Water Treatment Residue (WTR) is the solid waste material after the treatment of raw water for domestic use. It consists of fine silt and clay particles together with added flocculants. In South Africa it is currently considered a hazardous waste and has to be disposed of accordingly. With land treatment being perceived as a preferred method of disposal of the WTR, it was investigated how Phosphorus (P) and heavy metals would behave in the presence of this material. The WTR was sourced from a treatment works near Pietermaritzburg, South Africa where the main added chemicals are a cationic organic polymer and lime. Sorption studies of P were carried out on incubated samples and corresponding non-incubated samples of eleven contrasting soils. Soil samples were incubated for 140 days at ambient temperature and at field capacity with rates of WTR up to 1280 Mg/ha. The relationship between solution and sorbed P was established by shaking 5 g samples with 50 ml of 0.005 M calcium chloride solution containing different concentrations of P on an end-over-end shaker for 6 hours. From the data, the following general observations were made:- 1) Isotherms generally followed the classic smooth curve; 2) incubated and corresponding non-incubated samples did not sorb P to the same extent in some of the samples; 3) application of the WTR increased sorption capacity in some soils but decreased it in others; and 4) adsorption was not the only mechanism of P decrease in solution. The data, especially with respect to P requirement, could be reasonably fitted to the Freundlich isotherm. Explanations are suggested for these results. The sorption study for Cd, Ni and Zn involved only one added concentration of 50 mg/g. A 1 g sample was equilibrated on an end-over-end shaker for 6 hours with 50 ml of 0.005 M calcium chloride solution containing the cation. Based on time-sorption curves, the soils were grouped into relatively high-, moderate- and low-sorbing. Reasons for the differences in extent of sorption are presented. The high-sorbing soils also tended to sorb metals faster than those with low sorption capacity. Application of the WTR to soils increased the amount of metal sorbed. A parallel extraction procedure was used for fractionation of eight heavy metals from both the WTR and WTR-treated soils from a pot experiment and from the incubation experiment. The method separated the fractions into water soluble + exchangeable, inorganically bound, organically bound, and that bound in amorphous oxides. The WTR contained very high amounts of Mn in the inorganically bound fraction; all the other metals were very low in all fractions. In the pot experiment five of the eleven soils, on which had been grown perennial ryegrass (Lolium perenne), were used. The highest rate of application of the WTR was equivalent to 120 Mg/ha. Where metal fractions increased in the treated soils (both incubated and from the pot experiment) it was generally in the inorganic and amorphous forms, implying specific adsorption and mineral layer penetration, respectively. Two 5-year field experiments were established with the highest rate of application of the WTR being 1280 Mg/ha. One trial was situated on a Typic Haplustult and the other on a Typic Plinthaquept. Biologically-available P extracted from an incorporated treatment on the Typic Haplustult was consistently lower than that extracted from a mulched treatment. There was a decrease in exchangeable Mn at the 0-200 mm depth in both field trials. Possible reasons for these observations are given in relation to the supporting laboratory experiments. Discussion of these results is directed to predict the agricultural and environmental implications of the land disposal of the WTR.