Bay State Gas June 20 2006 Roundhouse Parking Lot assessment activities980 Washington Street Dedham, Massachusetts 02026 (781) 251-0200 (800) 446-5518 (781) 251-0847 (Fax)
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MEMORANDUM
TO:Wayne Feiden, Office of Planning and Development
FROM:Rob McGrath
CC:Peter LaGoy, Bay State Gas
DATE:June 20, 2006
RE:Test Pit Investigation Observations, Roundhouse Parking Lot
Test pits were completed in the Roundhouse Parking Lot in March and May 2006.The purpose of the
test pit investigation was to evaluate:
the presence or absence of former gas work structures and foundations (most notably tar wells);
the presence of recoverable liquids or MGP residuals;
odor and air emission is sues that may arise during full scale remedial or construction operations;
the volume of MGP-impacted soil.
Test pits were initially advanced in March 2006 to investigate the presence of any MGP residuals in the
subsurface near former structures (i.e., gas holder, water gas plant, etc.) in the Roundhouse Parking Lot
area as identified on Sanborn Fire Insurance maps. Additional test pits were advanced in May 2006 to
further evaluate additional former structures.
On March 18 and 19, 2006, W&C supervised the exploration of seven test pits (TP-5 through TP-11 )
within the Roundhouse Parking Lot to investigate former MGP structures (Figure 3 -1 ).W&C contracted
with Clean Harbors Environmental Services to provide and operate the excavation and support
equipment.A rubber track excavator with an approximately 0.5 cubic yard bucket was used to excavate
the test pits through fill materials. A Rusmar foam system was used to control fugitive odors, if
encountered, emanating from excavated soil. W&C visually evaluated the fill material and collected
representative soil samples for pre-characterization, field screening, and logging purposes. Upon
completion, test pits were backfilled and the ground surface was restored to its original condition.
During the excavation of the test pits, one air sample was collected on both March 18 and March 19 to
evaluate whether volatile and semi-volatile organic compounds originating from the test pits and
excavated soil impacted ambient air. An air sampling station was placed down wind of the test pit areas
in the southeast corner of the Roundhouse Parking Lot and an air sampling was collected for the duration
of excavation activities. The air sampling station was approximately 250 feet from the excavation area.
Sample collection tubes were provided by ESIS Environmental Health Laboratory of Cromwell, CT. Air
samples were collected for a total of 137 minutes on March 18 and 317 minutes on March 19.
Analysis of the air samples by ESIS Environmental Health Laboratory did not detect volatile organic
compounds in either the March 18 or March 19 sample. Two polycyclic aromatic hydrocarbons (benzo
(a) pyrene (1.2 ug/m3 ) on March 18 and acenaphthene (2.6 ug/m3) on March 19) were detected in the air
Client Name (Project #)2 Month date year
Document name
samples. These detected concentrations are less than the OSHA ceiling limit of air contaminants for coal
tar pitch volatiles (200 ug/m3) (29 CFR 1910.1000). Other sources, including nearby bus traffic, may
have contributed to the detected concentrations. Ambient air monitoring will be completed during future
response actions as described in Section 3.10 of the Phase IV report.
A summary of test pit observations are presented below.Test pit logs and a figure showing the location
of the test pits are attached.
TP-5 was advanced near a former aboveground oil tank located southwest of the Roundhouse. Coal tar
chunks and white ash were observed from one to 10 feet below ground surface (bgs). A concrete wall
with a slight curve (probable foundation for the former oil tank) was encountered at 3 feet bgs with a
concrete base encountered at 10 feet bgs, which was the maximum depth of the exploration. NAPL or
MGP residuals were not encountered. Groundwater was not encountered.
TP-6 was advanced within the former gas holder located west of the Roundhouse. The brick circular wall
of the former holder was encountered at 2 feet bgs. The holder was found to be backfilled with numerous
bricks, most likely from the walls of the former structure, with very little soil encountered. Coal tar-like
odors were noted on the bricks from 2 to 12 feet bgs and perched groundwater was encountered at 10 feet,
most likely trapped by the base of the former holder. The foam system was used to cover excavated soil
and reduce odors emanating from the soil stockpile. Due to the instability/undermining of TP -6 sidewalls
and odorous materials being removed from the holder, the exploration was not advanced beyond 12 feet
bgs. MGP residuals were observed within the former gas holder.
TP-7 was advanced within the eastern parking lot of the Roundhouse to investigate former retort
structures. A concrete floor or foundation was encountered at 1 foot bgs along the entire length of the 15-
foot long test pit. A second pit (TP-11)was advanced several feet west of the original pit and the same
concrete floor or foundation was encountered at 1 foot bgs along half of the pit, with a brick wall
containing a corroded valve pipe (abandoned) encountered over the southern half of the pit. No NAPL or
MGP residuals were observed.
TP-8 was advanced north of TP-7 and within the eastern parking lot of the Roundhouse to investigate the
former retort structures. Fill material was encountered to 5 feet bgs with a portion of the concrete floor or
foundation encountered at TP-7 extending into the central portion of the pit at 1 foot bgs. An abandoned
natural gas line was encountered at 5 feet bgs, and the exploration was not advanced deeper. No NAPL
or MCP residuals were observed.
