Understanding EPA Limits
The EPA sets various limits on drinking water contamination, these are broken down into several categories such as primary drinking water standards, secondary drinking water standards, or no standards.
Primary Drinking Water Standards
The Primary Drinking Water Standards were established as part of the National Primary Drinking Water Regulations (NPDWR) and were created to address parameters that can cause chronic health issues. Drinking water standards are typically monitored by the State Health Departments. These states must be at least as strict as the NPDWR but can choose to have stricter or additional regulations.
The Primary Drinking Water Standards are also known as “Maximum Contamination Levels” Also known as MCLs. These are the minimum standards that each state must reach to stay in compliance.
MCLG
The EPA also gives recommendations known as Maximum Contaminant Level Goals (MCLG). These limits are not enforced but are the goal that each state level agency should aim to achieve. If these are used as the standard as set by each state level agency.
Secondary Drinking Water Standards
The EPA also provides Secondary Drinking Water Standards, referred to as Secondary Maximum Contaminant Levels (SMCL). These standards are specifically concerned with Aesthetic or Cosmetic aspects of the water and not health effects. These secondary parameters may affect aspects such as:
- Taste, Smell, or appearance
- Cosmetic issues like damage to hair, skin, or teeth
- Negatively affects appliances or plumbing
Because these Secondary Standards are not health concerns, they are not enforced at the national level but up to the individual state health departments. While they are not health concerns, they can affect your quality of life and are important parameters when picking out filtration methods such as softeners.
No Standards
There are parameters that have no official primary or secondary standards from the EPA. For several of these parameters the EPA may set health advisory limits or lifetime consumption limits, but these are not enforced at the federal level.
There are other organizations that may set their own health limits for drinking water parameters that have placed limits on these parameters. If you are concerned about high levels of one of these parameters you can reference limits set by the World Health Organization (WHO), Environmental Working Group (EWG), State Agencies, or KnowYourH20.
Unregulated Contaminant Monitoring Rule
The EPA does monitor contaminants that are not set by the Primary Drinking Water Standards. Every 5 years some public utilities must monitor certain contaminants that are either of public interest (such as PFAS) or that may have health effects. This is referred to as the Unregulated Contaminant Monitoring Rule (UCMR).
This is based on what testing methodology is available and cost-effective and these requirements change often. If you see that your public utility has tested for a parameter that is not listed as a federal or state requirement, it may be due to a special testing requirement like the UCMR.
What If You Are on Well Water
Many customers are concerned about what happens if their water report falls outside of EPA limits and they are on well water. The short answer is, nothing. Because private wells are not regulated by any government agency there is no reporting or enforcement for private water wells.
But that doesn’t mean you shouldn’t do anything as a private well owner. If your lab report shows elevated levels of a contaminant, it’s up to you to take action to ensure that your water is safe for your family.
By comparing your lab results to these drinking water standards, you can get an idea of how your water quality is impacting your health and what effects it may have.