... 198 2.3. ASTM Annual Book of Standards, Part 31, D3 694 -78. Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,”American Society for Testing and Materials, ... mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4and 330.5 may be used for measurement of residual chlorine. Field test kits are 9 available for this purpose. 9. 3 ... Section 8.4.8. ASTM Annual Book of Standards, Part 31, D3370-76. Standard Practices for Sampling Water, ” American Society for Testing and Materials, Philadelphia. 9. Methods 330.4 (Titrimetric,...