77 Ill. Adm. Code 820 (Swimming Facility Code)
Illinois pool chemical log requirements
What a Illinois public or semi-public pool must test, the legal ranges, what goes in the log and how long to keep it — every rule with the section of the code. Checked September 19, 2026.
- Test
- At least twice a day, shallow and deep end77 IAC 820.350(b)
- Keep the log
- 3 years77 IAC 820.350(a)
- Rules
- Swimming pool77 Ill. Adm. Code 820 (Swimming Facility Code)
1.0 to 4.0 ppm · at least 2.0 when water is over 85 °F
7.2 to 7.6
no more than 100 ppm
50 to 200 ppm
no more than 0.5 ppm · above 0.5, superchlorinate
Swimming facility daily operational report · one month, letter landscape · columns for FC, pH
Sources (4) — every number above is cited
- 77 Ill. Adm. Code 820.320 — Water quality (Cornell LII copy) — Illinois Department of Public Health (text via Cornell LII)
- 77 Ill. Adm. Code 820.330 — Immediate closure (Cornell LII copy) — Illinois Department of Public Health (text via Cornell LII)
- 77 Ill. Adm. Code 820.350 — Records and testing (Cornell LII copy) — Illinois Department of Public Health (text via Cornell LII)
- Swimming Facility Daily Operational Report — Illinois Department of Public Health
Illinois tests the shallow and the deep areas separately.
Our copy of the rule (Cornell LII) shows amendments up to October 2013: check the Illinois register for anything newer.
Legal ranges
| Parameter | Pool | Spa | Source |
|---|---|---|---|
| Free chlorine | 1–4 ppm | 2–4 ppm | 77 IAC 820.320 |
| pH | 7.2–7.6 | 7.2–7.6 | 77 IAC 820.320 |
| Cyanuric acid | at most 100 ppm | at most 100 ppm | 77 IAC 820.320 |
| Total alkalinity | 50–200 ppm | 50–200 ppm | 77 IAC 820.320 |
| Combined chlorine | at most 0.5 ppm | at most 0.5 ppm | 77 IAC 820.320 |
Testing frequency
At least twice a day, shallow and deep end (77 IAC 820.350(b)). Disinfectant residual and pH on samples collected at least twice daily from the shallow and the deep areas of each pool.
- Combined chlorine at least weekly (77 IAC 820.350(b))
- Cyanuric acid at least weekly when cyanurates are used (77 IAC 820.350(b))
What the log must show
- Disinfectant and pH, shallow and deep, twice a day
- Combined chlorine weekly, cyanuric acid weekly
- Initials of the person testing (IDPH form)
- One form per pool
Keep it 3 years (77 IAC 820.350(a)). On the Department's report form, or an equivalent, kept at the facility for at least three years; a separate form for each pool.
What the inspector checks
- The daily operational report of the last 3 years, one per pool
- Free chlorine 1.0–4.0 ppm, pH 7.2–7.6
- Combined chlorine at 0.5 ppm or less
- A designated swimming facility manager/operator
When the pool must close
- Free chlorine below 0.5 ppm (bromine below 1.0)
- Total chlorine above 5 ppm (bromine above 10)
- pH below 6.8 or above 8.0
- Turbidity (bottom not visible)
- Equipment failure
Who may operate the pool
A swimming facility manager/operator must be designated; Part 820 names no certification.
Illinois tests the shallow and the deep areas separately.
Our copy of the rule (Cornell LII) shows amendments up to October 2013: check the Illinois register for anything newer.
Log Illinois readings on your phone
Every reading checked against the ranges above, the corrective action recorded, and the Illinois sheet filled for the inspector.
Sources
- 77 Ill. Adm. Code 820.320 — Water quality (Cornell LII copy) — Illinois Department of Public Health (text via Cornell LII)
- 77 Ill. Adm. Code 820.330 — Immediate closure (Cornell LII copy) — Illinois Department of Public Health (text via Cornell LII)
- 77 Ill. Adm. Code 820.350 — Records and testing (Cornell LII copy) — Illinois Department of Public Health (text via Cornell LII)
- Swimming Facility Daily Operational Report — Illinois Department of Public Health
This page summarizes the state code; your county or city health department may add requirements. It is not legal advice.