IEL Groundwater and Surface Water Monitoring 2016

Transcription

1 IEL Groundwater and Surface Water Monitoring 2016 Sigma Aldrich Ireland Limited Project Referee: /CKRP0001 Issue 2 For inspection purposes only Consent of copyright owner required for any other use 23 February 2017 Vale Road, Arklow, Co Wicklow EPA Export :03:04:45

2 IEL Groundwater and Surface Water Monitoring 2016 Quality information Project Referee: /CKRP0001 Issue 2 Prepared by Checked by Approved by Priipal Hydrogeologist Kevin Forde Technical Director Kevin Forde Technical Director Revision History Revision Revision date Details Authorized Name Position Distribution List Hard Copies PDF Required Association / Company Name 0 1 Dora Forde, Sigma Aldrich Ireland Limited For inspection purposes only Consent of copyright owner required for any other use Prepared for: Sigma Aldrich Ireland Limited AECOM EPA Export :03:04:45

3 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 Prepared for: Dora Forde Environmental Health and Safety Manager Sigma Aldrich Ireland Limited Vale Road, Arklow, Co Wicklow Prepared by: Priipal Hydrogeologist T: M: E: edelohannelly@aecomcom AECOM Professional Services Ireland Douglas Business Centre Carrigaline Road Cork Ireland T: aecomcom For inspection purposes only Consent of copyright owner required for any other use 2017 AECOM Ireland Limited All Rights Reserved This document has been prepared by AECOM Ireland Limited ( AECOM ) for sole use of our client (the Client ) in accordae with generally accepted consultay priiples, the budget for fees and the terms of referee agreed between AECOM and the Client Any information provided by third parties and referred to herein has not been checked or verified by AECOM, unless otherwise expressly stated in the document No third party may rely upon this document without the prior and express written agreement of AECOM Prepared for: Sigma Aldrich Ireland Limited AECOM EPA Export :03:04:45

4 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 Table of Contents 1 Introduction 6 11 General Introduction 6 12 Background 6 13 Objectives 6 2 Scope of Works 7 21 Task 1 Dip Round 7 22 Task 2 - Well Purging and Field Water Quality Measurements 7 23 Task 3 - Sample Collection 8 3 Results and Discussion of monitoring Programme 8 31 Site Hydrogeology and Groundwater Flow 8 32 Field Observations 9 33 Field Results 9 34 Laboratory Results Assessment Guidelines Volatile Organic Compounds and Water Soluble Solvents Hydrocarbons Polycyclic Aromatic Hydrocarbons Metals Major Ions and Indicator Parameters Microbiological Results Potential Pollutant Linkages Potential Sources Potential Pathways Potential Receptors SPR Linkages - Risk Screening 15 4 Assessment of Current Groundwater Impacts Extent of Plume and Trends VOCs Ammoniacal Nitrogen Impact on Receptors Chemical Status of Groundwater Body Remedial Strategy Groundwater Compliae Monitoring 18 5 Summary, Colusions and Recommendations Summary and Colusions Recommendations 18 Figures Tables Appendix A Laboratory Certificates Appendix B - Historic Monitoring Data For inspection purposes only Consent of copyright owner required for any other use Figures Figure 1 Site Layout with Monitoring Well Locations Figure 2 Groundwater Contours Round Figure 3 Groudwater Contours Round Figure 4 Cross Section Figure 5 Geology and Site Boundary Prepared for: Sigma Aldrich Ireland Limited AECOM EPA Export :03:04:45

5 IEL Groundwater and Surface Water Monitoring 2016 Tables Project Referee: /CKRP0001 Issue 2 Table 1 Well Installation Details Table 2 Groundwater Elevations and Purge Volumes Table 3 Field Observations and Water Quality Measurements Table 4 Sample Inventory Table 5 Volatile Organic Compound Results Table 6 Water Soluble Solvent Results Table 7 Total Hydrocarbon Results Table 8 Polycyclic Aromatic Hydrocarbon Results Table 9 Metal Results Table 10 Major Ion and Indicator Parameter Results Table 11 Microbiological Results For inspection purposes only Consent of copyright owner required for any other use Prepared for: Sigma Aldrich Ireland Limited AECOM EPA Export :03:04:45

6 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 1 Introduction 11 General Introduction AECOM, through its wholly owned subsidiary AECOM Ireland Limited (AECOM), is pleased to present this report to Sigma Aldrich Ireland Limited (Sigma) on results of groundwater and surface water monitoring conducted during 2016 This report, and the work reported herein, has been completed in accordae with AECOM proposals referee OPP and OPP , and authorised by Sigma under purchase order numbers and The project has been completed by staff from AECOM s Cork and Dublin offices: Kevin Forde, Project Director Edel O Hannelly, Project Manager Tom Kilbride, Michelle Wong, Colin Fitzgerald and Aleksandra Gadek, Environmental Scientists 12 Background The Sigma site is located on Vale Road, Arklow, Co Wicklow, approximately 2 km north-west of Arklow town The site has the capacity to carry out biochemical production and complex, multi-step organic synthesis of active pharmaceutical ingredients (API) and intermediates The facility operates under the terms of an Industrial Emissions Licee (IEL, number P ) issued by the Environmental Protection Agey (EPA) The following activities at the site are licensed by the EPA: The production of pharmaceutical products iluding intermediates on an industrial scale by chemical or biological processing; and The recovery or disposal of waste in a facility, within the meaning of the Act of 1996 Biannual monitoring of groundwater from ten wells on-site: wells BH1-BH10, is required under Condition 6 and Schedule C of the site s licee At the EPA s request, well BH14 was iluded in the biannual monitoring schedule from 2010 to 2013, and continues to be iluded in the monitoring scope Wells BH19 and BH20 were drilled and installed in 2011, at the request of the EPA, to investigate the presee of hydrocarbons down-gradient of a diesel spill which occurred in September 2009 Following their installation, it was recommended that they be monitored annually for total petroleum hydrocarbons Collection and analysis of four grab samples of surface water is also routinely iluded in monitoring rounds Two samples are collected from the surface water drainage ditch (SW1 and SW2) and two from the Avoca River (SW3 and SW4) The site layout and monitoring network is presented in Figure 1 13 Objectives For inspection purposes only Consent of copyright owner required for any other use The primary objective of the monitoring works completed during 2015 was to maintain the site s compliae with: Groundwater monitoring requirements as outlined in Schedule C6 in the site s IEL Additional monitoring requirements as specified by the Environmental Protection Agey (EPA), letter referee P \rf02bcdocx, received by SAIL on 18 August 2010 Prepared for: Sigma Aldrich Ireland Limited AECOM 6 EPA Export :03:04:45

