzene n/a •«n/s 1.00
Toluene n/a ••n/s 1000.00
Ethyl benzene n/a ••n/s 29.00
Xylenes, Total n/a •n/r n/s 400.00
Total BTEX n/a 0.00 0.00 n/s
MTBE n/a <2 • •n/s 200 00
EPA Method 825
Naphthalene n/a •n/s n/d
NOTES;All Results Reported in Parts Per Billion (ug/l)
• = Below Detection Limit of 1.00 ppb; • • = Below Detection Limit of 2.00 ppb
n/s = Not Sampled; n/r = Not Reported; n/d = No Detection;
Page 4
HOLLAND BP FACILITY
Wilson, North Carolina
RELATIVE GROUNDWATER ELEVATIONS
Table 3
Dato:3/17/93
Datd Messured:
Well ID: MW-1
Top of Casing:
Depth to Water
Groundwater Bevatlon:
7/6/92
99.46
6.62
92.84
9/24/92 10/24/92
99.05
9.00
90.05
1/27/93 2/4/93 2/13/93 3/10/93
99.05
6.10
92.95
99.05
4.74
94.31
99.05
5.34
93.71
99.07
5.54
93.53
99.07
5.23
93.84
Well ID: MW-2
Top of Casing:
Depth to Water
Groundwater Qevation:
98.24
5.45
92.79
98.08
4.76
93.32
98.08
4.81
93.27
98.08
3.23
94.85
98.08
3.84
94.24
97.85
4.07
93.78
97.85
3.72
94.13
WelllD: MW-3
Top of Casing:
Depth to Water
Groundwater Elevation:
95.60
5.36
90.24
95.40
4.77
90.63
95.40
4.98
90.42
95.40
3.33
92.07
95.40
3.99
91.41
95.17
3.92
91.25
95.17
3.36
91.81
WelilD: MW-4
Top of Casing:
Depth to Water
Groundwater Elevation:
100.24
7.35
92.89
100.15
6.75
93.40
100.15
6.74
93.41
100.15
5.34
94.81
100.15
5.89
94.26
99.84
6.08
93.76
99.84
5.76
94.08
WelllD: MW-6
Top of Casing:
Depth to Water
Groundwater Elevation:
93.66
6.21
87.45
93.02
6.00
87.02
93.02
5.98
87.04
93.02
5.12
87.90
93.02
5.26
87.76
93.25
5.40
87.85
93.25
5.22
88.03
WelilD: MW-6
Top of Casing:
Depth to Water
Groundwater Qevation:
99.22
6.80
92.42
99.22
6.75
92.47
99.22
6.05
93.17
99.22
6.61
92.61
99.04
6.70
92.34
99.04
6.44
92.60
WeHID: DW-1
Top of Casing:
Depth to Water
Groundwater Qevation:
99.20
10.70
88.50
99.20
10.43
88.77
99.20
9.24
89.96
99.20
9.34
89.86
99.21
9.52
89.69
99.21
9.93
89.28
NOTES:AH Meesurenrients In Feet Not Meesured
Page 1
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APPENDIX A
Air Sparging Feasibility Study Report
AIR SPARGING
FEASIBILITY STUDY REPORT
HOLLAND BP STATION
WILSON, N.C.
Prepared For;
MCHMOND ENVIRONMENTAL SERVICES, INC.
Prepared By:
Geo-Solutions. Inc.
2*0SAMdmwmDrtm
RmU^NC TTtm
(9Iff 7tS-0US
February 10,1993
Holland BP
Feasibility Study Report
INTRODUCTION:
The purpose of this investigation was to obtain on-site data to evaluate the feasibility of air sparging to
remediate soil and groundwater contamination at the Holland BP site in Wilson, NC. Air sparging is the
process of injecting air into contaminated groundwater in order to remediate subsurface contamination
from volatile organic chemicals. The technique is relatively new to the American scientific community,
but has been used successfully in Europe for years. Due to the relatively simple components of an air
sparging system, and the fact that remediation takes place in-situ, the overall costs for remediation by air
sparging are much less than most other conventional treatment technologies.
