Revised Conceptual Site Model Checklist

CSM Items Checklist

Too often consultants miss the basics and run afoul of opposing parties in legal disputes and regulators. This is a compendium of items that are needed for an inclusive Conceptual Site Model.

Using references such as those from ASTM International, Battelle Northwest, Lawrence Livermore, Los Alamos and Idaho National Laboratories, the Commonwealth Science, Investigation and Research Organization of Australia (CSIRO), the Canadian Council of Ministers of the Environment (CCME), the British Columbia Contaminated Sites Regulation guidance documents and technical protocols, Ontario Regulation 153/03, Alberta Tier 1 and 2 guidance documents and those from the United States Environmental Protection Agency, Department of Energy, various state and provincial regulatory bodies as required and Environment Canada, We have put together this checklist for those conducting such work.

I         Facility Information

1.      Identify current and historical facility structures (should also be displayed graphically on cross sections and in map view – this will aid in planning field investigation program).

a.      buildings,

b.     drain systems,

c.      sewer systems,

d.     underground utilities

e.     roads

f.       pavement (and condition)

                                                              i.     Are you in Eastern or Western North America (Asphalt and sealants may contain PAHs – more prevalent in Eastern North America)

g.      others

2.      Identify process areas, including historical processing areas

a.      loading/unloading,

b.     storage,

c.      manufacturing,

d.     others

3.      Identify current and historical waste management areas and activities

4.      Others (such as spill locations or pipeline breaches)

This portion of the CSM information is part and parcel of a Phase 1 Environmental Site Assessment (If you are in British Columbia this is called the Stage 1 Environmental Site Investigation) and I would refer you to both Canadian Standards Association and ASTM International standards for review. Many of the necessary documents are available from your municipality, air photos, topographic maps and planning maps from provincial, state and municipal archives.

Key though is the visiting of the site with experienced assessor. Too often when juniors have conducted this work they have missed key information and evidence. In every jurisdiction I have worked or reviewed reports for there have been legal cases where a lack of experience has resulted in significant legal liability for both the consultant of record and the client.

Section 1 required for the identification of preferred exposure pathways. Section 2 and 3 identify potential contaminant source areas.

II        Land Use and Exposure

1.      Identify specific land use(s) on the facility and adjacent properties

2.      Identify beneficial resources

a.      groundwater classification, including both regional and local aquifers

b.     lakes, wetlands, streams, rivers, deltas and saltwater  

c.      natural resources,

d.     others

3.      Identify resource use locations

a.      water supply wells,

b.     surface water intakes

c.      others (these can also include artificial lakes, dugouts open pits or underground workings, such as mines, utility and transit tunnels, and others – use your imagination).

4.      Identify subpopulation types and locations

a.      schools,

b.     hospitals,

c.      day care centers,

d.     neighbourhood zoning types

e.     others

5.      Identify applicable exposure scenarios (utilities, residential, industrial, recreational, farming, ecological, commercial installations such as shops, restaurants, offices, etc.), Care should be taken when dealing with water supplies, in the UK they studied the vulnerability of piping and even steel has transmissivity, see https://dwi.defra.gov.uk/research/completed-research/reports/dwi0772.pdf

6.      Identify applicable exposure pathways (contaminant sources, releases, migration mechanisms, exposure media, exposure routes, receptors)

III      Physical/Geological Features

1.      Identify and summarize climatic data

a.      Climatic data

b.     Precipitation rates

c.      Evaporation rates

d.     Evapotranspiration Rates

2.      Identify topographical features

a.      hills,

b.     gradients,

c.      surface vegetation (this includes crops and identify their water needs)

d.     pavement (pavements will impede infiltration but this is dependent upon condition – cracks, etc.)

e.     infiltration rates and percentages (this can be first be cited from literature, in some cases data from infiltrometers may be required, see Nielsen, 2005)

3.      Identify surface water features described in the text and shown graphically (including the elevation of the water body’s surface (this can be used as a guide during drilling of when to expect to encounter groundwater)

a.      routes of drainage ditches,

b.     historical or buried water courses

c.      links to water bodies,

d.     Are these gaining or losing water bodies (e.g. to or from aquifers) this is often available from Provincial or State ministries or Departments of the Environment, geologic and soil survey agencies. If not measurements should be undertaken as a part of the Phase 2 investigation.

