KeyCSM Network Diagrams helps Geotechnics Ltd to give a clearer proposal

Geotechnics Limited recently found that the use of the KeyCSM network diagrams was the perfect way to present possible pollutant linkages to Northampton Borough Council and ensure that the client fully understood the reasons for the Phase 2 investigation work.  Chris Swainston, Principal Geoenvironmental Engineer at Geotechnics Limited explains;

A geo-environmental Desk Study was undertaken by Geotechnics Ltd at a disused railway embankment site on the western side of Beckets Park in Northampton to assess the potential risks associated with developing the site for housing.  The desk study and site walk over identified the following potential sources of contamination:

• Hydrocarbons from ash, clinker, coal, lubricants, oils, sleeper preservatives and imported embankment materials
• Hazardous Gases from coal, ash and imported embankment materials
• Metals from waste, rolling stock, ash, clinker, sleeper preservatives and imported embankment materials
• Asbestos from brake linings and fittings on rolling stock
• Aggressive chemicals (acids, cyanides, sulphates) from coal and ash
• Hydrocarbons (including gas generation) from current use of filling station on adjacent site
• Pathogens from previous historical use of adjacent site as Livestock Market

We decided that network diagrams would be the clearest way to present how the identified potential sources of contamination would affect users, buildings and controlled waters.  

We ended up completing three network diagrams using KeyCSM simply because it only takes a click or two to produce them once you have the data in the program.  

The model creation and diagram creation process took around 20 minutes using KeyCSM and Envirocheck Analysis.

The initial network diagram from the Conceptual Model showed all the potential linkages.  However this model assumed that housing would be constructed with the embankment materials retained.  

Removal of the embankment as a source would, by definition, remove it from the model and leave fewer remaining linkages as clearly shown in the second network diagram.

Once we had taken away the embankment we were only left with two possible sources and relatively fewer contaminants to show, making the model much clearer for the client to see.

Records indicated that the redevelopment of the Cattle Market had included extensive tests to show that no significant Pathogens existed in the soil which left the Filling Station as the main source to investigate.  Liquid hydrocarbons were discounted on consideration of the underlying geology and the recent age of the development.

This left gas as the only potentially significant risk to be investigated along with an analysis of the soil underlying the embankment to determine if any significant leaching had occurred.

In the past we would probably have used AutoCAD for the production of the site conceptual model.  Using KeyCSM and Envirocheck Analysis in this way saved several hours of work and gave us a simple and understandable model to build further phases from.  The KeyCSM network diagrams definitely helped advance the case for the investigation and subsequent risk assessment.