Is potable water from municipal taps safe for human consumption in the United States (US), and what factors influence its safety?

From the Guidelines

Generally, tap water in the United States is safe to drink, but its safety can be affected by various factors, including the age and condition of plumbing infrastructure, geographic location, local industrial activities, and municipal water treatment effectiveness. The Environmental Protection Agency (EPA) regulates tap water under the Safe Drinking Water Act, establishing standards for approximately 90 contaminants 1. However, several factors can impact a household's tap water safety, such as:

• The age and condition of plumbing infrastructure, with older homes potentially having lead pipes or lead solder that can contaminate water, especially in homes built before 1986
• Geographic location, with some regions having naturally occurring contaminants in groundwater or being served by smaller water systems with fewer resources for treatment
• Local industrial activities, which can introduce pollutants into water sources
• Agricultural runoff containing pesticides and fertilizers, which can affect rural water supplies
• Municipal water treatment effectiveness, which can vary, with some systems struggling with aging facilities or limited resources
• Private wells, which serve approximately 15% of Americans and require regular owner testing, as they are not regulated by the EPA

Recent environmental disasters or infrastructure failures can temporarily compromise water safety, as seen in Flint, Michigan 1. For households concerned about their water quality, testing through local health departments or certified laboratories is recommended, and water filters certified by NSF International can provide additional protection against specific contaminants. According to the most recent study, consuming water instead of sugar-sweetened beverages can have health benefits, and tap water is the preferred source of drinking water, but in areas where tap water is known to be contaminated, filtered or bottled water is acceptable 1.

From the Research

Tap Water Safety in the US

• The safety of tap water in the US can be affected by various factors, including the presence of contaminants and the effectiveness of water treatment processes 2, 3.
• Some studies have reported the presence of bacteria, such as Chryseobacterium indologenes, in tap water, which can pose a risk to human health, particularly for immunocompromised individuals 2.
• The use of chlorine in water treatment can also contribute to the development of antimicrobial resistance in waterborne pathogens, which can have significant public health implications 3.

Factors Affecting Household Tap Water Safety

• The safety of tap water in households can be influenced by factors such as:
  • The quality of the water supply system
  • The effectiveness of water treatment and filtration systems
  • The presence of contaminants, such as bacteria, viruses, and chemicals
  • The storage and handling of water in the household
• Household practices, such as the use of cleaners and disinfectants, can also impact tap water safety, particularly if these products are not used or stored properly 4, 5.

Knowledge and Practices Related to Tap Water Safety

• Studies have shown that there are knowledge gaps among the general public regarding the safe use and storage of cleaners, disinfectants, and hand sanitizers, which can affect tap water safety 4, 5.
• Tailored communication strategies and health promotion campaigns can help address these knowledge gaps and promote safe practices related to tap water safety 5.