WIT Press

Public perception trends of drinking water quality over a 32-year period in the Pacific Northwest, USA


Free (open access)


Volume 4 (2021), Issue 2



Page Range

186 - 196

Paper DOI



WIT Press


Robert L. Mahler


The public in the Pacific Northwest considers the quality of their drinking water the most important aspect of water resources. Consequently, the purpose of this paper is to examine public perceptions of drinking water quality over a 32-year period between 1988 and 2019 in the states of Alaska, Idaho, Oregon and Washington. Mail-based surveys were used to collect data in 1988, 1993, 1998, 2002, 2005, 2007, 2010, 2012, 2015, 2017 and 2019. In each survey year, the minimum sample size was 400 adult residents. Residents were asked about their perceptions of: (1) drinking water safety and satisfaction, (2) use of in-home water filters, (3) use of bottled water, (4) water testing, and (5) water pollutants. Over 10,400 residents completed surveys over this 32-year period. Over 80% of the residents obtained their tap water from a city or community water system that was nationally regulated. Over this 32-year period, more than 78% of residents considered their drinking water safe; however, trends show that the perceived safety of drinking water has declined from 92.8% in 1998 to less than 79% in 2019. The use of secondary in-home water filters has increased from 18.2% in 1998 to 35.4% in 2019. The use of bottled water peaked at 34.9% in 2007 but has declined since and dropped to less than 17% of the public by 2019. In the last 32 years only about 15% of residents have had their drinking water tested at least once every 5 years. As far as contaminants in drinking water quality is concerned the major complaint over the last 32 years was hard water. Survey respondents over the age of 50 were more likely than residents younger than 35 to consider their drinking water safe and pollution-free, while younger residents were more likely to use bottled water and a secondary in-home water filter. Respondents that were male, older than 70, college educated, from Idaho or Alaska and from communities of more than 7,000 residents were most likely to consider drinking water safe. From a trend standpoint, more residents have thought that their drinking water has become less safe and fewer people are using bottled water compared to 32 years go. Conversely, the use of secondary in-home filters has substantially increased in the last 32 years.


bottled water, drinking water quality, in-home water filters, public opinion, urban water quality.