Dual Phase System Design Pilot Study Work Plan

Dual Phase System Design Pilot Study Work Plan
ADVANTAGE ENVIRONMENTAL CONSULTANTS, LLC
Dual Phase System Design Pilot Study Work Plan
Gasoline Fueling Station – Royal Farms #96
500 Mechanics Valley Road
North East, Cecil County, Maryland 21901
OCP Case No. 2011-0729-CE
MDE Facility No. 13326
AEC Project Number: 05-056 RF096
Prepared for:
Maryland Department of the Environment
Oil Control Program
Montgomery Park
1800 Washington Boulevard
Baltimore, Maryland 21230-1719
And
Royal Farms / Two Farms, Inc.
3611 Roland Avenue
Baltimore, Maryland 21211
Prepared by:
Advantage Environmental Consultants, LLC (AEC)
8610 Washington Boulevard, Suite 217
Jessup, MD 20794
Phone – (301)-776-0500
Fax – (301)-776-1123
October 27, 2011
Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
ADVANTAGE ENVIRONMENTAL CONSULTANTS, LLC
Dual Phase System Design Pilot Study Work Plan
Prepared by: Thomas E. Ruszin III
Title: Staff Scientist
Date: October 27, 2011
Reviewed by: Jeffery S. Stein, P.G.
Title: Principal
Date: October 27, 2011
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
TABLE OF CONTENTS
1.0
INTRODUCTION .................................................................................................. 1
1.1
Project Overview ................................................................................................... 1
1.2
Technology Background........................................................................................ 2
1.3
Project Objectives ................................................................................................. 2
1.3.1 Pilot Study 1 – Aquifer Pumping Test ............................................................... 2
1.3.2 Pilot Study 2 – Modified Step Drawdown and Dual Phase Recovery Tests ...... 3
1.4
Site Description and Background........................................................................... 3
1.5
Site Investigative Activities..................................................................................... 4
2.0
PILOT STUDY PROCEDURES............................................................................ 8
2.1
Pilot Study Location Selection ............................................................................... 8
2.2
Pilot Study 1 – Constant Rate Pumping Test ......................................................... 8
2.2.1 Equipment and Supplies ................................................................................... 8
2.2.2 Procedure ......................................................................................................... 8
2.2.3 Recovery Phase.............................................................................................. 10
2.2.4 Data Analysis .................................................................................................. 10
2.3
Pilot Study 2 – Modified Step Drawdown and Dual Phase Recovery Tests .......... 10
2.3.1 Equipment and Supplies ................................................................................. 11
2.3.2 Procedure for Modified Step Drawdown Test.................................................. 11
2.3.3 Procedure for Dual Phase Recovery Test........................................................ 12
2.3.4 Data Analysis .................................................................................................. 13
2.4
Waste Management Procedures ......................................................................... 14
3.0
SCHEDULING.................................................................................................... 15
4.0
REPORTING ...................................................................................................... 16
5.0
REFERENCES ................................................................................................... 17
APPENDICES
Appendix A Figures
Appendix B Design Basis Summary – Duel Phase Recovery System
Appendix C MDE Request for Additional Monitoring & Recovery Wells and
Supplemental Pilot Test
FIGURES
Figure 1
Figure 2
Figure 3
Site Vicinity Map
Site Features Map
Site Area Map
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
1.0
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
INTRODUCTION
Advantage Environmental Consultants, LLC (AEC) has prepared this Dual Phase
System Design Pilot Study Work Plan for the Royal Farms Store No. 96 located at 500
Mechanics Valley Road in North East, Maryland. Site Vicinity and Site Features Maps
are provided in Appendix A as Figures 1 and 2, respectively.
This Work Plan was prepared as a companion to the document titled Design Basis
Summary - Dual Phase Recovery System, prepared by AEC and dated September 13,
2011, and Maryland Department of the Environment (MDE) correspondence dated
October 6, 2011, which are included as Appendix B and C, respectively.
The aforementioned MDE correspondence requires an additional pilot test to confirm
that proposed system modifications outlined in the Design Basis Summary will be
capable of achieving the previously established radius of influence. The report of the
pilot studies outcome should include estimates of the maximum, minimum, and optimal
flow rates needed to establish hydraulic control, with consideration to a phased lowering
of the pumps over time to establish optimum recovery of the plume.
1.1
Project Overview
Based on abbreviated enhanced fluid recovery (EFR) pilot studies conducted on July 21
and 22, 2011 a Corrective Action Plan (CAP) was prepared and submitted to the MDE on
July 25, 2011. The CAP presented the following remediation system design criteria:
radius of influence (ROI) - 20 feet; individual recovery well flow rate – 3.2 gallons per
minute (gpm); individual recovery well drawdown - 2 feet below static groundwater; and,
individual recovery well air flow rate - 50 cubic feet per minute (cfm). Data collected during
the course of the initial pilot study did not provide some necessary final design parameters
associated with the feasibility of the technology and process/treatment equipment sizing.
As such, the performance of a full scale EFR pilot study was recommended in the CAP.
Based on the full scale EFR pilot study conducted on July 27, 2011, using equipment
enabling the necessary design data to be collected, a CAP Addendum (August 3, 2011)
was developed. The full scale EFR pilot study indicated the following remediation
system design criteria: ROI - 25 feet; individual recovery well flow rate – 4 to 6 gpm;
individual recovery well drawdown - 4 feet below static groundwater; and, individual
recovery well air flow rate - 50 cfm.
Both the CAP and the CAP Addendum planned on an EFR design using liquid ring pump
(LRP) technology. The CAP and CAP Addendum selected the LRP technology based on
recovery at eight recovery wells. Based on a technical meeting with the MDE, an
expansion of the recovery system to 10 wells was required. As a result of the increased
system flow rates from the additional wells, the standard LRP equipment would be
reaching its maximum design capabilities. As such, a Design Basis Summary was created
which introduced the dual phase approach using integrated vapor extraction/groundwater
extraction (VE/GE) recovery technology. The VE/GE will be implemented using pneumatic
submersible pumps for liquid removal and a positive displacement vacuum blower for
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
vapor removal. This technology is similar to LRP induced EFR but offers the capability for
increased flow rates.
1.2
Technology Background
Both EFR and VE/GE systems are designed to draw down the water table through
groundwater extraction so that residual Liquid Phase Hydrocarbon (LPH) saturations in
the smear zone may be removed by vacuum effects. An LPH smear zone may develop
when mobile LPH is floating on the aquifer capillary fringe and water table elevations
first drop, then rise. During water table decline, some LPH is left behind in the
unsaturated zone as residual saturations held in capillary tension in soil pore spaces.
During water table rise, a significantly larger residual saturation of LPH is trapped below
the water table in the saturated zone. It is the submerged LPH in the smear zone that
must be removed to significantly lower dissolved phase hydrocarbon (DPH)
concentrations in groundwater.
The groundwater extraction component must partially dewater portions of the site in
order for the VE/GE system to achieve remedial objectives. Since the VE/GE system
emphasizes VE as the active mechanism in remediating dewatered soils it is especially
important that a conservative VE design be utilized. Application of vacuum to a GE well
increases the effective gradient to groundwater flow and increases well yield for a given
drawdown (specific capacity). GE system well spacing should be such that intersecting
cones of depression create interference sufficient to meet target drawdown objectives
for the remedial zone (defined as the LPH and moderate to high DPH area).
The process of designing a VE/GE system is similar to that of a stand alone VE system.
