Guide · reporting
Monthly operating reports, explained
Short answer
A monthly operating report (MOR) is the form many states require from water systems that treat water. It summarizes each day's operation: chlorine residuals, water produced, chemicals used. It's usually due by the 10th of the following month. Texas uses a quarterly version, the DLQOR. The daily log is where its numbers come from.
What usually goes on it
Forms differ by state, but for a small chlorinated ground water system you'll typically see:
- Daily chlorine residual: entry point and/or distribution, free and/or total, often the lowest of the day
- Water produced or treated each day (from the source meter)
- Chemical use: solution strength, amount used, feed pump settings
- The monthly average, minimum and maximum residual, and number of samples
- The signature of the operator responsible for the system
Missouri's guidance, for example, asks systems to keep monthly operating reports of daily chlorine residuals, solution ratios and pump settings. Indiana's form has plant-tap and distribution columns for free and total chlorine.
Examples by state
| State | Report and deadline |
|---|---|
| Texas | DLQOR (TCEQ-20067), quarterly by the 10th |
| Pennsylvania | Results within 10 days after the month; monthly operational report kept on file |
| Ohio | Monthly operating report (Form 5002) via eDWR by the 10th |
| Illinois | Monthly operating reports within 30 days after the month |
| Indiana | Monthly Report of Operation (State Form 34609) by the 10th |
| Missouri | MO 780-2094 by the 10th (4-log systems); others keep records on file |
| Florida | Form 62-555.900(3) monthly operation report within 10 days |
| Washington | DOH 331-430 / 331-593 monthly by the 10th |
Community and non-transient systems that add chlorine also report quarterly toward the federal 4.0 mg/L maximum: the number of samples each month, monthly averages and the running annual average, within 10 days after the quarter (40 CFR 141.133 and 141.134). In some states that data rides on the monthly or quarterly form above.
Filling it in from your daily log
- Log in the same units and order as the form. If the form wants the lowest residual of the day, make sure your log shows every reading so the lowest is obvious.
- Keep meter readings, not daily gallons. Work out daily production from consecutive readings with the meter usage calculator, which handles missed days and resets.
- Check for gaps before month end. A missing day is easier to explain in writing the same week than a month later.
- Copy, then check. Transcription is where most errors creep in. Have a second person spot-check a few days against the log.
- Keep a copy for your state's retention period. See how long to keep water system records.
Questions
Is a monthly operating report the same as a daily log?
No. The daily log is your working record, kept on site. The monthly (or quarterly) operating report is the summary your state asks for: usually the daily values copied onto its form, plus averages, lows and totals.
Do transient systems like campgrounds file one?
It depends on the state. Texas transient systems complete the quarterly DLQOR but keep it rather than submit it, and Florida exempts some transient ground water systems from its monthly report. Check your state's page or ask your program.
Can an app file my MOR for me?
Not Water System Logbook. It keeps your daily records and exports them as PDF or CSV so you can fill in the state's form, but it doesn't submit anything to your state.
Sources
- 40 CFR 141.133 — Compliance requirements (running annual average)
- 30 TAC §290.110 — Texas disinfectant residuals
- TCEQ — Disinfection Level Quarterly Operating Report (DLQOR)
Last reviewed September 28, 2026. Rules change and states add their own; confirm with your state drinking water program.