GRAF UK supplies a range of sewage treatment plants for domestic, self-build, and larger residential and commercial projects. Our One2Clean is a compact, ultra-low energy system using just 0.63 kWh per day, designed for homeowners and self-builders seeking a quiet, reliable, and sustainable off-mains drainage solution. The One2Clean Xtra builds on this with a smarter control panel and safer desludging capability, ideal for those who want added convenience and peace of mind. For larger or more complex projects, the OneAdvanced offers a modular design scaling up to 1,000 PE, with customisable configuration to meet strict discharge requirements. All three systems deliver high treatment quality meeting UK environmental standards and can be configured to support nutrient neutrality in designated catchment areas. Free commissioning is included with every system. All units carry a 15-year tank warranty, a 50-year design life, and 1-year parts warranty following commissioning, extendable to 3 years with annual servicing. Free UK mainland delivery is included as standard.