US Midwest utility used TDG to tackle phosphorous limit impact on capital investment

The Transcend Design Generator (TDG) offers solutions for asset owners and utilities in capital planning. It streamlines the creation of engineering documentation for infrastructure assets, enhancing control over the process and reducing total ownership costs.

Key features include assessing multiple design options for sustainability and resilience, automating design generation for existing and new assets, and optimizing project development costs.

Here, we introduce a specific use case for TDG for utilities looking to address more stringent regulations and prioritize the investments needed to meet them.

A utility faced the challenge of prioritizing investments across its three wastewater treatment plants due to limited budgets and a new regulatory requirement to achieve a lower phosphorous limit of 1 mg/l. Their plants required upgrades, and the utility used TDG to compare and prioritize these needs effectively.

The people responsible for figuring out the solution were a:

Project Engineer (seconded from engineering firm): Seconded from the utility’s primary engineering partner, responsible for technical evaluations and design.

Head of Capital Planning: Oversees the strategic planning and allocation of capital investments.

Regulatory compliance Manager: Ensures adherence to environmental regulations and interfaces with regulatory agencies.

The Project Engineer gathered initial needs for each plant (1 MGD, 4 MGD, and 10 MGD) from operations teams and internal documentation, including Facility Master Plans.

The Head of Capital Planning provided estimates for OPEX and CAPEX costs to compare alternatives.

The Regulatory Compliance Manager communicated with the state regulatory agency to understand the specifics of the new phosphorous limit, which will be implemented with the renewal of each plant’s NPDES permit in 2 years.

The Project Engineer used TDG to generate conceptual designs for each facility to determine what changes will need to be made to each facility to meet the new phosphorous limit and necessary increases to plant capacity.

• The engineer inputted parameters such as flow, influent characteristics, effluent parameters, and existing capacity into TDG.

• The future increased flow was considered for the 1 and 4 MGD plants, which are nearing their 80% flow capacity limit.

• The engineer generated 3-4 design alternatives for each plant, obtaining comprehensive civil, mechanical, and civil documents within 2 days, followed by a 2-week evaluation period.

The adoption of TDG streamlined the alternatives evaluation process from the usual 6 months to just 1 month, allowing the Head of Capital Planning to include these projects in the upcoming capital improvement plan.

The Project Engineer presented these key findings from TDG to the Head of Capital Planning:

• The 10 MGD plant could upgrade to Biological Phosphorous Removal (Bio-P) within its existing capacity to meet the requirement.

• For the 4 MGD plant, Membrane Aerated Biofilm Reactor (MABR) technology was identified as a process intensification solution that wouldn’t require facility expansion.

• The 1 MGD plant required construction of a new biological train and conversion to Bio-P to manage both higher flow and phosphorous limits.

• Chemical phosphorous removal (ChemP) was deemed unfeasible due to high costs and supply chain volatility.

• The utility is now incorporating these projects into their 2025-2030 Capital Improvement Plan, informed and expedited by the use of TDG’s generative design capabilities.

• By accelerating the alternatives analysis process with TDG, the capital planning team now has additional time for thorough cost and supply chain analyses of the selected scenarios to reduce risk and optimize project outcomes.