Purves Environmental Inc. performed an Independent Study on effects of dissolved mercury on large volumes of water. The volumes selected are 1,000,000 liters and 1,000,000 gallons of water. The data comes from the analysis of discharges from dental offices into a municipal waste water treatment plant. The actual sampling points are at manholes in the street near the dental office and not from the actual separator.
The data and conclusions are presented in the links below.
Impact on Waste Water Treatment Plants (WWTPs)
An exhaustive study was performed by the City of Elyria in Ohio that demonstrated a significant quantity of mercury is being discharged into their system by dental offices. When calculating the volume differences per hour the dental offices still generate more dissolved mercury entering the waste water treatment plant than both the residential and industrial influents. When complying with EPA discharge requirements many PTOWs are having difficulty meeting their limits. Based upon the data generated above, small PTOWs may have mercury issues that are directly attributed to dental office discharges.