15A NCAC 18A .2500 (Public Swimming Pools)
North Carolina pool chemical log requirements
What a North Carolina 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 once a day15A NCAC 18A .2535(11)
- Keep the log
- 6 months15A NCAC 18A .2535(11)
- Rules
- Public swimming pool15A NCAC 18A .2500 (Public Swimming Pools)
at least 1.0 ppm · no maximum in the rule
7.2 to 7.8
no more than 100 ppm
Public swimming pool daily log · one month, letter landscape · columns for FC, pH
Sources (2) — every number above is cited
- 15A NCAC 18A .2500 — Public Swimming Pools (official compilation, incl. .2535 Water quality and .2537 Operation) — North Carolina Office of Administrative Hearings
- G.S. 130A-280 — Scope (public swimming pools) — North Carolina General Assembly
Cyanuric acid is mandatory in outdoor pools disinfected with chlorine.
North Carolina caps heated pools at 90 °F, not 104 °F: only spas may go up to 104 °F.
Legal ranges
| Parameter | Pool | Spa | Source |
|---|---|---|---|
| Free chlorine | at least 1 ppm | at least 1 ppm | 15A NCAC 18A .2535 |
| pH | 7.2–7.8 | 7.2–7.8 | 15A NCAC 18A .2535 |
| Cyanuric acid | at most 100 ppm | at most 100 ppm | 15A NCAC 18A .2535 |
| Water temperature | — | at most 104 °F | 15A NCAC 18A .2535 |
Testing frequency
At least once a day (15A NCAC 18A .2535(11)). The operator inspects the pool at least daily and records the disinfectant residual, pH, the temperature of heated pools and the condition of the drain cover.
- Total alkalinity and cyanuric acid weekly (15A NCAC 18A .2535(11))
What the log must show
- Disinfectant residual and pH, daily
- Temperature of heated pools and spas
- Drain cover condition
- Total alkalinity and cyanuric acid, weekly
Keep it 6 months (15A NCAC 18A .2535(11)). Keep the written records at the pool site for at least six months.
What the inspector checks
- Written daily records of the last six months, at the pool
- Disinfectant at least 1.0 ppm (bromine 2.0), pH 7.2–7.8
- Main drain grate visible from the deck
- Heated pools at 90 °F or below, spas at 104 °F or below
- Operator training documentation
When the pool must close
- Six-demerit items — disinfectant, pH, water clarity, temperature — allow immediate suspension of the operation permit
Who may operate the pool
The owner keeps documentation of the operator's training; a pool and spa operator certificate from the National Swimming Pool Foundation (now PHTA) is accepted.
Cyanuric acid is mandatory in outdoor pools disinfected with chlorine.
North Carolina caps heated pools at 90 °F, not 104 °F: only spas may go up to 104 °F.
Log North Carolina readings on your phone
Every reading checked against the ranges above, the corrective action recorded, and the North Carolina sheet filled for the inspector.
Sources
- 15A NCAC 18A .2500 — Public Swimming Pools (official compilation, incl. .2535 Water quality and .2537 Operation) — North Carolina Office of Administrative Hearings
- G.S. 130A-280 — Scope (public swimming pools) — North Carolina General Assembly
This page summarizes the state code; your county or city health department may add requirements. It is not legal advice.