Keywords

Plumbing, chlorine decay, stagnation, TOC, water quality

Presentation Type

Poster

Research Abstract

Drinking water safety is critical to the health of populations worldwide, and modern plumbing infrastructure can influence drinking water chemical characteristics. Inside residential and commercial buildings however, water use and contact with different plumbing components can vary. For example, water can endure lengthy stagnation periods and residual disinfectant agents like chlorine can decay, leaving the water vulnerable to microbial growth. Plastic cross-linked polyethylene (PEX) pipes have become popular and have shown to influence water quality. While several studies have been carried out on chemical leaching from PEX piping, none were found that examined the role of pipe diameter in relation to chlorine disinfectant decay. The study goal was to better understand chlorine decay in PEX piping associated with stagnation and pipe diameter. Different diameters (3/4”, ½”) of the same brand of PEX pipe were first obtained and cleaned. PEX pipe were filled with a laboratory prepared synthetic water with about 2 mg/L as Cl2 at pH 7.3 and stagnated up to 3 days at 50°C temperature. Chlorine disinfectant level, pH, and total organic carbon concentration were characterized periodically. Results will be compared against water samples that were not exposed to PEX pipe for the same time period.

Session Track

Environment and Sustainability

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Aug 2nd, 12:00 AM

Indoor Premise Plumbing: The Relationship Between Water Stagnation, Chlorine Decay, and Total Organic Carbon Levels

Drinking water safety is critical to the health of populations worldwide, and modern plumbing infrastructure can influence drinking water chemical characteristics. Inside residential and commercial buildings however, water use and contact with different plumbing components can vary. For example, water can endure lengthy stagnation periods and residual disinfectant agents like chlorine can decay, leaving the water vulnerable to microbial growth. Plastic cross-linked polyethylene (PEX) pipes have become popular and have shown to influence water quality. While several studies have been carried out on chemical leaching from PEX piping, none were found that examined the role of pipe diameter in relation to chlorine disinfectant decay. The study goal was to better understand chlorine decay in PEX piping associated with stagnation and pipe diameter. Different diameters (3/4”, ½”) of the same brand of PEX pipe were first obtained and cleaned. PEX pipe were filled with a laboratory prepared synthetic water with about 2 mg/L as Cl2 at pH 7.3 and stagnated up to 3 days at 50°C temperature. Chlorine disinfectant level, pH, and total organic carbon concentration were characterized periodically. Results will be compared against water samples that were not exposed to PEX pipe for the same time period.