PROTOCOL 27, SOIL LEACHING ASSESSMENT FOR USE IN DERIVING SITE SPECIFIC STANDARDS CSR STAGE 11 AMENDMENT WEBINAR #5 NOVEMBER 28, 2017

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1 PROTOCOL 27, SOIL LEACHING ASSESSMENT FOR USE IN DERIVING SITE SPECIFIC STANDARDS CSR STAGE 11 AMENDMENT WEBINAR #5 NOVEMBER 28, 2017 Lavinia Zanini, P.Geo. Contaminated Sites Officer This PowerPoint presentation and a recording of the audio will be posted on the web following the webinar

2 OBJECTIVE OF P27 Establishes procedures for using approved soil leaching tests in the development of site-specific numerical soil standards (SSSs) under Protocol 2 Site-Specific Numerical Soil Standards. Allows modification of matrix numerical soil standards for the site-specific factors protective of the groundwater pathway in the Contaminated Sites Regulation (CSR), Schedule 3.1 Part 1, based on soil leaching test results at a contaminated site. Outlines the requirements, leachate methods and processes to establish a leachate concentration that can be used in Protocol 2. 2

3 BC ENV/CSAP WORKING GROUP A task group was established to research and aid in the development of the protocol. Jointly funded by BC ENV and the CSAP Society of BC. Working group: Tony Gillett (facilitator) George Szefer, Lavinia Zanini (ENV reps) Patricia Carmichael, Bob Beck, Robert McLenehan (Industry reps) Will Gaherty (SAB rep) Barry Loescher (Lab rep) Methods Evaluated: TCLP - US EPA 1311 SPLP - US EPA 1312 LEAF - USEPA 1313 LEAF - USEPA

4 LEACHATE TEST METHODS Saturated Paste Extraction for Soils NEW! Approved for the following inorganic substances which have matrix numerical soil standards: chloride and sodium The approved method of evaluation under the CSR is the saturated paste extraction method. The regulated standards are considered the leachable fractions of these substances. 4

5 LEACHATE TEST METHODS The Liquid-Solid Partitioning (Leachability) of VOCs Prescriptive (BC VOC Soil Leachate Test) Approved for the following organic substances which have matrix numerical soil standards: benzene; ethylbenzene; toluene; xylenes; tetrachloroethene (PCE); trichloroethene (TCE); and naphthalene. 5

6 LEACHATE TEST METHODS BC VOC Soil Leachate Test US EPA Method 1311 TCLP Zero Head Extractor (ZHE) with modification TCLP and SPLP ZHE leachate extraction are currently the only available leachate test for soil contaminated with volatile organics Leaching results for the listed VOC s are generally not ph-dependant The test is conducted with reagent water as the extraction fluid Field sampling methods - minimize losses due to volatilization Modifications: Holding times: Samples must be extracted within 48 hours from the time of sampling, or within 14 days if frozen within 48 hours of sampling NEW! Sample collection: exclude large particles (>9.5 mm), no particle reduction 6

7 LEACHATE TEST METHODS Liquid-Solid Partitioning (Leachability) as a Function of ph (Metals, Inorganics, and SVOCs) Prescriptive - BC Soil Leachate Test Approved for the following substances that have matrix numerical soil standards: Organic substances: diisopropanolamine (DIPA); ethylene glycol; methanol; nonylphenol and nonylphenol ethoxylates; pentachlorophenol (PCP); perfluorooctanesulfonic acid (PFOS); phenol; and sulfolane. Inorganic substances: arsenic; barium; beryllium; cadmium; chloride; chromium; cobalt; copper; lead; manganese; molybdenum; nickel; selenium; sodium; thallium; uranium; vanadium; zinc. NEW! 7

8 LEACHATE TEST METHODS BC Soil Leachate Test ph sensitive: 3 parallel batch extractions on soil at ph 5, 7 and 9 4th batch extraction is done at soil s natural ph if < 4.5 or > 9.5 Extraction run at liquid-solid ratio (L/S) of 20 ml/g-dry Nitric acid or sodium hydroxide is added to each vessel to obtain specified final ph value The vessels are tumbled 48-hrs Samples are filtered and preserved for chemical analysis Constituent concentrations [mg/l] reported as a function of eluate ph Note: Some substances tested using this method are not ph sensitive and therefore require only one leach test (at natural ph). 8

9 LEACHATE TEST METHODS Vanderbilt University Webpage 9

10 LEACHATE TEST METHODS ph modification for ph sensitive substances: from 2 to 13 (US EPA) to 5 to 9 (BC): The BC Soil Leachate Test was developed to best predict the leaching and mobility of substances in various soil ph settings. ph range spans reasonable variations in ph that could occur [>90% of B.C. soil samples fall within ph 5 to 9] Future changes in site conditions (e.g. the deposit of organic or alkaline fill) would be captured by this range. 10

