Provide a conceptual site model of the site using a source-pathway-receptor model.

Assessed coursework

The client has contracted you to develop a contaminated land management plan for Site A, which is to be redeveloped as a leisure centre with an outdoor swimming pool. The site was the location of a factory making electrical components. Processes onsite included using hydraulic presses, machining and painting, and tanks for degreasing using Genklene & trichloroethene. The plant equipment including all tanks have been removed, but an Environmental Risk Assessment has concluded that the residual contamination at the site poses unacceptable risks to the future land-uses and receptors on and within the vicinity of the site.

There is a nature reserve to the south of the site, with a lake, children’s play area and farm shop (with animals) and café.  To the west is a commercial district with underground carpark.  To the east, there is a larger derelict site (Site B) with plans for redevelopment.  An environmental risk assessment of that site is underway.  The consultant managing that site has indicated that remediation is likely to take place in the near future and that there is ~6,500 m³ of contaminated soil at the site that may need to be remediated (this is not part of your brief). To the north, a railway line runs east-west.

You have been provided with the following results from recent site investigations.

Borehole location plan (pdf and dwg) showing sampling locations and the outline of the site (oriented north).

You can open the dwg file with the pdf file in the same folder in AutoCAD. You can edit this file to produce figures for your report, but use of AutoCAD/drawing software is not compulsory.  Hand-drawn figures are acceptable.

Borehole logs (pdf) of the drilling of the on- and off-site sampling locations, drilled in 2011 and 2015. These show bore log data from both deep (BHD) and shallow (BHS) wells at the site.

Soil investigation lab data 2011 (xlsx) and Soil investigation lab data 2015 (xlsx) showing laboratory analysis of the soil samples taken during the two drilling events.

NAPL analysis (xlsx) of NAPL that has been discovered at the site.

Field data 2016 (xlsx) showing well locations, depth to groundwater, depth to NAPL and height of the well casing for the BHS wells.  There is no groundwater data for the BHD wells.

Groundwater lab data 2016 (xlsx) showing laboratory analysis of samples taken at the site during the latest groundwater monitoring event in 2016.  This is for the BHS wells only.  There is no groundwater data for the BHD wells.

Prefix BH refers to boreholes only, so groundwater well D1 is in the same location as borehole BHD1. “D” indicates a deep well, “S” indicates a shallow well.

Note: Although the actual concentrations and locations of the contamination changes over time, you may assume that all data is current at the time of your report.

Read the task outlines below carefully and make sure you include all necessary content.

The report should contain:

Task 1. Site assessment Maximum 2 pages excluding tables and figures

Provide a conceptual site model of the site using a source-pathway-receptor model.  This should include:

a) Presentation of the site investigation data including groundwater and contaminant contours and tabulation as appropriate.

b) Comparison of the contaminant concentrations at the site against appropriate risk-based guideline values.

c) A conceptual site model detailing the contamination at the site and showing source-pathway-receptor linkages.

d) A network diagram identifying the potential pollutant linkages, highlighting the Significant Pollutant Linkages (SPLs).

e) Identification of the uncertainties in your CSM.

Task 2. Land management strategy Maximum 4 pages excluding tables and figures

Prepare a land management strategy to return the land to beneficial use appropriate to the proposed land-use and to protect nearby receptors.

This strategy should include:

• Remedial goals based on the SPLs identified in Task 1.
• Remediation Options Appraisal to identify three feasible remediation (or management) strategies that address all of the remedial goals.  You may not use the same technology/technique in any two strategies (e.g. you can’t propose to use soil washing in more than one strategy).
• Explanation of why each strategy is relevant to the site and addresses all SPL linkages.
• Identification of the stakeholders in the process.
• Comparison of the strategies based on cost, time, sustainability and impact on the stakeholders.  Selection (with justification) of one strategy to progress.
• For the chosen strategy, explain how they will be applied at this site (including well-field and process flow diagrams as appropriate).
• Develop remediation criteria for the chosen strategy.

Task 3. Remediation validation Maximum 3 pages

Plan a site investigation to validate the remediation against remediation criteria.

This should include:

• Development of detailed site-specific aims and objectives.
• A plan diagram of the site detailing sampling locations that are clearly linked to objectives.
• Selection of appropriate methods. This should include the installation of new soil bores if appropriate (a maximum of 10) and use of the existing groundwater monitoring wells.
• List of laboratory tests for each sample.

Make sure each test is justified.

Overall report

The report should:

• Be clear and concise, a coherent resource for the developer and any other stakeholders in the land management process.
• Clearly reference all sources.
• Contain only relevant information.
• Demonstrate a clear understanding of uncertainty.
• Demonstrate systematic decision-making.
• Use diagrams and tables to convey information effectively.

Do not repeat generic information from the lectures and other resources.  This will not attract any marks.  Everything should be site-specific.  Keep text brief and to the point

Submission Check-list – please include this page (complete with ticks!) after the title page of your submission

Task 1. Site assessment

• Maximum 2 pages excluding tables and figures
• Presentation of the site investigation data including groundwater and contaminant contours and tabulation as appropriate.
• Comparison of the contaminant concentrations at the site against appropriate risk-based guideline values.
• A conceptual site model detailing the contamination at the site and showing source-pathway-receptor linkages.
• A network diagram identifying the potential pollutant linkages, highlighting the Significant Pollutant Linkages (SPLs).
• Identification of the uncertainties in your CSM.

Task 2. Land management strategy

• Maximum 4 pages excluding tables and figures
• Remedial goals based on the SPLs identified in Task 1.
• Remediation Options Appraisal to identify three feasible remediation (or management) strategies that address all of the remedial goals.  You may not use the same technology/technique in any two strategies (e.g. you can’t propose to use soil washing in more than one strategy).
• Explanation of why each strategy is relevant to the site and addresses all SPL linkages.
• Identification of the stakeholders in the process.
• Comparison of the strategies based on cost, time, sustainability and impact on the stakeholders. Selection (with justification) of one strategy to progress.
• For the chosen strategy, explain how they will be applied at this site (including well-field and process flow diagrams as appropriate).
• Develop remediation criteria for the chosen strategy.

Task 3. Remediation validation

• Maximum 3 pages
• Development of detailed site-specific aims and objectives.
• A plan diagram of the site detailing sampling locations that are clearly linked to objectives.
• Selection of appropriate methods.  This should include the installation of new soil bores if appropriate (a maximum of 6) and use of the existing groundwater monitoring wells.
• List of laboratory tests for each sample.

Sample Answer