15.3 Procedure—Insert the dipper in the free-flowing stream so that a portion is collected from the full cross section
of the stream. Take portions at time intervals chosen so that a complete sample proportional to the pumped quantity is
collected. The gross amount of sample collected should be approximately 0.1 percent, but not more than 150 L (40 gal) of
the total quantity being sampled. Transfer the portions into the sample container as soon as they are collected. Keep the container closed, except when pouring a dipper portion into it. As soon as all portions of the sample have been collected, close and label the sample container and deliver it to the laboratory.