Soil and groundwater contamination at the Holland BP site is relatively minor. A search for drinking
water supply wells did not reveal any wells within a half mile radius of the site. The subsurface
conditions at the site are favorable for in-situ treatment technology due to the presence of a thin layer of
high permeability deposits on top of a clay aquitard. Low exposure risks and favorable subsurface
conditions prompted the consideration of this site for an air sparging pilot test.
Page 2
Holland BP
Feasibility Study Report
FTFT.D SUMMARY:
January 27.1993
On-site field work began on January 27, 1993. Mr. Rick Bolich of Geo-Solutions, Inc., and Mr. Duncan
McManus of Richmond Environmental Services, Inc. were on-site to perform the work. On this day,
attempts to install the air injection well and vapor monitoring wells using a stainless steel hand auger
were unsuccessful due to the presence of subsurface debris. All of the monitoring wells were sampled on
that day. These samples are to be analyzed for benzene, toluene, ethylbenzene, xj-lenes, and methyl tert-
butyl ether (MTBE).
January 28, 1993
Field work continued on January 28, 1993. Mr. Bolich and Mr. McManus rented a power soil auger
drilling machine to install the air injection well and the vapor morutoring probes. The power auger was
able to penetrate the debris with little difficulty. Four-inch diameter solid stem augers were used to create
the boreholes for the air injection well and the vapor probes. An air sparge test well was drilled and 6
temporary soil vapor probes were installed in the vicinity of the former pump island located in the front of
the existing building. The locations of the air sparge test well and the temporary vapor probes are shown
on Figure 1. The construction specifications for the air sparge test well are shown on Figure 2.
The soil vapor probes were installed at a depth of five feet below the ground surface. Each vapor probe
consists of five feet of two-inch diameter schedule 40 PVC well screen. The lop six inches of the annular
space is sealed with bentonite. The top of the PVC well screen is flush to the ground surface and sealed
with duct tape to prevent turbulent air flow across the top of the probe. Soil hydrocarbon vapor levels
were obtained by inserting the OVA probe directly into a small hole in the duct tape.
January 29.1993
The air sparging test was initiated on January 29, 1993. Baseline parameters were measured before the
air sparging test began. Vapor phase hydrocarbon levels were measured in each of the soil vapor probes
using a portable organic vapor analyzer equipped with a flame ionization detector (Foxboro OVA). Water
levels and dissolved oxygen concentrations were measured in monitoring wells MW-1, MW-4, and MW-
6. The water levels were measured with an electronic water level probe which was decontaminated
between measurements with de-ionized water. Dissolved oxygen levels were measured by lowering a
decontaminated probe directly into the monitoring wells.
Page 3
Holland BP
Feasibility Study Report
The test was run at an initial air injection rate of 2 cubic feet per minute (cfm) at a pressure of 7 pounds
per square inch (psi). The compressed air was initially supplied by an existing air compressor. This air
compressor was used to supply pneumatic power for the former retail gasoline station. The following
diagram is a schematic illustration of the components and controls of the air injection system;
FLOW REGULATOR5
AIR
IN
COALESCING FILTER
FLOW
- -T METER
sip
PRESSURE
REGULATOR
&
GUAGE
TO INJECTION WELL
Slight hydrocarbon odors were occasionally noted in the vicinity of the vapor probes during the period of
air injection. OVA readings taken around the annular space of the air injection well showed no
signiilcant leakage around the grout seal. Air escaping from the top of VM-3 caused vigorous bubbling
action due to the presence of some standing water in this location.
The flow rate into the injection well was increased to 4 cfm @ 7 psi after a period of three hours. Water
appeared in the flow meter fifteen minutes after the air flow rate was increased to 4 cfm. The presence of
water in the flow meter caused erratic fluctuations in the air injection rate, so the air supply was shut off.