7 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 In addition, an assessment of hydrogeological conditions beneath the site in terms of the additional items requested by the EPA and significant trends in groundwater chemistry has been completed and is presented in this report, with recommendations for further action as appropriate 2 Scope of Works Two monitoring rounds were conducted in 2016: Round , conducted on 18 and 19 April 2015 Round , conducted on 17 and 18 October 2015 During each monitoring round the following tasks were completed: Task 1 - Depth to water level measurement round ( dip round ) in all accessible wells Task 2 - Well purging and field measurement of unstable water quality parameters Task 3 - Collection of groundwater and surface water samples for laboratory analysis Each of these tasks is discussed in more detail below 21 Task 1 Dip Round Prior to sampling, a dip round of depth to groundwater measurements for accessible monitoring wells on site was recorded There are 17 wells on site which have been surveyed to a common site datum, an inventory of wells on site is provided in Table 1 Combining the depth to groundwater measurements on the day of sampling with known top of well casing elevations, allows groundwater elevations across the site to be calculated This, in turn, allows a groundwater contour map of the site to be drawn and the direction of groundwater flow to be assessed The wells were dipped with an interface probe which is capable of distinguishing between water and non-aqueous phase liquids (NAPL) Organic liquids lost to ground may accumulate and be detected as a light NAPL floating on the top of groundwater (such as fuel hydrocarbons) or as a dense NAPL sinking to the base of a monitoring well (such as chlorinated solvents) Dip measurements are presented in Table 2 with groundwater contour maps in Figures 2 and 3 22 Task 2 - Well Purging and Field Water Quality Measurements AECOM field staff sampled all wells according to AECOM groundwater sampling protocol (based on USEPA and BSI methods) Wells were first purged of between three and five well volumes using dedicated in-situ sampling equipment, wells BH3-BH10, BH14, BH19 and BH20 are equipped with HDPE inertial-lift sample tubing As wells BH1 and BH2 are equipped with electric pumps, the pumps were turned on and allowed to operate for a defined period of time, the flow rate from the pumps was noted Grab samples of surface water were collected For inspection purposes only Consent of copyright owner required for any other use During purging and sampling, AECOM field staff wore single use, disposable nitrile gloves to reduce the risk of cross-contamination between sampling locations Field measurements of water quality parameters were taken using a calibrated water quality meter during purging Stable readings of: ph, temperature, electrical conductivity, redox potential and dissolved oxygen were recorded Where possible, water quality readings were taken using a flow-through cell to reduce sample aeration Field readings of dissolved oxygen and redox potential recorded in this manner are particularly useful in assessing the redox state of groundwater and suitability of groundwater conditions to the in-situ biodegradation of various hydrocarbons and chlorinated solvents which may be detected Field water quality measurements are provided in Table 3 Prepared for: Sigma Aldrich Ireland Limited AECOM 7 EPA Export :03:04:45

8 IEL Groundwater and Surface Water Monitoring Task 3 - Sample Collection Project Referee: /CKRP0001 Issue 2 Samples were collected directly into laboratory-supplied sample containers, filtered and preserved where appropriate Samples for microbiological determination were collected into sterile containers Samples were labelled in the field and details entered onto a chain of custody form On site and during transit the samples were stored in chilled cool boxes Chain of custody documentation accompanied samples during transit to the laboratories As samples for microbiological analysis have short holding times, the time of sampling was recorded in the field notes and on the chain of custody In both monitoring rounds, samples from wells BH1-BH10 and BH14 and surface water samples were analysed for the following suite of parameters: Volatile organic compounds (VOC), iluding BTEX 1 compounds and MTBE 2 ; Water soluble solvents (iluding acetone) Total petroleum hydrocarbons (diesel and petrol range organics) Polycyclic aromatic hydrocarbons (PAH) Metals (iron and manganese) Major ions (chloride, fluoride, nitrite, nitrate, sodium, calcium, potassium and magnesium) Sulphate Ortho-phosphate Ammoniacal nitrogen (ammonia) Chemical oxygen demand Total alkalinity Total coliforms and E coli In addition, during Round , samples from wells BH19 and BH20 were collected and submitted for analysis of total petroleum hydrocarbons (diesel and petrol range organics, and mineral oil) Samples were sent via overnight courier to Alcontrol Laboratories, UK Alcontrol is an AECOM approved supplier with UKAS accreditation Given the time-sensitive nature of samples for microbiological analysis, they were analysed by City Analysts, Dublin Laboratory certificates are provided in Appendix A For inspection purposes only Consent of copyright owner required for any other use 3 Results and Discussion of monitoring Programme 31 Site Hydrogeology and Groundwater Flow Beneath the superficial made ground and fill, the site is underlain by a sequee of alluvial sediments overlying shale bedrock The alluvial sediments consist of interbedded sands and gravels with generally stiff clays Depth to the top of shale bedrock is reported to range from 3 m below ground level (bgl) to greater than 14 m bgl The majority of monitoring wells on site are screened within alluvial sediments, with only wells BH1 and BH2 screened within bedrock, both are deep wells, ~80 m bgl Depth to groundwater measurements (see Table 2) ranged between 048 m (well BH20) and 527 m (BH18D) in Round and between 048 m (well BH20) and 539 m (well BH18D) in Round In most monitoring wells, groundwater was deeper by approximately 012 m in Round compared to Round 1, this reflects seasonal variations in precipitation 1 Benzene, toluene, ethyl benzene and total xylene 2 Methyl tert butyl ether Prepared for: Sigma Aldrich Ireland Limited AECOM 8 EPA Export :03:04:45

