Other legislation protects us by limiting
concentrations of toxic substances in the water we drink and in
the treated wastewater that we discharge to the environment.
The Safe Drinking Water Act (1974) sets levels of toxic metals
and organic chemical permitted in water delivered to the public.
These limits are called maximum contaminant levels or MCLs. For
example, the MCLs for cadmium and PCBs are 5 and 0.5 parts per
The Clean Water Act (1977) seeks to make all of our nation's
waters 'fishable and swimmable'. Under this legislation,
127 priority pollutants (metals and organic chemicals) are identified
and limits set for their concentrations in wastewater treatment
plant effluent and in the lakes and rivers which receive those
discharges. All wastewater treatment facilities are required
to get a permit which specifies the quality of the treated wastewater
that they discharge to the environment.