EPA REQUIREMENTS FOR
DIESEL STANDBY ENGINES
IN DATA CENTERS
30
7X24 MAGAZINE FALL 2014
by Bob Stelzer
1.0 Introduction
In order to get the Air Emissions Permit
for facilities that have diesel standby
generators, it is necessary to comply
with EPA and local regulatory
requirements. Even though diesel
standby generators do not operate for
many hours per year, EPA requirements
can have a significant impact on large
data centers.
The EPA regulations are relatively
complex and are constantly changing.
This article provides an overview of the
EPA regulatory framework with a
concentration on those requirements
for stationary diesel emergency
standby generators that are greater
than 500HP. This size range is
commonly encountered in larger Data
Centers. This article also focuses on
new installations only – it does not
offer insight into the rules that govern
existing retrofit installations.
This article attempts to identify some
of the key EPA terminology such as
National Ambient Air Quality
Standards (NAAQS), New Source
Performance
Standards
(NSPS),
Reciprocating Internal Combustion
Engine (RICE) National Emission
Standards for Hazardous Air Pollutants
(NESHAP), Tier 2,3,4 and put them in
a framework that allows the Critical
Power Engineer to understand the
current regulations and how those
regulations influence the design of new
facilities.
2.0 What Emissions are of
Concern
A diesel engine generates certain
emissions which the EPA considers
“criteria”
pollutants.
“Criteria”
pollutants are deemed to be serious
health risks and are measured by the
EPA throughout the US in geographic
entities called “areas”. The key criteria
pollutants associated with a diesel
engine are: Nitrogen Dioxide (NO
2
),
Particulate Matter (PM) and Carbon
Monoxide (CO). Figure 1 shows
examples of these emissions.
3.0 Explaining the Regulatory
Environment
The Clean Air Act forms the regulatory
basis for all air compliance activity. It
was originally established in the early
1970’s. The most important recent
major amendments to the Act
occurred in 1990. These amendments
recognized the need to consider the
available technology as a component
in determining achievable standards.
The EPA terminology for this is
Maximum
Achievable
Control
Technology (MACT). Cost effective
technology advances in MACT have
created the platform for the EPA to
look at new emission requirements for
diesel engines.
Figure 1
Examples of Criteria Pollutants
