Tofu factories located in Sigunggung Subdistrict, Pekanbaru, produce 0.9 to 1 m3 of liquid waste every day, and are immediately disposed of without going through the processing process so that they pollute the environment. The analysis shows that the liquid waste is not in accordance with Permen LH No. 5 2014. In this study the electrocoagulation method was used to reduce COD, BOD, TSS and neut…