Designing for the Worst Hour, Not the Average Day: Pump Station Capacity Planning

On paper, it may appear simple: the water is pumped to different location. In practice, distances between the two locations could be affected by differences in elevation in the area, pressure requirements and solids and storage capacity, electrical equipment, restrictions on site and changes in the rate of flow.

Romtec Utilities starts the design of an pumping station by delineating these operational conditions, instead of selecting equipment from the catalog. Then, preliminary designs and budgetary requirements can be designed based on what the requirements of the project are.

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Start by asking a simple question: What are we doing?

The answer immediately changes the engineering.

Domestic sewage is often contaminated with solids and may experience significant fluctuations in daily flow. A wastewater lift station must move that wastewater reliably when gravity conveyance is unavailable or insufficient. Engineers must take into account the following: expected inflow the condition of the pump, its peak, capacity, behavior of the wet well discharge requirements and how equipment is maintained and operated.

Different challenges are presented by industrial water. Fluids that are caustic, oily or that have high temperatures or pressures might be needed by a processing or manufacturing facility. Romtec Utilities designs systems for industrial applications, ranging from food processing and power generation to databases, pharmaceutical waste, gasoline and oil-based facilities.

Rainfall can create a completely new operating process

Stormwater systems tend to be unoccupied for long stretches of time and then suddenly confront the possibility of a huge volume in the course of a storm.

For instance, a rainwater lift station that is associated with a detention basin is required to be in line with the overall drainage plan for the area. As the water flows into the basin, temporary storage controls the immediate volume, and a pumping system moves the collected water towards an authorized discharge point.

Romtec Utilities supplied this type of solution for a business park located in Norco, California. The pumping equipment was needed to empty the basin and then discharge it into the stormwater network. The station therefore had be designed as part of the drainage infrastructure instead of being viewed as an isolated piece of equipment.

“Package Does Not Denote “Off the shelf”

There is a common misconception that a system of pumping packages is simply a predetermined collection of components.

In the case of engineered infrastructure, packaging could mean coordinating all the key components into one particular project-specific system. Pumps and valves can be selected according to their duty specifications.

It is particularly useful to connect a new system to the existing infrastructure. Industrial facilities and well-established municipal facilities are not able to provide unlimited space or clean installation conditions. Equipment may need to be adapted around existing structures, piping systems or electrical systems as well as operating schedules.

The real consequences of capacity Planning

The price of undersizing goes up as the size of the facility increases.

Romtec Utilities supplied a sewer lift station located at Portland International Airport for the PDX Next extension. The station was designed to provide double the peak flow capacity of the previous system as the airport’s facilities grew.

This is a key principle of engineering: the construction conditions must not just reflect the way an installation operates in an average afternoon. Engineers need to be aware of what happens when demand rises.

The work isn’t over until the equipment arrives.

At the point where drawings and calculations must become an operational system. Installation coordination, startup and testing, documentation and understanding are all vital to ensure long-term success.

The time between construction and the success of an engineered pumping system is measured. The decisions made during initial design are clear when equipment needs maintenance as flows rise or when a storm hits.

Romtec Utilities combines these decisions into a pumping service that is tailored to a specific project. This helps transform individual equipment into a system designed for the conditions they will face.