9 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 Groundwater contour maps, taking groundwater elevations from shallow monitoring wells, are presented in Figures 2 and 3 for Rounds 1 and 2, respectively The general groundwater flow direction is north-eastward toward the Avoca River, which lies approximately 110 m from the site This is consistent with contour maps from previous monitoring rounds 32 Field Observations No floating or sinking NAPL layer was detected in any of the monitoring wells dipped Most water samples appeared either clear and colourless, or brown and slightly turbid, but with no obvious evidee of contamination However: A slight solvent/hydrocarbon-type odour was also noted when sampling BH6 and BH7 A slight sheen was noted on groundwater from wells BH3, BH6, BH7 and BH14 A slight hydrogen sulphide odour was noted from groundwater from wells BH8 and BH9 No physical evidee of contamination was noted at any of the surface water sampling locations Water from sampling location SW1 in Round appeared dark 33 Field Results Stable readings of water quality parameters were recorded and are presented in Table 3, with historic results from previous monitoring rounds in Appendix B Groundwater ph was close to neutral, and all readings fell within the normal range for Irish groundwater, between 60 and 90 in both monitoring rounds Surface water ph readings were also near-neutral, ranging between 65 and 75 EC readings for groundwater across the site fell within similar ranges in both monitoring rounds, with readings ranging between ~300 µs/cm and ~700 µs/cm) which are also similar to readings reported for previous monitoring rounds Surface water EC measurements were lower in the river (10 µs/cm) than in the drainage ditch (>400 µs/cm) These readings indicate a lower dissolved solid content in the river compared to the shallow, stagnant drainage ditch For inspection purposes only Consent of copyright owner required for any other use Overall, groundwater temperature readings were close to the normal range for Irish groundwater ( C), being slightly lower in Round (averaging 111 o C) compared to Round (averaging 134 o C) Temperature readings outside the normal range for Irish groundwater tend to be recorded for shallower wells, where buffering of surface ambient temperature variations is less than at greater depth The most elevated temperature reading of 154 o C was recorded in groundwater from BH3, located close to a number of hot baths Elevated groundwater temperature has been recorded from this well on previous sampling occasions The average surface water temperature readings from the Avoca River were 98 o C in Round and 107 o C in Round In the shallow drainage ditch, temperature readings were higher, ranging between 106 o C and 167 o C Dissolved oxygen readings in groundwater ranged between 016 mg/l and 473 mg/l, with an average in each round of <20 mg/l; all readings were within the ranges previously reported At the observed groundwater temperatures, fully aerated groundwater would be expected to have dissolved oxygen readings close to 1000 mg/l These lower values indicate that groundwater is low in dissolved oxygen Dissolved oxygen readings from the drainage ditch were slightly higher than those of groundwater but generally lower than measurements from the Avoca River, which were all higher than 105 mg/l Low dissolved oxygen readings from the surface water drainage ditch are to be expected, given the low volume of water and stagnant conditions which are generally present Prepared for: Sigma Aldrich Ireland Limited AECOM 9 EPA Export :03:04:45

10 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 Field ORP readings were adjusted to redox potential (Eh) readings (relative to a standard hydrogen electrode), as per instructions from the instrument manufacturer Adjusted redox potential readings in 2016 were generally <300 mv, and within ranges previously reported Readings <200 mv indicate that groundwater conditions are reducing and this assessment is consistent with field measurements of dissolved oxygen Redox conditions in the drainage ditch appear to be slightly reducing in Round 2 Readings for Round 1 and for the Avoca River in both rounds, appear to be more oxidising with Eh readings >250 mv Low dissolved oxygen and redox potential readings are generally associated together and indicate reducing groundwater conditions 34 Laboratory Results An inventory of samples collected and analyses scheduled is presented in Table 4 with laboratory results presented in Tables 5 to Assessment Guidelines Assessment of analytical data was completed by comparing laboratory results with the following published guidelines: EPA Interim Guideline Values (IGVs) Groundwater Threshold Values, Statutory Instrument No 366, 2016 (GTVs) IGVs represent negligible groundwater contamination and were developed using a number of existing water quality guidelines in use in Ireland, iluding existing national environmental quality standards, proposed common indicators for the groundwater directive, drinking water standards and Geological Survey of Ireland trigger values GTVs were initially published in January 2010 (Statutory Instrument No 9 of 2010) and updated in July 2016 Exceedee of a threshold value triggers further investigation to confirm whether the criteria for Poor groundwater chemical status are being met Neither of the above sets of guidelines apply to results for surface water samples Analytical results for surface water samples have instead been screened against the Environmental Quality Standards (EQSs) for Inland Surface Waters, from SI No 272, 2009 and amendment SI No 386, 2015 These standards have been primarily adopted from European Union Directives and relate to the aquatic environment 342 Volatile Organic Compounds and Water Soluble Solvents Results for VOCs are presented in Table 5, while water-soluble solvents are presented in Table 6 Historic results for selected VOCs are presented in Appendix B, with coentration trends graphed for selected wells and compounds No VOCs were detected above reporting limits in groundwater samples from well BH2 or in surface water samples SW3 and SW4 in either monitoring round in 2016 Chlorobenzene For inspection purposes only Consent of copyright owner required for any other use Chlorobenzene has been consistently detected in groundwater from BH7, with coentrations up to 420 µg/l However, sie May 2007, coentrations have been between the reporting limit and 50 µg/l; results for 2016 were within this range ( µg/l and 5 µg/l) Figure B71 illustrates coentration trends for low level detections (iluding chlorobenzene) in groundwater from well BH7 In 2016, chlorobenzene was also detected in groundwater from well BH6 (5 µg/l and 4 µg/l in Rounds 1 and , respectively) and BH5 (4 µg/l in Round ) Chlorobenzene has been detected in groundwater from these wells previously, with coentrations up to 125 µg/l detected; however, sie 2010 detections have been sporadic and with coentrations not exceeding 10 µg/l The IGV for chlorobenzene is 1 µg/l, all detections exceeded this; no GTV is defined Prepared for: Sigma Aldrich Ireland Limited AECOM 10 EPA Export :03:04:45

