Escherichia coli Drivers in Surface Water in Arid and Semiarid Regions of Arizona
Abstract
Freshwater is a fundamental resource for human and ecosystem health, yet it is constantly threatened by climate change and pollution, adding more strain on water resources especially in regions already facing water stress. Because surface water interacts most easily and most often with anthropogenic activities, it is chronically impacted by pollution. One of the most recurrent impairments of surface water quality is fecal contamination. Fecal contaminated water is a concern due to its potential to contain pathogens that can cause illness or death in human populations. In Arizona where water scarcity is an extant and worsening concern, fecal contamination is one of the most commonly reported causes of water quality contamination. Maintaining healthy water quality in places with little quantity is of high importance to water managers. While many existing studies examine the drivers of fecal contamination, these have primarily been in temperate and humid regions, with very few studies focused on arid and semiarid regions. We cleaned and synthesized observations of E. coli concentration from the Arizona Water Quality Database and completed two different statistical analyses to evaluate relationships to point and non-point sources, climatic and terrain conditions, land cover and stream networks. The statistical analysis revealed significant differences between E. coli concentration values distributions sampled from Artificial Path, Perennial, or Intermittent/Ephemeral sites, and under rain conditions from that under no rain conditions. At the watershed level, five of the one hundred and thirty-seven studied characteristics had the most significant relationship with E. coli concentration values, being Median cumulative rain up to day 9 [in], total number of CAFOs, dairies and farm/ranch by watershed area [unit/m2], Developed. High Intensity land area [m2], area of Evergreen Forest land by watershed area [m2/m2], and area of Pasture/Hay land by watershed area [m2/m2]. Outcomes of this work can help to identify sources and patterns in E. coli occurrence that will help create environmental management strategies to address human health risks.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H31F..01M