2018 Progress Report: An Integrated Modeling and Decision Framework to Evaluate Adaptation Strategies for Sustainable Drinking Water utility management under drought and climate change

EPA Grant Number: R835865
Title: An Integrated Modeling and Decision Framework to Evaluate Adaptation Strategies for Sustainable Drinking Water utility management under drought and climate change
Investigators: Ozekin, Kenan , Kasprzyk, Joseph Robert , Livneh, Benjamin , Rajagopalan, Balaji , Rosario-Ortiz, Fernando , Summers, R. Scott
Institution: Water Research Foundation , University of Colorado at Boulder
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2015 through August 31, 2018 (Extended to August 31, 2019)
Project Period Covered by this Report: September 1, 2017 through August 31,2018
Project Amount: $1,250,000
RFA: National Priorities: Systems-Based Strategies to Improve The Nation’s Ability to Plan And Respond to Water Scarcity and Drought Due to Climate Change (2014) RFA Text |  Recipients Lists
Research Category: Water

Objective:

Drought due to climate change and other extreme events such as wildfire and floods challenge drinking water utilities' ability to treat water to meet regulatory and public health protection goals, with turbidity and disinfection byproducts (DBPs) control as the critical water quality (WQ) issues. The objectives of the research are to:

(1) understand the flow and sediment generation from water supply watersheds in response to scenarios of hydro-climatological extremes and natural hazards,

(2) understand the mobilization and transport of organic matter and sediments, and in some cases nutrients, through the watershed and eventually to the water treatment plant (WTP),

(3) develop source water thresholds for turbidity and DBP precursors based on finished water regulatory constraints and using stream WQ data with extreme value theory predict WQ threshold exceedances, and

(4) evaluate a suite of adaptation and operation strategies (e.g., watershed management, wild fire mitigation, WTP modifications) along with their economic, societal and policy implications - with multi-objective optimization and multi-criteria analysis tools.

Progress Summary:

Major accomplishments in year 3 (this report period) include:

  1. Activity 1 performs hydrologic modeling to understand flow and sediment generation from drinking water supply watersheds in response to scenarios of hydro-climatological extremes and natural hazards. Since the last report, the research team has continued towards modeling the impact of wildfire disturbance on hydrology. The Variable Infiltration Capacity (VIC) model was modified to include a diverse set of sediment algorithms that calculate sediment transport, in addition to runoff. In addition to these modeling efforts, a rainfall simulator was constructed for the purpose of quantifying changes to runoff and erosion rates caused by soil heating (to approximate wildfire) during a simulated post-disturbance storm event. The laboratory-scale apparatus follows USDA-ARS design and applies a constant stream of simulated rainfall at intensities designed to mimic natural storms. The intent is to develop relationships between laboratory-controlled variables such as rainfall intensity, slope, and heating maximum temperature in order to evaluate differences in erosion rates among disturbed and undisturbed samples in order to ascertain key differences that may inform model parameterization.
  1. Activity 2 has focused on the examination of carbon mobilization from watersheds after wildfires. The work under this activity was divided into four tasks - Task 1 - Laboratory burn testing, Task 2 - Evaluate the impact of post-drought, post-wildfire sediment mobilization, Task 3 - Evaluate the flux and steady state DOM and nutrient concentrations from sediments, and Task 4 - Assess DOM reactivity towards DBPs. Throughout this year, progress has been initiated in Task 2 and Task 4 while Task 1 and Task 3 have been completed. Different sites have been examined, including more comprehensive analytical analysis of the molecular process to better understand potential DBP precursors.
  1. Goals of Activity 3 include developing statistical models that link climate properties with the prediction of influent water quality to drinking water treatment plants and the construction of total organic carbon (TOC) and turbidity thresholds in influent waters. In the last annual report we have discussed results of modelling turbidity and TOC using several regression methods, tree models, and random forests on data from a participating utility. An analysis of raw, settled, and filter effluent turbidity for another participating utility treatment plant was discussed to allude to the importance of developing a threshold raw turbidity to ensure filter effluent regulations were upheld. For the second, settling effectively removed any signal from the raw turbidity to the filter effluent, leading to the conclusion that a turbidity threshold would likely not be unnecessary for this plant. However, more plants needed to be examined to determine if a turbidity threshold is necessary for other locations experiencing differing raw water turbidity characteristics and plant designs. Data collected from several treatment plants representing various source water types and characteristics is currently being analyzed to find relationships among water quality constituents.

Future Activities:

The next reporting period, the project team will continue to work on all four activities and begin preparing for the final project report. Continuing activities include ensemble modeling involving calibration and validation of postfire simulations of streamflow and sediment (Activity 1), data analysis and additional lab testing (Activity 2), development of threshold and water quality forecasting methodology (Activity 3), and further development, testing, and dissemination of the decision support tool (Activity 4).


Journal Articles on this Report : 3 Displayed | Download in RIS Format

Other project views: All 40 publications 5 publications in selected types All 5 journal articles
Type Citation Project Document Sources
Journal Article Raseman WJ, Kasprzyk JR, Rosario-Ortiz FL, Stewart JR, Livneh B. Emerging investigators series: a critical review of decision support systems for water treatment: making the case for incorporating climate change and climate extremes. Environmental Science: Water Research and Technology 2017;3(1):18-36. R835865 (2016)
R835865 (2017)
R835865 (2018)
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  • Journal Article Samson CC, Rajagopalan B, Summers RS. Modeling source water TOC using hydroclimate variables and local polynomial regression. Environmental Science & Technology 2016;50(8):4413-4421. R835865 (2016)
    R835865 (2017)
    R835865 (2018)
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  • Journal Article Stewart, J.R., Livneh, B., Kasprzyk, J.R., Rajagopalan, B., Minear, J.T. and Raseman, W.J., 2017. A multi-algorithm approach to land surface modeling of suspended sediment in the Colorado Front Range. Journal of Advances in Modeling Earth Systems 2017; 9(7):2526-2544. R835865 (2017)
    R835865 (2018)
    R835603 (2017)
    R835603 (Final)
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  • Supplemental Keywords:

    sediments, turbidity, organic matter, DBPs, hydroclimate extremes, watershed modeling, drought, water quantity, multi-objective and multi-criteria analysis

    Progress and Final Reports:

    Original Abstract
  • 2016 Progress Report
  • 2017 Progress Report