The subsurface design is based on pilot test results and the extrapolation of these
results to air and liquid flows in the entire treatment zone. It should be noted that there
is not a specific set of criteria by which to measure the success of an EFR or dual phase
pilot study. Instead there are various lines of evidence that must together be evaluated
to reach an appropriate judgment as to the success of the pilot study (COE, 1999).
1.3
Project Objectives
The primary objective of this work plan is to confirm that the proposed system
modifications outlined in the Design Basis Summary are capable of achieving the
previously established ROI (25 feet). In order to accomplish this task the following
studies will be performed: a constant rate aquifer pumping test; and, a modified step
drawdown and dual phase recovery test.
1.3.1 Pilot Study 1 – Aquifer Pumping Test
A constant-rate aquifer pumping test will be conducted at select recovery and
monitoring wells to estimate aquifer parameters (hydraulic conductivity, coefficients of
transmissivity and storage) and the effective area of influence (capture zone) of each
well under a constant pumping rate. Recovery measurements will also be obtained for
similar time intervals and duration as the drawdown measurements. The data will be
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
used to establish GE well spacing, depth, and discharge rates. The objective will be
partial aquifer dewatering for the remedial zone. The flow modeling objective is to
optimize the required number of wells and pumps, total system discharge, and degree
to which partial dewatering target levels are achieved to obtain minimum capital and
operation and maintenance (O&M) costs.
1.3.2 Pilot Study 2 – Modified Step Drawdown and Dual Phase Recovery Tests
The modified step drawdown test entails pumping the recovery well at successively
higher flow rates for equal, or nearly equal, time steps. The step drawdown testing will
be used to evaluate an optimal flow rate for targeted drawdown levels of 2-, 4- and 6feet under VE conditions. It should be noted that application of vacuum to the recovery
well (or a nearby well) increases the effective gradient to groundwater flow and
increases well yield for a given drawdown (specific capacity). Using the results of the
step drawdown testing, flow rates for the targeted drawdown levels will be used for the
dual phase recovery test. The dual phase recovery test will be used to determine if
equivalent water and air flows as the design basis summary (4 to 6 gpm water flow and
50 cfm air flow) produce a similar radius of influence as the recent EFR test.
1.4
Site Description and Background
The Site is located southeast of the intersection of Mechanics Valley Road and Pulaski
Highway in a commercial/residential area in North East, Cecil County, Maryland. The
Site is developed with a convenience store/gasoline fueling station and associated
landscaped, asphalt- and concrete-paved areas. The surrounding properties include
single family residences to the west, and commercial properties to the south, east and
north. A Site Area Map is included as Figure 3 in Appendix A.
The Site recently underwent an underground storage tank (UST) system upgrade. The
Site formerly operated three double-walled, composite (steel with fiberglass reinforced
plastic (FRP)) USTs which distributed fuel to 12 product dispensers, including two
satellite diesel dispensers. The former system was installed in 1999 and consisted of
the following: a 20,000 gallon unleaded regular UST, a 12,000 gallon super unleaded
UST, and a 12,000 gallon diesel UST. The replacement USTs consist of one 20,000gallon and one 30,000-gallon double walled FRP USTs. The 20,000-gallon UST is split
into a 12,000-gallon compartment for diesel and an 8,000-gallon compartment for
premium unleaded gasoline. The entire 30,000-gallon UST contains regular unleaded
gasoline. Product piping consists of double-walled flexible plastic within plastic
corregated chase pipes, and stage II vapor recovery piping consists of double-walled
FRP.
On June 8, 2011, AEC was performing an annual groundwater sampling event in
accordance with Code of Maryland Regulations (COMAR) 26.10.02.03-04, when
approximately two-inches of LPH were detected in groundwater monitoring well MW-3.
The LPH was observed to be golden in color, indicating ‘un-weathered’ gasoline. AEC
inspected the submersible turbine pump (STP) containment sumps, which were
observed to be free of LPH. Royal Farms was informed of the field observations made
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
by AEC and a suspected release of petroleum was reported to the MDE Oil Control
Program (OCP) on June 8, 2011. On June 13, 2011 the MDE opened a case in
response to a report of evidence of a petroleum spill at the Site. Based on LPH plume
configuration, laboratory analytical data and field observations during UST system
piping removal, the source of the release is likely in the vicinity of dispensers 3/4 and
7/8 (see Figure 2 in Appendix A).
During July and August 2011, the three USTs and all associated piping components
were removed from the Site. Specifically, the UST removal was conducted on August 4
and 5, 2011. Removal of fuel dispensers and piping located beneath the canopy was
performed from July 21 to 28, 2011, and removal of two satellite diesel dispensers was
performed on August 11, 2011. The USTs were empty at the time of removal activities.
Suspect pinholes were observed in the secondary fiberglass layer of the 20,000-gallon
regular gasoline UST. During removal of product piping, petroleum impacted liquid was
encountered within the corregated chase piping. Perched water was identified on the
western side of the pump island trenching and the western end of the satellite diesel
trench.
1.5
Site Investigative Activities
Pursuant to the various MDE OCP directives the following documents and reports have
been prepared for the release investigation activities:
Emergency Subsurface Environmental Investigation Report, prepared by AEC and
dated July 19, 2011. This report details the collection of soil and groundwater samples
from 24 boring locations (B-1 through B-24). The borings were advanced to depths
ranging from 15 to 20 feet bgs. Temporary piezometers were installed in all but one of
the borings. In order to delineate the horizontal and vertical extent of the release , the
initial borings were advanced around MW-3 and the subsequent borings arrayed
outward from MW-3. Also conducted as part of the investigation was the collection and
analysis of groundwater samples from potable drinking water wells located in the Site
vicinity.
Corrective Action Plan, prepared by AEC and dated July 22, 2011. The CAP presents
the design for a multi-phase EFR system. The design is based upon data collected from
the abbreviated EFR pilot studies performed in July 2011, as well as site
characterization investigations, review of historical well gauging/sampling data, and vactruck EFR performance characteristics. Since data collected during the course of the
initial pilot study associated with the CAP did not provide some necessary final design
parameters with regard to feasibility of the technology and process/treatment equipment
sizing, it recommended that a 4- to 8-hour pilot study be conducted using a LRP skid.
Recovery Well Install Data Pack, prepared by AEC and dated August 2, 2011. This
document included boring logs, well construction diagrams and soil sample laboratory
analytical results from the installation of six groundwater recovery and five groundwater
monitoring wells between July 14 and 19, 2011. The wells were completed to depths
ranging from 24 to 26 feet bgs. The groundwater quality from the newly installed wells
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
had been recently tested but these results were pending.
illustrates the recovery and monitoring well locations.
Figure 2 in Appendix A
Corrective Action Plan Addendum, prepared by AEC and dated August 3, 2011. The
CAP Addendum describes the results of the EFR pilot study using the LRP skid. The
report concluded that the high permeability of the coarse grained soils below the Site
presents a challenging environment for the EFR remedy. The combined water flow rate
necessary for providing hydraulic control and meeting the primary remedial objective
(LPH removal to a sheen) will necessitate the use of relatively large capacity process
equipment. The report concluded that the EFR remedy is technically feasible but other
approaches to LPH removal may offer significantly reduced time frames for completion
of this task.
Surfactant Flush Pilot Study Work Plan, prepared by AEC and dated August 9, 2011.
This document was prepared as a companion to the August 3, 2011 CAP Addendum.
The primary objective of the work plan was to evaluate the effectiveness of surfactant
flushing assisted by EFR extraction for LPH removal. This approach would augment
current groundwater remediation efforts by promoting increased solubility and mobility
of the residual and mobile LPH within the release area. The work plan described the
surfactant injection/extraction means and methods, and pre- and post-flushing
groundwater monitoring activities.
