Contaminated Soil Monitoring Pornsri Suthanaruk, Ph.D Pollution Control Department (PCD) Ministry of Natural Resources and Environment Thailand Workshop on Strengthening Contaminated Soil Monitoring in Vietnam, November 2011

Outline 1. Introduction 2. Assessment Preliminary Assessment - Land use history - Soil sampling - Health and safety requirement - Soil quality standard Detailed Assessment - Determination of Field Sample Size 3. Soil monitoring Study case: 4. Management of contaminated areas

Common sources of soil contamination Illegal Dumping of chemicals Chemicals accidental site Industrial facility or chemicals warehouse Gas Station Mine Agriculture Landfill site New landfill site that filled by contaminated soil Areas nearby chemicals contaminated site

Soil Quality Standard Source : Notification of National Environmental Board No. 25, B.E. (2004) issued under the Enhancement and Conservation of National Environmental Quality Act B.E.2535 (1992) published in the Royal Government Gazette No. 121 Special Part 119 D dated October 20, B.E.2547(2004)Notification of National Environmental Board No. 25, B.E. (2004) Objectives: Protected human health Application: - Preliminary assessment - Health and ecological risk assessments are needed if contaminants are either directly or indirectly impact to people in and surrounding the contaminated areas. Information: - Standard vales /analytical technics/ soil collecting and sample preservation technics

Soil Quality Standards Parameter Standard value (not exceed) Habitat and Agriculture (mg/kg) Other Purposes (mg/kg) 1. Volatile Organic Compounds 1) Benzene ) Carbon Tetrachloride ) 1,2-Dichloroethane ) 1,1-Dichloroethylene ) cis-1,2-Dichloroethylene ) trans-1,2-Dichloroethylene ) Dichloromethane ) Ethylbenzene230 9) Styrene1,700 10) Tetrachloroethylene ) Toluene520 12) Trichloroethylene ) 1,1,1-Trichloroethane6301,400 14) 1,1,2-Trichloroethane ) Total Xylenes210

Soil Quality Standards Parameter Standard value (not exceed) Habitat and Agriculture (mg/kg) Other Purposes (mg/kg) 2. Heavy metals 1) Arsenic ) Cadmium and compounds ) Hexavalent Chromium ) Lead ) Manganese and compounds1,80032,000 6) Mercury and compounds ) Nickel, soluble salts1,60041,000 8) Selenium39010,000

Soil Quality Standards Parameter Standard value (not exceed) Habitat and Agriculture (mg/kg) Other Purposes (mg/kg) 3.Pesticides and herbicides 1) Atrazine ) Chlordane ) 2,4-D69012,000 4) DDT ) Dieldrin ) Heptachlor ) Heptachlor Epoxide ) Lindane ) Pentachlorophenol Others 1) Benzo (a) pyrene ) Cyanide and compounds1135 3) PCBs ) Vinyl Chloride1.58.3

Soil Sampling Methodology Source : Notification of National Environmental Board No. 25, B.E. (2004) issued under the Enhancement and Conservation of National Environmental Quality Act B.E.2535 (1992) published in the Royal Government Gazette No. 121 Special Part 119 D dated October 20, B.E.2547(2004)Notification of National Environmental Board No. 25, B.E. (2004) 1. Dividing the area into small plots. The small size of the plot depends on the size of area and landscape, aiming to obtain a representative sample of the total area. 2. Numbers of the drilling hole, depending on the size of the area. For example, the area of rais requiring holes spread across the plot. 3. To drill a hole, a depth of approximately inches (30-45 cm) is suitable to undisturbed the soil sample. Reference samples have to be collected.

Soil Sample Preservation ParameterContainerPreservativeHolding Time 1.) Volatile Organic CompoundsGlass 4° ±2 °C 14 Days 2) Heavy metals (Except Hexavalent Chromium and Mercury and compounds) Plastic/Glass"180 Days 3) Hexavalent Chromium "" - 30 Days before sample preparation - 4 Days after sample preparation 4) Mercury and compounds ""28 Days 5) Pesticides Glass" - 14 Days before sample preparation - 40 Days after sample preparation 6) Benzo (a) pyrene "" - 14 Days before sample preparation - 40 Days after sample preparation 7) Cyanide and compounds Plastic/Glass"14 Days before sample preparation 8) PCBs Glass" - 14 Days before sample preparation - 40 Days after sample preparation 9) Vinyl Chloride ""14 Days Source : Notification of National Environmental Board No. 25, B.E. (2004) issued under the Enhancement and Conservation of National Environmental Quality Act B.E.2535 (1992) published in the Royal Government Gazette No. 121 Special Part 119 D dated October 20, B.E.2547(2004)Notification of National Environmental Board No. 25, B.E. (2004)

Outline 1. Introduction 2. Assessment Preliminary Assessment - Land use history - Soil sampling - Health and safety requirement Detailed Assessment - Determination of Field Sample Size 3. Soil monitoring Study case: 4. Management of contaminated areas

Identify contaminated areas chemical accidents, illegal dumping of chemical wastes (industrial facilities, location of waste disposal or mining) Identify contaminated areas chemical accidents, illegal dumping of chemical wastes (industrial facilities, location of waste disposal or mining) Step 1: Preliminary assessment - Search of land used area and preliminary survey - compared to the environmental quality standards Step 1: Preliminary assessment - Search of land used area and preliminary survey - compared to the environmental quality standards Step 2 : Detailed assessment - Check for contaminants, exposure route and vulnerable populations - Assess the health risk Step 3 : Contaminated land management planning Management of risks to health / to ecosystem - Treatment or detention of contaminants - Restricting the use of the area. Step 3 : Contaminated land management planning Management of risks to health / to ecosystem - Treatment or detention of contaminants - Restricting the use of the area. Step 4 - Monitor the effectiveness of rehabilitation - Plan for implementation safety for workers in the contaminated areas - Continuous monitoring No action taken No action taken

