The selection of the Water System determines how the lab will process the sample. Potable water is suitable for human consumption, and non-potable water is not fit for human consumption. Select Potable if your sample is hot or cold water from sinks, showers, ice machines, or hot water return lines. Select Non-Potable if your sample is from a cooling tower or decorative fountain. Select Hot Water Tank only if the sample is from a bulk hot water generation device.