August 2011 Groundwater Sampling Data Package, prepared by AEC and dated
August 10, 2011. This document included a groundwater gradient map, a groundwater
quality map, a table of onsite groundwater sample analytical results, and laboratory
analytical reports dated August 4, 2011.
Design Basis Summary, prepared by AEC and dated September 13, 2011. The Design
Basis Summary was based on the July 27, 2011 EFR pilot study findings which
developed remediation system design criteria. The Design Basis Summary described
the dual phase (vapor and liquid) recovery technology which replaced the EFR technology
due to water and vapor recovery limitations of the EFR equipment. The document
described in detail the equipment to be used in the dual phase approach. The main design
change was the use of pneumatic submersible pumps for liquid removal and a positive
displacement vacuum blower for vapor removal.
September 2011 Groundwater Sampling Data Package, prepared by AEC and dated
September 23, 2011. This document included a groundwater gradient map, a
groundwater quality map, a table of onsite groundwater sample analytical results, and
laboratory analytical reports dated September 15, 2011.
Underground Storage Tank System Closure Report, prepared by AEC and dated
October 17, 2011. This report described the UST system removal activities and the
excavation oversight and confirmatory sampling associated with this task. The UST
system was removed in order to upgrade the storage and piping infrastructure and
further investigate the petroleum release.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
AEC has conducted EFR operations via a vac-truck since June 13, 2011. The EFR is
conducted using a “stinger” tube which is lowered into the wells to a depth of
approximately two-feet below the static water level. The stinger tube is then fitted at the
well head with a well seal to allow for both fluid and vapor extraction. Between June 13
and July 18, 2011 the vac-truck EFR operations were conducted on MW-3. As the
recovery wells became operational between July 16 and July 19, 2011, they were
added to the EFR program via a piping manifold. The vac-truck EFR operation is
conducted daily for four hours.
A recent review of the liquid level gauging data from June 13, 2011 through October 23,
2011 indicates the following regarding LPH thicknesses in the recovery and monitoring
wells:
Well Identification
MW-1, MW-1R, MW-2, MW-4, MW-5, MW-6,
MW-7, MW-8, MW-9, MW-10, MW-11, MW-12,
RW-5, RW-7, RW-8, RW-9, RW-10, RW-11,
RW-12
MW-3 (Sheen), RW-1 (Sheen),
RW-2 (Sheen), RW-3 (Sheen), RW-4 (Sheen)
RW-6 (0.01’)
Date of Last Appearance of LPH
No LPH observed since well installation
LPH last observed October 3, 2011
LPH last observed August 21, 2011
LPH last observed October 24, 2011
These reductions in LPH thicknesses have been realized by the sustained vacuum truck
recovery efforts.
There has been an expansion of the DPH plume as demonstrated by comparison of the
two groundwater testing data sets (August 4, 2011 and September 15, 2011). This
comparison is tabulated below:
Well
Identification
MW-2
MW-4
MW-5
MW-6
MW-7
MW-8
Groundwater Gradient
Position Relative to
Release Area
Down
Side
Up
Up
Down
Down
Relative Comparison
of DPH Quality (8-4-11
and 9-15-11 data sets)
Increase
Static
Static
Increase
Increase
Increase
Specific Comparison of
Total BTEX (8-4-11 and
9-15-11 data sets)
BDL/66
21.6/12.2
14.8/BDL
9/60
1847/26800
24.2/72.2
B = Benzene; T = Toluene; E = Ethylbenzene; X = Xylene
All results in parts per billion or µg/l
BDL = Below Detection Limits
The DPH has migrated in a down gradient direction and generally resides in the course
grained soil layer within the water bearing unit. EFR pilot studies have shown that this
course grained soil layer is highly transmissive for fluid and vapor flow.
Specific findings, results and conclusions from the various testing and investigation
events are detailed in the documents introduced in the preceding section.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
There are ongoing investigation activities being conducted at the Site. These activities
include additional installation of recovery and monitoring wells as required in MDE
correspondence dated October 6, 2011. The results of these investigation activities will
be provided under separate cover. These new recovery and monitoring wells will be
used in the pilot studies and are illustrated on Figure 2 in Appendix A.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
2.0
2.1
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
PILOT STUDY PROCEDURES
Pilot Study Location Selection
The proposed location of the pilot study is on the northeast quadrant of the Site. This
area is characterized by multiple temporary piezometers, monitoring and recovery wells.
This area is located on the hydraulically upgradient end of the LPH plume and side
gradient of the suspect source area (northeastern dispenser islands). Figure 2 in
Appendix A illustrates this area.
2.2
Pilot Study 1 – Constant Rate Pumping Test
The following is the site-specific standard operating procedure for the proposed aquifer
pumping test to be conducted at the Site. Specifically, the pilot study will use extraction
equipment which produces equivalent water flows as the design basis summary
descriptions (i.e., 4 to 6 gpm water flow creating a drawdown of approximately 4 feet).
This 4 feet drawdown target will assist in avoiding creation of a larger smear zone due
to possible drawdown of mobile LPH.
2.2.1 Equipment and Supplies










QED pneumatic AP-4 Auto Pump – top loading
Quincy Qt series Air compressor, 5 HP
20 KVA, 3-phase mobile generator
Insitu-brand Troll pressure transducers and data loggers
Laptop computer for data acquisition
Water flow meter
Oil-Water Interface Probe
Decontamination supplies
5-gallon bucket(s)
Stopwatch
2.2.2 Procedure
The constant rate test is the standard method for determining the aquifer parameters of
specific capacity, transmissivity and storativity (storage coefficient). The resultant
drawdown data will be plotted verses time and distance to develop these aquifer
parameters. The recovery well will be RW-13. Water levels in monitoring wells RW-2,
4, 6, and 7 will be recorded using pressure transducers. Water levels in monitoring
wells MW-6, RW-1 and RW-10 will be recorded using a water level meter. Based on
the previous EFR pilot study it is expected that equilibrium conditions will be reached in
approximately 4 hours. The observation well drawdown data will be evaluated after 4
hours and either the test will go into the recovery phase or will be extended for 2 to 4
more hours.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
 Take an initial round of water levels within each monitoring well using an electronic
oil-water interface probe accurate to 0.01-feet. The interface probe will be cleaned
(Liquinox and water rinse) prior to use in each well.
 Program each Troll pressure transducer/data logger (Troll) with the laptop computer
in accordance with the Troll instruction manual. Synchronize the beginning of data
collection to begin several minutes before the start of the test. Program the Troll to use
drawdown mode relative to the top of the casing. For transducers installed in monitoring
wells, obtain 30-second arithmetic data during pumping tests. For recovery well
installations and for rebound tests (in both monitoring and recovery wells), collect
logarithmic data to obtain more frequent initial data.
 Install the pressure transducers in the recovery well and three or four adjacent
monitoring wells. Record the elevation of the pressure transducer. The Troll will not be
set deeper than the transducer’s pressure range at the highest water level elevation.
Transducer-data logger data should be verified with manual (tape) water-level
measurements. Periodically manually confirm transducer monitored water levels.
 Complete the installation of the pneumatic pump in the recovery well. The wellhead
installation will include an accurate flow-measuring device. The pump intake will be set
as deep as possible to maximize drawdown.
