Water and Sediment is determined in accordance with ASTM D2709. The method requires the use of a centrifuge to separate free water and sediment from the fuel. Free water may be detected visually as a “hazy” appearance if gross contamination is present. Gross water contamination can lead to storage tank corrosion and provides an environment conducive to microbial growth. Water and sediment contamination may also be responsible for filter plugging and poor aerosol nebulization in fuel oil systems. Gross water contamination is more frequently observed during fuel storage rather than fuel production.
ASTM D6751 Requirement: a maximum for water and sediment of 0.050% by volume.