11 REDOX SENSITIVE INORGANIC SUBSTANCES In reducing conditions, the BC Soil Leachate Test may under predict actual field concentrations for certain redox sensitive species (literature review). Test for inorganics must not be used for the following redoxsensitive substances, unless it can be demonstrated that oxidizing conditions are present in the soil of interest: arsenic; chromium; copper; manganese; and vanadium. 11

12 REDOX SENSITIVE INORGANIC SUBSTANCES Oxidizing conditions are assumed to be present in: Unsaturated mineral soil that is not organic soil; and Saturated soil, provided that: ph + pe 13 where: ph = ph of water; pe (electron activity) = Eh/59; and Eh (oxidation-reduction potential of groundwater or porewater) is expressed in mv. Measurement of ph and Eh in the field must be carried out in accordance with standard industry practice (BC Field Manual) 12

13 MINIMUM REQUIREMENTS FOR USE OF P27 The presence and extent of soil and groundwater contamination in each Area of Environmental Concern (AEC) to be characterized by leachate testing has been investigated in accordance with ministry guidance and procedures and standard professional practice such that maximum concentrations of contaminants of concern (COCs) in soil have been identified; and Substance concentrations in groundwater in or below the AEC where soil has been leachate tested are less than or equal to the concentrations measured in the soil leachate determined using the leachate testing procedure presented in this protocol. 13

14 SAMPLING PROGRAM The collection and analyses of soil samples must be conducted to determine the following site-specific parameters: Maximum concentration(s) of the substance(s) investigated in soil for which leachate testing is to be performed Maximum concentration(s) of the corresponding substance(s) in groundwater in or below the soil for which leachate testing is to be performed Soil ph range, if applicable Soil redox conditions, if applicable 14

15 SAMPLING PROGRAM LEACHATE SAMPLES Leachate testing must be performed on a minimum of three soil samples collected within each AEC Leachate testing must be performed on samples that have soil concentration(s) equal to or greater than the 90 th percentile of the maximum measured concentration(s) of substance(s) to be tested 15

16 SAMPLING PROGRAM REMEDIATION SCENARIO Where an AEC is planned to be, or has been remediated (e.g. hot spot removal or risk assessment), leachate testing can be performed on the remaining contaminated soil. Leachate testing must be performed on a minimum of three remaining soil samples that have soil concentration(s) equal to or greater than the 90 th percentile of the maximum measured concentration(s) for substance(s) tested. 16

17 SAMPLING PROGRAM EXAMPLE REMEDIATION 17

18 SAMPLING PROGRAM The number of leaching tests must be proportionate (i.e. more than three samples) with : Large areas or volumes of contaminated soil (e.g. an area greater than 300 m 2 or a volume greater than 900 m 3 ) Contamination that contains randomly distributed substances, such as in contaminated fill 18

19 INTERPRETATION OF LEACHATE RESULTS Determination of Leachate Test Concentration (CL test) For substances that have at least three reported leachate concentrations (ph sensitive substances), obtained at ph leach values of 5, 7 and 9, and potentially a fourth corresponding to the natural site soil ph, select the highest reported leachate concentration. The substance concentration in soil leachate = the arithmetic mean of the highest leachate results measured for each soil sample tested. For all other substances that require a single leachate test (not ph sensitive), the substance concentration in soil leachate = the arithmetic mean of the leachate results measured for each soil sample tested. Note: A correction for highly soluble substances is required 19

20 INTERPRETATION OF LEACHATE RESULTS - EXAMPLE BC Soil Leachate Test : ph Sensitive - 3 ph values Sample 1: ph 5 ph 7 ph 9 Sample 2: ph 5 ph 7 ph 9 Sample 3: ph 5 ph 7 ph 9 Highest Result Highest Result Test CL = ( sample 1 + sample 2 + sample 3)/3 20

21 INTERPRETATION OF LEACHATE RESULTS NEW! correction of test leachate concentrations For substances that are highly soluble and have a low distribution coefficient or organic carbon partitioning coefficient (Kd< 5 or a Koc <1000) a correction to the substance concentration in soil leachate is required For highly soluble substances, leachate concentrations measured in the ministry approved tests are not equivalent to those that would be observed under field conditions because the relative amounts of soil and water used in the leachate tests are larger than what exists in natural soils 21

22 INTERPRETATION OF LEACHATE RESULTS Model (literature values ) of Kd Field (model) vs Lab (method) Liquid and Air/Solid ratios Field : 0.36 : 1 (field porosity) Lab: 20 : 1 (lab method) 22

