MONTEREY BAY UNIFIED AIR POLLUTION CONTROL DISTRICT

REGULATION IV

PROHIBITIONS

12/15/04 Rule 400 (Visible Emissions)

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RULE 400 VISIBLE EMISSIONS

(Adopted July 1, 1969; Revised April 26, 1995, June 18, 1997, March 22, 2000, October 15,

2003, and December 15, 2004.)

CONTENTS

PART 1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.3 Exemptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.4 Effective Dates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

PART 2 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 Abrasives Certified for Permissible Dry Outdoor Blasting . . . . . . . . . . . . . . . . . 4

2.2 Obscurant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.3 Opacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.4 Ringelmann Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.5 Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.6 Teepee Burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

PART 3 REQUIREMENTS AND STANDARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.1 General Visible Emission Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.2 Industry-Specific Visible Emission Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . 6

PART 4 ADMINISTRATIVE REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.1 Test Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
MONTEREY BAY UNIFIED AIR POLLUTION CONTROL DISTRICT

REGULATION IV

PROHIBITIONS

12/15/04 Rule 400 (Visible Emissions)

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PART 1 GENERAL

1.1 Purpose

The purpose of this Rule is to provide limits for the visible emissions from sources

within the District.

1.2 Applicability

The provisions of this Rule shall apply to all sources of air pollutant emissions in

the District.

1.3 Exemptions

The provisions of this Rule shall not apply to the following activities:

1.3.1 any open burning performed in compliance with Rule 407 {California Health and

Safety Code (HSC) Sections 41704 (a), (b), (c), and (e)};

1.3.2 use of any aircraft to distribute seed, fertilizer, insecticides, or other agricultural

aids over lands devoted to the growing of crops or raising of fowl or animals

{HSC Section 41704 (d)};

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

animals {HSC Sections 41704 (g) and (h)};

1.3.4 the use of visible emission generating equipment in training sessions conducted

by governmental agencies necessary for certifying persons to evaluate visible

emissions for compliance with applicable District rules and regulations {HSC

Section 41704 (l)};

1.3.5 emissions from vessels using steam boilers during emergency boiler shutdowns

for safety reasons, safety and operational tests required by governmental

agencies, and where maneuvering is required to avoid hazards {HSC Section

41704 (j)};

1.3.6 emissions from vessels during a breakdown condition, as long as the discharge is

reported in accordance with District requirements {HSC Section 41704 (k)};
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1.3.7 smoke emissions from teepee burners during the disposal of forestry and

agricultural residues or forestry and agricultural residues with supplementary

fossil fuels when the emissions result from the startup or shutdown of the

combustion process or from the malfunction of emission control equipment. 

This exemption does not apply to emissions which exceed a period or periods of

time aggregating more than 30 minutes in any 24 hour period, nor to emissions

which result from the failure to operate and maintain in good working order any

emission control equipment {HSC Section 41704 (m)};

1.3.8 smoke emissions from burners used to produce energy and fired by forestry and

agricultural residues with supplementary fossil fuels when the emissions result

from the startup or shutdown of the combustion process or from the malfunction

of emission control equipment. This exemption does not apply to emissions

which exceed a period or periods of time aggregating more than 30 minutes in

any 24 hour period, nor to emissions which result from the failure to operate and

maintain in good working order any emission control equipment {HSC Section

41704 (n)};

1.3.9 emissions from methanol fuel manufacturing plants which manufacture not more

than 2,000,000 gallons of methanol fuel per day from wood, agricultural waste,

natural gas, or coke (exclusive of petroleum coke). As used in this Subsection,

"manufacturing plant" includes all necessary support systems, including field

operations equipment that provide feedstock. However, this exemption shall be

available to only one methanol fuel manufacturing plant in the District, and is

effective only when the District is designated as an "attainment area" pursuant to

the Federal Clean Air Act (42 U.S.C. Sec. 7401 et seq.) This exemption shall

remain in effect with respect to a plant until five years after construction of the

plant and shall have no force and effect with respect to the plant on and after that

date {HSC Section 41704 (o)};

1.3.10 the use of an obscurant for the purposes of training military personnel and the

testing of military equipment by the United States Department of Defense on

any military reservation {HSC Section 41704 (p)};

1.3.11 wet plumes where the presence of uncombined water is the only reason for the

failure of an emission to meet the limitations of Section 3.1 of this Rule. The

burden of proof which establishes the application of this exemption shall be

upon the person seeking to benefit from its provisions;

1.3.12 the use of an orchard, field crop, or citrus grove heater which does not

produce unconsumed solid carbonaceous material at a rate in excess of that

allowed by State law, which is 1 gram per minute of unconsumed solid
MONTEREY BAY UNIFIED AIR POLLUTION CONTROL DISTRICT

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carbonaceous material. {HSC Sections 41860 and 41704 (f)}

1.4 Effective Dates

This Rule, as most recently revised, is effective on December 15, 2004.

