Detailed Quantitative Risk Assessments (DQRA) are sometimes required where large amounts of contamination (e.g. hydrocarbons) have been encountered on site, to determine whether the contamination presents an actual risk to an identified receptor (e.g. end users of a site or a nearby stream). Where remedial works are to take place, DQRA can also be used to derive clean-up concentrations for levels of contamination which can remain in the ground following any remedial works which have been undertaken.

DQRA's have been undertaken using various risk assessment software packages including RBCA, p20, CLEA 1.06 and RAM.

Please review some of our recently completed projects in our case studies section where DQRA's have been completed


All works must be approved by the Local Authority and Environment Agency (if controlled waters are involved) prior to any contaminated land planning conditions being discharged.

All contaminated land related works are undertaken in accordance with:

Government published Contaminated Land Regulation guidance (especially CLR11)
Planning Policy Statement 23
BS10175:2011 + A1: 2013  'Investigation of potentially contaminated sites – Code of Practice'
BS5930:2015 'Code of practice for site investigations'
CIRIA C665 'Assessing risks posed by hazardous ground gases to buildings'
NHBC Standards Plus 2017 Chapter 4.1 'Land quality – managing ground conditions'.