Norovirus, Rotavirus, Adenovirus, Emerging virus, Concentration method, Viral indicator, Polyomavirus, Asfarvirus-like virus, River water, Merkel cell polyomavirus, Klassevirus, QUALITY INDICATORS, QUANTITATIVE PCR, JC-VIRUS, WATER RESOURCES, ENTERIC VIRUSES, ENVIRONMENTAL SCIENCES, HUMAN ADENOVIRUSES, ENGINEERING, ENVIRONMENTAL, MOLECULAR-DETECTION, WASTE-W...