- Abstract The potential impact of oil and grease (O and G) to soils irrigated with greywater (GW) was investigated. Greywater streams were sampled and analyzed for O and G content, along with corresponding GW-irrigated soils. Untreated kitchen GW averaged 200 mg L − 1 O and G, over an order of magnitude more than other GW streams. GW-irrigated soils showed O and G accumulation of up to 200 mg kg − l within the first 20-cm of depth. To determine the potential effects of such O and G accumulation on water movement in soil, capillary rise and water drop penetration time (WDPT) experiments were conducted. The results showed up to 60% decrease in capillary rise when sand containing 250 mg kg − 1 O and G was used. Interestingly, no additional reduction in capillary rise was observed at concentrations above 250 mg kg − 1 . WDPT was observed to increase linearly with increased O and G content, up to 1000 mg kg − 1 . This work demonstrated that O and G in GW used for irrigation can accumulate in soil and may lead to a significant reduction in the soils ability to transmit water.