 Estimate an initial flow rate for the test (i.e., 5 gpm). Run an initial test to determine
whether the flow rate is optimal. Verify the flow rate with the 5-gallon bucket and the
stopwatch. Adjust the flow rate using the flow control valves on the pump setup. If the
initially estimated flow rate is acceptable, continue the test. Otherwise, stop the test and
allow the well to recover. All field equipment will be set in order to ensure that the test
runs smoothly from start to finish. The flow rate will remain as constant as possible
throughout the test. Early time data will be obtained in all wells expected to respond
within the initial 100 minutes.
 Analyze all field data during the course of the test, especially transducer/data logger
data. A preliminary understanding of aquifer parameters will be available before the end
of the proposed test period in order to decide whether to extend the test and also how
long the recovery period should last. Reasons to extend the test include the appearance
of a recharge or discharge boundary and the growth of the cone of depression to
intercept wells unaffected during the earlier portions of the test.
 If mechanical problems cause a premature termination of the pumping portion of
the test, recovery measurements will be obtained. The aquifer will be allowed to
completely recover if a termination of any length occurs within the first 100 minutes; the
pumping portion of the test may be continued if the problems are rectified in less than
about ten minutes for tests that exceed 100 minutes, however, this will be decided by
the analyst in the field and could further depend on the percentage of recovery to static
experienced by the test well. If drawdown was continuing to increase after 100 minutes
(a possible boundary effect), it may be necessary to allow complete recovery before
restart.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
 Flow rate measurements will be as accurate and timely as possible to allow a
constant flow rate to be maintained during the course of the test. A totalizer-type flow
meter will be verified using an alternate method (i.e., pail or five-gallon bucket). Pre-set
pump discharge valves will be adjusted to avoid early time rate adjustments which
cause water levels in the test well to fluctuate dramatically.
 Convert the raw data from the Trolls into an Excel spreadsheet for further data
manipulation.
 The fluids will be piped to a 500-gallon poly tank. During the study the evacuated
water will be removed from the holding tank via a vac-truck and appropriately disposed of
as hydrocarbon impacted liquids.
2.2.3 Recovery Phase
Recovery measurements will be obtained for similar time intervals and duration as the
drawdown measurements, although the length of the recovery test may have other
limiting considerations. Field analysis of the drawdown data will indicate what conditions
to anticipate for recovery. Recovery analysis in an aquifer test is extremely valuable,
especially allowing analysis of pumping rate conditions which may have been slightly
variable during the start-up phase.
2.2.4 Data Analysis
The pumping and recovery test data will be interpreted using one or several standard
methods for interpreting pumping tests for unconfined aquifers including the modified
Theis method (1935), the Theis recovery method (1935), the Cooper method (1946),
and the Neuman method (1975). The method will be selected based on an
understanding of the physical site conditions. Hydraulic conductivity, transmissivity,
specific capacity and storativity values will be estimated. Graphics of the data analysis
(typically distance-drawdown and time-drawdown plots) will be created. The pumping
test will also be used to establish GE well spacing using capture zone analysis using
Keely and Tsang (1983) and Javandel and Tsang (1986). The data will be analyzed
qualitatively to assess potential conditions such as multiple soil strata, soil
heterogeneity, groundwater sources or sinks, and impermeable areas.
2.3
Pilot Study 2 – Modified Step Drawdown and Dual Phase Recovery Tests
The following is the site-specific standard operating procedure for a modified step
drawdown and dual phase recovery tests to be conducted at the Site. Specifically, the
pilot study will use extraction equipment which produces equivalent water and air flows
as the design basis summary descriptions (i.e., 4 to 6 gpm water flow and 50 cfm air
flow) to determine if these flows produce a similar radius of influence as the recent EFR
test.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
2.3.1 Equipment and Supplies














Rietschle VLR 250 Vacuum Pump, 7.5 HP
QED pneumatic AP-4 Auto Pump
Quincy Qt series Air compressor, 5 HP
20 KVA, 3-phase mobile generator
Extech Model 407119A Hot Wire Anemometer
MiniRAE 2000 portable Photoionization Device (PID)
Insitu-brand Troll pressure transducers and data loggers
Laptop computer for data acquisition
Magnehelic differential vacuum gauges (0.1, 1 and 100 inch water)
Water flow meter
Oil-Water Interface Probe
Decontamination supplies
5-gallon bucket(s)
Stopwatch
2.3.2 Procedure for Modified Step Drawdown Test
The procedure entails pumping the test well at successively higher flow rates for equal
,or nearly equal, time steps. As originally devised (Jacob, 1946), the well is tested for
four or more steps and allowed to fully recover between steps, although current practice
is to continue increasing the flow rate without recovery. The flow rate in gpm and
pumping well drawdown are recorded at the end of each step. Increases in flow rate are
typically evenly spaced (i.e., 4, 5, 6, 7 gpm). The final flow rate should equal or exceed
predicted maximum yield of well. The normal time step is one hour. It is anticipated that
the pilot study will be conducted in four steps in a total of 4 hours. The step drawdown
testing will be used to evaluate optimal flow rates for targeted drawdown levels of 2-, 4and 6-feet under VE conditions. The recovery well will be RW-13. Water levels in wells
RW-2, 4, 6, and 7 will be recorded using pressure transducers. Water levels in wells
MW-6, RW-1 and RW-10 will be recorded using a water level meter.
 Take an initial round of water levels within each monitoring well and the recovery
well using an electronic oil-water interface probe accurate to 0.01-feet. The interface
probe will be cleaned (Liquinox and water rinse) prior to use in each well.
 Set up the recovery well to accommodate both the water and vapor recovery. The
recovery well head will be fitted with a 4-inch diameter PVC riser. The pressure
transducer cable, pump air supply hose and pump discharge hose will be installed through
a well sanitary seal placed on top of the riser. The VE piping will be connected to the riser
using a PVC tee below the sanitary seal. The blower will be fitted with an ambient relief
valve and a flow control valve.
 Program the recovery well’s Troll with the laptop computer in accordance with the
Troll instruction manual. Synchronize the beginning of data collection to begin several
11
Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
minutes before the start of the test. Program the Troll to use drawdown mode relative to
the top of the casing.
 Install the pressure transducer in the recovery well. Record the elevation of the
pressure transducer. Do not hang the Troll deeper than the transducer’s pressure range
at the highest water level elevation. Transducer-data logger data should be verified with
manual (tape) water-level measurements.
 Complete the installation of the pneumatic pump in the recovery well. The wellhead
installation will include an accurate flow-measuring device. The pump intake depth will
be set near the bottom of the recovery well.
 Vacuum readings will be measured in the observation wells, as well as the recovery
well. The vacuum readings will be collected using magnehelic differential vacuum gauges
attached to the well heads. Air-flow rates and air quality will be measured at the effluent
stack using a hot wire anemometer and PID, respectively. The air flow and quality data will
be collected up stream of the ambient dilution valve. Vapor recovery flow rates for the pilot
study will be calculated from recorded air velocity readings. Measurements will occur at a
frequency of one every five minutes for the first thirty minutes of the pilot study.
Subsequent measurements will be collected less frequently (every 15 minutes) as the pilot
study progresses. AEC will note the total volume of liquid extracted and the average
recovery rate during the pilot study.
 The fluids will be piped to a 500-gallon poly tank and the vapor will be discharged to
the atmosphere via a 4-inch diameter stack. During the study the evacuated water will be
removed from the holding tank via a vac-truck and appropriately disposed of as
hydrocarbon impacted liquids.