                                                              i.     expected infiltration exfiltration rates

e.     others

4.      Identify surface geology (include stratigraphic columns, maps, cross-sections and block diagrams as appropriate)

a.      soil types,

                                                              i.     Should include a stratigraphic column

                                                            ii.     Identify and describe geologic formations (this should include mineralogy and any mineralization that may cause interferences – ore bodies such as oil sand and shale, carbonates that can be oil wet and silicates that are water wet). This information will be needed for remedial design

b.     Soil parameters. (Many jurisdictions have done this as a part of Quaternary geologic surveys and those for agriculture). This is one that is often omitted.

c.       Outcrops (From Geological Survey Maps)

d.     Structural Geology available from geologic survey maps:

                                                              i.     Regional fault zones

                                                            ii.     faults

                                                           iii.     fractures

                                                          iv.     joints

                                                            v.     tectonic cave systems

                                                          vi.     evidence of karst

1.      Sinkholes

2.      caves

                                                         vii.     In volcanic terrains

1.      Lava tubes

2.      Columnar Basalts (Columbia River Plateau/Giants Causeway)

e.     Others

5.      Identify subsurface geology

a.      Stratigraphy

                                                              i.     Represented as a stratigraphic column and in fence diagram and cross-sections

                                                            ii.     Identification of geologic formations including their age, lithology, discontinuities, unconformities, strike and dip, etc.

                                                           iii.     Depositional or Emplacement Facies and Environments

b.     Areal Extent,

c.      Connectivity,

                                                              i.     others

d.     Structural geology elements (This can be done by oriented core and various down hole geophysical methods (see https://www.usgs.gov/media/videos/usgs-fractured-rock-geophysical-toolbox-method-selection-tool and https://water.usgs.gov/ogw/bgas/frgt/). Included in this discussion and effect of fracture/joint aperture size and orientation,

e.     Discussion of primary, secondary and tertiary porosity (interstitial, solution, fractures are examples) including the presence of cementation and type (Gypsum, Anhydrite, Calcite, etc.).

6.      Identify hydrogeological characteristics

a.      water-bearing zones, including both local and regional aquifers

                                                              i.     Water Well Drilling and aquifer test data in the area for wells in the area and their location relative to the study site.

                                                            ii.     expected depth to groundwater (if no drilling has been done use the nearest elevation of the nearest surface water body as an estimate)

                                                           iii.     Expected transmissivity and hydraulic conductivity (often this is on water well records and is needed to be measured and calculated in the field program)

                                                          iv.     Expected and measured groundwater flux rates

b.      hydrologic parameters (if reported, if not state so and endeavour to assess)

c.       impermeable strata,

                                                              i.     Is it fractured (many tills are fractured as are many indurated sands and sandstones, silts and siltstones, non-montmorillonite clays and shales)

                                                            ii.     What is the bulk expected transmissivity (does it leak)

d.     Expected and measured direction of groundwater flow and preferred flow pathways

e.     Recharge zones including expected and measured rates.

f.       Discharge zones including expected and measured rates

7.      Identify existing soil boring and monitoring well logs and locations

8.      others

IV      COC Release Information

1.      Identify potential source(s) of release(s)

2.      Identify potential contaminants of concern (COC) associated with each potential release

3.      Identify confirmed source locations

4.      Identify confirmed release locations

5.      Identify existing delineation of release areas

6.      Identify distribution and magnitude of COPCs and COCs

7.      Identify migration routes and mechanisms

8.      Identify fate and transport modeling results

9.      others

V        Risk Management

1.      Identify a summary of risks

2.      Identify impact of risk management activities on release and exposure characteristics

3.      Identify performance monitoring locations and media

4.      Identify contingencies in the event performance monitoring criteria is exceeded

VI      Cleanup Considerations

1.      Identify study options

2.      Identify study requirements

3.      Identify cleanup options

4.      Identify cleanup requirements