Aggressive marketing by beverage giants such as Coca-Cola Korea and Lotte Chilsung, and the introduction of the bottle cap tax payment system could soon see smaller companies on the verge of bankruptcy, say industry sources.The introduction of the bottle cap tax payment system, a government seal on a cork showing that the company has paid the necessary tax for improving water quality is also making things difficult for some companies, but hopefully means no more unauthorised water brands being available on the market.Aggressive advertising and sampling events by the major bottled water companies has impacted on the smaller players which once dominated the market. Coca-Cola Korea has begun pushing its Soonsoo 100 brand, and Lotte Chilsung plans to raise its market share through its distribution network of some 2,000 agencies. The company also intends to dominate the market with its own brand Isis.Industry sources said that the new, aggressive competition means around 50 mineral water producers could soon face bankruptcy.