Contaminated Site and Waste Remediation
TASK 1A : Project Proposal: Management
Project Proposal
Your company has been awarded a contract to undertake a Contaminated Site Assessment activity. This activity has been broken up into a project proposal (Task 1A) and the Project Report (Task 2A). The client for this Project proposal (Task 1A) will be senior management in your company who would eventually authorise the work.
TASK 1A REPORT STRUCTURE
Title Page
Table of Contents
Scope of Work
This should include Problem Statement, project context, Objectives, deliverables, tasks, inclusions and exclusions
Review of Data provided
Review any key data provided, particularly with respect to how it will be used (ie in Site conceptual model, Risk Assessment, Remediation Assessment) and any ambiguity, uncertainty in it.
Site Assessment Methodology
Site Conceptual model
Identify approach to used and limitations to the approach
Risk Assessment model
Identify approach to used, model and limitations to the approach
Remediation Assessment
Identify approach to used, model and limitations to the approach
Additional Data Requirements
Identify any key data needed to develop a defensible set of assessments (ie in Site conceptual model, Risk Assessment, Remediation Assessment).
Hints for undertaking Task 1A
1/ Scope of Work
This should include Problem Statement, project context, objectives, deliverables, tasks, inclusions and exclusions. You need to identify what is included (within scope) and what is excluded. For instance, this report The purpose of the Project Proposal (Task 1A) is to detail the scope of work required to complete Task 2A. Therefore, you must be familiar with what is required for Task 2A. You need to identify the adequacy of the information provided (eg uncertain, ambiguous, and imprecise) as well as potential issues associated with proposed investigation/assessment methods (technical practicability, data requirements) and management of uncertainty/contradictions in model inputs. What will be excluded in Task 1A is a detailed analysis and presentation of all the data provided. This detailed work will be undertaken in Task 2A.
2/ Review of Data provided
Review any key data provided particularly with respect to how it will be used and any ambiguity, uncertainty in it. A useful way to organize this may be to have a separate section (e.g. 2.1, 2.2 etc) for each set of parameters. These parameters could include organic contaminants, metal contaminants, groundwater flow (direction, gradient) etc
3/ Site Assessment Methodology
Site Conceptual model
Identify what types of information you will use to develop your site conceptual model. Where will you obtain this data? Is this primary data from the provided site data or do you need to obtain information from elsewhere (e.g. databases)? How will you process this information and put it in a form amenable to the analysis required for Task 2A? Are there any limitations to this approach?
How will you present your site conceptual model? Will you use cross sections/fence diagrams, if so what transects /directions will you use? What software package will you use? How will you present inferred contaminant distributions?
Risk Assessment
Identify the approach you will use to collecting data that can show the linkages between the contaminant sources, release mechanisms, pathways and receptors/targets. How will you structure this information (e.g. tabular, checklist, descriptive)? Do you currently have all the information you need? Do you have enough chemical analysis and/or site history to identify contaminant sources? Do you have enough information on contaminant transport paths to link contaminant sources and receptors.
Remediation Assessment
Identify the approach you will use to collecting data that can allow you to short-list a range of suitable remediation technologies. Have you identified the necessary information on the contaminants and their distribution: dominant types of contaminants present, the contaminant forms (vapor, napl, dissolved, sorbed) and the affected media? What sources of information (eg websites) will you use to identify technical aspects for suitable technologies based on contaminant present, community acceptace and site conditions amongst other factors listed?
Identify any short-term management options. What sources of information will you use to identify this option? What will you need to consider in terms of risk communication principles?
4/ Additional Data Requirements
Identify any key data needed to develop a defensible Site conceptual model, Risk Assessment and Remediation Assessment. What additional site data do you need? What types of samples and potential locations would be useful. Based on your requests the client may initiate additional data collection for your final report.
TASK 2A:
Project Report: Management
Your context in relation to Tasks 2A: Project Report
Senior management in your company has approved your Project Proposal (Task 1A) for the work and you can now undertake the detailed analysis of all the site data provided. This report that will
be provided to the client. It must be standalone since the report for Task 1A was not provided to the client. Below is the required Report Structure.
TASK 2A REPORT STRUCTURE
1/ INTRODUCTION
- Outline the context of this study: the scope of work and what assumptions are being made.
2/ SITE DESCRIPTION, REGULATORY HISTORY, OPERATIONAL HISTORY AND WASTE CHARACTERISTICS
- Identify a timeline listing all relevant activities onsite and for each land-use activity. Identify the major potential sources (locations and potential contaminants) at the site.
3/ CONTAMINANT DATA REVIEW
In this section of the report you will critically review known information about the contaminants sources and their distribution. You can also comment on the quality of the investigation (source characterization, sample location, sample analysis) and data obtained interms of it being used to clearly show all contaminant pathways (ie linkages between sources and contaminants collected for the Site Investigation. This information will be presented individually for each contaminant source.
- Review the information known about the waste/contaminant sources, their boundaries and the extent to which the source is contained against releases to the surface water, soil and groundwater.
- For each identified source identified the potential and actual contaminants present. You should also identify which samples are indicative of background concentrations.
4/ CONCEPTUAL MODELS FOR GROUNDWATER, SURFACE WATER AND SOIL
In this section of the report you will integrate information from the contaminant review section and information on contaminant transport processes. The information should be presented on a whole of site basis.
- Draw cross-sectional profiles through the site showing contaminant sources and potential contaminant distributions (groundwater, surface water, soil).
