Most of the US population is served by large-scale, centralized drinking water, wastewater, and storm water systems built in the late 19th and early 20th century. Multi-trillion dollar investments are needed over the next 20 years to restore failing infrastructure, expand service areas to accommodate growing populations, and meet rising service provision costs driven by environmental and regulatory factors. A formal plan that recognizes the socioeconomic complexity of water services provision in the US is needed to guide these investments. Rising residential water charges over the last 20 years have raised concerns about household affordability of basic water services. Meanwhile, anywhere from 9 to 45 million people (4-28% of the US population) are affected by health-based drinking water quality violations each year. New technologies and evolving social goals have the potential to reshape the sector as we know it. This dissertation is a first attempt at synthesizing the sub questions around which spending is most critical and how rates can be structured for more equitable outcomes.
Research on the determinants of historic charge growth has been hindered by a lack of long-term longitudinal data. Unlike energy and telecom utilities, less than 20% of all drinking water utilities (primarily the investor-owned utilities) are economically regulated by public utility commissions. Absent local requirements, municipal water systems whose operating revenues are insufficient to cover operating expenses can make up for budget shortfalls with net transfers from the city general fund. We combine 10 American Water Works Association (AWWA) rate surveys to construct an 18-year unbalanced panel of charges at 446 large utilities (i.e., population served ≥10,000), revealing elevated 2-year compound annual charge growth (CAGR) between 2008 and 2012.
We estimate heterogenous impacts of the Great Recession on CAGR with an event study design of 204 utilities, comparing those with 2007 operating ratios below 1.2 (PCR) to those with ratios of ≥ 1.2 (FCR). Despite having the same cumulative 18-year CAGR, 2009-2013 CAGR was 3.9, 5.2, 5.2, and 5.7 percentage points per year higher at PCR utilities for 500, 1,000, 1,500, and 3,000 cf/month, respectively. Our findings demonstrate that large utilities who were likely relying on the general fund at the start of the Great Recession had to sharply increase their charges in the short-term to make up for decreased availability of that funding source. This indicates more immediate affordability challenges at utilities with operating ratios below 1.2 in the event of a similar economic shock. Additional data is needed to evaluate generalizability of these results to smaller systems.
Willingness to pay (WTP) for improved drinking water quality is estimated based on the cost of household averting behaviors taken during violations. While buying bottled water is a well-documented reaction to these violations, demographic and socioeconomic differences in water intake, preferred water supply alternatives, and shopping behavior suggest heterogeneity in the timing and form (e.g. soda vs bottled water) of household responses. We quantify this heterogeneity with an event study design using monthly household purchases of soda, water, and juice from the Nielsen Homescan Consumer Panel Dataset from 2004 through 2017. We find that, while households spend an average 14.8% more on bottled water during a month with a nitrate violation, these responses are concentrated in non-hispanic (NHP) Black and NHP Other households below the poverty threshold. Bottled water spending is 91.8% higher than usual in violation months for the former group and 90.0% higher than normal in the month after a violation for the latter. A simultaneous 103% increase in juice spending results in a 30.6% increase in combined beverage spending for NHP Black households below the poverty line in a violation month.
Meanwhile, an 85.3% increase in soda spending at NHP Other households drives a 58.9% increase in combined beverage spending in months with a violation and a 134% increase in soda spending, along with increased bottled water purchases, results in a 106% increase in combined beverage spending the month after a violation. NHP Black households with an IPR between 1 and 2 spend 129% more on soda during a violation. Our results indicate that studies focused only on bottled water purchases have systematically undercounted the effects on Hispanic, NHP Black, and Other NHP American households below the poverty threshold in their measure of WTP for improved drinking water quality or for the true cost of violations. Additional analysis is needed to determine if the tap water substitutions made by Hispanic households and households below the poverty threshold are increasing their overall sugary beverage consumption, which can have negative long-term health effects that are also not being considered.
Finally, we explore the ongoing implementation of onsite and distributed water reuse systems (ODWRS) to better understand how sociotechnical transitions can be supported when they are deemed to be a socially optimal solution. ODWRS collect previously discarded water flows as alternative water sources (e.g. rainwater, stormwater, greywater, wastewater) from one or more buildings and treat that water close to the point of generation or point of use to a quality deemed safe for its intended end use. Widespread adoption of ODWRS requires both acceptance of new technologies (e.g., water treatment, engineering) and alterations to established social systems(e.g., norms, stakeholder engagement, regulations). This has often been discussed as a single transition for all types of systems at the same time. However, the types of ODWRS being implemented in different areas are not the same. We compile and analyze the first national dataset of system-level information on ODWRS to identify clusters of system types associated with specific drivers. We find evidence of multiple transitions based on the combination of original source contamination level and end use application contact level. Low-contamination, low-contact are almost in the final stage of sociotechnical transition for many locations. Many areas with water supply constraints have already begun the transition for high-contamination to low- or medium-contact systems. Wastewater ODWRS are being implemented in places with effluent disposal constraints and stormwater ODWRS are being implemented in areas with combined sewers or high flood risk, though usually only for low-contact end uses.
| Identifer | oai:union.ndltd.org:columbia.edu/oai:academiccommons.columbia.edu:10.7916/q6gf-7m61 |
| Date | January 2024 |
| Creators | Hayek, Carolyn |
| Source Sets | Columbia University |
| Language | English |
| Detected Language | English |
| Type | Theses |
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