Adaptation actions taken to mitigate climate damages may impose negative externalities on vulnerable populations. We study this in the context of groundwater in California and evaluate the effects of annual fluctuations in weather and surface water supplies on agricultural well construction and access to drinking water. Using the population of geocoded wells, we show that farmers respond to extreme heat and surface water scarcity through agricultural well construction. This mitigating behavior by agricultural users imposes costs, as extreme heat and surface water scarcity reduce local groundwater levels and lead to domestic well failures. Our findings demonstrate that an unintended cost of agricultural groundwater extraction is access to drinking water supplies in disadvantaged communities.

Nitrate contamination of drinking water is a widespread environmental concern and threatens human health. The magnitude of the environmental health consequences depend on an individuals’ ability to avoid exposure. However, there are a number of factors which may undermine one’s ability to avoid pollution exposure. This paper studies the heterogeneity in avoidance behavior following Safe Drinking Water Act nitrate violations. I find that consumers spend approximately $4.7 million annually on bottled water and soda to avoid nitrate contaminated drinking water. However, consumers in resource-constrained areas exhibit substantially less protective behavior. This lack of averting behavior corresponds with 143 additional infant deaths per year from nitrate contamination relative to areas with less-costly access to safe drinking water. These results underscore both there are substantial costs from nitrate pollution and that these costs are disproportionately distributed to those with less ability to protect themselves.