Definitions for "First Draw"
Water that has been sitting in pipes or plumbing fixtures overnight and is first drawn when taps are opened in the morning. For instance, where lead is present in plumbing, this water would have the highest levels of lead contamination.
This term refers to water that has been sitting in pipes or plumbing fixtures overnight and is first drawn when taps are opened in the morning. Such samples will usually have the highest levels of lead contamination. In homes with severe lead problems, first-draw readings for lead may be three times as high as purged-line samples. See purged line.
The first drawing operation in a series (often called the "cup") usually performed on a flat blank.