99029 Ground Rules for Contaminated Sites, Assessment 3

99029 Ground Rules for Contaminated Sites, Assessment 3

DSI design report for 160 Burwood Road, Concord NSW

Author:

Date:

Complete this template report to provide your submission for Assessment 3. You should retain the structure provided, and follow the instructions carefully. Delete the text in red in your submission.

Introduction

Write an introduction explaining briefly what this report is for, and including a summary of the Case Study information. Include the pictures showing the current layout with site boundary. You may find it helpful to mark the location of the former timber mill and wharf on the current layout.

Preliminary Conceptual Site Model (CSM)

Use the guidance provided in Canvas to help you prepare a CSM to communicate what you know about the potential Sources, Receptors and Pathways. You should:

Identify the potential sources with reference to the site history and what you know about how sites become contaminated. What contaminants are associated with the site uses detailed in the Case Study? Hint look in Canvas, and also do some internet research on how instant coffee is made what chemicals are used, and could they be potential contaminants? Also, remember to consider what could be in the fill materials.

Receptors: identify the potential human and ecological receptors, using the proposed future use scenario for the site. You may assume that the surrounding area will be the same as it is now after the site is developed.

Pathways: what are the mechanisms by which the sources you have identified come into contact with your receptors? You will need to think about contaminant transport by soil, groundwater flow, stormwater flow, and vapour/gas movement both through the soil and through the air. Where could the contaminants go to, and how? Drawing a cross section to help visualise the underground soil and rock layers, and the water table position will help you a lot here.

You should present your CSM in at least 2 of the ways included as examples in Canvas, to illustrate the source-pathway-receptor linkages that you believe could be present. You will need to provide explanatory text as well as diagrams.

Data Quality Objectives

The table below will help you understand what you are trying to find out. You can leave it in your submission, and if you wish you may add your own comments and details. It is not compulsory to write anything in this section.

Table of Data Quality Objectives

DQO Step DQO Detail

State the problem The site is to be developed for residential use and is potentially contaminated as a result of its industrial history. It is necessary to determine the nature and extent of contamination present.

Identify the goal of the study The goals of the study are:

to determine the concentrations of contaminants associated with the former site uses in soils, groundwater, surface water and soil gas;

to compare the concentrations measured to appropriate guideline values;

to decide whether further information and/or remediation action is needed to develop the site with no unacceptable risk to health or the environment.

Identify information inputs (i.e. what is required in order to be able to achieve the study goals) The Case Study

Modules 1 and 2 on Canvas

The lecture notes from the teaching block

Site investigation guidance in ASC NEPM Schedules B1 and B2

Guideline Values from ASC NEPM Schedule B1

The data that will be collected and which is detailed in Sections 4 10 below.

Define the boundaries of the study

The study area comprises the site area (within the red line), together with surrounding land and water as relevant to the assessment of the extent of contamination.

Develop the analytic (statistical) approach The study will use an estimation approach comprising use of the data generated and comparison with guidelines to determine whether a potentially unacceptable risk exists.

Soil samples: 95% upper confidence limit will be compared to guideline value (except where hotspots are suspected)

Groundwater, surface water and soil gas/vapour: all samples compared individually to guideline values

Decision on whether or not additional information is required will be made depending on the levels of potential risk, and evaluation of the remaining data gaps and uncertainties.

Specify performance or acceptance criteria Unacceptable risk will be deemed potentially present where guideline values are exceeded and a viable source-pathway-receptor linkage exists.

Develop the plan for obtaining data Provided in Sections 4-10 below.

Contaminants of Concern and Analysis Required

Complete the tables below. Add rows as necessary. Use the information in Canvas and Schedule B1 of the ASC NEPM to help you.

Soil Analysis

Primary source of contamination Chemicals of potential concern for analysis Guideline values to be used for assessment (mg/kg)

This is the former land use, or affected rock/soil layer, plus a list of the kinds of contamination associated e.g. petroleum hydrocarbons This is the actual chemical analysis you will need for the kinds of contamination you suspect. You can take these from Schedule B1 of ASC NEPM (only pick the ones you need no marks for copying the whole list!) Choose which guideline values are appropriate for your future site use. You should include values for human health and ecological risk. Note that you may need several of each!

Groundwater Analysis

Primary source of contamination Chemicals of potential concern for analysis Guideline values to be used for assessment (mg/L)

This is the former land use, or affected area of groundwater, plus a list of the kinds of contamination associated e.g. petroleum hydrocarbons. This is the actual chemical analysis you will need for the kinds of contamination you suspect. You can take these from Schedule B1 of ASC NEPM (only pick the ones you need no marks for copying the whole list!) Choose which guideline values are appropriate for your future site use. You should include values for human health and ecological risk. Note that you may need several of each!

Surface Water Analysis

Primary source of contamination Chemicals of potential concern for analysis Guideline values to be used for assessment (mg/L)

This is the former land use, or affected area of groundwater, plus a list of the kinds of contamination associated e.g. petroleum hydrocarbons. This is the actual chemical analysis you will need for the kinds of contamination you suspect. You can take these from Schedule B1 of ASC NEPM (only pick the ones you need no marks for copying the whole list!) Choose which guideline values are appropriate for your future site use. You should include values for human health and ecological risk. Note that you may need several of each!

Soil gas / vapour analysis

Primary source of contamination Chemicals of potential concern for analysis Guideline values to be used for assessment mg/m3

This is the former land use, or affected rock/soil layer, plus a list of the kinds of contamination associated e.g. petroleum hydrocarbons This is the actual chemical analysis you will need for the kinds of contamination you suspect. You can take these from Schedule B1 of ASC NEPM (only pick the ones you need no marks for copying the whole list!) Choose which guideline values are appropriate for your future site use. You should include values for human health and ecological risk. Note that you may need several of each!

Soil sampling

In this section, specify which soil layers you will sample, the depths at which you will sample, and explain why (i.e. what are you trying to find out with the strategy you propose).

Suggest suitable methods for obtaining soil samples and explain why you chose each method

Groundwater sampling

In this section, explain what your groundwater sampling is trying to find out. You will need to specify how deep you should drill groundwater wells and which soil/rock layer you expect to encounter the water table.

Surface water sampling

In this section explain what surface water sampling you believe is necessary (if any) and what you would be trying to find out by taking surface water samples.

Soil gas / vapour sampling

In this section explain what soil gas / vapour sampling is trying to find out. Say what depth you consider you should install soil gas/vapour wells. Do you need wells designed for gas monitoring, or vapour monitoring, or both?

Sampling layout plan

Use the diagram in the Case Study, or make your own site plan using a Google maps image, and mark the locations you propose for your soil samples, groundwater wells, surface water samples and gas and/or vapour wells. Note that you can take soil samples from a borehole and then install a groundwater or gas or vapour well in the same hole; equally you can drill a borehole where you only take soil samples; or you can have some of each. Make sure you show clearly what kind of sampling each point will be used for. Hint: use the CSM to help you with where your samples should be taken! You should think about targeting both areas you think are likely sources and also areas where you think receptors might come into contact with contaminated soils, groundwater, surface waters and gases/vapours. Write some explanatory text to accompany your layout plan to explain your reasons for the layout you propose.