2.3.3 Procedure for Dual Phase Recovery Test
Using the results of the step drawdown testing, flow rates for the targeted drawdown
levels will be used for the dual phase recovery test. Based on the previous EFR pilot
study it is anticipated that each step will take approximately 2 hours to reach water level
and vacuum equilibrium. As a result, the test will last between 6 and 8 hours. The
recovery well will be RW-13. Water and vacuum levels in wells RW-2, 4, 6, and 7 will
be recorded using pressure transducers and differential pressure gauges. Water and
vacuum levels in wells MW-6, RW-1 and RW-10 will be recorded using a water level
meter and differential pressure gauges.
 Take an initial round of water levels within each monitoring well using an electronic
oil-water interface probe accurate to 0.01-feet. The interface probe will be cleaned
(Liquinox and water rinse) prior to use in each well.
 Set up the recovery well to accommodate both the water and vapor recovery. The
recovery well head will be fitted with a 4-inch diameter PVC riser. The pressure
transducer cable, pump air supply hose and pump discharge hose will be installed through
a well sanitary seal placed on top of the riser. The VE piping will be connected to the riser
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
using a PVC tee below the sanitary seal. The blower will be fitted with an ambient relief
valve and a flow control valve.
 Program each Troll with the laptop computer in accordance with the Troll instruction
manual. Synchronize the beginning of data collection to begin several minutes before
the start of the test. Program the Troll to use drawdown mode relative to the top of the
casing. For transducers installed in monitoring wells, obtain 30-second arithmetic data
during pumping tests. For recovery well installations and for rebound tests (in both
monitoring and recovery wells), collect logarithmic data to obtain more frequent initial
data.
 Install the pressure transducers in the recovery well and the adjacent monitoring
wells. Record the elevation of the pressure transducer. Transducer-data logger data
will be verified with manual (tape) water-level measurements. The transducer monitored
water levels will be manually confirmed periodically.
 Complete the installation of the pneumatic pump in the recovery well. The wellhead
installation will include an accurate flow-measuring device. The pump intake depth will
be set near the bottom of the recovery well.
 Vacuum readings will be measured in the observation wells, as well as the recovery
well. The vacuum readings will be collected using magnehelic differential vacuum gauges
attached to the well heads. Air-flow rates and air quality will be measured at the effluent
stack using a hot wire anemometer and PID, respectively. The air flow and quality data will
be collected up stream of the ambient dilution valve. Vapor recovery flow rates for the pilot
study will be calculated from recorded air velocity readings. Measurements will occur at a
frequency of one every five minutes for the first thirty minutes of the pilot study.
Subsequent measurements will be collected less frequently (every 15 minutes) as the pilot
study progresses. AEC will note the total volume of liquid extracted and the average
recovery rate during the pilot study.
 The fluids will be piped to a 500-gallon poly tank and the vapor will be discharged to
the atmosphere via a 4-inch diameter stack. During the study the evacuated water will be
removed from the holding tank via a vac-truck and appropriately disposed of as
hydrocarbon impacted liquids.
2.3.4 Data Analysis
The step drawdown data will be interpreted using one or several standard methods
including the Bierschenk, W.H., 1964 method. Transmissivity and storativity values will
be provided, and an assessment of how well the data fit the model will be presented.
Graphics of the data analysis (typically log-log or semi-log plots) will be created.
Through pilot testing, a vacuum ROI can be determined as the radial distance from the
recovery well at which induced vacuum is too small to be measured. Vacuum radius of
influence has often been used as a design parameter to determine recovery well spacing.
However, air flow is the primary physical process removing volatile hydrocarbon vapors
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
and air flow rate is a function of both induced vacuum and soil permeability. Recovery well
spacing should be defined by the radial distance for which sufficient air flow will occur to
adequately remediate soils. Since the distribution of soil permeabilities and air flow cannot
be directly measured during pilot testing, the distribution of subsurface vacuum coupled
with recovery well air flow rates are used to model idealized subsurface air flow patterns.
A normalized plot of measured vacuum versus radial distance from the recovery well
wilI be prepared for interpreting pilot test results in the field. Assuming subsurface air
flow passes through a homogeneous porous media, induced vacuum should decrease
exponentially with increasing radial distance from the recovery well. Once vacuum and
air flow have stabilized, vacuum measured at a given distance from the recovery well
should increase linearly with increasing vacuum applied at the recovery well (i.e.,
doubling the recovery well vacuum should double the monitoring point vacuum).
Normalized pilot test vacuum data measured at similar depth Intervals below the
surface should conform reasonably well to a straight line fit when plotted against radial
distance from the recovery well on a semi-log graph. The slope of the best-fit line is a
function of the ratio of horizontal to vertical permeability (Kh/Kv). Sites with high Kh/Kv
ratios have proportionally greater horizontal air flow component and less vertical air flow
than sites with low Kh/Kv ratios. The higher the Kh/Kv ratio, the lower the slope of the
best-fit line on the normalized vacuum plot.
Pilot test vacuum data should be plotted in the field on semi-log plot paper. Each
vacuum step should be plotted separately. For each step, a stabilized vacuum reading
for each vacuum monitoring point will be plotted as a function of the radial distance from
the recovery well of that point. Stabilized vacuum readings will be normalized by
dividing the measured vacuum by the recovery well vacuum. This will yield a vacuum
value expressed as a percentage of the recovery well vacuum which is plotted on the
logarithmic scale of the semi-log graph. Radial distance from the recovery well of each
vacuum monitoring point will be normalized by dividing the radial distance of the point
by the depth of the water table at the recovery well. Normalizing both vacuum and
distance data will allow comparison of vacuum data from different vacuum steps, and
from different recovery wells.
2.4
Waste Management Procedures
Any hydrocarbon impacted water and LPH encountered during testing activities will be
collected and containerized in a vacuum truck. The contained fluids will be properly
characterized and transported off-site for final disposal or treatment at facility permitted
to accept impacted water originating from the State of Maryland. All trucking companies
used to transport the impacted soil will be certified, licensed, and insured to transport
hazardous waste in the State of Maryland and any other States through which the wastes
will travel or where wastes will ultimately be disposed/treated. AEC will retain copies of
all bills of lading, manifests, receipts and/or waivers that were signed prior to transport.
Copies of these documents will be included in the Work Plan Implementation Report.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
3.0
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
SCHEDULING
All field and reporting activities associated with this work plan are anticipated to be
completed within 48 days after authorization by the MDE and the client. The MDE will
be notified of AEC’s field schedule at least five business days prior to the start of work
plan implementation. The following is a summary of major project milestones and
associated estimated times of completion:
Event
MDE approves Work Plan
Complete Constant Rate Pumping Test
Complete Dual Phase Extraction Pilot Studies
Complete Data Analysis/Reporting
Completion of Report Peer Review
Submit Pilot Study Implementation Report to MDE
MDE approves Pilot Study Implementation Report
Submit Final Design Basis Summary or CAP Addendum to MDE
15
Approximate Schedule
(days)
Day X
X+7
X + 12
X + 24
X + 26
X + 28
Day Y
Y + 20
Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
4.0
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
REPORTING
A report will be prepared that describes the entire work plan implementation.
Specifically, the report will include:

A summary of pilot study results (include tables that summarize analytical results).

A complete description of the pilot study, including all data necessary to understand
the project in its entirety including all pilot study methods and procedures.

A discussion of key decision points encountered and resolved during the course of
the pilot study.

Graphical displays such as isopleths, cross-sections, plume contour maps (showing
concentration levels, isoconcentration contours), and Site maps (showing sample
and injection locations, etc.) that describe the report results.

An analysis of pilot study data to develop estimates of the maximum, minimum, and
optimal flow rates needed to establish hydraulic control, with consideration to a
phased lowering of the pumps over time to establish optimum recovery of the plume.