23 INTERPRETATION OF LEACHATE RESULTS Substances that require a correction to leachate concentrations measured in test leachate are: benzene Ethylbenzene methanol phenol tetrachloroethylene toluene diisopropanolamine [DIPA] ethylene glycol pentachlorophenol [PCP] sulfolane trichloroethylene xylenes, total 23

24 INTERPRETATION OF LEACHATE RESULTS Substance concentrations in soil leachate for these substances are corrected using one of the following methods: 1. Multiply the substance concentration in soil leachate by 20 to obtain a final estimate of the substance concentration in soil leachate; or 2. Calculate a test specific partition coefficient (Kdtest) for each soil sample. Using these results, calculate a field estimate of substance concentration in leachate (CLfield). 24

25 INTERPRETATION OF LEACHATE RESULTS Kdtest = is the test specific distribution coefficient (L/kg) Ct = the total concentration of the substance in the soil sample tested (mg/kg) Ms = the total weight of the soil sample used in the leachate test (0.05 kg) Ctest = the substance concentration determined in soil leachate test(mg/l) V = the volume of the eluent used in the leachate test (1 L) Kdtest = is the test specific distribution coefficient (L/kg) θw = water-filled porosity (0.119) θa = air-filled porosity (0.241) H = the dimensionless Henry s law constant ρb = dry bulk density of the soil (1.7 Kg/L) CLfield = estimate of substance concentration in field leachate (mg/l) The final estimate of substance concentration in soil leachate is the arithmetic mean of the calculated field leachate results (CLfield) for each soil sample tested. 25

26 QUESTIONS? LAVINIA ZANINI Advice provided during this webinar is based on information available at the time of recording and may be subject to change. This PowerPoint presentation and a recording of the audio will be posted on the web. If you do not wish your question to be on the public record, please the presenter following the webinar.

27 PROTOCOL 2 SITE-SPECIFIC NUMERICAL SOIL STANDARDS CSR STAGE 11 AMENDMENT WEBINAR #5 NOVEMBER 28, 2017 Annette Mortensen and Amy Sloma Senior Contaminated Sites Officers This PowerPoint presentation and a recording of the audio will be posted on the web following the webinar

28 UPDATED PROTOCOL 2 Highlights Total rewrite to increase usability User-friendly framework to derive site-specific numerical soil standards (SSSs) Derive SSSs under AP - Modified Groundwater Protection Model (GPM) method - Leachate Test method Option for Director s decision Flowcharts to help navigate document Developed with assistance from: - CSAP working group - Core 6 Environmental contract 28

29 SUPPORTING DOCUMENTS Protocols and Technical Guidance Protocol 27, Soil Leaching Tests for Use in Deriving Site-Specific Numerical Soil Standards Technical Guidance 24, Site-Specific Numerical Soil Standards, Model Parameters Technical Guidance 13, Groundwater Protection Model Protocol 28, Chapter 4, Derivation of Soil to Groundwater Protection Matrix Soil Quality Standards Other documents (available on ministry webpage) Results of a Sensitivity Analysis for the Omnibus Groundwater Model, Core 6 Environmental Estimation of Regional Infiltration Rates in British Columbia, Core 6 Environmental Defining the Contaminant Source Zone, Core 6 Environmental 29

30 PROTOCOL 2 INTRODUCTION Protocol 2 purpose Procedure to derive site-specific numerical soil standard (SSS) SSS can replace the corresponding numerical matrix soil standards in Schedule 3.1 Part 1 SSS can be derived for the site-specific factors protective of groundwater use: Groundwater used for drinking water (DW) Groundwater flow to surface water used by aquatic life (AW) Groundwater used for livestock watering (LW) Groundwater used for irrigation (IW) Protocol 21 SSS cannot be derived for the following site-specific factors: Intake of contaminated soil Toxicity to soil invertebrates and plants Livestock ingesting soil and fodder Major microbial functional impairment Mandatory 30

31 PROTOCOL 2 INTRODUCTION The numerical soil standard is determined as the lowest value of: the derived SSSs protective of the groundwater pathway(s) the mandatory matrix numerical soil standards site, i.e. intake of contaminated soil and toxicity to soil invertebrates and plants other applicable matrix standards When a SSS represents the lowest applicable numerical standard, the SSS can be use to determine if: a site is contaminated a contaminated site has been satisfactorily remediated soil is considered acceptable for deposit at a receiving site 31