TP-9 was advanced in the grass area north of TP-8, west of the concrete walkway, and east of the
Roundhouse to investigate a former water gas plant. Fill material was encountered to 5.5 feet bgs, which
was the total depth explored. An asphalt layer was encountered at 2.5 feet bgs, a concrete floor or
foundation was encountered at 3.5 feet bgs, and a brick wall was encountered at 5.5 feet bgs. The brick
wall could not be penetrated with the excavator and the exploration was not advanced deeper. No NAPL
or MGP residuals were observed.
TP-10 was advanced j ust south of the Roundhouse and west of TP-8 to investigate the former retort
structures.Fill material was encountered to 4.5 feet bgs underlain by a layer of material that appeared to
be hardened tar that was at least 2 feet thick over the entire length of the test pit. The tar layer was dense
and was not penetrated with the excavator beyond 2 feet. No NAPL was observed.
Client Name (Project #)3 Month date year
Document name
Additional test pitting was completed in the Roundhouse Parking Lot on May 12 and 13 to investigate the
presence of any MGP residuals in the subsurface near former structures (i.e., purifier building,
condensors, water gas plant, etc.) as identified on Sanborn Fire Insurance maps.
TP-12 and TP -1 3 were advanced adjacent to the former purifier building to the west of the Roundhouse.
Fill material was encountered to a depth of approximately 8 feet bgs. Silty clay was present beneath the
fill.No foundations were encountered.No NAPL or MGP residuals were observed.
TP-14 was advanced adjacent to monitoring well MW-8 to the southwest of the Roundhouse. Fill
material was present to approximately 9 feet bgs, and building foundations were encountered in two
separate locations. No NAPL was observed.
TP-15 was completed south of the Roundhouse and south of the former condensers.Fill material was
encountered to a depth of 9 feet BGS. No building foundations were encountered. No NAPL or MGP
residuals were observed.
TP-16 was completed adjacent to the former water gas plant to the southeast of the Roundhouse and near
the easternmost portion of the Roundhouse Parking Lot. A foundation was encountered at a shallow
depth in TP-1 6. At the edge of the foundation, a section of dirt-filled tile drain pipe, apparently used for
storm water drainage, was encountered close to the building foundation. No NAPL or MGP-residuals
were observed.
TP-17 was advanced in the grass to the east of the Roundhouse. A 4 -foot long section of riser pipe
consisting of a 1-inch copper pipe within an approximately 2-inch diameter steel tube was detected in the
excavation and a metal structure was detected beneath this pipe at a depth of approximately 6 feet below
ground surface. The riser pipe had a slight odor of MGP-residuals and is suspected to be the pump out
valve for a drip pot, with the structure at depth considered likely to be the drip pot on the old abandoned
gas line leading from the roundhouse tank. No NAPL or MGP residuals were observed
DES.BY:DR.BY:CK.BY:
SCALE:JOB NO.:206096
FILE NAME:DATE:June 2006
Roundhouse
Plaza
Roundhouse
Municipal Building
ApartmentBuildingTP-5
TP-6
TP-10
TP-9
TP-7TP-11
TP-8
TP-12
TP-13
TP-14 TP-15 TP-16
TP-17
TEST PIT LOCATIONS
FORMER NORTHAMPTON GAS LIGHT CO
Northampton,Massachusetts
TEST PIT
No.
TP-5
RTN 1-14222
JOB NUMBER 206096 START DATE March 18, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 18, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)10
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not Encountered
LOCATION Parking lot (west)DIMENSION (WxL):3' x 20'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 1'
Brown fine to coarse SAND, some fine gravel, loose, dry, no odor
1'1' - 10'
Gray, black and brown fine to coarse SAND, some fine gravel, dry, no odor,
2'large bricks, coal tar chunks, glass, granular white ash, cobbles
3'Concrete wall trending east-west encountered at 3' (15.5' south of curb).
4'Different fill material south of wall (i.e., poorly sorted medium SAND).
Test pit undermined on south side during excavation.
5'Concrete footing removed from pit.
6'Base of concrete encountered on south side of wall.
7'
8'FILL
9'
10'
Bottom of Exploration at 10 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
0-3
TEST PIT
No.
TP-6
RTN 1-14222
JOB NUMBER 206096 START DATE March 18, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 18, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)12
INSPECTORS JE & RM G. WATER DEPTH (FT.)10
LOCATION Former Gas Holder DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 2'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'
2'Brick circular wall (5 bricks thick) encountered at 2'
3'2' - 12'
Numerous bricks, little soil, coal tar odors, no visible NAPL
4'
5'
6'
7'
8'FILL
9'
10'Water at 10' (perched)
11'
12'
Bottom of Exploration at 12 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-7
RTN 1-14222
JOB NUMBER 206096 START DATE March 19, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 19, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)1
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION Parking Lot (east)DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 1'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'FILL
Smooth concrete floor encountered at 1' entire length of pit.
2'
3'Bottom of Exploration at 1 foot.
