Introduction. Page I

Author Index. Page II

Efficiency of Subsurface Sewage Disposal Systems in Removal of Contaminants From Domestic Sewage. M. Brandes. Page 1

Laboratory Techniques for Evaluating Batch Flotation of Activated Sludge. R. Gehr and J.G. Henry. Page 19

Toxicity of Oil Sands Plant Wastewaters and Associated Organic Contaminants. S.E. Hrudey, G.A. Sergy and T. Thackeray. Page 34

Flocculation of Neutralized Mine Drainage With Polymers. P.M. Huck and K.L. Murphy. Page 46

Dual-Media Filtration for Treatment of Refinery Waste Water. J.C. Kempling, T.E. Michniewicz and J. Eng. Page 57

Treatment of Dyebath Effluents by Polymeric Resin Adsorbents and Ion-Exchange Resins. A. Netzer and S. Beszedits. Page 62

Decolourization of Kraft Mill Effluents by Magnesium Coagulation. R.J. Rush, W.K. Oldham and W.E. Stepko. Page 75

Neutralization and Fertilization of Acidified Lakes Near Sudbury, Ontario. W. Scheider and P.J. Dillon. Page 93

Potential Effect of Methane Oxidation and Nitrification-Denitrification on the Oxygen Budget of Hamilton Harbour. W.J. Snodgrass. Page 101

Modelling Simulation and Control of an Existing Activated Sludge Wastewater Treatment Process. N. Thérien and P. Harrington. Page 108

Application of Hyodrologic and Water Quality Models For Preliminary Screening of Urban Development Alternatives. P.E. Wisner, K.F. Jalal, A.F. Roake and L. Torrens. Page 122

The Effects of pH on Lake Water Chemistry and Phytoplankton in a LaCloche Mountain Lake. N.D. Yan and P.M. Stokes. Page 127