Full service conceptual engineering and TIC cost estimating for replacement of an existing end of life reactor vessel with two new reactors to be used in the production of inorganic coagulants for water treatment. The FEL3 effort included laser scanning the existing site, review and revision of the existing process and P&IDs for the exothermic reaction, process hazard analysis (PHA) applying the Hazard and Operability (HAZOP) methodology, 3D modeling of the new project scope, material takeoffs, personnel protection for heat and acid, constructability review of the congested area, and TIC estimating. The project includes demolition of existing reactor and oxidizer vessels, foundations, and all associated equipment and piping. The new installation includes foundations, pipe rack, reactors, demister stacks, agitators, pumps, piping, electrical, lighting, load cells for tank telemetry, Coriolis metering, and other instrumentation.