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Daily chlorine residual log sheet

A month of chlorine readings on one page, with your water system's name, ID and sample points already filled in. Print it, save it as a PDF, or download a CSV for Excel.

Blank PDF

31 rows · 1 page · Letter portrait

Date	Time	Sample location	Free Chlorinemg/L	Initials	Notes
Range			to
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What a chlorine residual log needs to show

A residual reading is only useful as a record if someone else can tell when, where and how it was taken, and by whom. Federal rules list what a sample record must include (40 CFR 141.33), and the columns on this sheet map to it:

Column	What to write	Why
Date and time	When the sample was taken, not when you wrote it up	Date, place and time of sampling are part of the record
Sample location	The tap or site, named the same way every time	Shows the sample came from the planned point
Free chlorine	The result in mg/L, to the precision your kit reads (0.70, not 0.7)	The result of the analysis
Total chlorine	Only if you test it; required for chloraminated water	Free minus total is a rough measure of combined chlorine
Initials	The person who took and read the sample	Name of the person who collected and analyzed it
Test method (header)	For example “DPD colorimeter” or your kit's name	The analytical method used
Notes	Anything that explains a reading: tank refilled, line flushed, retest	Context for an inspector, or for you next month

How to fill it in

Set up the sheet once. System name, PWS ID, month and test method in the header, and the range you work to in the range row (see below).
Sample the same way every time. Same tap or planned sites, same flush time, same kit. The step-by-step testing guide covers the DPD method.
Write the result straight away, in ink. Copy the number exactly as the kit shows it, including trailing zeros.
Initial every line. If two people share the round, each initials their own readings.
Use Notes for anything unusual. A low reading followed by a retest should show both readings and what you did in between.
Sign off at month end. The “Reviewed by” line is where the responsible operator or owner checks the page before the results go onto your state report.

Free chlorine or total chlorine?

If your system adds chlorine (bleach, calcium hypochlorite tablets or a gas chlorinator), log free chlorine. That is the disinfecting form most rules are written around. If your water is treated with chloramines, as some purchased water is, log total chlorine. Many operators record both: total minus free gives a rough measure of combined chlorine. The testing guide explains the difference.

Filling in the range row

The range row under the column headings is left blank on purpose. Your minimum comes from your state's rules or your system's operating permit. Texas, for example, requires at least 0.2 mg/L free chlorine in the distribution system (30 TAC §290.110). The federal maximum residual disinfectant level for chlorine is 4.0 mg/L, measured as a running annual average (40 CFR 141.65). Many systems work to a narrower target range set by their operator. See chlorine residual requirements for federal rules and state pages.

Correcting a mistake

Draw a single line through the wrong entry so it stays readable, write the correct value beside it, and add your initials and the date. Don't erase, overwrite or use correction fluid. A late entry should say it was entered late. More detail: correcting logbook entries.

How long to keep the sheets

Retention depends on your state. Texas, for example, keeps distribution system residual results for three years (30 TAC §290.46(f)). Ground water systems doing 4-log compliance monitoring keep their lowest daily residual records for five years under federal rules (40 CFR 141.405). See how long to keep water system records.

More than chlorine on your round?

If you also read the source meter, pressure, tank level or pump hours, the daily water system log sheet builds one sheet for the whole round.

Questions

Is there a PDF version of this chlorine log sheet?

Yes. Use Print or save as PDF and choose Save as PDF in the print dialog, or download the blank PDF, which has days 1–31 and room to write the month, system name and ID.

Is there an Excel version?

Download the CSV. It opens in Excel, Google Sheets and Numbers with one row per day (and per sample location) already dated, and the reading columns left empty to fill in.

Will my state accept this sheet?

Many states give small systems their own reporting form, such as a monthly operating report or, in Texas, the Disinfection Level Quarterly Operating Report. Use this sheet as the daily working log at the tap, then copy the results onto the state's form when it's due. If your state requires a specific daily log format, use theirs.

How often should I test and record chlorine residual?

It depends on your system type, water source and state. Examples: a ground water system that provides 4-log virus treatment and serves 3,300 or fewer people takes a daily grab sample under the federal Ground Water Rule, while Texas lets small ground water systems check the distribution system at least once every seven days. Your state drinking water program sets your schedule.

Can I use it for a food truck or hauled water tank?

The sheet works for any chlorine residual log, but health departments that regulate mobile food units or water haulers often publish their own form. Check whether yours does before switching.

Can I keep this log on my phone instead?

Yes. The Water System Logbook iPhone app keeps the same record: readings, sample location, time and operator initials. It flags readings outside the range you set and produces a PDF or CSV at month end.

Sources

Last reviewed September 28, 2026. Rules change and states add their own; confirm with your state drinking water program.