TABLE OF CONTENTS 



Page 



ABSTRACT iii 



BACKGROUND ^ 



SECTION I. SUMMARY AND CONCLUSIONS 1 



Summary 1 



Average Nitrogen (nitrate-nitrogen) 



Concentrations 1 



Variations of Nitrogen Concentrations 1 



Levels and Sources 3 



Phosphorus (phosphate-phosphorus) 5 



Total Dissolved Solids 6 



Discharges "7 



Conclusions ^ 



SECTION II. INTRODUCTION 9 



Area of Investigation 9 



Isolated Tile Systems 10 



Objectives ^° 



SECTION III. TILE DRAINAGE IN THE 



SAN JOAQUIN VALLEY J-3 



Historic Background 13 



Tile Drain Design 13 



Materials, Construction, and Installation 1^ 



Conduit }^ 



Filter Materials f^ 



Installation ^^ 



17 



Sumps and Outlets ^' 



Vll 



