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At the Cornell Water Filtration Plant PAC is dosed in parts per million (ppm) relative to the amount of water running through the system. For this reason we can dose our water at the same ratio as the plant. PAC dosage does not vary as greatly as alum so it will remain in a range of 10-30 ppm. With temperature increase during warmer months PAC will likely need to be dosed higher considering that as it gets hotter algae becomes more active. With a higher level of organics, more PAC is needed to inhibit for floc formation.
Mixing
The peristaltic pump sends PAC through a thin tube to the first baffle spacing of the flocculator (which serves as a mixing chamber), where the turbulence from the water entering the flocculator serves to disperse the PAC uniformly.