Uptake and Release of Benzene from Stagnant Drinking Water Pipes
Citation:
Haupert, L. AND M. Magnuson. Uptake and Release of Benzene from Stagnant Drinking Water Pipes. American Water Works Association Water Quality Technology Conference, Cincinnati, OH, November 13 - 17, 2022.
Impact/Purpose:
Organic contaminants such as benzene can enter drinking water systems through several mechanisms such as oil spills, industrial accidents, and natural disasters. Recently, benzene contamination has been discovered in drinking water systems affected by wildfires in California. Examples of such incidents include Santa Rosa (2017-2018), Paradise (2018-2019), and Riverside Grove (2020). Benzene in a drinking water distribution system can permeate certain plastic water system components, including polyethylene service connections. Once permeated, plastic system components can act as reservoirs for benzene which complicate decontamination and sampling strategies. For example, an affected pipe with the potential to seriously contaminate water during an overnight stagnation may register a non-detect if sampled immediately after flushing. This example is especially relevant to service lines and premise plumbing, which commonly experience long periods of stagnation due to consumer use patterns. Numerical models for predicting the kinetics and equilibria of organic contaminants in stagnant pipes are available in the literature, but success in using these models depends upon the availability of equilibrium and kinetic parameters. The current availability of such parameters is limited to data reported in one paper for one specimen of polyethylene pipe. This presentation expands the available data to include pipes from different manufacturers, pipes of different sizes and densities, and pipes taken from wildfire-impacted areas. Specifically, uptake and release of benzene from these pipe materials commonly used in service lines and premise plumbing are studied experimentally, and the data are then used to estimate the parameters needed in the predictive models. Results from this study will aid water utilities and decision-makers in estimating the duration and cost of decontamination programs based on flushing and assist them in designing and interpreting sampling strategies.
Description:
Organic contaminants such as benzene can enter drinking water systems through several mechanisms such as oil spills, industrial accidents, and natural disasters. Recently, benzene contamination has been discovered in drinking water systems affected by wildfires in California. Examples of such incidents include Santa Rosa (2017-2018), Paradise (2018-2019), and Riverside Grove (2020). Benzene in a drinking water distribution system can permeate certain plastic water system components, including polyethylene service connections. Once permeated, plastic system components can act as reservoirs for benzene which complicate decontamination and sampling strategies. For example, an affected pipe with the potential to seriously contaminate water during an overnight stagnation may register a non-detect if sampled immediately after flushing. This example is especially relevant to service lines and premise plumbing, which commonly experience long periods of stagnation due to consumer use patterns. Numerical models for predicting the kinetics and equilibria of organic contaminants in stagnant pipes are available in the literature, but success in using these models depends upon the availability of equilibrium and kinetic parameters. The current availability of such parameters is limited to data reported in one paper for one specimen of polyethylene pipe. This presentation expands the available data to include pipes from different manufacturers, pipes of different sizes and densities, and pipes taken from wildfire-impacted areas. Specifically, uptake and release of benzene from these pipe materials commonly used in service lines and premise plumbing are studied experimentally, and the data are then used to estimate the parameters needed in the predictive models. Results from this study will aid water utilities and decision-makers in estimating the duration and cost of decontamination programs based on flushing and assist them in designing and interpreting sampling strategies