Abstract: A sample of an aqueous stream is conducted to an optical measurement device. A hydrophobic dye is added. The sample is fractionated into fractions according to particle size or mass. The fluorescence intensity values and light scattering intensity values for the fractions are measured. The fluorescence intensity values of the fractions are added together thus obtaining a sum of the fluorescence intensity values. The light scattering intensity values of the fractions are added together, thus obtaining a sum of the light scattering intensity values. A hydrophobicity density of the particles in the sample, is calculated by dividing the sum of the fluorescence intensity values with the sum of the light scattering intensity values, and the concentration of hydrophobic contaminants in the aqueous stream is monitored and controlled based on the calculated hydrophobicity density of the particles in the sample.

Abstract: An improved wading boot construction 10 including a boot member 20 having an upper portion 22 and a sole portion 21 wherein at least one side of the upper portion 22 is provided with a tongue unit 12. The sole portion 21 is provided with a reinforced sole unit 13 having a strap engaging unit 14 which operatively connects the user's footwear 100 to the reinforced sole unit 13.