It was also noted that the air compressor delivery pressure had dropped approximately 80 percent, raising
doubts about whether or not the existing air compressor would be sufficient to complete the lest. The
decision was made to terminate the test in order to obtain a larger air compressor and to construct a water
vapor trap in the air delivery line.
Page 4
Holland BP
Feasibility Study Report
Fehniarv 2,1993
The air sparging test at the Holland BP site resumed on February 2, 1993. A portable gasoline powered
air compressor rated at 125 cfm was rented to supply compressed air. A U-shaped galvanized steel water
trap was installed in the air control manifold just ahead of the coalescing filter Baseline parameters were
measured in the monitoring wells and vapor probes before air injection commenced. Data from the
aborted January 29 test indicated a significant (0.5 foot) rise in the water level in MW-1 at 4 cfm.
Therefore, the test was conducted at a flow rate of 3.5 cfm @ 7 psi.
Data from the previous lest indicated possible drift in the dissolved oxygen (DO) meter as a result of
constant deconning of the probe and movement between wells. Therefore, the DO meter probe was left
immersed in MW-1, the closest monitoring well to the injection well, and the well with the greatest prior
increase in water level. In order to provide more accurate information on water level fluctuations during
the test, a pressure transducer (15 psi) and data loggers (In Situ Hermit lOOOC) were used to monitor
water levels in a logarithmic data collection mode. The transducer and data logger were also placed in
MW-1. Water levels, soil vapor hydrocarbon levels, and DO levels were measured at approximately thirty
minute intervals.
The air injection began at 11;06 AM. The air injection rate was maintained at a constant 3.5 cfm @ 7 psi.
Water levels and soil hydrocarbon levels began to equilibrate after approximately two hours. The
dissolved oxygen showed concentration in MW-1 showed a slight increase after approximately four hours
of air injection. Therefore, air injection was terminated after an elapsed test time of 6 hours and 19
minutes. Test parameters continued to be monitored after air injection was discontinued. A new
logarithmic data collection mode was programmed into the data logger at the exact moment air injection
was terminated.
Page 5
Holland BP
Feasibility Study Report
DISCUSSION
The performance of the air sparging system was evaluated by monitoring water levels, soil hydrocarbon
vapor levels, and dissolved oxjgen levels in the groundwater. These paiamelers were measured before,
during, and after air was injected into the aquifer. These data provide information on the radius of
influence of the air sparging well.
Soil hydrocarbon vapor levels were measured in the vapor probes with a portable organic vapor analyzer.
Table 1 contains a summary of the vapor probe readings, and Figure 3 is a bar chart graph of these
readings. The measured distances from the probes to the injection well are 5.0 feet to VM-l, 7.7 feet to
VM-2. 5.2 feet to VM-3, 14.9 feet to VM-4, 22.3 feet to VM-5. and 15.2 feet to VM-6.
Vapor levels were relatively high in probes VM-2 and VM-3 before the test began. The levels in these
two probes were in excess of 1,000 ppm throughout the period of air injection. However, after air
injection was discontinued, the vapor levels in these two probes fell to levels significantly lower than the
pre-test levels. This indicates that soil hydrocarbon vapors in this area have been exhausted to the
atmosphere, and/or have migrated laterally away from the air source.
Soil hydrocarbon vapor levels in probes VM-4, VM-5, and VM-6 were relatively low before the test
began. The levels increased gradually diuing the first three hours of air injection, after which time they
exceeded the instrument quantitation limit of 1,000 ppm. The vapor level in these two probes remained
above 1,000 ppm after the air was shut off.
