The current major concerns in regard to water quality are lead and disinfection byproducts (Binnie et al, 2002). Lead is a key operational and treatment concern for municipal water treatment plants. It cannot be considered independently of other water quality and treatment issues. In fact, it seems that water disinfection and protection from lead infiltration are at odds with each other. The pH level required for disinfection must be below 8.0, but the pH level required to minimize lead solvency in plumbing systems is often 8.0 or higher. Water treatment plants provide clean, disinfected water to home plumbing systems, but this water is immediately contaminated from lead as it passes through the plumbing system. The solution to this problem may be the removal of lead from plumbing systems, a factor that would completely revolutionize the plumbing industry.
The rising concern over chlorine byproducts is also likely to affect the future of water filtration. It has long been recognized that chlorination of water results in the formation of THMs. THMs are harmful chemicals that form as a reaction between chlorine and natural, organic materials in water. The most well-known of the THMs is the poison chloroform. This poisonous gas, detrimental to the respiratory system when inhaled, is one of the most important reasons for the installation of shower filters or whole house water filters. It is likely that future research will find other byproducts of chlorination, and the use of chlorine for disinfection could be restricted.
Though these are all speculations, water filtration and treatment will, doubtlessly, continue to evolve in the future. The most important future development may well be the complete transformation of water filtration technology from municipal water treatment plants to whole house water filters, or a combination of the two systems.