An analysis of the effectiveness of the pilot study and a discussion of a scaled-up
design for total Site remediation.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
5.0
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
REFERENCES
Bierschenk, W.H., 1964. Determining well efficiency by multiple step-draw-down tests.
Intl. Assoc. Sc. Hydrol. Publ., 64: 493 - 507.
Cooper, H.H., Jr. and Jacob, C.E., 1946, A Generalized Graphical Method for
Evaluating Formation Constants and Summarizing Well Field History, Transactions,
American Geophysical Union, Vol. 27, No.4.
Jacob, C. E. 1946. Drawdown test to determine effective radius of artesian well.
Transactions, ASCE. v. 112, paper 2321, pp. 1047-1070.
Javandel and Tsang, Capture Zone Type Curves: a tool for aquifer cleanup,
Groundwater, 24(5), 616-625, 1986.
Keely, J. R. and Tsang, F. F. Y., 1983, Velocity Plots and Capture Zones of Pumping
Centers for Ground-Water Investigations, Ground Water, Vol. 21, No.6, pp. 701-714.
Kruseman, G. P. and N. A. de Ridder. 1990. Analysis and evaluation of pumping test
data. International Institute for Land Reclamation and Improvement, Wageningen, The
Netherlands. 2nd ed. (completely revised). 377 pp.
Neuman, S. P. 1975. Analysis of Pumping Test Data from Anisotropic Unconfined
Aquifers Considering Delayed Gravity Response. Water Resources., Vol. 11, pp. 329342.
Theis, C. V., 1935, The Relation Between the Lowering of the Piezometric Surface and
the Rate and Duration of Discharge of a Well Using Ground Water Storage,
Transactions, American Geophysical Union, pp. 518-524.
US Army Corps of Engineers, Engineering and Design, Multi-Phase Extraction, EM
1110-1-4010, June 1, 1999.
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Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
APPENDIX A
FIGURES
Figure 1 - Site Vicinity Map
Royal Farms #96
500 Mechanics Valley Road
North East, MD
Advantage Environmental Consultants, LLC
TN
Scale 1 : 28 125
MN
1" = 2 343 75 ft
© 2001 DeLorme. Topo USA® 3.0
11.7°W
0
¼
½
¾
1
Zoom Level: 12-7 Datum: WGS84
0
½
1
1½
2
mi
km
Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
APPENDIX B
DESIGN BASIS SUMMARY – DUEL PHASE RECOVERY SYSTEM
Design Basis Summary
Dual Phase Recovery System
Gasoline Fueling Station – Royal Farms #96
500 Mechanics Valley Road
North East, Cecil County, Maryland 21901
OCP Case No. 2011-0729-CE
MDE Facility No. 13326
Introduction
Based on the July 27, 2011 enhanced fluid recovery (EFR) pilot study findings AEC has
developed the following remediation system design criteria: Radius of influence (ROI) - 25 feet;
Individual recovery well flow rate – 6 gallons per minute (gpm); Individual recovery well
drawdown - 4 feet below static groundwater; and, Individual recovery well air flow rate - 50
cubic feet per minute (cfm). Based on a 10 recovery well use scenario the minimum treatment
system equipment sizing criteria will be: 30 gpm water flow rate and 500 cfm air flow rate. Dual
phase (vapor and liquid) recovery technology has been selected for use at this site. Dual phase
recovery will be implemented using pneumatic submersible pumps for liquid removal and a
positive displacement vacuum blower for vapor removal. This technology is similar to EFR in
concept and application. The following provides a summary of the equipment to be used for the
dual phase application at the site. Also provided are a Process and Instrumentation Diagram and
Trench and Well Head Details.
Soil Vapor Extraction System
25 HP Positive displacement vapor extraction system, Tuthill 5009SL or equal
600 ACFM @ 10"Hg. Capacity
Temperature gauge
High temperature switch
Inlet filter and inlet silencer
Universal SD series or better discharge silencer
Universal SD series or better
Belt drive
Automatic and manual dilution valves with silencer
200 Gallon Vertical Air/water Separator
Conductivity probe level switches
10" diameter clean out ports with vacuum rated quick release lids
Clear PVC sight glass piping to liquid ring pump, to check for water carryover
Liquid filled vacuum gauge
Vacuum assist line
2" drain valves
Vacuum relief valves
Dilution valve with filter/silencer
Inlet screen
MK Coalescing Oil/Water Separator System
Model C85 with 85 GPM capacity
9/13/2011
1
Coalescing separator with product skimming weir
Polypropylene coalescing pack with 1/2" spacing for efficient oil removal
Hopper bottom for sludge removal
Effluent chamber with stainless steel float level sensors
MK Low Profile Cascade Air Stripper System
0-150 GPM flow rating
800 CFM air flow rating
3-tray air stripper unit - Model LP150-3
Low profile air stripper with 7.5 hp AMCA Type B spark resistant aluminum blower
Nylon tube aeration air stripper for high mass removal rates with low maintenance
Low, high, and high-high sump conductivity probes
12" clean out hatch
Epoxy coated carbon steel construction
Sump level sight glass
99.8% Removal for BTEX @ 50 GPM, 60°F
Air Stripper Blower Silencer to Reduce Noise Level of the Stripper Blower
1.5 hp Transfer Pump
3450 rpm, TEFC motor
Cast Iron housing with bronze impeller, anti air lock design
Manual "Pump ON" button inside building for sampling
3 hp Transfer Pump (2)
3450 rpm, TEFC motor
Cast Iron housing with bronze impeller, anti air lock design
Manual "Pump ON" button inside building for sampling
Groundwater Inlet Manifold
Carbon steel with brass valves
2" main with (11) 1" points, with shut off valve, check valve, sample port, barb for each
groundwater pump.
Vapor Inlet Manifold
PVC
6" main with (11) 2" points, with shut off valve, union and sample port for each well.
Air Compressor
15 HP rotary vane with continuous run option
90 gallon receiver tank
Air cooled after cooler
Low oil switch
Tank auto drain
1/2" filter regulator
1/2" 3 way Asco solenoid valve
9/13/2011
2
Recovery Pumps - QED AP4 Long Top Fill Pneumatic Pumps (10)
10 GPM maximum flow rate
Down well hoses and support rope per well
Vacuum well seal
3/4" brass shut off at each well for groundwater
1/2" brass ball valve for compressed air at each well
Master Control Panel System
NEMA 3R control panel with blank front cover
Swing out sub panel for gauges, control operators, and switches
IEC Magnetic motor starters, safety switches, H-O-A controls
Control transformer
8 intrinsically safe relays, 8 alarm indicator LED's, 16 output channels
Hard wired relay logic
Exterior GFCI utility outlet
System run-time totalizing hour meter
Blower low pressure alarm
Anti-falsing alarm circuit to prevent nuisance tripping
Three phase voltage and phase monitor
Emergency E-stop LED red indicator light located on swing out sub panel
Telemetry System Model 570
16 analog inputs, expandable to 32
4 digital outputs
24 hour gel cell battery backup
10,000 line data logger
UL listed surge suppression
Manual or automatic control of outputs
8 number dial out list
Programmable dial out intervals
Site telephone with duplex RJ11 jack
Vacuum Transducer
Integrated into telemetry for real time monitoring
4-20mA
System Building
8.5'W x 28'L x 9.5'H aluminum/steel enclosure, fully insulated
Removable sliding wall panels for ease of maintenance
Exterior grade plywood floor, structural steel frame
Includes 100 watt XP interior light, and removable center grate for ease of maintenance
Breaker panel and control panel will be mounted on a vertical steel bracket attached to
platform end.
