It could make engineering simpler if all water traveled at the same rate.
It’s not.
Wastewater entering a residential system may vary through the day. Industrial and commercial buildings may be experiencing operating peaks. Stormwater levels can drastically change with the weather. Demand for clean-water also fluctuates according to the type of application.
To design a pump station, it is not a simple matter of selecting the best equipment to provide a certain flow. Engineers need to be aware of what kind of environment the system is likely to encounter.
Image credit: romtecutilities.com
Take into consideration the operating conditions and not just the Maximum Capacity
The maximum flow is important however it’s just part of the station’s operation. Imagine that a wastewater treatment system was developed to handle a huge flow at peak. Most of the time the flow coming in is less. During normal operating hours the station must function normally.
This raises questions regarding wet well size, pump operation and controls, head conditions and how equipment will react to an ever-changing demand.
A properly designed package pumping system brings these elements into the real needs of the location, instead of treating maximum pump capacity as the main design objective.
The daily cycle of wastewater
A wastewater lift station serving homes, businesses, or municipal infrastructure may experience changing influent conditions throughout its operating cycle.
The station needs an appropriate control system that permits the system to start the pumps, and also collect wastewater. The structural dimensions, pumps, valves, electric components, and controls all have roles in the process.
The design might also include considerations specific to the site. Romtec Utilities will incorporate any auxiliary systems, such as grinders vaults and odor-control devices as needed. The result is a station designed to meet the needs of the particular project, instead of being a generic design applied to all wastewater sites.
Stormwater Flows Change Much More Rapidly
Stormwater provides a totally different operating environment. During dry weather the stormwater lift station is likely to not be utilized much. But during the most severe weather conditions, the station is likely to experience a significant increase in activity. The station could be an element of a larger flood-control, detention, treatment, or drainage plan, making the plan for stormwater management surrounding it an essential element of the system design.
When designing these systems Romtec Utilities considers a variety of elements, including the flow rate required and head condition, the system size, site needs and environmental factors.
Stations that serve commercial developments could appear different than those designed for municipal stormwater systems.
Both head conditions and flow are crucial.
Moving 1,000 gallons of water is only part of the engineering problem. Engineers must be aware of the direction of the water and the amount of resistance it is likely to encounter.
Pumps can operate at different levels of head based on the design of the system, like the piping or discharge conditions.
This relation between head and flow is yet another reason why selecting the right pump solely on its rating isn’t enough. The pump technology and station configuration should match the specific hydraulic requirements of the whole application.
Plan the station in the conditions that it will experience
Romtec Utilities creates customized pumping system for stormwater, wastewater and clean water systems. They also design systems designed for industrial, booster and other uses. The process includes preliminary design plans, budgeting, set-ups along with system components, documentation, and startup and testing.
The basic engineering principle behind it is clear: the best pumps don’t have to spend their entire lives working under one comfortable set of rules.
They encounter shifting flows, changing needs, and specific project-specific hydraulic needs. This must be taken into account when designing a functional station.