Environmental Livability Index
Setting Health Standards
EPA sets MCLs based on a risk
assessment process that estimates the
cancer and noncancer risks of
prolonged exposure to that
contaminant. The levels are also based
on the ability of various technologies
to remove the contaminant and the
cost of treatment.
The MCL goals (MCLGs) are
generally lower than MCLs, and could
be a more accurate estimate of the
maximum levels that should be
allowable in the water. Below this
level there is no known or expected
risk to health.
Drinking water supplied by the Dayton Water Department to Dayton residents and to most
Montgomery County residents meets or exceeds federal standards and meets many of the federal goals
for the 83 substances that are regulated by the U.S. EPA. In addition, the city has an exemplary
program to prevent contamination of the groundwater that supplies drinking water. However, one-
third of county residents are served by smaller water systems that have had a history of not meeting
federal health standards.
Drinking Water Quality1
An important measure of drinking water quality is –
Ø Is the water safe to drink?
A new tool to help answer this question is the Consumer Confidence Report (CCR), which
community water systems with at least 15 service connections serving residents year-round are
required to deliver annually to their customers. The report lists some of the contaminants in the
drinking water and how the levels compare to federal health standards, referred to as Maximum
Contaminant Levels (MCLs).
The CCR can help to answer the following questions:
1. What are some of the contaminants that are in the drinking water and what are their levels?
2. Does the drinking water meet health standards?
3. What are the major sources of water pollution?
4. What are the state and local authorities doing to improve the water quality?
5. Are state and local efforts sufficient to ensure optimal drinking water quality?
1. What are some of the contaminants that are in
the drinking water and what are