Which of the following is NOT a principal function of the Safe Drinking Water Act?

The Safe Drinking Water Act (SDWA) is primarily focused on regulating public drinking water supply to protect the health of consumers. One of its key functions is to establish Maximum Contaminant Levels (MCLs), which are legally enforceable standards that set the maximum permissible levels of particular contaminants in drinking water. This ensures that the water supplied to consumers is safe for consumption.

Additionally, the Act involves monitoring states for compliance with these standards and regulations, ensuring that public water systems meet the required health standards. Another principal function is providing technical assistance, which supports public water systems in maintaining and improving the safety and quality of their drinking water.

However, developing new water sources is not a principal function of the Safe Drinking Water Act. While the Act can influence the quality and safety of the water supplied, it does not specifically focus on the development of new water resources. This is typically handled by other legislation or local water management strategies that deal with water supply and infrastructure development. Thus, identifying the development of new water sources as not being a principal function of the SDWA is correct.