32 SUBSTANCES IN SCHEDULE 3.1 PART 1 Mandatory SSS Mandatory SSS SSS SSS 32

33 SUBSTANCES IN SCHEDULE 3.1 PART 1 Inorganics Substance DW AW LW IW Arsenic x x x x Barium x x NS NS Beryllium x x x x Cadmium x x x x Chloride x x x x Chromium (3+) x x x x Chromium (6+) x x x x Cobalt x x x x Copper x x x x Cyanide (CN-) x x NS NS Lead x x x x Manganese x NS NS x Mercury (inorganic) NS NS NS NS Molybdenum x x x x Nickel x x x x Selenium x x x x Sodium x NS NS NS Uranium x x x x Vanadium x NS x x Zinc x x x x Organics Substance DW AW LW IW Anthracene NS NS NS NS Benzene x x NS NS Benzo[a]pyrene NS NS NS NS DDT NS NS NS NS Diisopropanolamine x x NS NS Ethylbenzene x x NS NS Ethylene Glycol x x NS NS Fluoranthene NS NS NS NS Methanol x NS NS NS Naphthalene x x NS NS Nonylphenol x x NS NS Pentachlorophenol x x x x PFOS x x NS NS Phenol x x NS NS PCB NS NS NS NS PCDD/PCDF NS NS NS NS Sulfolane x x x x Tetrachloroethylene NS x NS NS Toluene x x NS NS Trichloroethylene NS x x NS Xylene x x NS NS 33

34 SUBSTANCES IN SCHEDULE 3.1 PART 1 Inorganics Substance DW AW LW IW Arsenic x x x x Barium x x NS NS Beryllium x x x x Cadmium x x x x Chloride x x x x Chromium (3+) x x x x Chromium (6+) x x x x Cobalt x x x x Copper x x x x Cyanide (CN-) x x NS NS Lead x x x x Manganese x NS NS x Mercury (inorganic) NS NS NS NS Molybdenum x x x x Nickel x x x x Selenium x x x x Sodium x NS NS NS Uranium x x x x Vanadium x NS x x Zinc x x x x No soil to GW standard Organics Substance DW AW LW IW Anthracene NS NS NS NS Benzene x x NS NS Benzo[a]pyrene NS NS NS NS DDT NS NS NS NS Diisopropanolamine x x NS NS Ethylbenzene x x NS NS Ethylene Glycol x x NS NS Fluoranthene NS NS NS NS Methanol x NS NS NS Naphthalene x x NS NS Nonylphenol x x NS NS Pentachlorophenol x x x x PFOS x x NS NS Phenol x x NS NS PCB NS NS NS NS PCDD/PCDF NS NS NS NS Sulfolane x x x x Tetrachloroethylene NS x NS NS Toluene x x NS NS Trichloroethylene NS x x NS Xylene x x NS NS 34

35 SUBSTANCES IN SCHEDULE 3.1 PART 1 Inorganics Substance DW AW LW IW Arsenic x x x x Barium x x NS NS Beryllium x x x x Cadmium x x x x Chloride x x x x Chromium (3+) x x x x Chromium (6+) x x x x Cobalt x x x x Copper x x x x Cyanide (CN-) x x NS NS Lead x x x x Manganese x NS NS x Mercury (inorganic) NS NS NS NS Molybdenum x x x x Nickel x x x x Selenium x x x x Sodium x NS NS NS Uranium x x x x Vanadium x NS x x Zinc x x x x No soil to GW standard 35 Organics Substance DW AW LW IW Anthracene NS NS NS NS Benzene x x NS NS Benzo[a]pyrene NS NS NS NS DDT NS NS NS NS Diisopropanolamine x x NS NS Ethylbenzene x x NS NS Ethylene Glycol x x NS NS Fluoranthene NS NS NS NS Methanol x NS NS NS Naphthalene x x NS NS Nonylphenol x x NS NS Pentachlorophenol x x x x PFOS x x NS NS Phenol x x NS NS PCB NS NS NS NS PCDD/PCDF NS NS NS NS Sulfolane x x x x Tetrachloroethylene NS x NS NS Toluene x x NS NS Trichloroethylene NS x x NS Xylene x x NS NS Tox standards soil to GW standard Tox standards soil to GW standard (except CL, IL)

36 PROTOCOL 2 METHODS Methods to derive SSSs under an AP 1. Modified Groundwater Protection Model (GPM) Method 2. Leachate Test Method If using both methods, the highest derived SSS may be applied If a derived SSS is lower than the corresponding matrix standard, the matrix standard applies Obtain Director s decision for SSSs if using alternative methods Change parameters outside ranges provided in protocol Change parameters not included in protocol 36

37 MODIFIED GPM METHOD SSSs derived using the Modified GPM method Ministry s Groundwater Protection Model (GPM) Used to derive the matrix soil standards protective of groundwater use: (AW, DW, IW, LW) Default model parameters (simulate flow and transport in a Fraser River sand aquifer setting) Modified GPM method Modify model parameter to adjust for site-specific conditions Calculate a SSS protective of the applicable groundwater uses 37

