Council considers chlorine for pool

Trent Ernst, Editor


Council is currently considering spending $211,000 to install a new chlorinated gas system at the Tumbler Ridge Aquatic Centre.

This suggested changeover, says building official Ken Klikach, is due to the fact that the current saline system is breaking down. “The current system is past its life and expensive to maintain,” says Klikach. “The salt water is damaging the pipes. Everyone has gotten rid of that system: Fort St. John, Chetwynd…they’ve all gone back to Chlorine gas, because it’s more economical.”

The Tumbler Ridge Pool started out as a chlorine pool, but was quickly converted over to the current system which uses salt to treat the water.

The case for chlorine

To say that the pool is chlorine free would be inaccurate. All pools need something, traditionally chlorine in the water. In a chlorine-based system, this is chlorine. In a salt based system it is also chlorine.

Very simply, to disinfect the water in a salt-based system, the water is passed over metal plates which burn off impurities. While the water that is returned back into the pool is clean, what happens when a swimmer enters the pool without showering? They introduce impurities into the water which, in the absence of any inhibiting agent, will start to multiply faster than the water can be treated.

For the pool water to still be safe for swimming, the water needs to have something that will inhibit the growth of bacteria and neutralize other impurities: chlorine. Salt, which is a combination of sodium and chlorine, releases chlorine into the water as part of the electrolysis process. Some have argued that it is less harsh because of this, but chlorine is chlorine. So why are salt water pools considered less harsh on a person than one that is treated with chlorine gas?

Here’s where the whole thing gets science-y. In a chlorinated pool, there are two types of chlorine: free available chlorine (FAC) and combined available chlorine (CAC). FAC is the ions floating about the pool, waiting to do their job, while CAC is the chlorine that has done its job and formed into a new molecule, including something called chloramines. These are formed when the chlorine comes into contact with sweat or urine.

It is these chloramines that are the cause of the chlorine smell of pools, as well as skin and eye irritation, and are typically a sign that there is not enough free available chlorine. In these cases, a pool is “shocked” with five to ten times the normal amount of chlorine, which will burn off these CACs.

But a properly managed chlorine pool should be no more offensive than a salt water pool.

Many people in town remember when the pool was originally installed and all the troubles it had with people complaining about skin irritation and other problems that seem to have been caused by the chlorine.

But was it the chlorine, or was it just a poorly maintained system? Most experts maintain that an improperly maintained pool ph level is harder on skin than chlorine. Did chlorine just get a bad rap in Tumbler Ridge?

The folks at the Chetwynd seem to think so. Melissa Millsap is the Manager of Leisure and Facility Services there. She says they have two separate systems: the hot tub runs on a salt system, while the pool runs on chlorine. “If you came into our facility you wouldn’t know one was chlorine and one was salt,” she says.

At least, patrons can’t tell the difference. Staff, however, can. “The salt is very damaging,” she says. “It’s very corrosive. We have had to do some mechanical upgrades. For longevity of mechanical equipment, the longevity would be there with chlorine. Our staff prefers chlorine, and the staff is asking that the hot tub be moved to a chlorine system.”

In many pools they maintain the chlorine level anywhere from six to ten parts per million (ppm). When you have the chlorine that high, it is hard on a person’s system. Chlorine only needs to be at 2 ppm to do it’s job, and when it’s that low, says Millsap, people don’t notice it.

Staying with salt

In salt pools, the process of treating the water produces a low level of free chlorine ions. CACs that form in the pool are burned off by the electrolysis process. For some people that have sensitivities to chlorine, these systems are generally less harsh on their bodies, though this is not always the case.

Other benefits of salt systems in pools are the convenience and the constant delivery of pure chlorine-based sanitizer. The reduction of irritating chloramines versus traditional chlorinating methods and the “softening” effect of electrolysis, reducing dissolved alkali minerals in the water.

You catch that last bit? Salt systems act as a water softener. The electrolysis panels attract calcium and other minerals to the plates and Tumbler Ridge water? Has a lot of calcium in it.

According to some sources, salt water pools are cheaper to maintain throughout the year, since salt is significantly cheaper than the commercial chlorines, however, this is not the case in Tumbler Ridge, says Klikach. “If we aren’t going to change it, we still have to do a lot of work on it. The electrolysis panels are burning out.” He says that a lot of work needs to be done to maintain the pool, cleaning the panels and this is adding to the overall cost.

