Septic systems, also known as “on-site wastewater
treatment systems,” are widely used in rural and
suburban settings to dispose of wastewater. When
operating properly, septic systems remove many
pollutants and provide some measure of protection
for human health and for the environment. But
as rural populations grow and aquifers exhaust
their ability to dilute wastes from ever-increasing
numbers of septic tanks, water quality steadily
deteriorates. Most state and local governments
have regulations designed to protect public health
from the worst contaminants from septic systems:
water-borne pathogens and nitrates. But very few
governments have created effective measures to
address the increasing threat that septic tanks pose
to the ecosystems of rivers and lakes.