Hilo Bay Mixing Zone Study and Dilution Modeling
Working for the County of Hawaii, Brown and Caldwell conducted the Hilo Bay outfall mixing zone field study on May…
WEF/WERF Cooperative Study of BNR Plants Approaching the Limit of Technology: II. Statistical Evaluation of Process Reliability
The Water Environment Federation (WEF) and the Water Environment Research Foundation (WERF) cooperated in a comprehensive study of nutrient removal…
WEF/WERF Cooperative Study of BNR Plants Approaching the Limit of Technology:
The Water Environment Federation (WEF) and the Water Environment Research Foundation (WERF) cooperated in a comprehensive study of nutrient removal…
What is the Limit of Technology (LOT)? A Rational and Quantitative Approach
What is the Limit of Technology (LOT)? This question has been raised and answered by regulators, designers, operators, researchers and…
Thirty-six Years after the Clean Water Act * Time for a New Regulatory Framework
The Secondary Treatment Regulation that establishes technology-based limits for BOD5, cBOD5, and total suspended solids is no longer relevant to…
The Impact of Internal Recycles on the Nitrifier Maximum Growth Rate
The nitrifier growth rate constant, µA,max, is a critical parameter for design and performance of nitrifying activated sludge systems. Although…
The Application of PAX Compounds for Microthrix Parvicella Foam Control in BNR Systems
Case histories are presented for two BNR plants that have experienced long term Microthrix parvicella induced foaming and poor settling….
Accurately Modeling the Effect of Dissolved Oxygen on Nitrification
When tasked with meeting very low nutrient limits, it is often the variable nature of the effluent ammonia that causes…
Regulatory Update Needed
The 36-year-old Secondary Treatment regulation (40 CFR 133.102) has little relevance to wastewater treatment facilities that must meet stringent nitrogen…
The Right Tool for the Job
Wastewater treatment is an increasingly costly business, so project teams should use the most proven, advanced tools. This includes the…
IWA Celebrates Innovations in Engineering
The second IWA Project Innovation Awards ceremony was held at the IWA World Water Congress in Vienna, acknowledging excellence and…
Rigorous Project Management Practices Result in Successful Implementation of $180 Million Plant Expansion with Aggressive Schedule for EPA Consent Decree
The Orange County Sanitation District (Sanitation District) is undertaking a capital improvement program to provide secondary treatment for a portion…