This study investigated enrichment factor, geo-accumulation index and quantification of contamination of heavy metals in cassava mill effluents contaminated soil by smallholder cassava processors in a rural community in the Niger Delta region of Nigeria. Data used for the environmental risk assessment is from secondary sources. The assessment was carried out under two background scenarios viz: geometric (BGM) and median mean (BMM). 50% of mean detected individual metals was used as mean data for location that the metal was not detected. Assessment was carried out following well established protocol. Results showed that enrichment factor (EF), geo-accumulation index (Igeo), improved Nemerow Index (INI), Metal enrichment index (MEI) and quantification of contamination (QoC) in soil heavy metals (viz: Fe, Cr, Zn, Cu, Co, Ni, Mn, Pb and Cd) receiving cassava mill effluents in a rural community of the Niger Delta region of Nigeria revealed un-contamination to moderately contamination for Igeo, NMI, background rank to significant enrichment for EF, no enrichment to moderate enrichment for MEI, and positive values of quantification of contamination is an indication of pollution/contamination due to anthropogenic sources. The study further showed that cassava mill effluents are contributing to soil heavy metal contamination in study area.