NOx State Implementation Plans - Introduction

The generation of electricity with fossil fuels releases Sulphur Dioxide (SO2), Nitrogen Oxide (NOx), mercury and Carbon Dioxide (C02). The Environmental Protection Agency (EPA) currently caps the total emissions of SO2 and NOx.

In the case of NOx, states with very bad air pollution are allocated the right to emit a certain amount of NOx, and must budget those permits among the potential emitters - sometimes refered as "NOx Credits."

The generators must either reduce their emissions or purchase permits from those with excess or unneeded permits. Many states are currently developing state implementation plans (SIPS) to demonstrate how they will live within their NOx budget.

Further Detail:

• Hypothetical Example -


• Implementation Path Description (SIP Process) -


• State Initiatives Map for state specific NOx SIP programs -