This dataset contains pH, turbidity, conductivity and viral concentration information in river and estuarine water, wastewater, sediment and mussel samples collected in the Conwy River and estuary. The aim of data collection was to monitor wastewater contamination in the freshwater-marine continuum. Samples were collected by trained members of staff from Bangor University at four weekly between March 2016 and August 2017. Treated and untreated wastewater samples were collected at four wastewater treatment plants along the Conwy River. Surface water samples were collected at four sites, sediments at three sites and mussels at two sites. The VIRAQUA project was funded by the Natural Environment Research Council (NERC) under the Environmental Microbiology and Human Health (EMHH) Programme (NE/M010996/1)