*3.2. Descriptive Statistics*

Bottled water had the highest frequency of use among residents and drinking from a sink filter the lowest (Table 1). A substantial portion of residents chose to drink from a mixture of two or more sources rather than from one source alone, as indicated by the low to moderate means and medians for each water source.


**Table 1.** Descriptive statistics for water source choice item. Statistics for each water source include number of observations (*n*), mean, median, standard deviation (SD), minimum scale value (minimum) and maximum scale value (maximum).

Most respondents (61%) reported that they *mostly* or *completely* trusted their utility to deliver safe drinking water to them (Table 2). The majority of residents believed the safety of their water was a low risk both cognitively and affectively and believed they would experience moderate to severe consequences if their access was compromised. The majority of residents considered bottled water equally as safe as tap water (45%). Drinking water was a low salience topic for the majority of respondents, with most (63%) reporting that they *never* noticed changes in their tap water and had *little* to *no* information about their neighborhood water quality (61%). Finally, the majority of residents (53%) had generally favorable impressions of their tap water quality, ranking their tap's smell, odor, taste, and general characteristics as *very* or *extremely* acceptable.

**Table 2.** Descriptive statistics for predictor variables. Statistics for each survey item include number of observations (*n*), mean, median, standard deviation (SD), minimum scale value (minimum) and maximum scale value (maximum).


### *3.3. In-Home Drinking Water Behavioral Choice Patterns*

We selected a six-cluster solution for water source choice behavior groups, which was the solution with the best fit (Figure 2; Table S1).

We labeled the clusters based on the mean frequency patterns of bottled, sink filter, tap, and appliance filter water use (Figure 3). Almost two-thirds of the respondents (64%) drank primarily from a single water source. The largest cluster reflected people who drink bottled water exclusively (24% of the respondents; Figure 3A). The next largest cluster (22% of the sample) drank exclusively from an appliance filter (Figure 3B), followed by a cluster exclusively drinking tap water (18% of the participants; Figure 3C). Combined patterns included a cluster that equally drinks bottled and tap water (16%; Figure 3D), followed by mixes of all sources except for a sink filter (12% of the participants; Figure 3E) and a cluster that mixes sources but predominantly uses a sink filter (8%; Figure 3F).

**Figure 2.** Dendrogram for the hierarchical cluster analysis.

**Figure 3.** Means of the frequency of water source use for each cluster. Dark blue bars represent water source usage at or above *50% of the time*. Medium blue bars represent water usage between *<50% of the time* and *50% of the time*. Light blue bars represent water usage near *<50% of the time.* Grey bars represent water usage at or close to *almost never.*