The soil hydrocarbon vapor level in VM-l was low before the test began, but increased to over 1,000 ppm
an hour after air injection commenced. After the air was shut off, the vapor concentration level in this
probe dropped at least 20 percent, but did not return to the pre-test level. It is likely, however, that vapor
levels in all of the probes will eventually return to their pre-test levels. It is very likely that the fact that
most of the test site area is paved with asphalt or concrete contributed to the high vapor levels in the
probes. However, it should be noted that this situation should improve the efficiency of the final remedial
design, if vapor controls are implemented.
Page 6
Holland BP
Feasibility Study Report
Water levels obtained during the air sparging test revealed a significant rise in the elevation of the water
table due to air injection at monitoring wells MW-1 and MW-6. The water levels in monitoring well
MW-4 also indicate a rise in elevation, but to a lesser degree. Table 2 is a summary of the water table
elevations based upon the readings from the hand held electric water level probe. Figure 4 is a line chart
summary of the water levels. Figures 5 and 6 contain the water level data taken by the electronic data
logger in MW-1. This data shows that there was a time lag of 2.0 minutes from the time that air flow was
started or stopped until water levels in MW-1 (12.9 feet away) were affected.
The water table elevation data show a fairly sharp rise in water levels after the air was injected followed
by a slightly more gradual decline. This is most likely a result of air moving laterally through the aquifer
until reaching a point of higher vertical permeability. Air flowing through the aquifer will travel through
preferred pathways due to inhomogeneities in the medium. As the air migrates laterally, it displaces
groundwater, creating a temporary rise in the (water table) elevation until the air reaches the vadose zone
or the density of the overall medium reaches equilibrium. The water levels in the observation wells
remained slightly higher than their pre-test levels after falling off the peak rise. However, after the air
was shut off, the water levels fell to below pre-test elevations. The reason for this decline may be a
reduction in the overall density of the aquifer due to the air injection. Another possible explanation is that
there was a regional decline in water levels that was masked by the effects of air sparging.
The fact that water levels in MW-6 were impacted by the air sparging indicates that the radius of
influence of the air injection well is at least 50 feet. Since the air injection caused water levels to rise by
about 0.5 foot in the wells closest to the sparge well, it is likely that the hydraulic gradient increased
slightly near the injection well during the test. An increase in the hydraulic gradient could result in an
increased rate of contaminant migration, but this effect may be palliated by the beneficial aspects of air
sparging (removal of contaminants and increased oxygen content).
The dissolved oxygen levels in MW-1 showed a significant increase approximately five hours into the test.
Table 3 contains a summary of the dissolved oxygen data. The DO concentration in MW-1 increased by
more than 100 percent, which is compelling evidence that the increase was a result of the air sparging.
Page?
Holland BP
Feasibility Study Report
CONCLUSIONS
The data from the pilot test indicate that air spargmg is a viable technology to remediate the soil and
