Yuchuan Lai

Example Application: Effects of Warming Climate on Drinking Water Temperature and Quality in Distribution Systems

• Water temperature in drinking water distribution systems (DWDS) is estimated using ambient air temperature
• Historical and projected DWDS water temperature is estimated using air temperature observations and projections
• Changes of DWDS water temperature are used to estimate the effect of warming temperature on drinking water quality parameters

Applying the climate projections to engineering applications through the procedures as described in Using Climate Model Projections, the impacts of climate change on the engineering design, management, and operation of infrastructure can be assessed. An example of assessing drinking water temperature and water quality parameters in DWDS was carried out in this work.

An empirical model was utilized to apply local ambient air temperature records to estimate daily drinking water temperature in DWDS. This empirical model was developed by National Renewable Energy Laboratory and is based on the heat exchange between air and soil and between soil and buried drinking water mains (e.g., the DWDS water temperature generally reaches the same temperature as the soil temperature at the buried depths of the mains). The results of estimated monthly average DWDS water temperature can be found in the interactive plot below. The DWDS water temperature varies among different locations because of the annual average air temperature and required buried depths of water mains at different regions (required to be below the frost lines).

Interactive plots for historical and future projected DWDS water temperature

The interactive graphs below present the empirical results on the estimated DWDS water temperature. Calibration of model parameters was performed using measured DWDS water temperature at several locations but was not conducted for individual cities presented. The results presented are intended for providing general information only.
It may take up to a minute for the graphs to be loaded. View the webpage with the desktop version is recommended.

In addition to the use of recent air temperature records, historical air temperature records and future projections of air temperature were used to estimate the changes of DWDS water temperature. The historical and future projected estimates of DWDS water temperature can be found in the interactive plot also.

On the basis of the DWDS water temperature, the effect of water temperature increases on water quality parameters (such as chlorine decay and disinfection by-products) can be estimated. The further discussions on the effect of increasing temperature on drinking water quality parameters and additional details of this study can be found in Lai, Y. and D.A. Dzombak. 2021. Assessing the Effect of Changing Ambient Air Temperature on Water Temperature and Quality in Drinking Water Distribution Systems. Water. 13(14), 1916, https://doi.org/10.3390/w13141916 .

Acknowledgement The research was supported by a Carnegie Mellon College of Engineering Dean’s Fellowship to Yuchuan Lai, and by the Hamerschlag Chair of Professor Dzombak.