This dataset comprises operational data for a novel decentralised drinking water treatment platform (DWTP) and water quality data for three sampling points within the treatment system. The dataset captures a period of 12 weeks between November 2019 and February 2020. The DWTP was continuously operational throughout this time period with samples from across the system being collected at nine timepoints throughout this three-month period. Operational data from the remote telemetry unit on the DWTP reports flow rate through the system, transmembrane pressure for the ultrafiltration and both the oxidation-reduction potential (ORP) and the free chlorine of the treated water. Data is also provided for a suite of biological, physicochemical, chemical, metals, hydrocarbons and disinfection byproducts. This data was produced from water samples which were sent to an accredited UK laboratory. The data reports for all samples for each of the 3 sampling locations within the treatment system are summarised into .csv files. Information about the location of each sampling point and the level of treatment received at each point can be found in the supporting documentation. Full details about this dataset can be found at https://doi.org/10.5285/98148025-e8ef-40f9-907e-dae8b28106d2