An Approach to Select an Appropriate Sidestream Deammonification Technology


  • Sarah Galst - Hazen and Sawyer

The Philadelphia Water Department (PWD) is evaluating the implementation of a deammonification process for sidestream treatment. The department is proactively investigating options for sustainable nutrient management and preparing for future regulations. The project team has developed a novel approach to technology selection, incorporating not only the Net Present Lifecycle Cost, but also a quantitative strategy to evaluate and compare operational complexity, flexibility, adaptability, and sensitivity. These criteria are important to consider when selecting a new technology, as they reflect the real day-to-day impact of a system operation and management on a utility. They are also the most challenging criteria to quantify.

Numerous criteria of concern were developed by Hazen and PWD, including: operational complexity, amount of time and level of effort required to recover from various process upsets, maintenance requirements, technical support and spare part availability, and range of acceptable long and short term loading conditions to maintain treatment. These criteria, among others, were included with the treatment preformance requirements and a request for a scope of supply, in an official Request for Information (RFI) sent to various deammonification vendors.

Systems were evaluated based on the information provided by the vendors in their RFI responses. Conceptual designs and cost estimates were also completed, consistant with a Level 4 AACE Cost Estimate. A selection matrix developed with a scoring technique was applied to evaluate and rank the vendors for each of the cost and non-cost criteria. Each criterion was weighted based on the preferences of PWD, tailoring the analysis to ensure that the most compatible technology is selected.

By taking into account both cost and non-cost criteria, PWD will ensure that the process chosen will meet treatment and operational requirements and will fully integrate with the culture of the utility.

For more information, please contact the author at

Hear about new publications with our email newsletter

We will never share your details with anyone else.


Newsletter Newsletter

Horizons Fall 2017 (pdf)

Horizons showcases significant water, wastewater, reuse, and stormwater projects and innovations that help our clients to achieve their goals, and can help you achieve yours. Articles are written by top engineers and process group leaders, demonstrating and explaining the beneficial application of a variety of technologies and tools.

View previous issues »