groundwater contamination at this site The soil hydrocarbon vapor levels, groundwater elevations, and
dissolved oxygen data obtamed from the pilot test suggest that the radius of influence of the air sparging
well IS at least 50 feet The potential cost savmgs of air spargmg over time versus conventional pump and
treat - excavate and haul technology warrants strong consideration for air spargmg, even m areas with
less than ideal conditions The data suggests that this site is an excellent candidate for remediation by air
spargmg
There are two factors that need to be carefully considered m the final remedial design The first factor is
that the soil vapor probe data mdicate that there will be a significant amount of hydrocarbon vapors
produced durmg air spargmg These vapors need to be controlled and removed to attam optimum
effiaency Therefore a soil vapor extraction system should be an integral part of an air spargmg system at
this site ^
Another factor that bears consideration for an air spargmg system conceptual design is mimmizmg the
mounding effect m the water table caused by the mjection of air It appears that decreasing the air
mjection rate to minimize groundwater mounding will result m a decrease m the eflBciency of
remediation Therefore, carefiil consideration of the benefits versus drawbacks of higher mjection rates is
warranted
Page 8
Table 1
Holland BP Station
Air Sparging Test
Soil Vapor Probe Readings (ppm)
TIME VM-1 VM-2 VM-3 VM-4 VM-5 VM-6
1040 90 900 1000 1 3 200
1130 1000 1000 1000 60 12 1000
1209 1000 1000 1000 220 71 1000
1253 1000 1000 1000 300 200 1000
1434 1000 1000 1000 1000 1000 1000
1522 1000 1000 1000 1000 1000 1000
1608 1000 1000 1000 1000 1000 1000
• 1645 1000 1000 1000 1000 1000 1000
1738 800 620 850 1000 1000 1000
Table 2
Holland BP Station
Air Spraging Test
Water Level Summary
TIME MW-1 MW-4 MW-6
1046 93 78 94 34 92 62
1137 94.30 94 40 92 71
1204 94 30 '94 41 93 48
1256 , 94.00 94 40 92.71
1344 93 92 94.39 92.70
1440 93 94 94 38 92 68
1525 93.92 94 37 92.67
1610 93.89 94 36 92.67
1647 93 88 94.36 92 66
1723 93 87 94.35 92 66
1743 93.52 94 29 92 58
1758 93.45 94.28 92.51
Table 3
Holland BP Station
Air Sparging Test
Dissolved Oxygen Concentrations
Time (Hrs)DO (mg/1)
1046 0.6
1137 0.6
1202 0.5
1256 0.6
1344 0.5
1440 0.6
1524 0.7
1610 1.2
1647 1.3
1723 1.4
1743 1.7
® = Wiorwtonn^ Well l^ocation
® = Air lnjecti(?n Te^t Well
MW-3
MW-2
MW-fe
MW-4
Highw^iy 3(91
^6)U^GE:
Richmond Environmential ^ervice^j Inc.
Gomprehen<?ive 3>ite A'p^e^'bment Report
Gctoher 3G,Geo-Solutions, Inc.
HGUUANP D-R ^TATIGN
EEA^DLITY ^TUQY
RERGRT
Ei^ure I
AiR ^RARGING
TEE)T WEUU UGGATIGN^
METhCD DRILLED;
Power Auger
V
HOLE D!A
I
TOP OF RISER CASING;
GROUND SURFACE
BACKFILL
TYPE; 5'/. BENTONITE GROUT
RISER CASING
OIA: 2 INCH
TYPE: GALVANIZED STEEL
-TOP OF SEAL
ANNULAR SEAL
TYPE: 3/8" BENTONITE PELLETS
BOTTOM OF SEAL
TOP OF SCREEN
BACKFILL TYPE; NATURAL
SCREEN DIA: 2 INCH TYPE; GALV.
OPNG, WIDTK 10 SLOT TYPE; MACHINE
BOTTOM OF SCREEN
—BOTTOM OF POINT
BOTTOM OF HOLE
Depth
6.0
8.0
11.1
13.2
14.0
14.0
COMMENTS;
WpII DrivFTi Intn (Vninrl
By Hammer for Lost Thiree Feet
Geo-Soiutions, Inc FIGURE 2
HOLLAND BP
AIR SPARGING
WELL SPECS.
1000
900
800
700
a
500
iO 400
300
200
100
1040
Background Levels
1130 1209 1253 1434 1522 1608
Time (Hrs)
1645
Air Shut Off
' □ VM-I
■ \m-2
I a VM-3
a vM-4
a VM-5
□ VM-6
Holland BP - Water Levels
94.50 -r
94.00
93.50 --
n
.2 93.00 +
>
0)
92.50 --
92.00 --
s.
S
s.
91.50
MW-1
MW-4
MW-6
1046 1137 1204 1256 1344 1440 1525 1610 1647 1723 1743 1758
Time (Hrs)
94. 10n
94.00
93.90
>
93.80
L
93.70-
0
FIGURE 5
nw-1
Air Sparging Pi lot Test
Ho [land BP St.
