<Page.Resources>
        <ObjectDataProvider MethodName="GetValuez"
                        ObjectType="{x:Type my1:dSource}"
                        x:Key="reservoirs" >
            <ObjectDataProvider.MethodParameters>
                <sys:Int32>1</sys:Int32>        
            </ObjectDataProvider.MethodParameters>
        </ObjectDataProvider>
    </Page.Resources>
...
<DataGrid Name="fuelGrid" ItemsSource="{Binding}">
            <DataGrid.Columns>
                <DataGridTextColumn x:Name="fuelC" Binding="{Binding Path=id, Converter={StaticResource fuel2name1}}" Header="Топливо" IsReadOnly="True" Width="*"/>
                <DataGridTextColumn x:Name="volumeC" Binding="{Binding Path=volume}" Header="Объем" Width="SizeToHeader" IsReadOnly="True" />

                <DataGridComboBoxColumn x:Name="resC" Header="Резервуар"  
                                        ItemsSource="{Binding Source={StaticResource reservoirs}, Mode=OneWay}" ?????!!!!
                                        DisplayMemberPath="num">                    
                </DataGridComboBoxColumn>
</DataGrid.Columns>
        </DataGrid>

public class dSource
    {
        public IEnumerable<reservoir> GetValuez(int id)
        {
            FuelTermDataContext fc = new FuelTermDataContext();
            return                     from r in fc.reservoir
                                       where r.fuel == id
                                       select r;
        }
    }