38 GROUNDWATER PROTECTION MODEL - GPM Protocol 28, Chapter 4 Derivation of Soil to Groundwater Protection Matrix Soil Quality Standards 38

39 GROUNDWATER PROTECTION MODEL - GPM 39

40 GROUNDWATER PROTECTION MODEL - GPM Soil Leachate Partitioning Unsaturated fate and transport Leachate/ groundwater mixing 40 Saturated fate and transport

41 GROUNDWATER PROTECTION MODEL - GPM Deriving soil standards protective of groundwater use using the GPM 1. Water use standard at point of compliance, C x Saturated fate and transport 2. Groundwater concentration below source, C gw Leachate/groundwater mixing 3. Leachate concentration at water table, C z Unsaturated fate and transport 4. Leachate concentration at source, C L Soil Leachate Partitioning 5. Soil concentration at source, C s 6. Adjusted soil concentration, C c = soil standard protective of respective water use 41

42 GROUNDWATER PROTECTION MODEL - GPM Default model parameters Used for deriving the matrix numerical soil standards in Schedule 3.1 Part 1 Category Model Parameter Symbol Unit Default value Source dimensions Source length X m 10 Source width Y m 30 Source depth Z m 3 Infiltration Infiltration I m/yr 0.55 Hydrogeology Total porosity n Water filled porosity n w Effective porosity n e Dry bulk density ρ b g/cm Fraction of organic carbon f oc ph of soil ph soil ph of groundwater ph water Hydraulic conductivity K m/s 3E-5 Hydraulic gradient I Average linear velocity v m/yr 30.3 Aquifer thickness d a m 5 Depth to water table d m 3 Distance to point of compliance x m 10 Substance Half-life t 1/2s X Substance Distribution coefficient K oc /K d X Substance 42 Henry s Law constant H X Substance Solubility S X Substance

43 MODIFIED GPM METHOD SSSs derived using the Modified GPM method Determine site-specific model parameters Category Model Parameter Symbol Default Look-up table Literature Site-specific Source dimensions Source length X X X Source width Y X X Source depth Z X X Infiltration Infiltration I X X Director Hydrogeology Total porosity n X X X Water filled porosity n w X X Effective porosity n e X X X Dry bulk density ρ b X X X Fraction of organic carbon f oc X X ph of soil ph soil X X ph of groundwater ph water X X Darcy flux (K and i) V X X Aquifer thickness d a X X Depth to water table d X X Distance to point of compliance x X X Substance Half-life t 1/2s X Director Distribution coefficient K oc /K d X Director Henry s Law constant H X Director Solubility S X Director 43

44 MODIFIED GPM METHOD SSSs derived using the Modified GPM method Determine site-specific model parameters Category Model Parameter Symbol Default Look-up table Literature Site-specific Source dimensions Source length X X X Source width Y X X Source depth Z X X Infiltration Infiltration I X X Director Hydrogeology Total porosity n X X X Water filled porosity n w X X Effective porosity n e X X X Dry bulk density ρ b X X X Fraction of organic carbon f oc X X ph of soil ph soil X X ph of groundwater ph water X X Darcy flux (K and i) V X X Aquifer thickness d a X X Depth to water table d X X Distance to point of compliance x X X Substance Half-life t1/2s X Director Distribution coefficient Koc/Kd X Director Henry s Law constant H X Director Solubility S X Director 44

45 MODIFIED GPM METHOD Infiltration Rate: I = P (ET+RO) Infiltration table and map Map constructed based on 44 climate stations Most recent five years of climate data used and averaged Minimum value of 80 mm/year Further details in Estimation of Regional Infiltration Rates in British Columbia, Core 6 Environmental 45

46 MODIFIED GPM METHOD SSSs derived using the Modified GPM method Determine site-specific model parameters Category Model Parameter Symbol Default Look-up table Literature Site-specific Source dimensions Source length X X X Source width Y X X Source depth Z X X Infiltration Infiltration I X X Director Hydrogeology Total porosity n X X X Water filled porosity n w X X Effective porosity n e X X X Dry bulk density ρ b X X X Fraction of organic carbon f oc X X ph of soil ph soil X X ph of groundwater ph water X X Darcy flux (K and i) V X X Aquifer thickness d a X X Depth to water table d X X Distance to point of compliance x X X Substance Half-life t 1/2s X Director Distribution coefficient K oc /K d X Director Henry s Law constant H X Director Solubility S X Director 46

