You can go online at Costco.com and apply for a Costco Membership there by adding it to your shopping cart if you are shopping for the first time. Your membership card will be mailed to you within 7-10 days but you can actually shop at the online store immediately.
The three most common chlorine-containing substances used in water treatment are chlorine gas, sodium hypochlorite, and calcium hypochlorite.
While chlorine has been praised for a century for its powerful sanitizing potential, today it is rendered a threat to the lives of people. Water is treated with chlorine chemicals to kill harmful bacteria. The method is used by almost every household and public facility that houses a swimming pool.