11 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 Chlorobenzene was not detected above reporting limits in any of the surface water samples in 2016 Total Xylene Total xylene 3 was detected above reporting limits in groundwater from wells BH6 and BH8 in 2016 Total xylene is occasionally detected in groundwater from BH6 but, sie 2008, coentrations have rarely exceeded 100 µg/l (see Figure B62 in Appendix B) In 2016, total xylene was detected at 4 µg/l in Round 1 and 6 µg/l in Round 2, with both results less than the IGV of 10 µg/l Total xylene is routinely detected in groundwater from BH8 In 2016, the coentration of total xylene ireased from 925 µg/l in Round 1, to 1,331 µg/l in Round 2 However, reported coentrations for 2016 are less than those reported historically Coentrations have followed a general declining trend sie 10,250 µg/l was detected in 2012 The only detection of total xylene in surface water during 2016 was in SW2 in Round 1, at a coentration of 21 µg/l However, it declined below the reporting limit in Round Total xylene is occasionally detected historically in surface water at SW2 (see Appendix B Figure B11) Toluene In groundwater, toluene was only detected above reporting limits in groundwater from BH6 during 2016 The coentrations detected were low, at 2 µg/l and 4 µg/l in Rounds 1 and 2 respectively, which are below the IGV of 10 µg/l Toluene was historically detected at coentrations up to 4,000 µg/l in groundwater from BH6, but sie 2007 has fluctuated between the detection limit and 30 µg/l, see Appendix B Figure B62 In all other groundwater samples during 2016 toluene was below detection limits In surface water, toluene was detected in SW2 at 1 µg/l in Round 1 and declined below the detection limit in Round 2 In all other surface water samples toluene was below detection limits in both rounds Toluene is occasionally detected in surface water from SW2 Ethyl Benzene Ethyl benzene was below detection limits in all groundwater samples during 2016 Ethyl benzene is occasionally detected in groundwater from well BH6, generally at coentrations below the IGV of 10 µg/l In groundwater from BH8, ethyl benzene was detected at coentrations up to 1,000 µg/l between 2011 and 2014, but throughout 2015 and 2016 coentrations have been between the detection limits and the IGV, see Appendix B Figure B82 In surface water, ethyl benzene was detected at SW2 at a coentration of 4 µg/l in Round and was below detection in all other surface water samples during 2016 Ethyl benzene is occasionally detected at low coentrations (0 µg/l) in SW2 MTBE For inspection purposes only Consent of copyright owner required for any other use MTBE was detected in groundwater from five wells in both monitoring rounds in 2016 In groundwater from wells BH9, BH10 and BH14, MTBE coentrations were less than 10 µg/l In addition, MTBE was also detected at 0 µg/l in groundwater from BH3 in Round These coentrations are consistent with those of previous years MTBE was detected between 50 µg/l and 75 µg/l in groundwater from BH8, which is within the range of coentrations previously reported, see Appendix B Figure B81 These coentrations exceed the IGV of 30 µg/l Detected coentrations were slightly higher in groundwater from BH4, at 70 µg/l in Round 1 and 101 µg/l in Round 2 MTBE coentrations have been following a general declining trend in BH4 sie 2010, see Appendix B Figure B4 The highest MTBE coentrations continue to be detected in groundwater from BH7, with coentrations of 522 µg/l and 548 µg/l detected in Rounds 1 and 2, respectively These 3 Total xylene is the sum of m, p and o isomers Prepared for: Sigma Aldrich Ireland Limited AECOM 11 EPA Export :03:04:45

12 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 coentrations are at the lower end of those previously reported for this well, see Appendix B Figure B72 In surface water, MTBE was detected at low coentrations (0 µg/l) in water from SW1 and SW2 but was below detection in surface from SW3 and SW4 This is consistent with results for previous years 1,2-Dichloroethane Trace coentrations of 1,2-dichloroethane, 5 µg/l, were detected in groundwater from BH1 in both monitoring rounds in 2016, with a detection of 6 µg/l in groundwater from BH5 in Round ,2- Dichloroethane was below detection limits in all other groundwater and surface water samples These results are consistent with those of recent years Other VOCs No other VOCs were detected in surface water samples during 2016 Following a detection of 48 µg/l in groundwater from BH7 in Round , chloroethane was again detected in 2016 at coentrations 0 µg/l, there is no corresponding IGV or GTV for this compound It does not appear from available historic data to have been detected prior to Chlorotoluene was detected in groundwater from BH6 at coentrations <5 µg/l 2-Chlorotoluene is occasionally detected in groundwater from this well at low coentrations (0 µg/l), there is no corresponding IGV or GTV for this compound Water soluble solvents can also be detected but, due to the soluble and readily biodegradable nature of most of these compounds, detections are intermittent In 2016 only, tert-butyl alcohol was detected at coentrations less than 40 µg/l in groundwater from wells BH4 and BH7, there is no corresponding IGV or GTV for this compound In surface water samples SW2 and SW4, acetone was detected in Round at coentrations of 2,410 µg/l and 295 µg/l respectively In Round , acetone declined below detection limits in SW4 and to 1,780 µg/l in SW2 Iso-propanol was also detected in SW2 in Round , at 903 µg/l, and declined below the detection limit in Round Hydrocarbons For inspection purposes only Consent of copyright owner required for any other use Hydrocarbon results are presented in Table 7 and ilude diesel and gasoline range organics, BTEX and MTBE, therefore there is some overlap with VOC results, which also ilude BTEX and MTBE No fuel hydrocarbons were detected above reporting limits in groundwater from wells BH1, BH2, BH3 and BH9 in either monitoring round, or in wells BH10 and BH19 in Round Hydrocarbons were detected in groundwater from wells BH4, BH5, BH6, BH7, BH8 and BH14 in both monitoring rounds The gasoline range hydrocarbons detected in groundwater from BH4 and BH7 appears to correspond to MTBE, while in groundwater from BH8 it corresponds to total xylene For wells BH5 and BH6 hydrocarbon coentrations were within the ranges previously reported Diesel range organics ireased in groundwater from well BH7 compared to 2015, but declined between Rounds 1 and 2 in 2016 Groundwater from wells BH19 and BH20 was also sampled in Round and analysed for hydrocarbons Hydrocarbons were below detection in groundwater from well BH19, with gasoline range only detected in groundwater from BH20 (96 µg/l) In surface water, low coentrations of hydrocarbons were detected in SW1 and SW2, with hydrocarbons generally below detection in SW3 and SW4 in 2016 Prepared for: Sigma Aldrich Ireland Limited AECOM 12 EPA Export :03:04:45

