All systems need labels or signage that instruct and direct users. The most important label shows whether the system is potable or not. In addition to labels, consider nudges and point-positive design in your system. Nudges help users to do the right thing by gently reminding them. For example, if a user is intended to clean the borehole regularly, consider placing the first-flush nearby and facing a commonly used path so that the user sees the hole and is reminded.
Point positive design focuses on what a user should do, instead of what they shouldn’t do. For example, if a system is for use only on ornamental plants, in addition to the “Not Potable” sign, consider placing permanent irrigation in a way that reaches only the ornamentals and not the edibles or a drinking location.
Communication through signs is a subtle art. Consider using common symbols and as few signs/words as possible to avoid over-saturation. In addition, prototype your signage. Prototyping is a way to test early whether your signage works. Prototype signs can be accomplished with cardboard and markers, before upgrading to more indelible materials. When prototyping, watch how people use the system without your guidance to see what errors might arise. The confusing signage at the Bayside Park Farm, a community-supported agriculture and educational park in Bayside, California, resulted in rainwater being significantly underused. The sign (Figure 2-34) stated that the water from the first-flush should not be used on plants. After some turnover of employees, that sign was interpreted to mean that none of the rainwater (not just the first-flush water) should be used on crops. Therefore, the water was only being used for tool cleaning, which in turn meant that there was much more water storage than necessary.
Since safety is paramount, all non-potable rainwater systems, especially those accessible to the public, should be well labeled to prevent drinking. Tanks or spigots of untreated water should be labeled according to local law or custom to prevent accidental consumption (Figure 2-35).