Certified Linings for Water & Wastewater Infrastructure

NSF/ANSI 61 (Drinking Water System Components - Health Effects) is the North American standard for materials in contact with potable water. It specifies limits on the leaching of contaminants into drinking water and is widely accepted internationally as the benchmark for potable water contact materials. For reservoir linings, NSF 61 certification means the product has been independently tested to confirm it does not leach heavy metals, organic compounds, or other substances above safe thresholds at the concentrations used. In the EU, the equivalent framework is the European Drinking Water Directive (DWD) and related national approvals. Gemite's potable water lining systems hold relevant certifications and our technical team confirms compliance requirements for each country on request.

Spin-Cast (also known as centrifugal casting or spinning) is a trenchless pipeline rehabilitation method. A rotating head is pulled through the pipe while simultaneously applying cementitious mortar or polymer coating, which is centrifugally distributed and compacted against the pipe wall. The result is a uniform lining of 5-20 mm thickness depending on the requirement. The method is suitable for circular pipes from approximately DN 200 to DN 3000 and can accommodate bends and fittings with appropriate equipment. Gemite supplies purpose-formulated mortars for Spin-Cast application - with controlled rheology, high bond strength, and sulphate resistance or NSF 61 approval depending on the application.

Biogenic sulphuric acid corrosion (BSC) occurs in the crown and upper walls of sewers where there is an air space above the wastewater. Dissolved sulphates in wastewater are reduced to hydrogen sulphide (H₂S) by anaerobic bacteria in the biofilm on submerged pipe walls. H₂S gas then oxidises in the moist air space above the waterline to form sulphuric acid (H₂SO₄), which attacks the concrete surface - dissolving the calcium silicate hydrate binder and leading to structural weakening at rates of 1-10 mm per year in severe conditions. Prevention and rehabilitation require linings with extremely low pH stability - either sulphate-resistant cementitious products or impermeable polymer linings that exclude all moisture and oxygen from reaching the concrete substrate. Gemite's sewer lining systems are formulated and tested for BSC resistance.