<simpleType name="FractionEnumType">
  <annotation>
    <documentation>Simple type: FractionEnumType</documentation>
  </annotation>
  <restriction base="string">
    <enumeration value="Bed Sediment">
      <annotation>
        <documentation>Sample fraction consisting of bed sediment material.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Dissolved">
      <annotation>
        <documentation>Sample fraction containing dissolved constituents in solution.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Free Available">
      <annotation>
        <documentation>Sample fraction representing freely available material.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Non-filterable">
      <annotation>
        <documentation>Sample fraction that cannot pass through a filter, typically suspended or particulate matter.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Non-settleable">
      <annotation>
        <documentation>Sample fraction that does not settle out of suspension under normal conditions.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Recoverable">
      <annotation>
        <documentation>Sample fraction that can be recovered or extracted from the sample.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Suspended">
      <annotation>
        <documentation>Sample fraction consisting of suspended solids or particulates in the sample.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Total">
      <annotation>
        <documentation>Complete sample fraction including all constituents without separation.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Total Residual">
      <annotation>
        <documentation>Total residual fraction remaining after processing or treatment.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="Vapor">
      <annotation>
        <documentation>Sample fraction in vapor or gaseous phase.</documentation>
      </annotation>
    </enumeration>
  </restriction>
</simpleType>