13 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue Polycyclic Aromatic Hydrocarbons PAH results are presented in Table 8 As in previous years, the majority of PAH results in 2016 were either below reporting limits or at trace coentrations Relevant guideline thresholds were only exceeded by coentrations of benzo(a)pyrene in groundwater from wells BH5, BH9 and BH14; the exceedees were marginal 345 Metals Metal results are presented in Table 9, with historic results tabulated in Appendix B Reported metal coentrations were within previously reported ranges for all surface water samples; there are no corresponding screening criteria for the metals analysed in surface water In groundwater, reported metals coentrations were within previously reported ranges Coentrations of iron and manganese were above their corresponding IGVs in groundwater from the majority, if not all, wells This correlates with field readings of dissolved oxygen and redox potential, which indicated reducing groundwater conditions Under reducing groundwater conditions, as are present at the site, iron and manganese, which are common constituents of minerals in soil and bedrock, enter into solution more readily, hee their relatively high coentrations Potassium was above its IGV of 5 mg/l in groundwater from BH7 in both monitoring rounds and BH4 in Round Historically, potassium has been detected up to 123 mg/l in groundwater from BH7, with 103 mg/l the highest coentration in 2016 Potassium is occasionally above 5 mg/l in groundwater from BH4 346 Major Ions and Indicator Parameters Major ion results are presented in Table 10, with historic results tabulated in Appendix B The majority of results were within previously reported coentration ranges Ammoniacal nitrogen was below detection in groundwater from wells BH2, BH3, BH9 and BH10 throughout 2016 and in groundwater from BH14 in Round It was detected in all other groundwater samples throughout 2016 at coentrations exceeding the IGV of 0117 mg/l 4 For inspection purposes only Consent of copyright owner required for any other use Ammoniacal nitrogen coentrations in surface water samples vary from below the detection limit (02 mg/l) to coentrations generally <05 mg/l; however, when detected, ammoniacal nitrogen exceeds the EQS (0065 mg/l) In 2016, ammoniacal nitrogen was detected in SW1 in Round 1 and was below detection in all other surface water samples throughout 2016 Chloride coentrations in groundwater ranged between 23 mg/l and 85 mg/l, with the majority of results above the IGV of 30 mg/l The highest coentration in both monitoring rounds was detected in groundwater from BH4, this is consistent with results of previous monitoring rounds Chloride coentrations in 2016 were within previously reported coentration ranges Chloride coentrations in surface water samples were within a wider range in SW1 and SW2 (between 45 mg/l and 387 mg/l) compared to SW3 and SW4 (between 8 mg/l and 10 mg/l) This is consistent with coentrations reported for previous monitoring rounds Nitrate coentrations ranged between the detection limit and 076 mg/l in 2016 which did not exceed the IGV or GTV Nitrate coentrations in groundwater were within previously reported coentration ranges Nitrate coentrations were lower in surface water sample SW1 compared to the other three, with coentrations <02 mg/l compared to coentrations between 1 mg/l and 2 mg/l Coentrations of fluoride, ortho-phosphate and nitrite in groundwater were below detection limits throughout 2016 This is consistent with previous monitoring results Total alkalinity and COD in groundwater were also within previously reported coentration ranges, see Appendix B 4 The IGV for ammonia is given as 015 mg/l as NH 4, which is equivalent to 0117 mg/l as N Prepared for: Sigma Aldrich Ireland Limited AECOM 13 EPA Export :03:04:45

14 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 In surface water, results for these parameters were also generally within previously reported ranges In Round , the COD of SW1 was higher than usual at 5,700 mg/l, although it has fluctuated above 1,000 mg/l previously at SW1, where the volume of water is generally low and near-stagnant In 2016, the COD of SW1 was lower and within the more usual coentration range 347 Microbiological Results Microbiological results are presented in Table 11, with historic data presented in Appendix B Total coliforms were detected in the majority of groundwater samples, with faecal coliform (E coli) generally below detection limits, particularly in Round In Round , faecal coliforms were detected in five groundwater samples, with colony counts ranging from 3 cfu/100 ml to 34 cfu/100 ml In surface water samples, colony counts for total coliforms and E coli tended to be quite a bit higher than in groundwater, this reflects the more exposed nature of surface water sampling locations 35 Potential Pollutant Linkages The hydrogeological review completed in 2014 presented a coeptual site model (CSM) of groundwater flow beneath the site, based on available information The CSM identified potential sources of contamination on site, potential pathways for contaminants to migrate through the subsurface and potential receptors that could be exposed to that contamination: Source-Pathway- Receptor (SPR) linkages Each of these elements can exist independently and a potential risk can be created only where all three are linked together 351 Potential Sources Potential sources of contamination to groundwater related to site activities ilude losses of materials due to poor handling practices, or due to failures in storage or containment infrastructure In 2009, there was a documented loss of 400 L of diesel on site, following which some soil removal was completed and the remainder treated by in-situ bioremediation solutions In response to this, and at the request of the EPA, monitoring wells BH19 and BH20 were installed down-gradient of this location In addition to this, the detection of several VOCs in groundwater sie monitoring wells were installed in the early 2000s, indicates that losses of VOCs to ground occurred at the site historically However, the overall declining coentration trends of dissolved contaminants indicate that losses are not current and the continued detections in groundwater are due to residual mass in the overburden aquifer Given the generally low VOC coentrations detected, it is considered that the residual VOC mass sorbed to the aquifer matrix is also small For inspection purposes only Consent of copyright owner required for any other use Only two of the monitoring wells sampled are screened within bedrock (BH1 and BH2), and the very low to non-detect coentrations reported for groundwater from these wells indicate that there is no appreciable residual VOC source in the bedrock aquifer Water soluble solvents are generally below detection in groundwater and occasionally detected in surface water from SW2, often associated with detections of VOCs This indicates short-term, intermittent, small volume losses of alcohol solvents to surface water drainage Other parameters which can be detected at elevated coentrations in groundwater are considered to represent ambient conditions in the aquifer, rather than being elevated as a result of site operations For example, dissolved iron and manganese can be high, but this is due to reducing groundwater conditions which result in iron and manganese entering into solution from common minerals in subsoil and rock There is a sanitary effluent wastewater treatment plant located up-gradient of SW1, this may be a contributory factor in the occasionally high COD readings and detections of E coli and ammonia at this monitoring location The treatment system, which iludes a mechanical aeration system, was installed in 2009 (planning register number 09/926 from Wicklow County Couil), began operation in 2010 and is regularly inspected Other potential factors in the detections at this location are the facts Prepared for: Sigma Aldrich Ireland Limited AECOM 14 EPA Export :03:04:45