- Construct a schematic conceptual model for risk assessment. You should identify contaminant sources, release mechanisms, pathways and receptors/targets.
5/ REMEDIATION ASSESSMENT
Review available site information and identify a list of remedial technology options that are potentially applicable to the remediation of the identified contaminated media at the Site. Each technologies should be ranked from 1 (low) to 5 (high) based on the following four criteria:
- Applicability - Consider: - lithology; - the chemical and physical properties of the contaminant including the physical ability to reduce contaminant concentrations to below clean-up goals; - distribution in the subsurface (vadose/saturated zone); - access and space constraints; - efficacy.
- Technology Status - acceptance of technology locally and internationally by remediation practitioners (consultants/academics/regulators) as being proven or innovative as well as availability of remedial equipment/infrastructure; -acceptance of the technology by the community
- Secondary Treatment Requirements - identification of additional treatment requirements including the disposal of wastes;
- Monitoring - short-term and long-term monitoring requirements for implementation of technology to assess remediation performance and/or adverse impacts;
6/ SITE MANAGEMENT
- Identify short-term management actions that are needed to minimise contaminant exposure to the surrounding environment. These can include site security, exposure notification, inter- media contaminant transfer, stormwater diversion, and institutional control on surface/groundwater extraction. Do not include additional onsite sampling points.
7/ CONCLUSIONS
Summarise the major findings of this report
Hints for undertaking Task 1A & TASK2A
- In your task you will only need to use a subset of the Data provided in the provided Site Inspection Report (ie task 2/3 scenario). So just because information is provided in the Site Investigation do not put it in the report unless it is relevant
- The data provided in the Site Inspection report is fragmented into various tables. While this is systematic in terms of media sampled it may not be helpful for you trying to understand the important source-pathway-receptor relationships necessary for the conceptual model. You should consider representing the data to better communicate these relationships.
- The scenario was in imperial units and I have left it in those units since the modelling software also uses those units. So you may need to find some unit conversion software to get the sense of scale that you are more familiar with.
Specific hints for CONCEPTUAL MODELS FOR GROUNDWATER, SURFACE WATER AND SOIL
- It is suggested that you need to develop a conceptual model for how surface/groundwater moves through the site. You then need to develop an evidence based model on how contaminants are distributed across the site. These should then be critiqued across compounds to identify where there is agreement/disagreement in expected and actual contaminant distributions. Areas of disagreement then should be further investigated to see if the inconsistency is due to a lack of data/incorrect assumption of your conceptual model/ incorrect data. For example, an example of disagreement in your site conceptual model maybe that two compounds with similar physio-chemical properties that were thought to have a single release may have different relative distributions (plume legth/width). Since contaminant fate properties (eg sorption, degradation) may be expected to be similar, these inconsistencies may arise from suspect data, multiple sources etc. These are what I call conceptual model disagreement or inconsistencies. Any inconsistencies that can't be resolved satisfactorily should be identified for further work.
- Use the material in the Learner Resources related to Groundwater System Conceptualisation to help develop surface-groundwater interaction in the cross sectional profiles. The possible contaminant distributions will be somewhat speculative since the mass of contaminant disposed of and other data is not directly available, however there is some existing contaminant data from various media (groundwater, soil, surface water). Therefore this activity is strongly linked to the development of Conceptual models and really just provides feasible transport pathways for the observed data. The purpose of these conceptual models is to guide the development of any further sampling. Each student may have a different set of assumed contaminant distributions and hence different sampling plans. However the adequacy of your sampling plan will be judged against your inferred conceptual model.
- To get a 3D understanding of possible source-pathway-receptor relationships I found it useful to create a single table. For example on the groundwater data I created a table with all wells (both the background and release wells) along with aquifer, depth, well type and
contamination. I then highlighted concentration above background in different colors and then marked them on a map. By including the contaminant data on the same table as the contaminant data I could then see if the pathway was plausible in the vertical dimension by looking at the well depth screen intervals. Once that data was put on the map I could then see if the ppossible pathway made sense in terms of the groundwater/surface water flow direction.
Hints for the RISK ASSESSMENT
- In the Site Conceptual Model section of the report a comprehensive representation of site contamination was presented. You build on this material. This included contaminant sources, pathways and receptors.
- For the environmental receptors, indicate whether any sensitive environments are present. A sensitive environment is a terrestrial or aquatic resource, fragile natural setting, or other area with unique or highly valued environmental or cultural features.
- For human health risks identify any receptors. The pathways can include ingestion, inhalation, dermal contact.
1. Indicate whether surface water supplies drinking water. Identify distance from probable point of entry (PPE) to each drinking water intake.
2. Indicate whether groundwater supplies drinking water. Identify nearest domestic and municipal wells and populations served by them. Identify the aquifers used.
3. Indicate whether surface water contains fisheries. A fishery is an area of a surface water. body from which food chain organisms are taken or could be taken for human consumption on a subsistence, recreational, or commercial basis. Food chain organisms include fish, shellfish, crustaceans, amphibians, and amphibious reptiles. Identify distance from probable point of entry (PPE) to each fishery.
4. Indicate whether any site workers could be impacted and through which pathways.
Specific hints for the REMEDIATION ASSESSMENT
- Start by narrowing down available technologies to those appropriate for the contaminants present
- Petroleum hydrocarbon contaminants may be listed as Fuels in some remediation databases
- See Learner Resource material in UTSOnline for support materials
Attachment:- Task_scenario.rar