Is it safe to drink?: Enteric Microorganism Monitoring in a State-of-the-Art Water Reclamation Facility and Lake Lanier, GA

Study Objective: Water scarcity has increased use of reclaimed water. The microbial quality of water from water reclamation facilities is often a concern for communities considering reuse options. This study monitored five enteric viral pathogens and two indicator organisms at a state-of-the-art water reclamation facility in Georgia, and at the intake for a drinking water treatment facility in Lake Lanier. This study examined the reduction and persistence of enteric viruses at selected treatment stages.

Methods: 20 and 100-liter samples were collected every two weeks from six locations in the water reclamation facility and Lake Lanier for one year. Samples were first concentrated by ultrafiltration, then by polyethylene glycol (PEG). Sample concentrates were tested for E. coli and male-specific coliphage by standard culture methods and for adenovirus, enterovirus, hepatitis A virus, norovirus, rotavirus A by real-time PCR.

Results: The ultrafiltration and PEG methods were able to simultaneously concentrate multiple target microorganisms. Microbial levels were reduced in the final effluent compared to the primary influent and secondary effluent samples. Adenovirus and noroviruses were the most frequently detected viruses (70% and 64%). Enterovirus and rotavirus were detected in 5% of the samples. Hepatitis A virus was identified in one sample of primary influent.

Conclusion: Although the target microorganisms were effectively reduced by the multiple treatment processes, enteric viruses were still frequently detected in the final effluent. These findings provide critical guidance for improving the efficacy of advanced treatment for water reclamation and its use to supplement a surface water supply.