Online Methods for Evaluating the Safety of Reclaimed Water

To implement such a system, fish were employed in an investigative mode to evaluate the water quality of shallow ground water originating from the SAR and allow a better evaluation of risk due to the consumption of recycled water. After staggered seasonal treatments of seven and nine months of continual exposure,  no statistically significant differences in gross morphological endpoints, overall mortality, gender ratios histopathology or reproduction were observed in fish from SAR treatement compared to reconstituted control water.  There was no evidence of exposure to bioavailable estrogenic compounds in either treatment. However, higher mortality apparently associated with septicemia within the control animals were observed in Orange-Red and see-through (ST-II) stocks of fish suggesting longterm exposure to reconstituted water may not be a suitable control system. Differences were observed between the different stocks of fish utilized with the ST-II mutant stock significantly more sensitive to mortality particularly in control-reconstituted water. Conducting a third exposure with modification of the control conditions, SAR water was passed through a granular activated carbon (GAC) filter which significantly reduced mortality relative to the reconstituted water.  

Following a three month exposure to SAR and GAC-treated SAR water under lower temperature conditions and lower light:dark cycles, reproduction and exposure to bioavailable estrogenic compounds was evaluated with no significant differences observed between treatments. In summary, GAC-treated test water served as the best control system and allowed fish to be maintained for long-term on-line evaluation of ground water.