Public Swimming Pools

Yes – there are several companies that offer a class and exam to become a Certified Pool Operator (CPO). Find a class near you.

The pool/spa should be closed anytime an immediate and imminent health risk exists. These could include the following: excessive water cloudiness (the main drain is not visible); no free residual level of disinfectant/sanitizer (e.g., chlorine); the filtration and/or automatic disinfection system is not operable; the covers over the main drain or the equalizer lines are broken or missing or there is a suction hazard; the underwater light fixture has water in it; chemicals are added to the water and sufficient time has not elapsed for proper mixing; or any time you feel there is a health risk to patrons.

YES! The law requires all public pools and spas to have an on-site operable test kit, and a daily log of chlorine, pH levels, and other maintenance actions. You should have basic knowledge of pool maintenance and water chemistry balance. If the pool chemistry is not correct on any given day, adjustment must be made as soon as possible to keep the water safe for patrons.

Chlorine (or other approved disinfectant) and pH levels should be checked and recorded on a maintenance log at least once per day. Cyanuric acid levels should be checked and recorded at least once per month. Other chemical tests (such as alkalinity, calcium hardness, and total dissolved solids) should be checked regularly to maintain proper water balance.

Chemical Requirements

When to Check
and Record
Free chlorine without
1.0 ppm 1.5 ppm 10 ppm Daily
Free chlorine with
1.5 ppm 1.5 – 3.0 ppm 10 ppm Daily
“Stabilizer” (i.e.,
Cyanuric Acid)
0 ppm Up to 50 ppm 100 ppm Monthly
pH 7.2 7.4 – 7.6 8.0 Daily

Cyanuric acid is an acid that is marketed as a chlorine “stabilizer” for swimming pools. It is also referred to as a “conditioner.” When exposed to the ultraviolet rays of the sun, the free chlorine in the pool water will break down and escape. Cyanuric acid is intended to reduce this loss of chlorine. Cyanuric acid is often a component of chlorine tablets used in automatic chlorinators. It is also available in powder form. Cyanuric acid residual remains in the water and will increase in concentration as additional amounts of cyanuric acid are added to the water. At high concentrations (>50 ppm), cyanuric acid can substantially decrease the effectiveness of chlorine.

It is likely that the chlorine has combined with organic matter in the pool and has formed chloramines. Chloramines have a chlorine-like smell and can cause eye and skin irritation. Use a test kit to determine the amount of combined chlorine. The combined chlorine level should not exceed 0.4 ppm. Adding the appropriate amount of addition free available chlorine will help to eliminate chloramines.

It is important to have the correct concentration of free available chlorine in the water at all times when the pool or spa is available for use. Unlike combined chlorine, free available chlorine is efficient at destroying the majority of harmful microorganisms. A minimum of 1.0 ppm free available chlorine is required if cyanuric acid is not used as a conditioner. Otherwise, a minimum free chlorine residual of 1.5 ppm is required. The maximum concentration of free available chlorine must not exceed 10 ppm while the pool is available for use. Chlorine must be dispensed through a properly-sized automatic chlorinator to ensure consistent levels of chlorine.

Pools should be disinfected continuously by a chemical which imparts a residual effect. Chlorine is a type of “disinfectant”, also called a “sanitizer”. Disinfectants or sanitizers destroy living microorganisms and bacteria, preventing the transmission of disease. There are several types of disinfectants, such as chlorine, bromine, ozone and UV light. Public pools need a disinfectant with a measurable residual.

When a fecal, vomit, blood contamination, near drowning, or drowning incident occurs, the pool operator shall immediately close the affected pool to users. The pool operator shall complete the disinfection procedure stated in the Recommended Response for Fecal, Vomit, Blood Contamination, Near-Drowning, or Drowning Incidents flyer. The pool operator shall also document each fecal, vomit, blood contamination, drowning, or near drowning incident. Please see our Incident Report for Fecal, Vomit, Blood Contamination, Near-Drowning, or Drowning form.

Not at this time, but it is highly recommended. Properly maintaining a public pool requires proper training. Basic pool training is best acquired in a Certified Pool Operator class.

Generally speaking, if pool equipment is replaced with the same make and model number (like for like), there is no need to notify the Health Department. Otherwise, contact the health department, plan check section, for approval prior to any equipment installation/replacement. New pumps must be able to maintain the same turnover rate. Filters must be properly sized for the system. Chlorinators must be sized properly to ensure adequate disinfection.

You must maintain daily test records for pH and free chlorine. In addition you need to include in your records any maintenance performed and monthly cyanuric acid checks (if pool stabilizer is used).

At the minimum, you need a test kit that can accurately check pH and “free chlorine” in the pool water. To accurately check “free chlorine”, the test kit should use DPD tablets or liquid. “OTO” (yellow liquid) type chlorine test kits are difficult to use to accurately determine free chlorine. The test kit must be able to test for free chlorine from 0.5 to 3 ppm (parts per million). However, it is suggested that test kits with a higher free chlorine range (to 5 or 10 ppm) be used. If pool stabilizer is used, cyanuric acid must also be checked, at least once per month. Cyanuric acid test kits are available but you can also take a water sample into some pool supply companies once per month. Most test kits will also check for combined chlorine, total alkalinity, and calcium hardness, which are useful for properly maintaining a pool.

Public pools are posted closed by Environmental Health as a preventative measure when significant health or safety violations are observed during an inspection. Most closures are because of very low or very high chlorine levels, very cloudy water, or safety items like missing main drain covers. Actual bacterial samples of the pool water are rarely taken.