10" structural steel base with 4" steel cross members
Steel corner posts and roof frame
9/13/2011
3
Continuous sheet aluminum roof
2 XP heater with thermostat, 12,000 BTU each
Groundwater Flow Totalizer
Pulse output and flow calibration button
Equipment Electrical Installation
Includes XP wiring, XP seal off connectors, liquid tight flexible conduit
UL listed equipment.
Equipment Mechanical Installation
Includes mounting, piping and connectors
Brass fittings, sample ports, pressure gauges and sight glasses
400 Amp meter base and (2) 200 amp fused disconnects or breakers for the system and
oxidizer
Weatherhead with extension pole and bracket support
Electric meter socket base installed
MKE Model 500E Electric Oxidizer with 50% Effective Heat Exchanger
500 CFM capacity 99% destruction efficiency; flame arrestor
Watlow controls
First out detector
Honeywell 2-pen chart recorder
Located outside system enclosure
Includes 200 amp circuit breaker in main panel
Air/water Separator Knock Out Tank
Located prior to oxidizer to minimize condensed liquids from entering burner or vapor phase
carbon bed.
VF-400 Vapor Phase Carbon Vessels
Filled with activated carbon for odor control and vapor capture when the oxidizer is off, during
remote restart conditions
Air/water Separator Knock Out Tank
Located prior to oxidizer to minimize condensed liquids from entering vapor phase carbon bed
for air stripper
500 Gallon Product Holding Tank
UL listed with emergency vents
Stainless steel high-level float switch and intrinsically safe channel in the control panel
Electrical Service Installation
200 amp 3/60/460 volt 3 wire plus ground electrical service to NEMA 3R control panel
Interior electrical will comply with NEC requirements for Class 1, Division 2, Group D
Hazardous locations
9/13/2011
4
Motors will be TEFC construction
Nationally Recognized Testing Laboratory (NRTL) Approvals
MET Labs certified manufacturer
Recovery Well Vaults
2’ by 2’ by 18” side skirt traffic rated well vaults with hydraulic arms
Recovery Well Trenches
Trenches will be saw-cut in asphalt and/or concrete
Trenches will be installed 24” wide and 30” deep
Pipes will be bedded in pea-gravel
Trenches will be backfilled in one foot lifts with crush and run gravel or removed fill
Disturbed areas will be placed back to its original condition i.e. asphalt, concrete, soil
Soil Vapor Extraction System Lines
Recovery wells will have independent SVE lines
Lines will be installed using 2" diameter PVC conduit from treatment building to recovery wells
Recovery Pump Air Line and Discharge Line
Recovery wells will have independent air and discharge lines
Lines will be installed within 4" diameter PVC conduit from treatment building to recovery wells
Air lines to recovery pumps will be 1/2" diameter
Discharge lines from recovery pumps will be 3/4" diameter
Due to the number of 90 degree turns, PVC "sweeps" will be used so that the air/water lines
can be easily installed and removed for maintenance
Treated Effluent Discharge Line
Discharged approximately 85 feet to the northeast to the sanitary sewer drain
Effluent line will be 1.5” diameter black PE plastic
Installed three feet below grade
9/13/2011
5
Gasoline Fueling Station – Royal Farms #96
OCP Case No. 2011-0729-CE
Dual Phase System Design Pilot Study Work Plan
AEC Project # 05-056RF096
APPENDIX C
MDE REQUEST FOR ADDITIONAL MONITORING & RECOVERY WELLS AND
SUPPLEMENTAL PILOT TEST
MARYLAND DEPARTMENT OF THE ENVIRONMENT
Oil Control Program, Suite 620, 1800 Washington Blvd., Baltimore MD 21230-1719
410-537-3442 • 410-537-3092 (fax)
1-800-633-6101
Robert M. Summers, Ph.D.
Secretary
Martin 0 'Malley
Governor
Anthony G. Brown
Lieutenant Governor
October 6, 2011
Mr. Robert Rinehart
Two Farms, Inc.
tla Royal Farms
3611 Roland Avenue
Baltimore MD 21211
RE: REQUEST FOR ADDITIONAL MONITORING & RECOVERY WELLS
AND SUPPLEMENTAL PILOT TEST
Case No. 2011-0729-CE
(Closed Case No. 99-2S95-CE)
Royal Farm Store #%
SOO Mecbanies Valley Road, Nortb East
Cecil County, Maryland
Facility tD. No. 13326
Dear Mr. Rinehart:
The Oil Control Program recently completed a review of the case file for the above-referenced property,
including the following documentation: Corrective Action Plan - July 22, 2011; Corrective Action Plan
Addendum -August 3, 2011; Surfactant Flush Pilot Study Work Plan - August 9,2011; and the Design Basis
Summary Dual Phase Recovery System (hereinafter referred to as the "Design Summary"), received via email
September 13,2011. Following detections of measurable liquid phase hydrocarbons (LPH) in monitoring
well MW-3 on June 8, 2011, twenty-four direct push borings were advanced to define the horizontal and
vertical extent of petroleum contamination. Based on the preliminary subsurface characterization data, ten
additional monitoring and recovery wells were installed on-site. Interim daily vacuum extraction events
continue to recover LPH, as required. As of September 13, 2011, it has been estimated that over 1,200
gallons of LPH has been recovered and LPH detections within the monitoring well network continue to
fluctuate. Gauging of on-site monitoring wells detected groundwater levels between 6.75 and 18.25 feet
below ground surface (bgs). The most recent projections show groundwater flow to the southwest.
The on-site drinking water supply well was retrofitted with a granular activated carbon (GAC) filtration
system in 2006 following detection of methyl tertiary-butyl ether (MTBE) at 28 parts per billion (ppb).
Sampling of the GAC filtration system for petroleum constituents has been below regulatory levels since
2006. Required off-site private drinking water supply well sampling detected the presence of petroleum
constituents above State action levels at two properties (505 and 513 Mechanics Valley Road). The
Department required installation of GAC filtration units at these properties and monthly monitoring, which
has been initiated.
Mr. Robert Rinehart
Case No. 2011-0729-CE
Page Two
The on-site monitoring well network currently includes: twenty-four temporary monitoring points; six
4-inch diameter recovery wells; five 4-inch diameter monitoring wells; and three 2-inch diameter monitoring
wells. To date, measureable LPH have been detected in monitoring well MW-3; recovery wells RW-l,
RW-2, RW-3, and RW-4; and borings B-4, B-6, B-9, B-IO, B-I3, and B-22. The sampling event conducted
August 4, 2011 detected the following dissolved phased hydrocarbons: benzene at 730 parts per billion (Ppb);
toluene at 2,700 ppb; ethylbenzene at 800 ppb; naphthalene at 400 ppb; total petroleum hydrocarbons/gasoline
range organics (TPHIGRO) at 13 parts per rni1lion (ppm); and total petroleum hydrocarbons/diesel range
organics (TPHlDRO) at 6.6 ppm.
During July and August 20 II, Department representatives oversaw removal of the three registered
underground storage tank (UST) systems and all associated piping components. Visible perforations were
observed in the secondary fiberglass layer of the 20,000-gal!on regular gasoline UST. During removal of
chase piping, petroleum impacted liquid was encountered within the piping. All soils were field screened
with a photo ionization detector (PID); readings ranged from 0.0 to 3,000 units. Perched water was identified
on the western side of the pump island trenching and the western end of the satellite diesel trench. The
Department awaits submission of the final UST System Removal Report documenting the analytical results
from all soil samples collected post-UST system removal and a final determination of the quantity of
petroleum impacted soils excavated no later then Oetober 17.2011. A preliminary soil sampling results
map, received during the August 23, 2011 technical meeting, depicted detections of total BTEX (benzene,
toluene, ethylbenzene, and xylene) up to 56,920 ppb and TPHIGRO up to 1,000 ppm.
