For water and wastewater utilities across Arizona and the Southwest, pump systems are typically the single largest energy expense in the operating budget. Treatment plants, lift stations, and distribution booster stations run continuously — and when they run inefficiently, the cost accumulates quietly, one billing cycle at a time.
The challenge is that an inefficient pump rarely announces itself. The lift station still empties the wet well. The treatment plant still meets effluent standards. Flow is being delivered. But the pump may be consuming significantly more energy than the process actually requires — and that difference shows up in the utility’s power bill, not in an alarm.
Evaluating pump energy consumption gives municipal operators a systematic way to find those hidden losses. By comparing actual energy use against real system requirements, utilities can identify where efficiency improvements will deliver meaningful savings — without compromising process performance or reliability. DXP Arizona works with municipal water and wastewater customers across the region to conduct these evaluations and identify practical next steps.
Start with Actual Operating Conditions
A pump selected and installed years ago may now be serving a very different system than the one it was designed for. Population growth, water conservation programs, and changes in source water or treatment chemistry can all shift the operating conditions a pump faces — sometimes dramatically.
In many municipal systems, flow has declined as conservation measures have taken hold, leaving distribution and treatment pumps oversized for current demand. A pump that was properly matched to design conditions a decade ago may now be operating far from its best efficiency point on a daily basis.
Measurements of actual flow and pressure help determine where the pump is currently operating on its performance curve. Comparing the actual operating point with the best efficiency point reveals whether the pump is well-matched to current demand — or working harder than it needs to while moving less fluid than it was designed to handle.
Measure Energy Use
Tracking motor power consumption establishes a baseline for how much energy the pump system actually draws under normal operating conditions. For utilities operating multiple lift stations or booster pumps, this baseline makes it possible to compare similar equipment and identify outliers that deserve closer attention.
Trend data is particularly useful in municipal operations. A gradual increase in power consumption at a lift station — without a corresponding increase in influent flow or operating hours — can indicate declining pump efficiency due to impeller wear, bearing degradation, or changes in wet well conditions. Catching this trend early allows planned maintenance rather than emergency response.
Utilities with SCADA systems already have the infrastructure to collect this data systematically. Energy monitoring through existing instrumentation turns routine operational data into an efficiency management tool.
Look Beyond the Pump
High energy consumption at a pump station does not always mean the pump itself is the problem. System conditions are frequently the cause — and addressing a pump without understanding the system often produces disappointing results.
In municipal systems, common sources of system-level inefficiency include partially closed isolation valves that create unnecessary head loss, aging piping with accumulated deposits that increase friction, and control strategies that throttle pump output rather than match pump speed to actual demand. Each of these wastes energy by generating pressure only to dissipate it before the fluid reaches its destination.
Changes in system demand can also leave pumps operating well outside their efficient range. A distribution pump sized for peak summer demand may run most of the year at flows that push it to the far left of its performance curve — consuming disproportionate energy for the flow it delivers.
Evaluating the complete system — pump, motor, controls, piping, and operating strategy — is the only way to determine where the loss is occurring and which intervention will actually address it.
Identify Opportunities for Improvement
Once the source of energy loss is understood, the improvement path usually becomes clearer.
Variable frequency drives represent one of the most consistent opportunities in municipal applications. Lift stations, treatment plant recirculation systems, and distribution boosters all experience significant flow variation across the operating day and across seasons. A pump running at fixed speed during low-flow periods consumes far more energy than necessary. VFDs allow the pump to match its speed to actual demand — reducing energy consumption during off-peak periods while maintaining reliable performance at peak load.
For pumps that have been running for years, internal wear may have quietly eroded hydraulic efficiency. Restoring worn impellers and wear rings to original clearances can recover efficiency that has gradually been lost — often at a fraction of the cost of pump replacement and without the lead time challenges that replacement equipment can create for public procurement.
In some cases, an oversized pump can be corrected through impeller trimming or replacement with a better-matched unit. These modifications are often more practical for municipal budgets than full pump replacement and can produce meaningful energy savings immediately.
Turning Energy Data into Long-Term Savings
An energy evaluation should produce more than a one-time snapshot. Establishing baseline performance data for each major pump station makes it possible to track efficiency trends over time and recognize when conditions begin to deteriorate — well before they become operational problems.
For utilities facing rate review cycles, capital project justification, or grant applications for infrastructure improvements, documented energy performance data strengthens the case for investment. Quantified savings from proposed projects are more compelling than estimates, and baseline measurement data provides the foundation for that documentation.
Regular monitoring also allows utilities to verify whether efficiency improvements are delivering their expected results — closing the loop on capital investments and creating accountability for long-term energy management.
DXP Arizona works with Arizona and Southwest municipal water and wastewater customers to evaluate pump performance and identify practical opportunities for system optimization. If your utility is experiencing rising energy costs, wants to assess the efficiency of aging pump stations, or is preparing a capital project that includes pump system upgrades, contact DXP Arizona to discuss a performance evaluation and identify strategies for improving efficiency and reducing long-term operating cost.
