Which of the following entities is primarily responsible for establishing water quality standards?

The Environmental Protection Agency (EPA) is primarily responsible for establishing water quality standards in the United States. This responsibility is rooted in the Clean Water Act, which mandates that the EPA develop regulations aimed at protecting the quality of the nation's waters. These standards are designed to ensure that water is safe for various uses, including drinking, swimming, and recreational activities.

The EPA sets criteria based on scientific research and public health considerations, evaluating the levels of contaminants that can be present in water without posing risks to human health or the environment. This includes stipulations for drinking water quality standards and monitoring requirements, ensuring that water suppliers maintain safe and acceptable levels of pollutants.

While other organizations like the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA) play important roles in public health and safety, their responsibilities differ. The WHO provides international guidelines and recommendations, the CDC focuses on disease control and prevention, and the FDA oversees food safety, including bottled water, but does not set the primary water quality standards as the EPA does.