Water Quality Differences between the Ohio River and the Storage Reservoir of the City of Newport Drinking Water Plant

摘要

The City of Newport pumps water from the Ohio River into a storage reservoir. Until promulgation of the Stage 1 Disinfection Byproduct Rule (DBPR), the City of Newport considered their reservoir to be their source water because it is the reservoir water that they coagulate. Under the Stage 1 DBPR, the source water for Newport Plant is by definition, the Ohio River because potassium permanganate is added to the water at the intake for zebra mussel control. Newport is faced with the question, “What is the difference between their source Ohio River water and the water they coagulate from the storage reservoir and what are the implications for total organic carbon (TOC) removal under stage 1 DBPR?” In the past, Newport only regularly monitored the storage reservoir. The goal of this one-year research project initiated in March 1999, was to identify a monitoring strategy for the Newport Plant situation. The objectives included determining the differences between Ohio River and storage reservoir water qualities and developing a monitoring protocol. Throughout the study, the hardness, alkalinity, and UV254 of the Ohio River and storage reservoir waters were similar. During the summer months however, the reservoir water quality was significantly different than the river. The extracted chlorophyll a levels were three times higher in the storage reservoir than the Ohio River water. The TOC concentration was approximately 10% higher in the storage reservoir water than the Ohio River water. The pH of the storage reservoir averaged about 0.3 pH units higher than that of the Ohio River water. The algal densities and community assemblages were significantly different in the storage reservoir as compared to the Ohio River. This year-long monitoring study of the Ohio River and the City of Newport storage reservoir suggests that there are significant water quality differences between the Ohio River and the reservoir. The cyanobacteria in the Ohio River and storage reservoir peak at different times suggesting that both should be monitored until a long-term historical record is established. The higher TOC concentrations in the reservoir relative to the Ohio