15 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 that this sampling location generally has a low volume of near-stagnant water present and is accessible to wildlife, which could also be contributory factors with some of the occasionally high results 352 Potential Pathways As there are no current or recent losses of VOCs or hydrocarbons to ground, the main pathway for contaminants to migrate is laterally with groundwater flow from the sources noted above Should a loss to ground occur which was not contained by site infrastructure, then migration would be vertically downward through the unsaturated zone to the water table, migration would then be lateral with groundwater flow down-gradient from the source of the loss on site 353 Potential Receptors Potential receptors ilude: Shallow groundwater in the overburden aquifer beneath the site Deeper groundwater in the bedrock aquifer beneath the site Groundwater abstraction wells located down hydraulic gradient of the site Surface water down-gradient of the site Given that the nearest groundwater abstraction well to the site is a poorly productive domestic well located up-gradient of the site at Ballyraine, it is not considered to be a viable receptor There is no known abstraction well situated down-gradient of the site The elevation of the drainage ditch located along the north-eastern site boundary is unknown, so it is not known if it is in hydraulic continuity with shallow groundwater However, analytical results for surface water samples collected from the drainage ditch (SW1 and SW2) indicate that impacts are short-term, intermittent and due to small volume losses to surface water drainage These characteristics suggest that the drainage ditch is independent of potential interaction with shallow groundwater The main receptor of groundwater flow from the site is the Avoca River, located approximately 110 m north-east of the site VOCs, water soluble solvents and hydrocarbons are generally below laboratory method detection limits in surface water samples from the Avoca River (SW3 and SW4) collected on a biannual basis Results for SW4 in particular, as it is the down-stream sampling location, indicate that contaminants dissolved in groundwater underlying the site and potentially discharging to the river are not having an adverse impact on water quality in the Avoca River 354 SPR Linkages - Risk Screening For inspection purposes only Consent of copyright owner required for any other use While the main viable SPR linkage for dissolved contaminants in groundwater originating from the site is to migrate via groundwater flow and discharge to the Avoca River, it is not considered to be a High risk SPR linkage, as the majority of contaminants are volatile and biodegradable In addition, on-site groundwater coentrations are following declining trends and the contaminants of coern are not detected in surface water from the Avoca River and, therefore, groundwater discharge is not adversely impacting the river This SPR linkage is therefore considered to be of Low to Moderate risk In consideration of groundwater itself as a receptor, the risk is considered Moderate, given that current site infrastructure is designed to prevent losses to ground, and groundwater is not used as a resource down-gradient of the site A cross-section illustrating the geological sequee beneath the site and the CSM is presented in Figure 4 The bedrock geology beneath the site is illustrated in Figure 5, indicating that the site is underlain by the Kilmacrea Formation, consisting of dark grey slate and minor pale sandstone (Ordovician metasediments) Prepared for: Sigma Aldrich Ireland Limited AECOM 15 EPA Export :03:04:45

16 IEL Groundwater and Surface Water Monitoring Assessment of Current Groundwater Impacts Project Referee: /CKRP0001 Issue 2 As noted above, monitoring data do not indicate that there are current losses to ground occurring at the site, so those contaminants that are detected in groundwater are considered to be related to historic losses at the site In addition, the site has a detailed programme of testing the integrity of secondary containment structures (bunds) and underground pipelines This is reported in the site s Annual Environmental Report each year Bunds are tested on a three year cycle, while underground pipelines are tested annually, although they too are only required to be tested on a three year cycle Any defects which are noted during tests are repaired Therefore, the site is actively preventing potential current losses to ground 41 Extent of Plume and Trends Where potential pollutants are detected in groundwater, it is necessary to demonstrate whether there is a significant upward trend in coentrations and if those coentrations are greater than generic assessment criteria As noted, historic data are presented in Appendix B with results compared against IGVs and GTVs as appropriate generic assessment criteria for the site Coentration trend graphs for key parameters are also illustrated in Appendix B, no upward coentration trends are apparent 411 VOCs As discussed, the majority of VOCs in groundwater from the majority of monitoring wells are detected intermittently and at low coentrations (typically <50 µg/l); as a consequee, these VOCs are not considered in this section The highest coentrations of VOCs are detected in groundwater from monitoring wells BH7 and BH8 MTBE is the VOC detected at the highest coentration in groundwater from BH7, with chlorobenzene also consistently detected, but at low coentrations MTBE is also consistently detected in groundwater from BH8, but with total xylene being detected at much higher coentrations in groundwater from BH8 MTBE MTBE coentrations in groundwater from BH7 are currently above 500 µg/l, and historically were above 1,000 µg/l Wells located down hydraulic gradient from BH7 are BH4, BH8, BH9 and BH10 Coentrations of MTBE in groundwater from BH4 and BH8 are close to or below 100 µg/l Further down-gradient, in groundwater from BH9 and BH10, MTBE coentrations are less than 10 µg/l For comparison, the GTV for MTBE is 10 µg/l and the IGV is 30 µg/l, therefore, MTBE coentrations in the most down-gradient wells are consistently below these criteria In addition, the MTBE coentration trend in groundwater from BH7 is declining, see Appendix B Figure B72 Therefore, the MTBE plume is not expanding In addition, MTBE is below detection in surface water samples SW3 and SW4 from the Avoca River Therefore, MTBE in groundwater from beneath the site is not having an adverse impact on water quality in the receptor: the Avoca River While the overall MTBE coentration trend is downward in groundwater from BH7, variability in the data prevent the coentration versus time decay rate to be calculated Chlorobenzene For inspection purposes only Consent of copyright owner required for any other use Chlorobenzene is also consistently detected in groundwater from BH7, with coentrations <25 µg/l in recent years compared to a peak of 340 µg/l in October 2006 When detected, chlorobenzene coentrations in BH7 are above the IGV of 1 µg/l Down-gradient of BH7, chlorobenzene is Prepared for: Sigma Aldrich Ireland Limited AECOM 16 EPA Export :03:04:45

