What's the problem with a hydraulic lift?
Water ingress into a lift pit where a traction lift is fitted is bad enough, but water ingress into a a lift pit with a hydraulic lift is much worse, put the reservoir tank in the base of the lift pit and it gets worse still!
Subject to the depth of your lift pit or the outside ground conditions, ground water can enter your lift pit all year round and remain relatively constant (i.e. water never raises above 50mm for instance), or more likely during wet weather water can ingress into a pit, sometimes 500mm or more for a few days or even just a couple of hours, then it will either drain away and leave a damp floor with a ‘tide mark’ on the walls or revert back to its normal level of say 50mm.
Where does the water go?
This is the problem, the water doesn’t magically disappear it returns back to the ground only this time it’s contaminated with oils & grease.
The Environment agency’s General guide to the prevention of pollution (PPG1) unsurprisingly has something to say on this
Section 3 Legal Framework
Controlled waters” include all watercourses, lakes, lochs, canals, coastal waters and water contained in underground strata (or “groundwater”), and it is an offence to pollute such waters – deliberately or accidentally. In addition, the formal consent of the Agency is required for many discharges to controlled waters, including direct discharges and discharges to soakaways. Such consents are granted subject to conditions, and are not issued automatically
What do I do next?
First of all we need to stop the water ingress!, on top of that we should also consider creating a bund to contain any future oil spills. Fortunately Cook group are experts in this field. We can design a waterproofing system that also acts as an oil resistant bund.