Cover systems in redevelopment projects

Useful remediation or lazy conceptualisation?

The answer, probably both.

Clean cover systems are a legitimate and useful means of isolating end users, in both residential and commercial settings, from elevated concentrations of inorganic determinants that could present a health risk. Cover systems are a form of remediation and as such will need a clear implementation and verification plan; the source of soil used in the cover should be carefully selected and soil import, stockpiling and placement carefully managed and validated. Material management plans and CL:AIRE DoWCoP declarations need to be in place prior to soil import. Adopting cover systems as a remediation option in redevelopment scenarios is not a quick fix, if done inappropriately or without proper planning, this can be extremely costly to the developer and a complete headache to the Regulator.

We see clean cover systems recommended in almost every residential development report reviewed. Sometimes this is necessary and appropriate, but often it is a result of a single marginal exceedance of a generic screening value, lack of appropriate statistical assessment, poor site conceptualisation and a misunderstanding of what detailed risk assessment is.

Implementing cover systems where these are not required can increase the production of waste, increase highways traffic movement and is not sustainable development.

Hart Environmental recommendations:

  • Check if suitable intrusive investigation has been carried out
  • Check if the contamination is a risk or just a marginal elevation with a normal range
  • Check what ‘normal’ is for your area
  • Check if the site could be zoned to reduce the affected area
  • Check if detailed risk assessment might be appropriateAnd if you do need to go ahead with remediation:
  • Check you have a clear material management plan, implementation plan and verification plan in place before works start
  • Check it is followed throughout the entire project, so remediation is suitably validated.

If in doubt, get some further advice or perhaps commission some additional targeted investigation. Spending a little more upfront can save time and money later, so well worth the investment and always worth asking informed questions.