COST-BENEFIT ANALYSIS OF INCREASED WATER TREATMENT PLANT SERVICE GOALS ON REDUCING WATER QUALITY RISK
College of Engineering and Polymer Science
Date of Last Revision
Number of Credits
Bachelor of Science
Date of Expected Graduation
To treat water to make it safe to drink, disinfection processes are used in water treatment plants. These disinfection processes produce disinfection byproducts (DBPs) through the reaction of organic matter and the disinfectant, such as chlorine. DBPs have been shown to pose a cancer risk to consumers. In this report, the focus is on two types of DBPs, trihalomethanes (THMs) and haloacetic acids (HAAs). The cancer risks associated with DBPs are analyzed through ingestion and inhalation pathways. Ingestion and inhalation consist of common water uses like drinking, cooking, or bathing. In addition to this, DBPs have been shown to increase through stagnation as they travel throughout water distribution systems, plumbing pipes, and hot water tanks. Methods for reducing the cancer risks associated with DBPs include consumers utilizing point of use (POU) filtration, whole house water filtration systems, or decreasing dissolved organic carbon (DOC) leaving the water treatment plant.
The cancer risks associated with DBPs found in the city water of Akron, Ohio are calculated in this report. It is important to mention that various assumptions were made in the calculation processes, such as average body weight and average household water usage per day. Other types of assumptions include the assumed number of service connections in Akron that had different POU and whole house filtration systems. The methodology for this research includes obtaining quarterly data at numerous water distribution site locations in the City of Akron and obtaining data and costs for POU filtration and whole house filtration. The next portion of the methodology includes calculating cancer risks from THM and HAA exposure (including stagnation effects), calculating cancer risks when treatment options are utilized (based on the removal efficiency for each filter type), and calculating cancer risks from THM and HAA exposure when the DOC levels are reduced leaving the water treatment plant. From here, cancer risks and filtration costs are analyzed to provide insight to the public and the water treatment staff and leadership on the different cancer risks with the unfiltered water, filtered water, and when DOC concentrations are decreased.
Some conclusions gathered from this research are that a reduction in DOC from the treatment plant will lower the cancer risks for all the consumers in the Akron water distribution system. Additionally, households who have a POU or whole house filtration system save money from the lowered DBP levels associated with a decreased DOC. Net consumer savings of around $230,000 were achieved by a reduction in DOC of 0.1 mg/L. Further conclusions are that whole house filtration systems provide the greatest reduction in cancer risk from DBPs, due in part to the fact that they work for both ingestion and inhalation pathways. For POU devices, the Zerowater water pitcher reduced cancer risk due to ingestion the most but was more expensive. The GE refrigerator filter performed best for POU filters when considering cost and cancer risk reduction due to ingestion. For the POU devices, cancer risk in the water due to inhalation was not impacted since these only treat ingestion pathways. For whole house filtration systems, the RKIN whole house treatment system was the most affordable option, therefore this made it the highest performing whole house system since the same removal efficiency was assumed for all the whole house filtration options. Further analysis on the impact of DOC reduction on THMs and HAAs and further analysis on the efficiency of whole house filtration systems would allow for even more beneficial insight to consumers in Akron and water treatment plant staff and leadership.
Dr. Christopher Miller
Dr. Anil Patnaik
Dr. William Schneider IV
Honors Faculty Advisor
Dr. Ping Yi
Proprietary and/or Confidential Information
Polen, Briton and Sanner, Kendra, "COST-BENEFIT ANALYSIS OF INCREASED WATER TREATMENT PLANT SERVICE GOALS ON REDUCING WATER QUALITY RISK" (2023). Williams Honors College, Honors Research Projects. 1681.
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