How Do I Apply for Sewer Credits in My City?

Quick Answer

To apply for sewer credits, call your utility’s commercial accounts department and confirm it offers a credit or evaporation adjustment program. Then install submeters on water uses that never reach the sewer — for cooling towers, that means meters on the makeup and blowdown lines. Collect 60 to 90 days of baseline meter data, and submit an application package with your readings, equipment specifications, a piping diagram, and your last 12 months of water and sewer bills. Approval takes anywhere from 30 days to 6 months depending on the city, and the credit appears on your next billing cycle. Most programs require annual or biannual renewal with updated metering data.

You’ve learned that your commercial building qualifies for sewer credits — now what? The application process varies from city to city, but the core steps remain consistent. Here’s a practical walkthrough that applies to most municipalities across the country.

Step 1: Confirm Your Utility Offers a Program

Most large and mid-size municipalities offer some form of sewer credit, sewer adjustment, or evaporation credit program. The fastest way to find out is to call your utility’s commercial accounts department and ask specifically about “sewer credits for non-consumptive water use” or “cooling tower evaporation credits.” Some utilities publish their programs online; others require you to ask directly.

Don’t assume your city doesn’t have a program just because it’s not prominently advertised. Many utilities offer credits but don’t actively promote them — the programs exist because regulations require them, not because the utility wants to reduce its revenue.

Step 2: Install Submeters on Non-Sewer Water Uses

Every sewer credit application requires metering data that proves how much water bypasses the sewer system. For cooling tower installations, this typically means two meters: one on the makeup water line (measuring total water entering the tower) and one on the blowdown line (measuring water discharged to the sewer). The difference between makeup and blowdown is your evaporation — the water that qualifies for credits.

The EPA’s WaterSense program for commercial buildings emphasizes submetering as a foundational step for any water management strategy, not just credit applications.

Step 3: Collect 60 to 90 Days of Baseline Data

Utilities want to see consistent data, not just a snapshot. Plan to collect at least two to three months of meter readings before submitting your application. This baseline period demonstrates your building’s typical water use pattern across varying weather conditions and occupancy levels. Digital meters with automatic logging make this effortless — the data collects itself.

Step 4: Submit the Application Package

A typical application includes your completed application form (available from the utility), submeter readings covering the baseline period, cooling tower or equipment specifications, a simple diagram showing your water piping and meter locations, and your most recent 12 months of water and sewer bills. Some cities also require meter calibration certificates or a letter from a licensed engineer. Check your specific utility’s requirements carefully — a missing document can delay approval by months.

Step 5: Receive Adjusted Billing

Approval timelines range from 30 days in streamlined cities to six months in slower bureaucracies. Once approved, your sewer charges will be reduced starting with the next billing cycle. Most programs require annual or biannual renewal with updated metering data — this is where continuous monitoring through submetering pays off, because you always have current data ready.

What If My City’s Process Is Different?

Some cities have unique requirements. Dallas, for example, has a specific evaporation credit application that differs from the standard Texas process. Other cities require third-party verification of your metering data. Our guide to sewer credit requirements by city breaks down the variations across major metropolitan areas.

The Department of Energy’s cooling tower management guidelines provide additional context on the water measurement standards that most utilities reference when evaluating credit applications.

How the Credit Actually Shows Up on Your Bill

Most utilities bill sewer service on a simple assumption: every gallon that passes through your domestic water meter eventually goes down the drain. A sewer credit corrects that assumption. Once your application is approved, the utility subtracts your documented evaporation — the difference between makeup and blowdown — from the billable sewer volume each cycle.

The dollar impact depends on your local sewer rate, which in most metropolitan areas runs between $3 and $12 per 1,000 gallons and is often higher than the water rate itself. A cooling tower that evaporates 1 million gallons per year at a $6 sewer rate represents roughly $6,000 in annual charges for water that never touched the sewer. Some utilities apply the credit as a line-item adjustment; others rebill the account with a corrected sewer volume. Ask which method your utility uses so you can verify the math on your first adjusted bill.

Common Mistakes That Delay or Sink Applications

The most frequent failure point is meter selection. Utilities generally expect meters that meet AWWA accuracy standards — typically within 1.5 percent across the flow range — and some require a calibration certificate at installation and again at each renewal. An undersized or oversized meter that runs outside its accurate flow range can invalidate months of data.

Gaps in the data log are the second killer. If your baseline period has missing weeks because a logger battery died or someone forgot manual readings, most utilities will make you start the clock over. Automatic logging eliminates this risk. Finally, watch the seasonality of your baseline: a 60-day sample collected in mild spring weather understates summer evaporation, so many utilities either require a full cooling season of data or apply seasonal adjustment factors. Ask before you submit rather than after a rejection.

Questions to Ask Your Utility Before You Apply

Five minutes of questions can save months of rework. Ask the commercial accounts department: Does the program require specific meter types, sizes, or brands? Is a professional engineer’s stamp or third-party verification required? How long must the baseline period be, and does it need to cover the cooling season? How often is renewal required, and what documentation does renewal need? Is the credit forward-looking only, or can it be applied retroactively — and if so, how far back?

Get the answers in writing where possible. Utility staff turnover is real, and an email confirming program requirements protects you if the person who approved your approach moves on before your application is processed.

Don’t Wait for the Perfect Moment

The most expensive thing you can do is nothing. Every month you delay your application is another month of full sewer charges on water that never touched the sewer. The application process takes some effort upfront, but the ongoing savings make it one of the highest-return investments a commercial facility can make. Start with step one — pick up the phone and call your utility’s commercial department today.