93.60^6-*-*-*-* Air On
93.50 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ''''''''' I
0.00 100.00 200.00 300.00 400.00
T I mo ("m I n )
93.80n
93.70-
® 93.60H
>
®
L 93.50 -
0
93.40-
93.30
FIGURE 6
* * * * * Air Off
nw-1
Air Sparging Pi lot Tost
Ho I I a n d BP St.
I I [ I I I I I I I I I I I I
0 . 00 1 0 . 00
I I I I I I I I I I I I I I I I
20.00 30.00
I I 1 I I
40. 00
Tit mo m t n
SEIOOOC
Environmental Logger
^ 02/03 09:05
Unit# 00592 Test 0
INPUT 1: Level (F) TOC
Reference 50.000
Linearity 0.100
Scale factor 15.090
Offset 0.090
Delay mSEC 50.000
Step 0 02/02 11:07:42
Elapsed Time INPUT 1
0.0000 50.181
0.0033 50 176
0.0066 50.181
0.0100 50.181
0 0133 50.181
0.0166 50.181
0.0200 50.181
0.0233 50.181
0.0266 50.181
0.0300 50.181
0.0333 50.181
0.0366 50.181
0.0400 50.181
0.0433 50.181
0.0466 50.181
0.0500 50.181
0.0533 50.181
0.0566 50.181
0.0600 50.181
0.0633 50.181
0.0666 50.181
0.0700 50.181
0.0733 50.181
0.0766 50.181
0.0800 50.181
0.0833 50.181
0.0866 50.181
0.0900 50.181
0.0933 50.181
0.0966 50.181
0.1000 50.181
0.1033 50.181
0.1066 50.181
0.1100 50.181
^ 0.1133 50.181
)0.1166 50.181
0.1200 50.181
0.1233 50.181
0.1266 50.181
0.1300 50.181
0.1333 50.181
0.1366 50.181
0.1400 50.181
0.1433 50.181
/-^1466 50.181
> jl500 50.181
0.1533 50.181
0.1566 50.181
0.1600 50.181
0.1633 50.181
0.1666 50.181
0.1700 50.181
0.1733 50.181
0.1766 50.181
0.1800 50.181
0.1833 50.181
0.1866 50.181
0.1900 50.181
0.1933 50.181
0.1966 50.181
0.2000 50.181
0 2033 50.181
0.2066 50 181
0.2100 50.181
0.2133 50 181
0.2166 50.181
0.2200 50.181
0.2233 50 181
0.2266 50.181
0.2300 50.181
).2333 50.181
il.2366 50.181
0.2400 50.181
0.2433 50.181
0.2466 50.181
0.2500 50.181
0.2533 50.181
0.2566 50.181
0.2600 50.181
0.2633 50.181
0.2666 50.181
0.2700 50.181
0.2733 50.181
0.2766 50.181
0.2800 50.181
0.2833 50.181
0.2866 50.181
\ 0.2900 50.181
0.2933 50.181
0.2966 50.181
0.3000 50.181
0.3033 50.181
0.3066 50.181
0.3100 50.181
^ 0.3133 50.181
^ y.3166 50.181
^^0.3200 50.181
0.3233 50.181
0.3266 50.181
0.3300 50.181
0.3333 50.181
0.3500 50.181
0.3666 50.176
0.3833 50.181
Ni).4000 50.176
J).4166 50.176
0.4333 50.181
0.4500 50.181
0.4666 50.181
0.4833 50.181
0.5000 50.181
0.5166 50.176
0.5333 50.181
0.5500 50.181
0.5666 50.181
0.5833 50.176
0.6000 50.176
0.6166 50 176
0.6333 50.176
0.6500 50 181
0.6666 50.176
0.6833 50.181
0.7000 50.176
0.7166 50.176
0.7333 50.176
0r7500 . 50.176
0.7666 50.176
0.7833 50.176