Based on preliminary pilot testing, your consultant proposed the installation of a dual phase remediation
system to enhance the recovery ofLPH, dissolved phase hydrocarbons, and absorbed phase hydrocarbons in
soils. Pilot study results established a minimum radius of influence of20 feet utilizing a liquid ring pump.
On September 13, 2011, the Department received the "Design Summary", which denoted modifications to the
system proposed in the Corrective Action Plan Addendum - August 3, 2011. The current equipment
modifications propose utilizing submersible pneumatic pumps and vapor extraction with a central blower in
lieu of the previously proposed and pilot tested liquid ring pump.
At this time, the Department will not approve the use of surfactants within the subsurface. Based on the
aforementioned findings, the Department hereby requires the following:
REQUEST FOR SUPPLEMENT AI.. PILOT TEST:
(1) Prior to granting approval to implement the CAP as modified in the September 13, 2011 "Design
Summary," the Department requires an additional pilot test to confirm that proposed system
modifications will·be capable of achieving the previously established radius of influence. No later than
October 31. 2011. submit a Pilot Test Work Plan to verify that the modified equipment has the
capabilities to create the same recovery parameters and meet the same radii of influence. Report
findings to the Oil Control Program that include estimates of the maximum, minimum, and optimal flow
rates needed to establish hydraulic control, with consideration to a phased lowering of the pumps over
time to establish optimum recovery of the plume.
Mr. Robert Rinehart
Case No. 2011-0729-CE
Page Three
ADDITIONAL WELLS REQUIRED:
(2) To reduce and control migration of the dissolved phase hydrocarbon plume, the Department requires the
installation of two additional recovery wells (MDE-RWI and MDE-RW2) between the eastern end of
the pwnp island and store (see enclosed site map). The Department reserves the right to require
additional recovery points as necessary.
(3) Due to the extensive damage during UST installation activities, monitoring well MW-I must be properly
abandoned and replaced by a Maryland-c.ertified well driller (see enclosed site map). Prior to well
replacement, obtain a proper well pennit from the Cecil County Hearth Department and provide notice
of work activities to the Oil Control Program.
(4) The Department hereby approves proper abandonment of the temporary monitoring points installed in
June 20 II during the initial emergency subsurface investigation. All remaining temporary well points
must be abandoned by a Maryland-certified well driller.
(5) To properly monitor the dissolved phase hydrocarbon plwne, the Department requires the installation of
a minimwn of eight additional monitoring wells, MDE-I through MDE-8 (see enclosed site map). Once
the monitoring wells have been installed, all wells must be surveyed to a reported known elevation point
of reference. The Department reserves the right to require additional monitoring and/or recovery wells
based on future sampling data.
(6) Upon completion of well installation and abandonment activities, provide a copy of the well completion
and abandonment reports to both the Oil Control Program (Attn: Mr. Chad Widney) and the Cecil
County Health Department (Attn: Mr. Charles Smyser). The Oil Control Program anticipates receiving
the well completion and abandonment reports no later than November 1,2011.
(7) To further assess contaminant migration to private off-site drinking water supply wells, the Department
requires a Work Plan for the installation of three bedrock monitoring wells located between the known
contaminant plwne and three off-site bedrock supply wells. The Work Plan must include: detailed well
construction plans (including proposed depths); specify distance between nested wells; and approx imate
drilling locations. Preliminary well locations for the deeper wells are present on the enclosed site map
(MDE-5D, MDE-6D, MDE-7D). The Work Plan must outline a detailed schedule of all work necessary
to implement and complete monitoring well installation. The schedule must specify the dates and time
frames for implementing and completing each phase of the proposed Work Plan. The Work Plan must
be submitted to the Oil Control Program no later than November 30, 2011.
Mr. Robert Rinehart
Case No. 2011-0729-CE
Page Four
CONTINUED MONITORING:
(8) Begin quarterly (every three months) gauging and sampling of the monitoring well network. Sample
all monitoring wells that do not exhibit LPH. All samples collected must be analyzed for full-suite
volatile organic compounds (VOCs), including fuel oxygenates, using EPA Method 8260B and for
TPHIDRO and TPHiGRO using EPA Method 8015C.
(9) If measurable LPH are detected within the monitoring well network, the Department must be notified
within 2 hours. 1f LPH are consiStently detected witi'Jn a.'ly given monitoring point ~
implementation, the Department will require that monitoring point(s) be converted to recovery point(s).
(10) Conduct monthly sampling of the on-site and select off-site drinking water supply wells located at 500,
493,487,475, and 463 Mechanics Valley Road and 10 Montgomery Drive. Continue to analyze for
full-suite VOCs. including fuel oxygenates, using EPA Method 524.2. If analytical results exceeding
State action levels and/or maximum contaminant levels are detected, contact the Oil Control Program
and the Cecil County Health Department immediately.
(II) Continue to maintain and sample the GAC filtration systems retrofitted to the private drinking water
supply wells located at 513 and 505 Mechanics Valley Road on a monthly basis. Continue to collect
pre-, mid-, and post filtration samples and analyze for full-suite VOCs. including fuel oxygenates,
using EPA Method 524.2.
(12) The Department recommends that carbon within the GAC filtration systems be replaced, at a minimum,
on an annual (once a year) basis. If petroleum constituents are detected at the mid-filter point or
beyond, take corrective action, which may include replacement of the carbon. Provide written
confirmation to the Oil Control Program regarding all re-bedding/carbon change-out events.
Final approval of the CAP will be contingent upon the Department's review of the results of
supplemental pilot testing. Upon receiving CAP approval and final confirmation of complete system start-up,
the Department will approve discontinuance of the required vacuum events.
All information, data, reports, or plans generated for this site must be submitted to the Oil Control
Program for review by dates specified and/or agreed upon with the Department. Failure to perform the
advised actions may result in enforcement proceedings that could include the issuance of civil penalties and
other legal sanctions.
Mr. Robert Rinehart
Case No. 2011·0729·CE
Page Five
When submitting docwnentation to the Oil Control Program, provide four (4) hard copies and an
electronic copy on a labeled compact disc (CD) for updating the Oil Control Program's Remediation Sites list
on the MDE website. If you have any questions, please contact the case manager, Mr. Chadwick Widn~y,
at 410·537·3386 (email [email protected])ortheRegionalSupervisor.Ms.SusanBull.at
410-537·3499 (email: [email protected]).
Sincerely,
~#-
c~~r ~ston, Administrator
;,
Oil Control Program
CW/nln
Enclosure (map)
cc: Mr. David Carter (505 and 513 Mechanics Valley Road)
Raymar, LLC (463 Mechanics Valley Road)
Mr. and Mrs. Curtis and Betty Johnson (475 Mechanics Valley Road)
Mr. and Mrs. Robert and Debra Dean (487 Mechanics Valley Road)
Mr. and Mrs. Charles and Debra Pelletier (493 Mechanics Valley Road)
Montgomery Bros., Inc (10 Montgomery Drive)
Mr. Jeff Stein (Advantage Environmental Consultants, LLC)
Mr. Charles Smyser (Cecil County Health Dept.)
.
Ms. Susan R. Bull
Mr. Thomas L. Walter
Priscilla N. Carroll, Esquire
Mr. Horacio Tablada
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