It would make engineering simpler if all water traveled at the same speed.

It isn’t.

The quantity of wastewater flowing into the residential system can vary throughout the day. Industrial and commercial buildings could have operating peaks. Stormwater conditions can alter dramatically in response to the weather. The need for clean water can also change depending on its application.

It is not enough to choose equipment that will achieve a specific flow rate when designing a pumping station. Engineers must be aware of the possibilities of the conditions in which the system can be utilized.

Image credit: romtecutilities.com

Consider operating conditions Think in Operating Conditions, Not just Maximum Capacity

A high flow is definitely important however, it’s only one element of station operation. If a system for wastewater is constructed to handle a large peak flow. In most cases the flow that enters it could be significantly lower. In normal operating hours the station must be able to function properly.

This introduces questions about wet-well sizing, pump operation, head conditions, controls, and how equipment reacts as demand changes.

A properly engineered package pumping system brings these considerations together around the actual requirements of the site instead of treating maximum pump capacity as the entire design objective.

The daily cycle of wastewater

During the life cycle of a wastewater lift station the conditions of the influent can change.

The station’s control plan determines how the system takes in wastewater and runs its pumps. Dimensions of the structure, pumping equipment, valves, pipes, electrical components and controls all have roles in the process.

Other considerations for the specific site may enter the design. Romtec Utilities is able to include additional equipment, such as grinder vaults and odor control equipment, based on the specific application. It’s more economical to create an entire station around a particular project than to apply a generic configuration for every wastewater disposal site.

Stormwater Flows Change Much More Rapidly

Stormwater is a totally different kind of operating environment. During dry weather an apex stormwater lift station might not be used much. However, during extreme weather events the station will see a significant increase in activity. The station can be part of a larger flood control, detention, treatment, or drainage plan, which makes the surrounding stormwater plan an essential element of the system design.

When designing these systems Romtec Utilities considers a variety of variables, including the flow rate that is required and head condition, the system size, site needs and environmental concerns.

The layout of a station used for commercial use could be quite different from that of a station designed to handle stormwater in municipal areas.

Head Conditions are Important as well as Flow

Moving 1,000 gallons of water is only part of the engineering problem. Engineers also need to know the direction of the water and what kind of resistance the pumping system has to overcome.

The changes in elevation, the piping configuration discharge conditions, and other aspects of the system contribute to the head conditions in which pumps function.

The connection between flow and head is the reason why choosing a pump based on a capacity rating doesn’t suffice. Technology and station layout must meet the hydraulic demands of the particular application.

Plan for the conditions that the station will experience

Romtec Utilities creates customized pumping system for wastewater, stormwater and clean water systems. They also design systems for industrial, booster and other applications. The procedure can involve budgeting and design in the beginning and plans for complete systems, supply, documentation, and startup, testing, and commissioning.

The principle of engineering that underlies it is clear: the best pumping systems don’t live their lives under a convenient set of conditions.

They have to contend with changing flows, changing demand and specific hydro requirements for projects. The station that is successful must be designed to meet the demands of the future.