0.8000 50.176
0.8166 50.176
)0.8333 50.181
0.8500 50.176
0.8666 50.176
0.8833 50.181
0.9000 50.181
0.9166 50.181
0.9333 50.181
0.9500 50.181
0.9666 50.181
0.9833 50.181
1.0000 50.181
1.2000 50.181
1.4000 50.181
1.6000 50.181
1.8000 50.181
2.0000 50.176
2.2000 50.172
2.4000 50.172
2.6000 50.167
2.8000 50.167
3.0000 50.162
3.2000 50.157
3.4000 50.157
3 6000 50.152
3.8000 50.148) 4.0000 50.148
4.2000 50.143
4.4000 50.138
4.6000 50.129
4.8000 50.124
5.0000 50.114
5.2000 50.109
5.4000 50.105
5.6000 50.095
"^000 50.090
Joooo 50.090
6.2000 50.086
6.4000 50.076
6.6000 50.071
6.8000 50.062
7.0000 50.057
7.2000 50.047
7.4000 50.043
7.6000 50.033
7.8000 '50.028
8.0000 50.019
8.2000 50 014
8.4000 50.004
8.6000 50.000
8.8000 49.995
9.0000 49.995
9.2000 49.995
9.4000 49.990
9 6000 49.985
9.8000 49.980
10.0000 49.976
12.0000 49.923
14.0000 49.880
16.0000 49.837
A8.0000 49.799
Yoooo 49.780
22.0000 49.770
24.0000 49.761
26.0000 49.741
28.0000 49.741
30.0000 49.741
32.0000 49.746
34.0000 49.741
36.0000 49.741
38.0000 49.732
40.0000 49.741
42.0000 49.746
44.0000 49.765
46.0000 49.775
48.0000 49.799
50.0000 49.832
52.0000 49.832
54.0000 49.837
56.0000 49.832
58.0000 49.813
60.0000 49.823
62.0000 49.827
64.0000 49.823
66.0000 49.827
48.0000 49.856
jo.oooo 49.880
^72.0000 49.899
74.0000 49.918
76.0000 49.933
78.0000 49.952
^ 80.0000 49.966
82.0000 49.971
84.0000 49.971
86.0000 49.985
^^,.0000 49.985
^^J.OOOO 49.990
92.0000 49.990
94.0000 49.985
96.0000 49 995
98.0000 49.990
100.000 49.995
110.000 50.004
120.000 50.014
130.000 50.004
140.000 50.004
150.000 50.004
160.000 50 009
170 000 50.004
180.000 50.000
190.000 49.995
200.000 49.995
210.000 50.004
220.000 49.995
230.000 50.004
240.000 50.000
250.000 50 000
260.000 50.000
270.000 50.000
280.000 50.004
290.000 49.995
')0.000 50 009
^^,10.000 50.014
320.000 50.004
330.000 50.004
340.000 50.004
350.000 5I0.OOO
360.000 50.004
370.000 50.009
SEIOOOC
Environmental Logger
02/03 08:57
Unit# 00592 Test 0
INPUT 1: Level (F) TOC
Reference 50.000
Linearity 0.100
Scale factor 15.090
Offset 0.090
Delay mSEC 50.000
Step 1 02/02 17 23:32
Elapsed Time INPUT 1
0.0000 50.000
0 0033 50.000
0.0066 49 995
0.0100 50 000
0 0133 50 000
0.0166 50.000
0.0200 50.000
0.0233 50.000
0.0266 50.000
0.0300 50.000
)0.0333 50.000
0.0366 50.000
0.0400 50.000
0.0433 50.000
0.0466 50.000
0.0500 50.000
0.0533 50.000
0.0566 50.000
0.0600 50.000
0.0633 50.000
0.0666 50.000
0 0700 50.000
0.0733 50.000
