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Quarterly Report (Q3 & 4) July - December 2018
Assessment of EPA Approved Ground Water Remediation Program
Prepared by Brendan O’Connell December 2018.
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Contents Introduction ............................................................................................................................................ 3
Executive Summary ................................................................................................................................. 3
LNAPL Recovery ...................................................................................................................................... 4
Jar Sampling ............................................................................................................................................ 5
Jar Sampling – Trending ...................................................................................................................... 6
Measurement of depth to product/groundwater .................................................................................. 8
Interface Probe Results ..................................................................................................................... 10
Influence of off-site sources ................................................................................................................. 10
Pumping ................................................................................................................................................ 15
Down Time ........................................................................................................................................ 15
Pump Timing ..................................................................................................................................... 15
Conclusion ............................................................................................................................................. 16
Figure 1- LNAPL captured by 1st chamber of IBC interceptor2 .............................................................. 4
Figure 3- New Booster pump fitted to MW8 .......................................................................................... 4
Figure 4- Jar sampling records 2018: Total contribution (mm) and %.................................................... 5
Figure 5- Sample of clean water taken from outlet of IBC interceptor .................................................. 5
Figure 6- Total mm (Jar Samples) 2017 vs 2018 (34 Sampling events in 2017 Vs 19 in 2018) ............... 6
Figure 7- Average weekly LNAPL (mm) in Central (Source area) wells ................................................... 6
Figure 8- Average weekly LNAPL (mm) in Downgradient wells .............................................................. 7
Figure 9- Total LNAPL per sampling date 2018 ....................................................................................... 7
Figure 10 - Location of former Oil Depot .............................................................................................. 11
Figure 11 - Analysis showing presence of gasoline ............................................................................... 12
Figure 12- Improving parameters before off site work ........................................................................ 13
Figure 13- Work being carried out on land south of railway (including excavation) ............................ 14
Figure 14- Increased ammonia and chloride levels in December 2017 ................................................ 14
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Introduction A meeting was held on the 29th of February 2016 between four representatives of the Environmental
Protection Agency (EPA) and Cold Chon (Galway) Ltd. to review and assess the effectiveness of the
Groundwater remediation plan Rev. B, which was approved by the Agency on 24th September 2012.
On the request of the Agency, a number or changes as to how groundwater data is collected and
reported was requested in light of the positive progress that has been made recently. The following is
the report for the 3rd and 4th quarters of 2018 and is submitted alongside OCM’s Groundwater Report
for the same period.
Executive Summary The period of July to December 2018 saw approximately 230 lts of LNAPL recovered by the IBC
pumping process, an increase of 9.5% on the previous reporting period (210 lts). There has been a
reduction in the average amount of LNAPL in Jar samples between the two periods but an increase
in the average amount of LNAPL in probe monitoring (highly skewed due to 825mm reading in June
monitoring round). The latest OCM groundwater report indicates the possible continued influence of
off-site sources and the presence of gasoline in 6 wells (Gasoline is not and has never been used on-
site). Overall, results from OCMs report indicate that groundwater quality in source area and
downgradient wells is improving. The increase in LNAPL being recovered is indicative that the new
focused pump timings are successfully targeting LNAPL layers within the wells.
The Jar sampling is the method most reflective of what is being recovered / treated, as this is a direct
sample of what is being pumped to the IBC recovery process at the time of sampling. Measuring
LNAPL using the oil / water interface probe has many variables such as pump height, ground water
re-charge of well etc. The interface probe has been found to be an invaluable tool to indicate which
pumping wells need height adjustment and manual extracting, using the fishing technique.
A booster pump has been fitted to MW-8 to increase the pumping rate and product recovery from
this well.
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LNAPL Recovery The LNAPL was measured in the groundwater interceptor using an oil-water interface probe and the
amount measured equated to 230 litres. No product layer was found in the second, third, or fourth
chamber of the interceptor, indicating its functionality.
Figure 1- LNAPL captured by 1st chamber of IBC interceptor2
Q3 & 4 of 2017 yielded 70lts of free product. The increased product recovery in 2018 is indicative
that the new pump timings and targeted pumping is more effective at removing free product than
the previous regime. Regular monitoring of LNAPL levels in the wells enables us to target the worst
affected wells.
Each pump now runs on more frequent, shorter 7 min bursts instead of 15 min bursts. Wells which
have generally had more LNAPL than others are pumped more often, while wells with less or no
product layer are pumped less often. This enables us to set the pump heights higher in the water
column to target the settled LNAPL more efficiently and effectively. In the event a large product
layer is detected, the pump timing can be altered or switched to run constantly until the product
layer is removed. A Booster pump was fitted to MW8 to increase the rate of product recovery in this
area. These changes may have resulted in an increase of product recovery.
Figure 3- New Booster pump fitted to MW8
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Jar Sampling The groundwater pumping programme is monitored on a regular basis for LNAPL. The monitoring
process involves obtaining a sample of groundwater from each well during the scheduled pumping
operations. This sample is recovered in a clear glass container. The sample is allowed to settle before
the LNAPL is measured in millimetres. The sample is always taken from the very top of the water
column, to ensure that any product layer present is always detected.