Step 1 Preliminary Assessment

Preliminary Assessment of Contaminated site Assessment processes 1.Find the land use history 2.Survey and interview local people 3.Soil, surface water and ground water sampling 4.Sampling handling and samples analysis If the concentrations are higher than the standard values, go to…. Step 2 : Detailed assessment

Land Use history

Source of Information: 2008 Emergency Response Guidebook

Source : NIOSH (National Institute for Occupational Safety and Health)

Tool Kit for Hazardous waste measurement

pH paperRadioactive Meter

Toxic gas and VOC meters

O 2 meter

Soil sampling

Step 1 : Preliminary Assessment The purpose of collecting soil samples is to identify the contamination. If the contaminants exceed the environmental quality standards, we go the step 2 which is health risk and ecological risk assessments. Soil Sampling

Soil sampling points will be selected by using information gathered from the land used history, survey and interview with local people in order to find the type of chemicals used, collected and/or disposed in the area. Soil sampling should be conducted in the following cases. The area adjacent to areas where the activities which may cause contamination. This includes areas of the landfill and chemical storage tanks located or the location where its topography is lower that the contaminated area. Reference or background samples will be collected to compare the data with the contaminated sites. It should be recorded the numbers and location of sampling point on the map.

Samples were collected at three depth form the serface as follows: How to collect soil samples From the surface to 0.10 meter-depth 0.4 to 0.5 meters 0.9 to 1.0 meters If soil is heterogeneous mixed, the samples will be collected from each layer/ soil type. If land was contaminated vertically, samples will be collected every 0.5 meters depth from the surface or collected to above the groundwater level.

1-2 inch 30 cm. Surface soil sampling

Field record Form

Core sampling

Cleaning sampling equipments

Step 2 Detailed assessment

Identify the scope and level of contamination Identify the source of contamination Assess the distribution of contaminant into soil and groundwater Identifying the impact and risk of external areas, environmental and public health Contaminated sites management plan

Determination of Field Sample Size Grid sampling were used to determine the scope and level of contamination by soil sampling at the same distance vertically and horizontally. Soil samples were collected every horizontal distance of 15 meters and at a depth of 5 meters. This should be cover the area of hazardous substances contamination and the areas of potential contamination. Grid site may be large or small depend upon the purpose of the assessment. In the case of a large area, grid size may be lager than that of the small contaminant area.

To calculate the number of sampling points N = kA / a when N = number of sampling points A = area of contamination (m 2 ) a = area hotspot (m 2 ) k = hotspot shape constant (Vary the shape of the contaminated area) D = (A/N) ½ when D = size of square (m) A = area (m 2 ) N = number of sampling points To calculate the size of the grid Predicted hotspot shape Hotspot shape constant (k) Circle1.08 Oval1.25 unpredictable1.50

Example The contaminated area is 20,000 square meters and the size of the hotspot is 500 square meters. Assuming that the hotspot shape is a circle. (k = 1.08) 1. To calculate the number of sampling points N = kA / a N = (1.08 x 20,000) / 500 = A number of sampling points is To calculate the size of the grid D = (A / N) ½ D = (20,000 / 44) ½ = 21.3 The grid size is 21 x 21 square meters.

Outline 1. Introduction 2. Assessment Preliminary Assessment - Land use history - Soil sampling - Health and safety requirement Detailed Assessment - Determination of Field Sample Size 3. Soil monitoring Study case: 4. Management of contaminated areas

Outline 1. Introduction 2. Assessment Preliminary Assessment - Land use history - Soil sampling - Health and safety requirement - Soil quality standard Detailed Assessment - Determination of Field Sample Size 3. Soil monitoring Study case: 4. Management of contaminated areas

Management of contaminated areas

Management of contaminated areas Contaminated sites management plan must be possible, achieve the purpose, acceptable to society, not harmful to the environment and crate risks to human health and ecosystems from contaminants in the area, all of which can be managed by controlling the factors that cause is described below. Chemicals : The main objective is to eliminate chemical contamination. However, some chemicals can not be cleaned up, such as heavy metals, etc. Chemicals exposure pathway : The path that chemicals can enter the human body. The routes, through which chemicals enter the body, can be controlled by prevention. Vulnerable populations : People, plants or animals may be affected by contamination. So, preventing the entry of contaminated sites is a best alterntive to avoid health risks.

Health risk assessment Non-cancer HQ (Hazard quotient) = Intake / RfD Cancer Risk = CSF x Intake Standard Risk < 10-5 Standard HQ < 1

Intake = C x CR x EF x ED BW x AT when C = concentration CR = contact rate EF = exposure frequency ED = exposure duration BW = body weight AT = averaging time

Recommendations to new technical guidelines and contaminated soil monitoring

Your GuidelineThailand Std. (Health Risk) 5 HMs 39 pesticides 8 HMs 9 pesticides 15 VOCs 4 Others Comparing Information Contaminants

Beneficial Use Your Guideline (Draft)Thailand Std. Agricultural Forestry residential and recreational commercial and service Industrial Residential and agricultural Others

Technical Survey Your Guideline (Draft) Thailand Std. 3 steps Basic Condition Detailed 2 steps Preliminary survey Detailed assessment

Thank you for Your Attention