47 MODIFIED GPM METHOD Source definition under Protocol 2 Petroleum hydrocarbon sources Defined by the greater of the horizontal and vertical extent of either: NAPL presence, as defined in Protocol 16 or soil concentrations of: - VH s6-10 greater than 100 µg/g; or - EPH s10-19 greater than 1000 µg/g; or - EPH s19-32 greater than 1000 µg/g All other sources Defined by the horizontal and vertical extent of soil concentrations: greater than the applicable matrix standard; or greater than the local/regional background soil quality; or No source: Matrix standards protective of applicable groundwater use(s) does not apply greater than a SSS derived modifying one or more of the following model parameters: I, n, n w, n e, ρ b, foc, ph, K, i, da 47 Further details in Defining the Contaminant Source Zone, Core 6 Environmental

48 MODIFIED GPM METHOD Hydrogeological parameters Site-specific source dimensions are required to modify: Depth to water table Distance to point of compliance For DW, IW, LW: Distance to point of compliance can be modified to the downgradient property boundary if groundwater on site meets applicable standards For AW: Distance to point of compliance can be modified to 10 m from aquatic receptor if groundwater meets applicable standards at property boundary 48

49 MODIFIED GPM METHOD Site-specific model parameters Acceptable parameter ranges Category Model Parameter Symbol Unit Default value Acceptable range Source dimensions Source length X m 10 5 Source width Y m 30 5 Source depth Z m 3 3 Infiltration Infiltration I m/yr Hydrogeology Total porosity n and 0.4 Water filled porosity n w n w n Effective porosity n e and 0.4 Dry bulk density ρ b g/cm Fraction of organic carbon f oc and ph of soil ph soil and 9 ph of groundwater ph water and 9 Hydraulic conductivity K m/s 3E-5 - Hydraulic gradient I Average linear velocity v m/yr and 250 Aquifer thickness d a m 5 5 and 20 Depth to water table d m 3 1 Distance to point of compliance x m and 500 Substance Half-life t 1/2s X Substance Distribution coefficient Koc/Kd X Substance 49 Henry s Law constant H X Substance Solubility S X Substance

50 MODIFIED GPM METHOD Site-specific model parameters Ranking of model parameters based on sensitivity Further details in Results of a Sensitivity Analysis for the Omnibus Groundwater Model, Core 6 Environmental

51 MODIFIED GPM METHOD - EXAMPLE Modified GPM method benzene example Commercial land use, DW apply DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = µg/g Site-specific model parameters Infiltration rate I = m/year (Victoria) SSS = µg/g 51

52 MODIFIED GPM METHOD - EXAMPLE Modified GPM method benzene example Commercial land use, DW apply DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = µg/g Site-specific model parameters Unsaturated thickness b = 1 m (depth to water table d = 4 m) SSS = 0.45 µg/g 52

53 MODIFIED GPM METHOD - EXAMPLE Modified GPM method benzene example Commercial land use, DW apply DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = µg/g Site-specific model parameters Infiltration rate I = m/year (Victoria) Unsaturated thickness b = 1 m (depth to water table d = 4 m) SSS = 10 µg/g 53

54 QUESTION BREAK PLEASE TYPE YOUR QUESTION NEXT: LEACHATE TEST METHOD PROTOCOL 2 EXAMPLES

55 LEACHATE TEST METHOD SSSs derived using the Leachate Test method Leachate test following Protocol 27 provides: - the max soil concentration - the corresponding soil leachate concentration, C L,test Leachate test Max soil concentration C L,test 55

56 LEACHATE TEST METHOD The SSS is determined as the maximum soil concentration if: 1. the soil leachate concentration is the numerical water use standard or 2. the soil leachate concentration is to the modelled leachate concentration C L,default derived using the GPM and default parameters or 3. the soil leachate concentration is to the modelled leachate concentration C L,site-specific derived using the GPM and site-specific model parameters For substances that don t degrade, C L,default = 3.3 x water use standard Where 3.3 is the dilution factor obtained by mixing Leachate test Max soil concentration SSS Cs SSS Cs SSS Cs C L,test C L,default C L,site-specific 56 C x C x C x

57 LEACHATE TEST METHOD - EXAMPLE Leachate Test method - cadmium example Commercial land use, DW apply, ph <7.5 (run model at ph=7.3) DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = 4.5 µg/g Leachate test C max =25 µg/g The SSS is determined as the maximum soil concentration if: 1. the soil leachate concentration is the numerical water use standard; DW standard = 5 µg/l C L,test = 20 µg/l 57

58 LEACHATE TEST METHOD - EXAMPLE Leachate Test method - cadmium example Commercial land use, DW apply, ph <7.5 DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = 4.5 µg/g Leachate test C max =25 µg/g The SSS is determined as the maximum soil concentration if: 1. the soil leachate concentration is the numerical water use standard; DW standard = 5 µg/l 2. the soil leachate concentration is to the modelled leachate concentration C L,default derived using the GPM and default parameters; C L,test = 20 µg/l C L,default = 3.3 x 5 µg/l = 16.5 µg/l 58

