Meeting New Dissolved Oxygen Requirements Through Ammonia Reduction: Evaluation and Intensification Strategies for Existing WWTPs
Presented by:
Juan Pablo Vicuna-Reyes, P.E., Yuan Fang, PhD.
Stantec, Philadelphia
ABSTRACT:
Emerging dissolved oxygen (DO) criteria for the Delaware River are driving the need for more stringent ammonia effluent limits at major wastewater treatment plants in the region. These evolving regulatory requirements call for a systematic evaluation of existing treatment processes to ensure reliable and sustained nitrification performance under increasingly restrictive permit conditions.
This presentation outlines the regulatory drivers linking ammonia loading to DO compliance and introduces a structured technical framework for achieving ammonia reduction at existing facilities. The framework begins with a comprehensive assessment of current plant operation and performance, including process capacity, aeration system constraints, operational flexibility, and seasonal nitrification limitations. As part of this evaluation, opportunities for near‑term operational and control‑based improvements (“low‑hanging fruit”) are identified.
The presentation then explores process intensification strategies designed to increase treatment capacity within existing footprints. These strategies include densified activated sludge, membrane-based technologies, and carrier-based systems. Additional focus is placed on aeration optimization and enhanced process control approaches. Planning‑level evaluations are used to demonstrate how utilities can prioritize alternatives, assess regulatory risk, and align ammonia compliance strategies with long‑term capital improvement planning and permitting requirements.
SPEAKER BIOS:
Juan Pablo Vicuna‑Reyes, P.E.is a Senior Project Manager with Stantec in Philadelphia, with over 20 years of experience in water, wastewater, stormwater, and biosolids infrastructure. His professional background includes master planning, feasibility studies, regulatory‑driven evaluations, and the design and delivery of complex treatment and conveyance projects.
Juan Pablo has served as project manager and technical lead on major municipal infrastructure programs across the United States and internationally, supporting projects that must balance stringent regulatory requirements, operational reliability, environmental performance, and long‑term community needs. His work emphasizes practical, sustainable solutions that integrate technical excellence with economic and social considerations.
He is a licensed Professional Engineer in the United States and has experience collaborating with multidisciplinary teams to advance resilient water systems that adapt to local conditions and evolving regulatory frameworks.
Dr. Fang has over 20 years of engineering consulting experience in the wastewater industry, with a strong specialty in conventional and advanced nutrient removal. Her work focuses on the evaluation, optimization, and upgrade of biological treatment systems to achieve reliable nitrogen and phosphorus removal under a wide range of operating conditions.
She has led and supervised extensive efforts involving nutrient removal troubleshooting, benchmarking and optimization of biological nutrient removal (BNR), flow and load projections, mass and energy balance development, and identification of bottleneck processes that limit nutrient performance. Her expertise includes evaluating alternative nutrient removal strategies—such as step‑feed, IFAS/MBBR, anaerobic selectors, and sidestream treatment—to help utilities meet increasingly stringent regulatory requirements.
Dr. Fang is proficient in multiple wastewater process simulation platforms, including BioWin, SUMO, and GPS-X, and frequently uses whole‑plant modeling to assess nutrient reduction potential, optimize aeration and chemical usage, and support planning and design decisions.
In addition to liquid treatment processes, her experience spans beneficial biogas utilization (CHP, RNG), combined sewer overflow (CSO) long‑term control planning, and sewer collection system modeling and simulation.
Engineers:
This seminar qualifies for 1.0 Professional Development Hour (PDH). A Certificate of Attendance will be available for AWRA-PMAS members only. The meeting price for non-members who wish to receive a Certificate of Attendance for the PDH is $10.00 ($3.00 for meeting + $7.00 for certificate).
Please note:
Thank you!