4'
5'
6'
7'
8'
9'
10'
11'
12'
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-8
RTN 1-14222
JOB NUMBER 206096 START DATE March 19, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 19, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)5
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION Parking lot (east)DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 5'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'Portion of concrete floor encountered at 1' in TP-7 extended into mid portion
of TP-8; 4 inches thick with rebar.
2'
3'FILL
4'
5'Former natural gas line encountered at 5'
Bottom of Exploration at 5 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-9
RTN 1-14222
JOB NUMBER 206096 START DATE March 19, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 19, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)5.5
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION Grass next to walkway DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 5.5'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'
FILL
2'
Asphalt layer encountered at 2.5'
3'
Concrete floor encountered at 3.5'
4'
5'
Brick wall encountered at 5.5'
Bottom of Exploration at 5.5 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
0-5
TEST PIT
No.
TP-10
RTN 1-14222
JOB NUMBER 206096 START DATE March 19, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 19, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)6.5
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION South of Roundhouse DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 4.5'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'
FILL
2'
3'
4'
Tar layer encountered at 4.5' (at least 2' thick)
5'over entire length of pit
6'
Bottom of Exploration at 6.5 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
0-5
TEST PIT
No.
TP-11
RTN 1-14222
JOB NUMBER 206096 START DATE March 19, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE March 19, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)1
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION Parking Lot (east)DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 1'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'Concrete slab encountered at 1 foot; Brick wall near southern end of pit
old valve pipe (diconnected) encounted FILL
2'
3'Bottom of Exploration at 1.5 feet.
4'
5'
6'
7'
8'
9'
10'
11'
12'
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-12
RTN 1-14222
JOB NUMBER 206096 START DATE May 12, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE May 12, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)9
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION West of Roundhouse DIMENSION (WxL):3' x 30'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 7'
Brown, black, and gray fine to coarse SAND, some fine gravel, cobbles,
1'bricks, loose, no odor
2'
no evidence of foundations
3'FILL
4'
5'
6'
7'
8'
7' - 8'
9'Gray silty CLAY
Bottom of Exploration at 9 feet.
10'
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-13
RTN 1-14222
JOB NUMBER 206096 START DATE May 12, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE May 12, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)9
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION West of Roundhouse DIMENSION (WxL):3' x 30'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 8'
Brown, black, and gray fine to coarse SAND, some fine gravel, cobbles,
1'bricks, dry, no odor.
2'
3'FILL
4'
5'no foundations envountered
6'
7'
8'
8' - 9'
9'Gray CLAY
Bottom of Exploration at 9 feet.
10'
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-14
RTN 1-14222
JOB NUMBER 206096 START DATE May 13, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE May 13, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)10
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION Southwest of RoundhouseDIMENSION (WxL):3' x 40'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 9'
Brown fine to coarse SAND, some gravel and cobbles, bricks, loose, dry,
1'no odor
FILL
2'
3'Two foundations perpendicular to test pit encountered at 3 feet.
4'
5'
6'
7'
8'
9'
9' - 10' Gray silty CLAY
10'Bottom of Exploration at 10 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-15
RTN 1-14222
JOB NUMBER 206096 START DATE May 13, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE May 13, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)8
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION South of Roundhouse DIMENSION (WxL):3' x 30'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 8'
Brown fine to coarse SAND, some fine gravel, bricks, loose, dry, no odor
1'
FILL
2'
3'
4'No foundations encountered
5'
6'
7'
8'
Bottom of Exploration at 8 feet.
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-16
RTN 1-14222
JOB NUMBER 206096 START DATE May 13, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE May 13, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)4
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION South of Roundhouse DIMENSION (WxL):3' x 30' (T-shaped)
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 4'
Brown fine to coarse SAND, some gravel, bricks, loose, dry, no odor
1'
Concrete slab encountered at 1 foot across portion of test pit
2'
Bottom of slab at 3'FILL
3'Dirt filled ceramic drain pipe encountered (filled with sand)
4'
Bottom of Exploration at 4 feet.
5'
6'
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts
TEST PIT
No.
TP-17
RTN 1-14222
JOB NUMBER 206096 START DATE May 13, 2006 PAGE
CONTRACTOR Clean Harbors FINISH DATE May 13, 2006 1 of 1
EQUIPMENT Track Excavator TOTAL DEPTH (FT.)6.5
INSPECTORS JE & RM G. WATER DEPTH (FT.)Not encountered
LOCATION East of Roundhouse DIMENSION (WxL):3' x 15'
Sample PID
Depth Range (ppm) Field Description and Remarks
0 0' - 6.5'
Brown and black fine to coarse SAND, some fine gravel
1'
FILL
2'
3'
4'
Section of copper pipe (4 feet long) and metal tube encountered at 3 feet
5'Likely pump out valve for drip pot
6'
Metal object encountered at 6 feet; Probable drip pot of former gas line
7'
Bottom of Exploration at 6.5 feet.
8'
980 Washington Street
Dedham, Massachusetts 02026
SITE LOCATION
TEST PIT LOG Former Northampton Gas Works
Northampton, Massachusetts