A sewer credit application is only as strong as its documentation. Missing or incomplete paperwork is the number-one reason applications get delayed or denied — and every month of delay is another month of full sewer charges on water that never reached the sewer. Here’s exactly what you need to prepare.
The Standard Documentation Package
While specific requirements vary by utility, most sewer credit applications require the following documents. Gathering these before you start the application can shave weeks off your approval timeline.
Submeter readings are the foundation of every application. You need logged data from both your makeup water meter (measuring water flowing into the cooling tower) and your blowdown meter (measuring water discharged from the tower to the sewer). Most utilities require 60 to 90 days of continuous readings, though some accept as few as 30 days. Digital meters that log automatically produce the cleanest, most convincing data sets.
Cooling tower specifications help the utility verify that your evaporation claims are physically plausible. Include the manufacturer, model number, rated tonnage, design flow rate, and number of cells. If you have the original engineering submittal or cut sheet, include it — utilities appreciate documentation they can cross-reference.
Building mechanical drawings showing the piping layout from the main water meter through the cooling tower system are often required. The utility wants to see where your submeters are installed relative to the main meter and confirm that no water uses are being double-counted. A simple single-line piping diagram is usually sufficient — you don’t need full architectural drawings.
Recent water and sewer bills covering the past 12 months establish your baseline consumption and show the utility what your current charges look like. This helps them calculate the financial impact of your credit and verify that your submeter readings are proportional to your overall water use.
Meter calibration certificates prove that your submeters are measuring accurately. Most utilities require meters to meet American Water Works Association (AWWA) accuracy standards, typically within plus or minus 2 percent at normal flow rates. New meters come with manufacturer calibration certificates; existing meters may need field calibration by a certified technician.
The utility’s application form is the final piece. Every utility has its own form — some are a single page, others are multi-page packages. Download the form early in the process so you know exactly what format the utility expects for your supporting documentation.
What the Utility Is Really Looking For
Understanding the utility’s perspective helps you prepare a stronger application. They’re asking three fundamental questions: Is the claimed non-sewer water volume physically reasonable given the equipment installed? Is the metering data reliable and from properly calibrated instruments? And is there a clear, auditable trail from the main meter through the submeters that accounts for all water?
The Department of Energy’s cooling tower management guidelines provide the technical framework that many utilities reference when evaluating applications. Aligning your documentation with these standards strengthens your application.
Common Documentation Mistakes
Avoid these pitfalls that frequently delay applications. Submitting only a few days of meter readings when the utility requires 60 or more days is the most common mistake. Providing estimated data instead of actual meter readings will almost always result in a denial. Forgetting to include calibration certificates — even if your meters are brand new — can stall an otherwise complete application. And submitting bills from a different account number than the one you’re applying for (common in multi-building portfolios) creates unnecessary confusion.
For a broader view of how submetering fits into the sewer credit process, our submetering guide covers everything from meter selection to installation. And if you’re still determining whether your building qualifies in the first place, start with our eligibility guide.
Ready to Find Out What You Could Save?
RPM Water Equity Solutions helps commercial facilities recover money lost to sewer billing assumptions. If your building has cooling towers, you may be paying sewer charges on water that never reaches the sewer system.
Request your free assessment today and find out how much you could recover.
Let RPM Handle the Paperwork
Gathering documentation is the least exciting part of saving money on sewer charges — but it’s also the most important. RPM handles the entire documentation package as part of our service: meter specification, installation coordination, data collection, and application preparation. We know exactly what each utility requires and in what format, so nothing falls through the cracks.