59 LEACHATE TEST METHOD - EXAMPLE Run GPM with default model parameters Drinking water standard, C x = 5 µg/l Modelled leachate concentration, C L,default = 16.5 µg/l Site-specific soil standard, C c = 4.5 µg/g 59

60 LEACHATE TEST METHOD - EXAMPLE Leachate Test method - cadmium example Commercial land use, DW apply, ph <7.5 DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = 4.5 µg/g Leachate test C max =25 µg/g The SSS is determined as the maximum soil concentration if: 1. the soil leachate concentration is the numerical water use standard; DW standard = 5 µg/l 2. the soil leachate concentration is to the modelled leachate concentration C L,default derived using the GPM and default parameters; C L,test = 20 µg/l C L,default = 3.3 x 5 µg/l = 16.5 µg/l 3. the soil leachate concentration is to the modelled leachate concentration C L,site-specific derived using the GPM and site-specific model parameters 60

61 LEACHATE TEST METHOD - EXAMPLE Run GPM with site-specific model parameters Infiltration I=80 mm/year Drinking water standard, C x = 5 µg/l Modelled leachate concentration, C L,site-specific = 57.3 µg/l Site-specific soil standard, C c = 15 µg/g 61

62 LEACHATE TEST METHOD - EXAMPLE Leachate Test method - cadmium example Commercial land use, DW apply, ph <7.5 DW water use standard = 5 µg/l Matrix numerical soil standard protective of DW use = 4.5 µg/g Leachate test C max =25 µg/g The SSS is determined as the maximum soil concentration if: 1. the soil leachate concentration is the numerical water use standard; DW standard = 5 µg/l 2. the soil leachate concentration is to the modelled leachate concentration C L,default derived using the GPM and default parameters; C L,test = 20 µg/l C L,default = 3.3 x 5 µg/l = 16.5 µg/l 3. the soil leachate concentration is to the modelled leachate concentration C L,site-specific derived using the GPM and site-specific model parameters C L,site-specific = 57.3 µg/l 62 SSS=25 µg/g

63 DIRECTOR S DECISION Director s decision for derived SSSs Modified GPM method and Leachate Test method not sufficient Example of alternative methods applied: Change parameters outside ranges provided in Protocol 2 Change parameters not included in Protocol 2 Submit application to ministry 63

64 QUESTION BREAK PLEASE TYPE YOUR QUESTION NEXT: PROTOCOL 2 EXAMPLES

65 EXAMPLE KAMLOOPS GAS STATION Kamloops gas station This is a real site, but identifiers have been removed Site Region Land use standards Water use standards Interior CL DW/AW Fresh Site-Specific Parameter Value Units Source Lenth 10 m Source Width 30 m Source Depth 3 m Fraction of Organic Carbon Infiltration Rate 80 mm/year Distance to Receptor 10 m Aquifer Thickness 5 m Depth to Water Table 3 m Groundwater Velocity m/yr Hydraulic gradient (i) c to c m/m Hydraulic Conductivity (K) 3.00E-05 m/s Reported Contaminant in Soil/GW Concentration Range Units benzene (CL soil) 4.3 ug/g ethylbenzene (CL soil) 24.3 ug/g toluene (CL soil) 60.1 ug/g xylene (CL soil) 98 to ug/g benzene (GW-DW) 6 to 883 ug/l ethylbenzene (GW-DW) 3.9 to 220 ug/l 65 toluene (GW-DW/AWf) 26 to 482 ug/l xylene (GW-DW/AWf) 305 to 2080 ug/l

66 EXAMPLE KAMLOOPS GAS STATION INPUT Site-specific model parameters Infiltration rate Hydraulic gradient 66

67 EXAMPLE KAMLOOPS GAS STATION OUTPUT Model output Benzene 67

68 EXAMPLE KAMLOOPS GAS STATION OUTPUT Model output Xylene 68

69 EXAMPLE KAMLOOPS GAS STATION STANDARDS Model results Substance Stage 10 standard (µg/g) SSS (µg/g) Benzene (DW) 0.2 (DW) Ethylbenzene 15 (DW) 200 (DW) Toluene 0.5 (AWf) 55 (AWf) Xylene 6.5 (DW) 100 (DW) Reported Contaminant in Soil/GW Concentration Range Units benzene (CL soil) 4.3 ug/g ethylbenzene (CL soil) 24.3 ug/g toluene (CL soil) 60.1 ug/g xylene (CL soil) 98 to ug/g benzene (GW-DW) 6 to 883 ug/l ethylbenzene (GW-DW) 3.9 to 220 ug/l toluene (GW-DW/AWf) 26 to 482 ug/l xylene (GW-DW/AWf) 305 to 2080 ug/l 69

