Assessing wastewater operating costs means connecting energy, chemicals and work records to treatment volume and quality. Real-time data reveals changes, while verified records and a comparable baseline support investment decisions.
Define cost scope and evidence
Separate electricity, chemicals, maintenance, labour and waste handling. Identify dedicated measurements and shared costs. Document allocation rules when a meter or expense covers more than one process.
Establish a comparable baseline
Align billing, consumption and treatment periods. Record influent characteristics, operating modes, maintenance and equipment changes. Choose a period representing the conditions the proposed improvement should address.
Use intensity and totals together
Energy intensity can be calculated as kWh divided by treated m³ over the same scope and period. Mark missing records or zero volume as unavailable. An illustrative 12,000 kWh over 10,000 m³ equals 1.2 kWh/m³; this is not a facility benchmark or project result.
Check the cause of any improvement
Separate consumption changes from price and production changes. Include implementation, support and maintenance costs. Check treatment outcomes and abnormal events. Avoid adding overlapping benefits from changes affecting the same equipment.
Records to check
| Record group | Evidence to review |
|---|---|
| Energy | Meter scope, kWh and operating mode |
| Chemicals | Consumption, product and price |
| Results | Volume, quality and comparable period |
Prepare an assessment with X-IRIS
Bring cost records, treatment volume, quality data and the equipment groups being considered for improvement. Review the implementation roadmap and request an assessment to agree a scope that can be tested.
Technical reference: EPA's energy guidance recommends identifying baseline use and where energy is consumed before prioritizing improvements.
