‘Sump’thing in the Ground


Excavation with Services Exposed and Sump Installed

Remediation is always challenging, but it’s made much harder when we are asked to do it at a busy filling station which needed to remain open throughout our works. Having previously determined that the contamination was confined to a relatively thin layer of gravel but was migrating offsite, we decided to install some small diameter sumps across the site in preparation for a programme of ISCO (treatment using in situ chemical oxidation).

Fitting the sumps between buried services was always going to be tricky, so we pre-excavated each location using vacuum drilling techniques. As you can see from the photographs, it was a good job that we did, with numerous pipes and ducts exposed (and duly avoided).

The excavation has now been backfilled and the pavement reinstated, leaving us with a  small manhole cover to provide access to our sump when we return to start treating the ground. The filling station remained open throughout our works.