Figure 4- Jar sampling records 2018: Total contribution (mm) and %
Figure 5- Sample of clean water taken from outlet of IBC interceptor
Figure 5 shows the effective treatment provided by our IBC
interceptor. Clean, treated water is fed from the interceptor into
our production reservoir where it is used in the Cold Chon
production process.
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Jar Sampling – Trending
Figure 6- Total mm (Jar Samples) 2017 vs 2018 (34 Sampling events in 2017 Vs 19 in 2018)
Less total product has been recovered by jar samples in comparison to last year, however there have
been significantly less sampling events. A comparison of mm per sampling event shows a reduction
from 7.7mm to 6.5mm in 2018
Figure 7- Average weekly LNAPL (mm) in Central (Source area) wells
Total mm 2017 Total mm 2018
Total 262 124.5
0
50
100
150
200
250
300
mm
LN
AP
L
Total LNAPL 2017 v 2018 from Jar sampling (mm)
22-Jan-18
13-Feb-18
26-Feb-18
13-Mar-18
12-Apr-18
23-Apr-18
04-May-18
15-May-18
05-Jun-18
18-Jun-18
12-Jul-18
13-Aug-18
27-Aug-18
14-Sep-18
24-Sep-18
23-Oct-18
01-Nov-18
12-Nov-18
20-Nov-18
Series1 1.3 0.6 1.0 1.5 1.0 0.4 0.6 0.5 0.8 1.0 1.0 2.6 0.9 0.5 1.4 2.5 1.0 0.4 0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
mm
/jar
Central Well Average mm
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Figure 8- Average weekly LNAPL (mm) in Downgradient wells
Figure 9- Total LNAPL per sampling date 2018
We can see from the jar sampling trending analysis that the amount of product being detected in
bimonthly samples is generally reducing, save for occasional spikes, while the amount of product
being recovered has increased, suggesting that the adjustments made have increased the rate at
which product is being recovered.
22-Jan-18
13-Feb-18
26-Feb-18
13-Mar-18
12-Apr-18
23-Apr-18
04-May-18
15-May-18
05-Jun-18
18-Jun-18
12-Jul-18
13-Aug-18
27-Aug-18
14-Sep-18
24-Sep-18
23-Oct-18
01-Nov-18
12-Nov-18
20-Nov-18
Series1 0.4 0.2 0.3 0.3 0.6 0.5 0.4 0.3 0.9 0.3 0.3 0.3 0.3 0.7 0.5 0.5 0.4 0.4 0.4
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
mm
/jar
Down Gradient Well Average mm
0
2
4
6
8
10
12
14
mm
LN
AP
L
Total settled LNAPL (mm) from Jar Sampling per sample date 2018
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Measurement of depth to product/groundwater LNAPL is measured using oil / water interface probe from the top of the well casing (see case height
below). The table shows thickness (mm) of LNAPL per well, depth to product layer (LNAPL Level -
mbtc), and depth to water (water level) along with mOD equivalents.
Before measurement with the interface probe, all pumps are switched off at around 4:30pm the
previous working day, thereby allowing wells to re-charge. Probe monitoring then takes place the
following day with groundwater at its natural level.
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Figure 8- 2018 Monitoring results from Oil-Water Interface probe
*** DG = Downgradient CW = Central Well (source area) UG = Upgradient well mbtc = M below top of casing mOD = Ground Level (mOD) + case height (m) – mbtc value (m)
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Interface Probe Results
Figure 9- Individual monitoring well LNAPL (2017-2018)
Influence of off-site sources
As mentioned previously in a document submitted to the agency “Review of possible off site sources
of groundwater contamination” there are a number of contamination sources which could be
influencing groundwater quality on site. Two of the potential sources mentioned were the railway
line (up-gradient to the south of the site) and lands to the south of the railway line - specifically the
former oil depot. The Galway-Dublin Railway line runs along the southern boundary of the site. The
railway line is situated at a higher ground level than the site and is supported by rock ballast. The
railway line is a potential off site source of contamination. Historically, the Oranmore Railway station
was located along the Cold Chon boundary. The standing trains would be a potential historical
source of both fuel and hydraulic oil leaks on to a permeable surface. As seen in the latest OCM
groundwater monitoring report, possible gasoline traces were present in 6 wells. Gasoline is not and
has not ever been used on the Cold Chon site. Recent groundworks in the vicinity of where the oil
0
100
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400
500
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1000
MW1 MW3 MW4 MW5 MW6 MW7 MW8 MW9 MW10 PW1 PW2 PW3 PW4 PW5 PW6
Interface Probe - Total mm LNAPL layers (2017 vs 2018)
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depot once stood may have caused the increased levels of off-site contamination encroaching onto
the Cold Chon site.
Figure 10 - Location of former Oil Depot
It has been documented previously that there were historical potential sources of hydrocarbon
contamination in lands located immediately south of the railway line including an ESSO oil depot to
the south of the railway line. Approved planning permission from 1977 showed drawings of the
depot including fuel delivery area from the railway line to underground storage tanks located at the
depot. As per Planning Ref. old24642, there was 2 additional oil storage tanks of approximately
817m3 and 122m3 respectively installed, to be filled from rail tank cars parked on the adjacent
railway siding. There were existing tanks onsite at the time also.
