All small WPL Diamond packaged wastewater (sewage) treatment products are supplied with a lifetime process guarantee from the date of delivery, ensuring you peace of mind. Warranty on the WPL Diamond tank is 25 years with two years on the air blowers. This is subject to consistent influent conditions and regular plant maintenance as per the manufacturer’s instructions. These guarantees are all subject to our terms and conditions. For more information please see our Service, Maintenance and Parts page.