Water Quality Implications of Contaminated Plumbing Systems: Softeners, Wildfires, Hydrocarbons
Creators: name: Jankowski, Caroline Maria
Publisher: name: Purdue University Graduate School
Year: 2022
Subjects: Other environmental sciences not elsewhere classified
Health and ecological risk assessment

description: Globally, millions of people rely upon plumbing to help store and deliver safe water to building inhabitants. This water is used for drinking, cooking, washing, appliances, and other activities to protect public health and support economic activity. Water softeners are common devices used to remove minerals from water to limit scale formation in plumbing thereby protecting appliances and improving drinking water taste. Despite tens of millions of these devices in U.S. homes, little is known about how these devices impact chemical drinking water quality. Further, many homes that have softeners have been impacted by disasters such as chemical spills and wildfires and encountered hydrocarbon contaminated drinking water. At present, no information is available about hydrocarbon fate in softeners and how to decontaminate these devices. The objectives of the first chapter were to (1) determine how bench-scale and full-scale water softeners impact drinking water organic carbon, chlorine disinfectant, total cell count, and sulfur concentrations, and (2) assess the softener’s ability to be decontaminated by water flushing after hydrocarbon contamination. The objectives of the second chapter were to (1) better understand the effect wildfires have on private drinking water well infrastructure, water quality, and (2) identify practical research needs. Chapter 1 experiments revealed that both new and aged softener resins leached organic carbon compounds into drinking water, and this prompted notable reductions of drinking water free chlorine disinfectant levels. Newly installed water softeners caused first flushed water to have high levels of organic carbon (934 mg/L) with about 40% particulate organic carbon. Total sulfur concentration was also elevated. After 1 week of use, water softeners caused drinking water to have 4-8 mg/L organic carbon levels. When exposed to hydrocarbon contaminated drinking water, resins absorbed and leached benzene, toluene, ethylbenzene, and total xylenes (BTEX) for more than 2 weeks. Chapter 2 results revealed that for the private drinking water wells sampled after the 2021 Marshall Fire, semi-volatile organic compound (SVOC); No SVOCs exceeded health-based drinking water limits. No volatile organic compounds were found in either shallow or deep wells or within homeowner plumbing. Heavy metals (Li and V) were found in several wells, but these contaminants were not associated with the fire. A private well water system serving 8 properties was damaged, lost pressure, and had not been flushed or repaired 7 months after the fire due to financial and technical challenges. Thesis results provide new knowledge for utilities, health officials, and building owners who desire to better understand commercially available softeners and wildfire damage considerations for private drinking water wells. Results described here can be used to inform communications with homeowners, public health recommendations regarding plumbing safety and water use decisions following suspected or confirmed building chemical contamination and wildfires.