Water Reservoir Liner Installation

Which liner materials are used for potable and raw water storage?

Potable water contact requires materials certified to NSF/ANSI 61, the drinking water system components standard, while raw water storage allows a broader range of geomembranes selected for durability and cost. EC Applications installs smooth and textured HDPE and LLDPE, drain liners, XR reinforced geomembranes, CSPE (Hypalon), reinforced and unreinforced polypropylene, geosynthetic clay liner (GCL), EPDM, and PVC.

Material selection is driven by the structure and the service. Reinforced membranes such as XR geomembranes, CSPE, and reinforced polypropylene hold their dimensions well and suit mechanically attached installations on concrete and steel, where the liner hangs on walls rather than resting in an anchor trench. HDPE and LLDPE offer excellent chemical resistance and long service life in earthen basins. GCL and composite constructions add a self-sealing clay layer beneath the geomembrane where regulators or site conditions call for redundancy.

For rehabilitation work, the existing substrate often decides the material. A cracked concrete reservoir with active leakage calls for a liner and attachment system that can bridge movement, while a corroded steel tank floor may be better served by a drain liner system that intercepts and monitors any future weepage.

How is a liner installed in an existing concrete reservoir or steel tank?

Lining an existing structure starts with draining and cleaning the reservoir, repairing the substrate, and then deploying geomembrane panels that are seamed together in place and mechanically attached to the walls, columns, and penetrations. Unlike an earthen basin, where the liner terminates in a soil anchor trench, a concrete or steel structure requires mechanical terminations: stainless steel batten bars compressing the membrane against the wall over a gasket, anchored into the concrete or fastened to welded studs on steel.

Surface preparation is the step that determines liner life. Spalled concrete, protruding aggregate, sharp edges, and abandoned fittings are repaired or ground smooth, and a geotextile cushion is installed where the substrate could abrade the membrane. Columns, inlet and outlet piping, drains, and hatches each receive fabricated boots and sealed terminations so the finished lining is continuous across every penetration.

Every field seam is tested before the reservoir returns to service. Dual-track fusion welds are air pressure tested and extrusion welds are vacuum box or spark tested, following the destructive and non-destructive seam evaluation practices of ASTM D4437 and the material manufacturer's QC requirements. On potable installations, the finished lining is then disinfected in accordance with the utility's standard practice before the reservoir is refilled.

Can liners be combined with floating covers and baffle curtains?

Yes, and on potable reservoirs the liner and floating cover are frequently designed and installed as one system, with the cover sealed to the same perimeter attachment so the stored water is fully encapsulated. EC Applications installs both, which keeps the interface details, material compatibility, and warranty under a single installer instead of split between trades.

Baffle curtains complete the hydraulic side of the system. Suspended or floating baffles installed inside the lined reservoir lengthen the flow path between inlet and outlet, improving disinfectant contact time and eliminating dead zones. Because baffles, covers, and liners all terminate at the same walls and penetrations, sequencing them under one contractor avoids the conflicts that appear when each component is detailed in isolation.

When should a reservoir be relined instead of repaired or replaced?

Relining makes sense when the structure is sound but no longer watertight: leakage through cracks, joints, or corroded floors that patching has failed to stop, or seepage from an earthen basin that shows up as wet ground or rising water loss numbers. A geomembrane lining addresses the entire wetted surface at once rather than chasing individual leaks, and it typically costs far less than demolishing and rebuilding storage capacity.

Persistent water loss is usually quantified before lining with a simple drawdown test, isolating the reservoir and measuring level change over time against evaporation. That baseline confirms the problem, sizes the benefit, and gives the utility a before-and-after comparison once the liner is in service. Whether the driver is rehabilitation of an existing reservoir or a lining specification for new construction, ECA can support the design conversation early, when material and attachment choices are cheapest to get right.

Applications

• Potable water reservoir lining
• Concrete reservoir lining and rehabilitation
• Steel tank liners and floor drain liner systems
• Clearwell liners at treatment plants
• Earthen and raw water reservoir lining
• Single and composite lined systems
• Floating covers over lined reservoirs
• Baffle curtains for contact time and flow control
• Mechanical attachments, battens, and penetration boots