The problems associated with leaking tanks , whether they are above or below ground level are both serious and wide ranging. Deteriorating fuel and chemical tanks can threaten public health and safety if they leak or spill hazardous substances into the environment.

Most of these problems can be traced to a common source: Steel tanks can weaken and leak as a result of repeated expansion and contraction of the welded joints or by corrosion as a result of galvanic action, chemical or other oxidative reactions. Concrete structures can become weakened through erosion of the supporting soil either as a result of groundwater presence or by time-related failure of the sealing compounds of the expansion joints.

Concrete structures can also be corroded by the long term storage of liquids with low pH values, pure demineralised water attack or water with very low levels of calcium hardness.

Until relatively recently , techniques to monitor and control leakage from tanks have been poor and leakage rates have not been properly verified. However, because of the seriousness of the problem, legislation has necessitated the use of retrofitted or new secondary containment systems to individual tanks or to entire tank farms.

Flexible geomembrane liner systems have played a major role in meeting the objectives of these regulations.

Secondary Linings to tanks and containment areas involve essentially the same design principles as are applied to primary linings, but are applied to generally more critical application areas. Essentially these secondary lining systems are not in direct contact with the stored liquid until leakage occurs through the primary installed liner.

The design of the secondary liner system should be undertaken in such a way so as to ensure that it is never subjected to the full operational liquid head in the tank unless there is a catastrophic failure of the main structure or primary lining.

Typically, Linings which fall into this category can be divided, but certainly not limited to the following groups: Petroleum / Oil and gas Tank farms and Bunded areas / underground steel or concrete tank liners / Spill containment liners.

Enviro Seal can advise and recommend on the most cost-effective, safe and appropriate lining solutions to meet clients specific requirements. Contact Enviro Seal now for a fully professional service relating to advice on product selection, capability profiling and quotations for the supply and /or installation of lining solutions for specific projects.