Reusable bottles are better for your wallet, the planet, and in some cases, your body too. Companies that sell plastic bottles of water often spend more time creating the ultimate marketing campaign than verifying water quality. Some bottled water is sourced from public tap water, but toxins (like microplastics) can still leak into the water even though it's higher quality. A study published in the Guardian showed that 90 percent of bottled water tested contained levels of microplastics.