Q. I just noticed that a pool that I swim in was closed. Should I be concerned?
A. 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.
Q. What kind of pool test kit do I need for my public pool?
A. 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. 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, but only 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.
Q. What kind of records must I maintain for a public pool?
A. 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).
Q. Do I need to notify the Health Department if I change pool equipment?
A. Sometimes. If you are only replacing equipment with like equipment, then notification is not required. If you are changing equipment to a different type or size you should check with Environmental Health to see that the equipment will be acceptable for the size and type of your pool. New pumps must be able to maintain the same turnover rate as the original design (usually 6 hour turnover rate). Filters must be sized for the pump size (and flow) and be suitable for the type of filter cleaning or backwashing facilities that are available.
Q. Does my public pool have to be maintained by a Certified Pool Operator?
A. 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.
Q. What should I do after a fecal accident in a public swimming pool?
A. We suggest reading the CDC guidelines (see web link in “links” section). The recommendations are basically split into two sections; formed fecal accidents and loose stools.
First, close the pool. For formed fecal accidents, after removing the stool, the pool operator should raise the free chlorine to 3-10 PPM at a pH of 7.2-7.5 for 19 minutes with the filter running.
Note: Chlorine is more effective at a pH of 7.2-7.5 even though a pH of 7.2-8.0 is legal in California.
For loose stools or vomit, after removing as much fecal matter as possible, the pool operator should to raise the free chlorine to 10 PPM at a pH of 7.2-7.5 for 16 hours with the filter running. After 16 hours the filter must be backwashed (or change cartridge) and the backwash water discharged to some acceptable place other than back into the pool (as sometimes done with older pools using separation tanks). The 16 hour time period can be shortened by raising the level of free chlorine to higher levels (CDC recommends 20 PPM) but then the free chlorine level will have to be lowered back to 10 PPM or less prior to reopening the pool. Also, most commonly available pool test kits cannot accurately measure free chlorine levels above 10 PPM.