Maricopa County Environmental Health Code, Chapter VI (the state rule, A.A.C. R18-5, covers design and equipment only)
Arizona pool chemical log requirements
What a Arizona 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 dayMCEHC Ch. VI §2 Reg. 6
- Keep the log
- 12 monthsMCEHC Ch. VI §2 Reg. 6
- Rules
- Pool in Maricopa County (semipublic)Maricopa County Environmental Health Code, Chapter VI (the state rule, A.A.C. R18-5, covers design and equipment only)
1.0 to 5.0 ppm · public and semipublic pools
7.2 to 7.8
60 to 180 ppm
no more than 100 ppm
Daily pool operating log (Maricopa County) · one month, letter landscape · columns for FC, pH, TA, Temp
Sources (3) — every number above is cited
- Maricopa County Environmental Health Code, Chapter VI, Section 2 — Water quality standards (public and semipublic swimming pools) — Maricopa County Environmental Services Department
- Maricopa County Environmental Health Code, Chapter VI, Section 1 — General requirements (definitions, closure) — Maricopa County Environmental Services Department
- A.A.C. R18-5-234 — Water quality and chemical feed (design rule; Cornell LII copy) — Arizona Department of Environmental Quality (text via Cornell LII)
Arizona has no statewide operating rule: A.A.C. R18-5-201 to -251 covers design and equipment, and its design limit for cyanuric acid (150 ppm) is looser than Maricopa County's operating limit (100 ppm).
Other counties (Pima, Yuma, Mohave…) have their own codes. These numbers are Maricopa County's.
Maricopa's log must be shown to a member of the public who asks, not only to the county.
Legal ranges
| Parameter | Pool | Spa | Source |
|---|---|---|---|
| Free chlorine | 1–5 ppm | 3–5 ppm | MCEHC Ch. VI §2 Reg. 4(a) |
| pH | 7.2–7.8 | 7.2–7.8 | MCEHC Ch. VI §2 Reg. 4(a) |
| Total alkalinity | 60–180 ppm | 60–180 ppm | MCEHC Ch. VI §2 Reg. 4 |
| Cyanuric acid | at most 100 ppm | at most 100 ppm | MCEHC Ch. VI §2 Reg. 4(c) |
| Water temperature | — | at most 104 °F | MCEHC Ch. VI §2 Reg. 5(b) |
Testing frequency
At least once a day (MCEHC Ch. VI §2 Reg. 6). Disinfection level, pH, total alkalinity and temperature tested at least once daily; free chlorine by the DPD method.
What the log must show
- Results of the daily tests: disinfectant, pH, total alkalinity, temperature
Keep it 12 months (MCEHC Ch. VI §2 Reg. 6). Keep the operating log for 12 months and show it to the county, any other regulatory authority, or a member of the public who asks.
What the inspector checks
- The operating log of the last 12 months
- Free chlorine by the DPD method, inside 1.0–5.0 ppm (spas 3.0–5.0)
- Main drain clearly visible from the deck
- Working filtration and disinfectant feeder
When the pool must close
- No approved disinfectant in the water
- Main drain not clearly visible to an adult standing on the deck
- Filtration system not working
- Disinfectant feeder missing, not working or malfunctioning
Who may operate the pool
The county code names no operator certification; only lifeguards need a certificate.
Arizona has no statewide operating rule: A.A.C. R18-5-201 to -251 covers design and equipment, and its design limit for cyanuric acid (150 ppm) is looser than Maricopa County's operating limit (100 ppm).
Other counties (Pima, Yuma, Mohave…) have their own codes. These numbers are Maricopa County's.
Maricopa's log must be shown to a member of the public who asks, not only to the county.
Log Arizona readings on your phone
Every reading checked against the ranges above, the corrective action recorded, and the Arizona sheet filled for the inspector.
Sources
- Maricopa County Environmental Health Code, Chapter VI, Section 2 — Water quality standards (public and semipublic swimming pools) — Maricopa County Environmental Services Department
- Maricopa County Environmental Health Code, Chapter VI, Section 1 — General requirements (definitions, closure) — Maricopa County Environmental Services Department
- A.A.C. R18-5-234 — Water quality and chemical feed (design rule; Cornell LII copy) — Arizona Department of Environmental Quality (text via Cornell LII)
This page summarizes the state code; your county or city health department may add requirements. It is not legal advice.