There were fifteen separate fuel unloading points in an unpaved, pervious area where any spills and
leaks would have been absorbed into the permeable surfacing (Washed Gravel). From the drawings,
it appears that underground pipes in the fuel depot were not protected and any damage and leaks
could have led to significant contamination of the area. The fuel depot was in operation at a time
when environmental work practices were not as developed. Gasoline, which is not used on our site
was found to be present in eight out of fifteen wells (MW6, MW8, MW9, PW1, PW2, PW3, PW4 and
PW6) in the monitoring November 2016 and in December 2017 it was detected in five wells (MW6,
MW8, MW9, PW1, PW2). In the previous monitoring round (June 2018), gasoline was detected in
thirteen of the fifteen wells (no interpretation possible in MW3 & MW10). In the latest monitoring
round (being submitted alongside this report), possible gasoline residues were found in six out of
fifteen wells.
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Figure 11 - Analysis showing presence of gasoline
Following closure of the Oil depot there were a number of large Plant and Tool Hire firms (Leada
Acrow Ltd, A Plant Ltd, MacRental & CatRental), again operating for a number of years on permeable
ground, and more than likely, not to the same environmental standards as licensed activities.
The railway line is located at a higher level than the site and any spill into the ballast would reach the
bedrock beneath the line very quickly given both the permeable nature of the ballast and the
shallow depth to bedrock.
In the months preceding the second annual groundwater monitoring event, there was work being
carried out on these lands. This work has led to increased permeability in the area. The subsequent
deterioration of water quality in up-gradient wells leads us to believe that the disturbance of these
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lands may have contributed to the deterioration of water quality on-site. The affected wells are up-
hydraulic gradient of historical on-site sources of contamination.
Figure 12- Improving parameters before off site work
* Noticeable downward trend of parameters (aromatic, aliphatic hydrocarbon, PAH, VOC) from June
16 onwards until a spike in the December 17 report- Groundworks began after the previous June
2017 monitoring. **Updated graphs for 2018 can be found in OCM’s two reports for this year.
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Figure 13- Work being carried out on land south of railway (including excavation)
Figure 14- Increased ammonia and chloride levels in December 2017
Elevated levels of Ammonia and Chloride found across the site could be indicative of saline
influences or possibly off site point source discharges from septic tanks, or other un-sewered
wastewater discharges, not associated with Cold Chon. This may have been exacerbated due to
adverse weather and increased off-site ground permeability in the lead up to groundwater sampling.
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Pumping
Down Time Downtime is kept to a minimum through the management of the system by the Environmental Co-
Ordinator, who monitors the process every day. Upon discovery of a failed pump in the daily
inspection, they are immediately replaced. Two wells (MW9 & PW6) experienced reduced flow as a
result of clogging, which may have impacted on the remediation program. The issue has since been
resolved in each well, both of which will be monitored closely to avoid the same happening again.
Pump Timing Our new pump timing system is on 24hrs per day instead of 16hrs per day (with the exception of
PW5 & MW7 which run on batteries 8hrs per day continuously) and enables us to target the LNAPL
on the top of the water column by setting the pumps higher in the well column. Because the pumps
are on for 7mins instead of 15mins there is less chance of the well running dry while pumping. A
booster pump was fitted to MW8 to increase the rate of product removal in this area.
They now pump two or three times per hour, instead of once, therefore increasing the level of
LNAPL % recovered, as has been seen in the results i.e. less LNAPL detected in sampling trends (Jar &
Probe), however increased volume of LNAPL in IBC system e.g. 45lts in Q1 & Q2 2016 to 70lts in Q3
& Q4 2017, 210lts in Q1 & Q2 2018, and 230lts in Q3 & Q4 2018. This proves the effectiveness of the
removal technique and subsequent adjustments made to the system.
Well Min/Hour
Old (16hrs)
Min/Hour
New (24hrs)
MW1 15mins/hr 2x7mins/hr
MW7 8hrs/pd 8hrs/pd
MW8 15mins/hr 3x7mins/hr
MW9 15mins/hr 2x7mins/hr
PW1 15mins/hr 3x7mins/hr
PW2 15mins/hr 3x7mins/hr
PW3 15mins/hr 3x7mins/hr
PW4 15mins/hr 2x7mins/hr
PW5 8hrs/pd 8hrs/pd
PW6 15mins/hr 2x7mins/hr
Figure 14 – New Pump Timings
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Conclusion
The groundwater remediation program continues to be an effective method of removing
contamination, particularly LNAPL. We have seen an increase in the recovery rate of LNAPL in Q1 &
2, as well as Q3 & 4 of 2018 due to modified pump timings and targeted pumping. A total of 230lts
was removed during the current reporting period.
The latest OCM groundwater report shows a continued influence of possible off-site sources in
upgradient areas, while there is a general trend of improvement of water quality in central and
down gradient wells.
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