The City of Boca Raton Florida will construct a 40 mgd nanofiltration plant in the coming year. This will be the largest plant of its kind in the world. This paper focuses on the design features of the plant and the results of extensive pilot and bench-scale tests. The pilot and bench-scale tests were conducted to find ways to reduce the severe fouling caused by the very high organic content of the raw ground water. Some interesting results from the testing are discussed including zeta potential and electrophoretic testing and side-by-side comparisons of various membranes and antiscalants.