PLACER COUNTY 

AIR POLLUTION CONTROL DISTRICT

STAFF REPORT

RULE 242 

STATIONARY INTERNAL COMBUSTION ENGINES

4/10/03 
Staff Report 

Rule 242 

Page 2 

BACKGROUND

This proposed rule category is included as Nitrogen Oxide (NOx) and Carbon Monoxide 

(CO) control measures in the Sacramento Area Regional Ozone Attainment Plan, which 

was adopted by the Board on December 20, 1994. NOx emissions are Ozone 

precursors. The Attainment Plan was adopted in response to the 1990 Amendments to 

the Federal Clean Air Act (CAA), which required areas designated “serious” for Ozone 

by the United States Environmental Protection Agency (USEPA), to submit a State 

Implementation Plan (SIP) revision. Adoption of this control measure by 2004 is 

required in order for Placer County Air Pollution Control District (District) to be compliant 

with the SIP requirements. 

 This proposed rule was written after reviewing similar rules now in effect in other nearby 

California counties, specifically El Dorado, Sacramento and Yolo-Solano. The 

standards proposed for Rule 24 are generally equivalent to the recently amended Rule 

2.32 in Yolo-Solano AQMD. The Sacramento Rule 412 for Stationary Internal 

Combustion (IC) Engines, adopted in June, 1995, applies only to Major Sources and is 

therefore not applicable when considering rule consistency among the nearby Districts. 

Placer County has no Stationary IC Engine Major Sources. 

 

In April, 2002 the Air Resources Board (ARB) published a draft Air Toxics Control 

Measure (ATCM) that included suggested control limits on particulate emissions for 

stationary diesel engines. These limits were not included in this proposed Rule 242 

because the proposed ATCM is an air toxic control measure that is separate from the 

attainment plan. 

Although the requirement for this rule is based on the Sacramento Area Regional 

Ozone Attainment Plan, the staff is recommending that the proposed rule be applicable 

for all of Placer County. This maintains uniformity within the District and avoids the 

need for multiple rules within the County. 

 

DISCUSSION OF PROPOSED RULE

Public notices of the proposed adoption of this rule were published in local newspapers 

on March 10, 2003. The notice and draft rule were made available on the District's 

website. Advisory notices were mailed to the permitted sources that had engines, 

including exempt and non-exempt. 

The majority of the stationary internal combustion engines in Placer County are 

emergency engines. These are typically emergency generators, fire pumps or ski lift 

engines. These are exempt from this rule because NOx or CO emissions for the low 

number of hours normally in use are not significant. 

 This rule may affect engines at the following companies or parties: 

 
Staff Report 

Rule 242 

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 Chevreax Aggregate, Meadow Vista 

 City of Roseville, Waste Water Treatment Plant, 1800 Booth Road 

 Coherent 

 Energy 2001 

 Hewlett Packard 

 NEC Electronics 

 Patterson Sand and Gravel 

 Robinson Sand and Gravel 

 Sierra Pacific Power 

It is expected that Coherent, Hewlett Packard, NEC Electronics and Sierra Pacific 

Power may change their permit to operate conditions to limit operation of each engine to 

less than 200 hours per year to exempt their engines. Energy 2001 is not currently 

operating but has met the general standards during prior testing. 

New stationary engines will be required to meet the best available control technology 

(BACT) pursuant to Rule 502, New Source Review, which will be more stringent than 

the standards identified in this rule. 

Purpose:

This Section, Section 101, states that the purpose is to limit the emission of NOx and 

CO from stationary internal combustion engines. 

Applicability:

Section 102 states that the Rule applies to facilities located anywhere in Placer County. 

Specifically, the rule applies to any stationary internal combustion engine rated at more 

than 50 horsepower. Engines powered by any gaseous fuel or liquid fuel (including 

liquefied petroleum gas, gasoline or diesel fuel) are included. Engines used exclusively 

for agricultural operations necessary for the growing of crops or the raising of fowl and 

animals are excluded from the provisions of this rule. 

Exemptions:

 Section 103 exempts engines operated less than 200 hours per calendar year, and 

those operating emergency standby power sources. Emergency generators, fire 

pumps, flood control pumps, and backup ski lift engines are exempt. Also exempted 

are: (1) engines used for research, testing and evaluation, (2) engines with a permitted 

capacity factor of 15% or less and (3) engines used to power cranes and welding 

equipment. 

Definitions:

 Seventeen key definitions are included. 