17 IEL Groundwater and Surface Water Monitoring 2016 Project Referee: /CKRP0001 Issue 2 intermittently detected below 10 µg/l in groundwater from wells BH4, BH5, BH6 and BH8; and it is consistently below detection limits in groundwater from the furthest down-gradient wells BH9 and BH10, and in surface water from SW3 and SW4 Therefore, the chlorobenzene plume is not expanding and is not having an adverse impact on water quality in the receptor: the Avoca River While the overall chlorobenzene coentration trend is downward in groundwater from BH7, variability in the data prevent the coentration versus time decay rate to be calculated Total Xylene Historically, total xylene was detected in groundwater from many monitoring wells on site but, in recent years, detections are limited to groundwater from wells BH8 and BH6 Coentrations in BH6 are generally below the IGV of 10 µg/l Coentrations of total xylene in groundwater from BH8 appear to have peaked on two occasions: in October 2006 at a coentration of 10,800 µg/l, and again in November 2012 at 10,250 µg/l The pattern of declining coentrations following each peak has been similar The calculated coentration versus time half-life for total xylene in groundwater from BH8 is calculated at approximately 260 days from the first peak, see Appendix B Figure B12 A similar trend had been in coentrations from the second peak, but variability in coentration data in recent years hampers repeating the calculation, see Appendix B Figure B13 Wells BH9 and BH10 are located down-gradient of BH8 Total xylene is below detection in groundwater from each well and it is also below detection in surface water from SW3 and SW4 on the Avoca River Therefore, the total xylene plume centred on well BH8 is not expanding 412 Ammoniacal Nitrogen Ammoniacal nitrogen coentration trends are presented in Appendix B Figures B14 to B17 No ireasing coentration trends are apparent in groundwater from the majority of wells When the hydrogeological assessment was completed in 2014, an upward coentration trend was identified in groundwater from BH2 and BH8 Ammoniacal nitrogen coentrations are frequently below detection limits and the IGV in groundwater from well BH2 For well BH8, following ammoniacal nitrogen results reported in 2014, 2015 and 2016, there is no longer considered to be a statistically significant upward trend in groundwater from this well For inspection purposes only Consent of copyright owner required for any other use While ammoniacal nitrogen coentrations are frequently elevated above the IGV and GTV in groundwater and above the EQS in surface water, it does not appear that ammoniacal nitrogen coentrations in groundwater discharging to the river are adversely affecting surface water quality In groundwater from the majority of wells, ammoniacal nitrogen coentrations frequently exceed 15 mg/l, and in groundwater from down-gradient wells BH9 and BH10 ammoniacal nitrogen coentrations rarely exceed 10 mg/l Therefore, ammoniacal nitrogen coentrations decline down-gradient of the site There is no evidee of ireasing coentration trends in BH9 and BH10 In surface water samples SW3 (upstream) and SW4 (downstream), ammoniacal nitrogen coentrations rarely exceed 05 mg/l In addition, there is a strong correlation between ammoniacal nitrogen coentrations in the upstream surface water sample (SW3) and the down-stream surface water sample (SW4) This further indicates that there is no adverse effect on surface water quality with regard to ammoniacal nitrogen due to groundwater from the site discharging to the river between SW3 and SW4 Water quality in the Avoca River, based on data from 2004, was classified as Moderate to Poor upstream of the site at Wooden Bridge and Avoca; both of these surface water monitoring stations are located some distae up-stream of the site (at least 5 km upstream) Prior to 2004, the river water quality was classified as Bad at Shelton Abbey, located 16 km upstream of the site, with this classification applying up-stream as far as Wooden Bridge As ammoniacal nitrogen coentrations fluctuate, with no downward trends apparent, it is not possible to estimate a timeline for coentrations in groundwater to decline to the IGV Prepared for: Sigma Aldrich Ireland Limited AECOM 17 EPA Export :03:04:45

18 IEL Groundwater and Surface Water Monitoring Impact on Receptors Project Referee: /CKRP0001 Issue 2 As discussed in the preceding section, the presee of VOCs and ammoniacal nitrogen in groundwater beneath the site is not having an adverse effect on the Avoca River 43 Chemical Status of Groundwater Body The site is situated within the Arklow Urban groundwater body (IE_EA_G_042) which is classified as being of Good status 5 44 Remedial Strategy Based on the above assessment of groundwater impacts, no remedial intervention is required at the site 45 Groundwater Compliae Monitoring Continuation of the biannual groundwater and surface water monitoring programme is recommended, in particular monitoring of groundwater from B9 and BH10 which are the two wells located furthest down-gradient of the operational site area and still up-gradient of the main receptor, the Avoca River 5 Summary, Colusions and Recommendations 51 Summary and Colusions Biannual monitoring of groundwater and surface water was completed in April and October 2016 The direction of groundwater flow is consistent with that observed previously, to the north-east, discharging to the Avoca River which is identified as the main receptor of groundwater from the site; there are no users of groundwater down-gradient of the site between the site and the river The majority of results were within previously reported coentration ranges The main VOCs detected are MTBE and total xylene However, the highest coentrations are limited to single wells, with the highest MTBE coentrations detected in groundwater from BH7 and total xylene in groundwater from BH8 Coentration trends for both VOCs in both wells are downward, with coentrations also decreasing with distae down-gradient Given the downward coentration trends, plumes of MTBE and total xylene in groundwater appear to be shrinking Neither VOCs nor ammoniacal nitrogen in groundwater appear to be having an adverse impact on water quality in the Avoca River, which is the main receptor 52 Recommendations For inspection purposes only Consent of copyright owner required for any other use Continuation with the biannual groundwater and surface water monitoring programme is recommended, but no remedial intervention is warranted 5 Prepared for: Sigma Aldrich Ireland Limited AECOM 18 EPA Export :03:04:45

