Impacts of Storage on Water Quality of Reclaimed Water 

Dr. Gerard Miller, Elizabeth Quinlan, Pam Kenel, and Alan Rimer
Black & Veatch
Email: MillerGR


Abstract
This paper presents the results of research supported by the Water Environment Research Foundation (WERF) on the Impact of Surface Storage on Reclaimed Water for Non-potable Use: Seasonal and Long Term. The research objectives were to develop (1) a better understanding of the effects of storage on reclaimed water quality, (2) a methodology to help understand/predict water quality changes during storage, and (3) effective management tools for minimizing water quality problems. To meet these objectives, the Research Team focused on six general areas: Literature Review, Water Quality Criteria, Water Quality Parameters, Management Strategies, Models, and Recommended Water Quality Management Tools. 

The literature review included more than 100 published articles. A gray literature survey was developed and conducted to analyze the impact of surface storage on reclaimed water quality. The Research Team also evaluated federal guidelines for reclaimed water and developed a brief update on what individual states are doing. It was determined that state and federal water quality objectives can be met at the treatment site. However, because of the seasonal nature of reclaimed water use, the water often must be stored in open reservoirs, where changes occur that can affect water quality. The nature of these changes was evaluated, including physical, chemical, and biological processes. 

Several reservoir management strategies to improve water quality were evaluated, including destratification, oxygenation, wetlands, copper sulfate/cuprine treatment, advanced waste treatment for phosphorus and nitrogen, dredging and alum treatment. The study also evaluated twelve water quality models to assess their applicability for reclaimed water storage reservoirs. The models ranged from simple steady state empirical models to highly complex 3-dimensional models. 

Matrices and flow charts were developed to distill the information learned in the study into a useful format for risk assessors and water quality managers. These tools will enable users to readily equate their specific storage reservoirs to representative examples and to identify actions most applicable to their specific reclaimed water systems.
 

 
International Water Demand Management Conference 2004 Updates