0.0766 50.000
0.0800 50.000
0.0833 50.000
0.0866 50.000
0.0900 50.000
0.0933 50.000
0.0966 50.000
0.1000 50.000
0.1033 50.000
0.1066 50.000
0 1100 50.000
0.1133 50.000
)0.1166 50.000
^0.1200 50.000
0.1233 50.000
0.1266 50.000
0.1300 50.000
0.1333 50.000
O O O O O o O O O O O OWWWWWWWWWUiWtOtOWU>tOtON)l-'l-'l-^0 0, OVO^Owoa\woo\u>oa\u>oa\wwoa\woaswoa\woa\<>iOOOOOOOOOOOOOOOOC^'to to to to to to to to to to to to to to to tovOOOOOOO-0-0-0<^ONa\U>t-fi<Oi-f^-t^4^ooN(>iOO\Woc^wooNWoa\t-oooa\wooNU)oa\woa\woa\woo o o ^to to to to to tow Oi w to to toC7\ W O ON u> o(0\ W O Os U) ooooooooooooooooo o o o o o ^ ^to to to to to to h-^ h-^ h-^ h-^ h-^l_k|_L|_kOOO^^^OOOOOO(O\woa\ojoa\u>oc\wo0NU)oa\u>o<0\WO0N(>)oo o o(0^woa^wo<o\wo<i^cooo^0\U)OCAWOO\WOC7\WOONLnLfxLhLnLnLnLnLnooooooooooooooooooo^oooooooooooooooooooooooooooooooooooooooo _ooooooooooooooooooooooooooooobbbbbbbbbbbboooooooooooooooooooooooooooooooooooooooooooooo o^o oooooooooooooooo-QQQOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
0.3500 50.000
0.3666 50.000
0.3833 50.000
/^4000 50.000
V^j4166 50.000
0.4333 50.000
0.4500 50.000
0.4666 50 000
0.4833 50.000
0.5000 50.000
0.5166 50.000
0.5333 50.000
0.5500 50.000
0.5666 50.000
0.5833 50.000
0 6000 50 000
0.6166 50.000
0.6333 50 000
0.6500 50.000
0.6666 50.000
0.6833 50.000
0.7000 50.000
0.7166 50.000
0.7333 50 000
0.7500 . 50.000
0.7666 50.000
0.7833 50.000
0.8000 50.000
_0.8166 50.000
(" ).8333 50.000
-6.8500 50.000
0.8666 50.000
0.8833 50.000
0.9000 50.000
0.9166 50.000
0.9333 50.000
0.9500 50.000
0.9666 50.000
0.9833 50.000^
1.0000 50.000
1.2000 50.000
1.4000 50.000
1.6000 50.000
1.8000 50.028
2.0000 50.033
2.2000 50.038
2.4000 50.052
2.6000 50.057
2.8000 50.062
3.0000 50.062
3.2000 50.066
3.4000 50.066
3.6000 50 071
/^.3.8000 50.071
f \oooo 50.095
^4.2000 50.095
4.4000 50.100
4.6000 50.133
4.8000 50.133
5.0000 50.133
5.2000 50.133
5.4000 50.138
5.6000 50.138
^.8000 50.181
i.OOOO 50 181
b 2000 50.181
6.4000 50.186
6.6000 50.186
6.8000 50.186
7.0000 50.186
7.2000 50.186
7.4000 50.186
7.6000 50.186
7.8000 50 234
8.0000 50.234
8.2000 50 234
8 4000 50.234
8 6000 50 234
8.8000 50 234
9.0000 50 234
9.2000 50.234
9.4000 50.234
9.6000 50.234
9.8000 50.234
10.0000 50.238
12.0000 50.281
14.0000 50.291
16.0000 50.291
18.0000 50.348
^.0000 50.348
^ .^2.0000 50.358
24.0000 50.363
26.0000 50.358
28.0000 50.363
30.0000 50.449
32/.0000 50.444
34.0000 50.439
36.0000 50.444
38.0000 50.434