Abstract: A method and system for treating a fluid containing entrained cementitious particles involves drawing the fluid from a storage location, pre-filtering the fluid, dividing the pre-filtered fluid into a flow of permeate and a flow of bypass by passing said pre-filtered fluid through a tangential flow filter. The permeate flow is fluid that has passed through a polymeric membrane filter media disposed in the tangential flow filter, while the bypass flow is flow exiting said tangential flow filter without passing through said membrane filter media. The system and method also includes a pH probe for testing the pH of the filtrate, and a metering pump operated by a controller which injects a neutralizing agent into the filtrate to reduce the alkalinity of the filtrate before discharge.