A field investigation of land application of tomato process water was conducted in the Central Valley of California. The purpose of the field investigation was to determine the percolate water quality following land treatment of food processing wastewater with varying BOD loading rates. Percolate water quality was sampled with suction lysimeters at the depth of 0.6 m (2 ft) following furrow irrigation. Vadose water was sampled twice from each field during the processing season. Moisture content and redox potential were monitored continuously during the season. Results of this observation study showed that tomato-processing wastewater applied at the described loading rates demonstrated significant removal of nitrogen and organics. For BOD loading range investigated, 150 to 1047 lb BOD/ac, increasing the loading rate did not significantly increase the TOC in the percolate water.