19 IEL Groundwater and Surface Water Monitoring 2016 Figures Project Referee: /CKRP0001 Issue 2 For inspection purposes only Consent of copyright owner required for any other use Prepared for: Sigma Aldrich Ireland Limited AECOM EPA Export :03:04:45

20 KEY N Process Drain Storm Water Drain Domestic Foul Drain BH 8 Sampling Location Warehouse Area Drumstore / WWTP Area Main Production Area Tank Farm Area Administration Area SW 3 AVOCA RIVER SW m Approximate Scale drainage ditch BH 12 SW 1 BH 5 BH 1 BH 6 BH 11 1 BH 13 BH 8 2 BH 4 BH 9 BH 10 SW 2 BH 18 D BH 15 S BH 2 BH 15 D For inspection purposes only Consent of copyright owner required for any other use 3 BH 16 BH 7 BH 14 BH 3 BH 18 S Douglas Business Centre, Carrigaline Road, Douglas, Cork Tel: +353 (0) wwwurscom CLIENT SIGMA ALDRICH IRELAND LIMITED BH 19 BH 20 PROJECT 5 4 GROUNWATER AND SURFACE WATER MONITORING 2016 DRAWING TITLE FIGURE 1 SITE LAYOUT WITH MONITORING WELL LOCATIONS DRAWN TRACED CHECKED APPROVED DH EO H EO H/COR SCALE AS SHOWN DRG NO DATE DEC 2016 REV EPA Export :03:04:45

21 KEY N Process Drain Storm Water Drain Domestic Foul Drain BH 8 Sampling Location Warehouse Area Drumstore / WWTP Area Main Production Area Tank Farm Area Administration Area SW 3 AVOCA RIVER SW 4 56m GROUNDWATER CONTOURS METRES ABOVE SITE DATUM m Approximate Scale INFERRED GROUNDWATER FLOW DIRECTION drainage ditch BH 12 SW 1 BH 5 BH BH 6 BH BH 13 BH BH BH 10 BH m 5m 6m SW 2 BH 18 S BH 18 D 692 7m 3 BH 7 BH BH BH 15 S BH 2 BH 15 D 8m BH For inspection purposes only Consent of copyright owner required for any other use Douglas Business Centre, Carrigaline Road, Douglas, Cork Tel: +353 (0) wwwurscom CLIENT SIGMA ALDRICH IRELAND LIMITED 5 BH 19 BH m PROJECT GROUNWATER AND SURFACE WATER MONITORING 2016 DRAWING TITLE FIGURE 2 GROUNDWATER CONTOURS ROUND (18 APRIL 2016) DRAWN TRACED CHECKED APPROVED DH EO H EO H/COR SCALE AS SHOWN DRG NO DATE DEC 2016 REV EPA Export :03:04:45

22 KEY N Process Drain Storm Water Drain Domestic Foul Drain BH 8 Sampling Location Warehouse Area Drumstore / WWTP Area Main Production Area Tank Farm Area Administration Area SW 3 AVOCA RIVER SW 4 56m GROUNDWATER CONTOURS METRES ABOVE SITE DATUM m Approximate Scale INFERRED GROUNDWATER FLOW DIRECTION drainage ditch BH 12 SW 1 BH 5 BH BH 6 BH BH 13 BH BH BH BH SW 2 BH 18 D 718 BH 15 S BH 2 BH 15 D For inspection purposes only Consent of copyright owner required for any other use 3 BH 16 BH 7 BH BH 3 BH 18 S 702 Douglas Business Centre, Carrigaline Road, Douglas, Cork Tel: +353 (0) wwwurscom CLIENT SIGMA ALDRICH IRELAND LIMITED 5 BH 19 BH PROJECT GROUNWATER AND SURFACE WATER MONITORING 2016 DRAWING TITLE FIGURE 3 GROUNDWATER CONTOURS ROUND (17 OCTOBER 2016) DRAWN TRACED CHECKED APPROVED DH EO H EO H/COR SCALE AS SHOWN DRG NO DATE DEC 2016 REV EPA Export :03:04:45

23 SOUTH WEST NORTH EAST SITE BOUNDARY PRODUCTION BUILDINGS TANK FARM 110m DRUM STORAGE WWTP RAILWAY EMBANKMENT DITCH BH3 FIRE WATER RETENTION POND BH16 to f c Fo op r i yr ns ig pe ht ct ow ion ne pu r r rp eq os ui es re o d nl fo y ra ny ot he ru se AVOCA RIVER BH9 ns en BH15D Co VALE ROAD BH10 CLIENT SIGMA ALDRICH IRELAND LIMITED PROJECT GROUNWATER AND SURFACE WATER MONITORING 2016 DRAWING TITLE FIGURE 4 CROSS SECTION Douglas Business Centre, Carrigaline Road, Douglas, Cork wwwaecomcom Tel: +353 (0) DRAWN TRACED DH SCALE AS SHOWN DRG NO CHECKED APPROVED EO H EO H/COR DATE DEC 2016 REV EPA Export :03:04:45

24 N Kilmacrea Formation Site Boundary For inspection purposes only Consent of copyright owner required for any other use Douglas Business Centre, Carrigaline Road, Douglas, Cork Tel: +353 (0) wwwurscom CLIENT SIGMA ALDRICH IRELAND LIMITED PROJECT GROUNWATER AND SURFACE WATER MONITORING 2016 DRAWING TITLE FIGURE 5 GEOLOGY AND SITE BOUNDARY DRAWN TRACED CHECKED APPROVED DH EO H EO H/COR SCALE AS SHOWN DRG NO DATE DEC 2016 REV EPA Export :03:04:45