(CBS) — The weather is finally perfect for spending the day at the pool, but how clean is the water there?

The Centers for Disease Control says reports of illnesses associated with swimming are increasing.

CBS 2’s Marissa Bailey has details on what to watch out for.

Is chlorine keeping your local pool sparking clean…or not? Emergency medicine doctor Jake Deutsch says yes and no.

“Chlorine is eliminating most contaminants and bacteria but it doesn’t guarantee that everything is removed,” he said.

In fact, a strong smell of chlorine at your pool can actually be a sign the pool is not necessarily clean. According to the Centers for Disease Control, the stronger the chlorine smell, the more urine could be in the pool. And if after swimming your eyes turn very red, that’s also a sign the chlorine can’t fight all the urine, sweat, and whatever else swimmers are bringing into the water with them.

“When we go into a swimming pool,” said epidemiologist Melvin Kramer. “We’re actually putting our face where a lot of people have put their rear-end.”

The CDC found 58 percent of pool samples tested positive for E. coli, bacteria normally found in feces, which can make us quite sick.

“When we’re swimming, we consume water through our mouth, our nose, our eyes,” said Kramer.

Pool water, some experts say, can also carry legionella, bacteria that can cause pneumonia.

Gastrointestinal problems can be caused by norovirus as well as by a bug called which is becoming more common even in well maintained pools because it tolerates chlorine.

“Look, we don’t live in a bubble,”said Kramer. “I go swimming all the time.”

What you need to do, Kramer says, is limit your risk.

The CDC advises that one of the best things you can do is to shower with soap before and after you swim. In addition, Dr. Jake Deutsch says, “Ask around, moms know as much of what’s going on as any health official and if somebody’s kid has gotten sick you want to make sure that you’re aware of that and protecting your family as well.”

The most common illness associated with pools is diarrhea, but skin, ear, eye and respiratory infections can also occur.

The same concerns also apply to water parks and hot tubs.

For more information from the CDC on recreational water illnesses, click here.

For the CDC’s list of steps for health swimming, click here.