70 EXAMPLE LOWER MAINLAND PULP MILL Lower mainland pulp mill This is a real site, but identifiers have been removed 3 Site Region lower mainland 4 Land use standards IL 5 Water use standards DW/AW Fresh/AW Marine Site-Specific Parameter Value Units 1 Source Lenth 10 m 2 Source Width 30 m 3 Source Depth 3 m 4 Fraction of Organic Carbon 6.00E-03-5 Infiltration Rate 550 mm/year 1 Distance to Receptor 10 m 2 Aquifer Thickness 10 m 3 Depth to Water Table 3 m 4 Groundwater Velocity m/yr 5 Hydraulic gradient (i) 0.05 m/m 6 Hydraulic Conductivity (K) 4.85E-06 m/s Reported Contaminant in Soil/GW Concentration Range Units 1 arsenic (IL soil) 17.7 to 339 ug/g 2 trivalent chromium (IL soil) 78 to 196 ug/g 3 lead (Il soil) 292 to 3040 ug/g 4 copper (IL soil) 253 to 2580 ug/g 5 cadmium (IL soil) 3.9 to 7.5 ug/g 6 zinc (IL soil) 339 to 2010 ug/g 7 barium (IL soil) 465 to 1950 ug/g 8 benzene (IL soil) ** 0.06 ug/g 9 tetrachloroethylene (IL soil) ** 0.04 ug/g 10 ethylbenzene (GW-DW) 5.7 to 6.6 ug/l 11 lead (GW-DW) 11 ug/l 12 benzo[a]pyrene (GW-DW) to 0.03 ug/l 13 uranium dissolved (GW-DW) 25 to 319 ug/l sodium dissolved (GW-DW) to ug/l 15 chromium dissolved (GW-DW) 13 to 140 ug/l 16 arsenic dissolved (GW-DW) 12 to 30 ug/l

71 EXAMPLE LOWER MAINLAND PULP MILL INPUT Site-specific model parameters Infiltration rate Hydraulic conductivity / hydraulic gradient 71

72 EXAMPLE LOWER MAINLAND PULP MILL OUTPUT Model output Cadmium, ph = 5 72

73 EXAMPLE LOWER MAINLAND PULP MILL OUTPUT Model output Cadmium, ph = 9 73

74 EXAMPLE LOWER MAINLAND PULP MILL OUTPUT Model output Lead, ph = 6.5 Mandatory standards apply 74

75 EXAMPLE LOWER MAINLAND PULP MILL STANDARDS Model results Substance Stage 10 standards (µg/g) SSS (µg/g) Concentration Range (µg/g) Arsenic 10 (DW and AW) 10 (DW and AW) Barium 350 (DW) 350 (DW) Benzene (DW) (DW) 0.06 Cadmium 1 (DW) 75 (Tox)* ph is Chromium (iii) 250 (Tox) Copper 75 (AW) -300 (Tox)* 75 (AW) -300 (Tox)* Lead 120 (DW) (Tox)* ph (Tox)* Zinc 150 (AWf) (Tox)* ph ph9 (AWm) PCE

76 EXAMPLE FORMER GAS STATION UNKNOWN LOCATION Gas station, unknown location This is a real site, but identifiers have been removed 76

77 EXAMPLE FORMER GAS STATION Site-specific model parameters Benzene in soil Source dimensions X=20m Y=40m Z=20m d = 22m clean groundwater 77

78 EXAMPLE FORMER GAS STATION INPUT Site-specific model parameters Source dimensions X, Y, Z Depth to water table 78

79 EXAMPLE FORMER GAS STATION OUTPUT Model output Benzene 79

80 EXAMPLE FORMER GAS STATION Model results SSS for benzene is 3.0 ug/g All benzene concentrations in soil meet the SSS 80

81 TAKEAWAYS ON EXAMPLES USING MODEL METHOD Understand the hydrogeological system, the substance exceedances and how the GPM sensitivity can work in your favour PHC contaminated sites in the Interior will likely benefit the most Easy to substitute in an appropriate infiltration Worthwhile to collect foc for these sites Additional benefit if one determines source dimensions, particularly source depth invokes an uncontaminated vadose zone Inorganic contaminated sites, especially those in the lower mainland, are unlikely to have significant changes to SSS Easy to substitute in an appropriate infiltration Dependent on the ph of the soil Additional benefit if one determines source dimensions, particularly length implications on distance to point of compliance, mainly AW though May need to consider Protocol 27 and the Leachate Test method 81

82 QUESTIONS? ANNETTE MORTENSEN OR (778) AMY SLOMA OR (778) Advice provided during this webinar is based on information available at the time of recording and may be subject to change. This PowerPoint presentation and a recording of the audio will be posted on the web. If you do not wish your question to be on the public record, please the presenter following the webinar.