Will the tank be built to any particular code requirements? Since it is oily water and the volume is 10000 liters, you have to make sure it doesn't leak petroleum product into the ground or groundwater.
QA would be the same as any concrete structural system. Control the concrete, control the rebar placement, control the dimensions, make sure the waterproofing/leakproofing are intact, etc.
Concrete strength will depend on the design. Test the concrete for compliance. Do a leak test when the tank is built....not sure what your acceptance criteria will be, but you might check leak criteria under API code.
The leak test procedures used for concrete tanks is not as simple and precise as the one used for steel tanks. It is difficult to prove a concrete tank is water tight.
since it is difficult to test for watertightness which should be done after installation and backfill, most tanks are designed and constructed with conservative measures to promote "water tightness" such as:
high strength, dense concrete
thick walls
additional steel reinforcement
additional cover over reinforcement
water stops
good curing
good subgrade compaction
good backfill
these are the things that will need to be QC'd to provide a tank that is reasonably assured of "leak proof" service
this is a relatively small tank and should be pre-cast. Ask your pre-caster for the typical specifications and process.
concrete is a darker color when it gets wet. fill the vault full of water and look all around the outside for any discoloration. this is how the inspectors check to see if our vaults leak. i know this because i work for a precaster and this is how it is done.
IAPMO (intl. assoc. of plumbing & mechanical officials) has design requirements regarding strength, rebar clearances, etc.
go to oldcastleprecast.com and click on a location near you. We sell CPS (coalescant plate seperators which are IAPMO listed. for 10,000 L capacity you would need a 612-2 CPS vault. Our vaults are guaranteed not to leak or we repair it free of charge.