 
Staff Report 

Rule 242 

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Standards:

 Section 301 - NOx and CO emission limits are specified for rich burn engines, lean burn 

engines and diesel engines. Rich burn NOx limit is 90 parts per million by volume 

(ppmv) and rich burn CO limit is 2000 ppmv. Lean burn NOx limit for engines greater 

than 100 hp is 150 ppmv and CO limit is 2000 ppmv. Lean burn NOx limit for engines 

equal to or less than 100 hp is 300 ppmv and CO limit is 2000 ppmv. Diesel engine 

limits are 600 ppmv for NOx and 2000 ppmv for CO. Existing diesel engines that 

require retrofit to meet the standard are allowed a longer time for compliance with the 

proposed rule (see Administrative, below). 

 Section 302 requires an Engine Operation Inspection Plan for any engine subject to the 

provisions of Section 301. The Plan shall include equipment description, control 

systems (if any), company identification, location and procedures for emission 

inspection and maintenance. 

 In lieu of meeting the above emission limits, the owner/operator may choose to 

permanently remove a stationary IC engine from service, or replace it with an electric 

motor. (See Administrative, Compliance Schedule, Section 401.4, below.) 

 Section 301.4 requires non-resettable fuel consumption and non-resettable elapsed 

time meters for all engines subject to this rule, including emergency standby engines 

operated less than 200 hours per year. 

Administrative:

 Section 401.1 - The effective date for compliance is 90 days after adoption of the rule 

for new and existing engines meeting the standards as specified above. Operator 

inspection plans or support documentation showing compliance are also required. 

 Section 401.2 - For engines requiring retrofit to meet the standards, inspection plans 

and support documentation are required by 90 days after adoption of the rule, and 

construction of the necessary equipment and changes must be completed by July 1, 

2004. 

 Section 401.3 requires that any owner/operator constructing a new or replacement 

engine after the date of adoption of this rule shall complete an application for Authority 

to Construct before beginning construction and shall demonstrate that the unit will be 

operated in compliance with all applicable provisions of this rule within 60 days after the 

date of initial startup 

 

 Section 401.4 requires specific compliance dates for permanently removing a stationary 

internal combustion engine or replacing it with an electric motor 
Staff Report 

Rule 242 

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 Section 402 requires annual reports for permitted units, specifying fuel consumption, 

actual operating hours, engine technical data, summary of maintenance and testing 

reports and an annual emissions report. 

 Section 403 requires quarterly screening analyses using a portable NOx analyzer. Data 

obtained shall be reported to the District. 

 Section 404 requires an emission source test at least once every 24 months. 

Procedures, protocol and reporting are included. 

Section 405 discusses violations and owner/operator responsibility

Monitoring and Recordkeeping:

 Section 501 requires maintenance of operating inspection logs and lists the specific 

information needed. 

 Section 502 lists specific recordkeeping requirements for operators claiming exemption 

under Section 103. 

 Section 503 discusses retention requirements for operating records. 

 Section 504 lists appropriate test methods. 
Staff Report 

Rule 242 

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FINDING DEFINITION REFERENCE

Authority The District is permitted or required to adopt, 

amend, or repeal the rule by a provision of law or a 

state or federal regulation. 

California Health and Safety Code, Section 

40702 and Section 41010; 1990 Federal Clean 

Air Act, Section 110(a)(2)(H) and Section 

182(d). 

Necessity The District has demonstrated that a need exists for 

the rule, or for its amendment or repeal. 

It is necessary for the District to adopt this rule 

in order to fulfill the requirements of the 

Federal Clean Air Act Amendments of 1990. 

Clarity The rule is written or displayed so that its meaning 

can be easily understood by the persons directly 

affected by it. 

There is no indication at this time that the rule 

is not written in such a manner that the person 

affected by the rule can easily understand it. 

Consistency The rule is in harmony with, and not in conflict with 

or contradictory to, existing statutes, court 

decisions, or state or federal regulations. 

The District has found that the rule is 

consistent with existing state and federal 

guidelines, and rules in nearby Districts. 

Non-duplication The rule does not impose the same requirements 

as an existing state or federal regulation, unless the 

District finds that the requirements are necessary 

or proper to execute the powers and duties granted 

to, and imposed upon the District. 

There does not exist any state or federal rule 

or regulation that applies to surface 

preparation and cleanup solvents operations 

within the District. 

Reference Any statute, court decision, or other provision of law 

that the District implements, interprets, or makes 

specific by adopting, amending, or repealing the 

rule. An example of this would be the 1988 EPA 

State Implementation Plan call to revise District 

rules. 

This rule is being proposed because of the 

requirements of the Federal Clean Air Act 

Amendments of 1990.