Another issue with salt, says Klikach, is it is causing damage to the concrete around the pool. The cause of this is up for some debate, though. One expert we talked to claimed that the trouble was improper grounding of the electrolysis device, saying that the salt in the water was enough to carry a slight current to the concrete, causing it to break down.

Others blame the salt directly. Whatever the problem, Klikach says it could cut the expected life of the pool down seriously if something isn’t done.

However, many patrons of the Tumbler pool are still resistant to the idea of going back to a chlorine system.

Crys White says she doesn’t want to see the pool go to chlorine without at least looking at what can be done with the current system. “My main concern is the health issues,” she says. “Chlorine causes respiratory issues. It causes skin problems. Some people say it may be a carcinogen.”

White isn’t speaking just as a fan of the current pool. She says she’s worked in recreation centres in the past. Some of them, she says, the chlorine was so strong, she wouldn’t let her kids swim in the pool.

“My question is: why?” she says. “Why make the change? It’s such a nice system. If there’s an issue with the concrete then seal it. [White’s husband] Larry has looked at it from an engineering point of view. He talked to Ken Klikach and Ken said he had talked to an engineer and they gave a solution. ‘No’, said, Larry, ‘they gave an option.’

“I don’t believe that all the troubles they’ve had are because of the salt. The troubles with the climbing wall was the fact that it was poorly designed, not because of the salt.”

White says even if they go to a chlorine system, she will keep going. Her husband, who has skin sensitivities, will not. “I just want them to do due diligence. I want them to investigate all the options. If they do decide to go this way, okay, as long as they investigated all the options.

Another option

But if salt is too hard on the facilities and chlorine is too hard on the patrons, what option is there?

Turns out, there are a couple.

Over at the North Peace Leisure Pool, they have indeed gotten rid of their salt water system. However, says Corey Callison, the maintenance supervisor for the pool, they have chosen a third path.

Rather than kill bacteria chemically, they use ultraviolet lights to purify the water.

Ultraviolet (UV) pool sanitizers is a relatively new, non-chemical process that uses germicidal UV light rays to sanitize the water. Ultraviolet lights used in these systems emit a high intensity germicidal light ray that alters or disrupts the DNA or RNA of targeted organisms such as algae, bacteria, viruses, cysts and protozoa. Highly concentrated electromagnetic energy also destroys organic matter, eliminating the formation of those nasty-smelling chloromides.

In this type of system, FAC levels are maintained at a much lower level then either the chlorine system or the salt system. Chlorine is still needed in the pool, but it can be maintained at a much lower level than in most chlorine or Salt pools, about 0.5 ppm, or about a quarter of the recommended 2 ppm in either of the other systems.

The drawback? A UV system is far more expensive than a chlorine system, about three times as much. But it would save on both maintenance costs and consumables at the pool. “When the pool was using salt, we were putting 800 lbs of salt into our pool a night,” says Callison. “That gets expensive. The amount of chlorine we use is fairly low. And the UV system is pretty low maintenance. The maintenance is way less. We were spending an hour or two hours a day just on manpower cleaning electronator cells, compared to this system, which we might do some work on once every three weeks. We’re probably saving $1000 in labour alone.”

Of course, Tumbler Ridge’s pool is not the same size, nor does it require the same amount of work as the North Peace pool. Still, maintenance sets aside a few hours every Sunday to do work on the system.

One of the people opposed to the idea of changing to chlorine is Councillor Joanne Kirby. She says she remembers when the pool went to salt. “There were lots of complaints about the chlorine,” she says. “People complaining about skin irritation and eye irritation. I’d rather have healthy swimmers than healthy pipes.”

One final option would be to use Ozone. Ozone is a special type of molecule made up of three oxygen atoms (typically, oxygen molecules have two oxygen atoms).

In an ozone pool, the ozone is used to purify the water, but a small level of chlorine is maintained in the pool to kill any containments that are introduced into the water. But like a UV system, ozone is expensive. And unlike a UV system, you’re not getting away from treating the water with chemicals. Ozone does smell a little like chlorine, and has many of the same issues with skin irritation.