1.5 References

1.5.1 The requirements of this Rule arise from the provisions of: California Health &

Safety Code Sections 39043.5, 41701.5, 41701.6 ,41704 and 41860; Title 17

Section 92000 et seq. of the California Code of Regulations, and the Code of

Federal Regulations (CFR) Part 60, Part 61, and Part 63.

1.5.2 Other related rules include: Rule 407 (Open Outdoor Fires), Rule 403

(Particulate Matter), Rule 404 (Sulfur Compounds and Nitrogen Oxides), Rule

423 (New Source Performance Standards), and Rule 424 (National Emission

Standards for Hazardous Air Pollutants). 

PART 2 DEFINITIONS

2.1 Abrasives Certified for Permissible Dry Outdoor Blasting

The abrasive blasting material defined in Title 17 of the California Code of

Regulations Sections 92000 et seq. 

2.2 Obscurant

Fog oil released into the atmosphere during military exercises which produces a

smoke screen designed to eliminate the detection of persons or objects by visual or

electronic means of observation within a localized area. {HSC Section 39043.5}

2.3 Opacity
MONTEREY BAY UNIFIED AIR POLLUTION CONTROL DISTRICT

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PROHIBITIONS

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The degree to which light is prevented from passing through an emission plume. Its

measure is expressed as one (1.0) minus the optical transmittance of a smoke

plume, screen target, etc. as determined by the test methods in Section 4.1 below. 

Dark plumes are expressed as numbers 1 through 5 on the Ringelmann chart, while

light plumes are expressed as equivalent percentages. Thus, Ringelmann 1

corresponds to 20% opacity, Ringelmann 2 corresponds to 40% opacity,

Ringelmann 3 to 60% opacity, Ringelmann 4 to 80% opacity, and Ringelmann 5

corresponds to 100% opacity. 

2.4 Ringelmann Chart

The chart used to designate shades of darkness of emissions as published by the

United States Bureau of Mines. 

2.5 Startup

The period of time, as defined by District permit, when a gas turbine goes from a

non-operational to a fully operational state.

2.6 Teepee Burner

A conical shaped device used to burn flammable forestry and agricultural product

waste material in an enclosed fixture effective in preventing the spread of sparks or

fire, situated in an area cleared of grass, grain, brush, slash, litter, and snags for a

distance of 100 feet surrounding the device or by landfill or other methods which

meet applicable state and local fire safety, air, and water quality standards. A burn

permit pursuant to Rule 407 must be obtained for use of such device. 

PART 3 REQUIREMENTS AND STANDARDS

3.1 General Visible Emission Limitations

A person shall not discharge into the atmosphere from any emission source 

whatsoever any air contaminant for a period or periods aggregating more than three

minutes in any one hour, which is as observed using the appropriate test method

referenced in Section 4.1:
MONTEREY BAY UNIFIED AIR POLLUTION CONTROL DISTRICT

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3.1.1 as dark or darker in shade as that designated as No. 1 on the Ringelmann

Chart, as published by the United States Bureau of Mines; or

3.1.2 of such opacity as to obscure an observer's view to a degree equal to or

greater than does smoke described in Subsection 3.1.1 above. 

3.2 Industry-Specific Visible Emission Limitations

3.2.1 Abrasive Blasting

Notwithstanding the requirements of Subsection 3.1 above, abrasive

blasting operations shall not exceed visible emissions limits set by 

Sections 92000 et seq. of Title 17 of the California Code of Regulations,

which are 20% opacity for indoor operations using non-certified

abrasive blasting material and 40% opacity for more than 3 minutes in

any hour for outdoor operations using the following methods: wet

abrasive blasting, hydroblasting, vacuum blasting, or abrasives certified

for permissible dry outdoor blasting.

3.2.2 Drinking Water Systems

Notwithstanding the requirements of Section 3.1, emissions of visible

smoke from any diesel auxiliary engine or generator used exclusively to

operate a drinking water system shall not exceed Ringelmann 2, when

operated under emergency circumstances, or operated not more than 30

minutes each week, or two hours each month, under non-emergency

circumstances. {HSC Section 41701.6}

3.2.3 Gas Turbines

Notwithstanding the requirements of Section 3.1, visible emissions from

gas-fired combustion turbines may exceed Ringelmann 1 during startup,

provided that visible emissions during such startups shall not exceed

Ringelmann 2 (or equivalent 40% opacity) for a period or periods

aggregating more than three minutes in any one hour.

3.2.4 Pile Drivers

Notwithstanding the requirements of Section 3.1, pile driver operations

shall not exceed the visible emission limits set by Health and Safety

Code Sections 41701.5, which are Ringelmann 1 for no more than 4
MONTEREY BAY UNIFIED AIR POLLUTION CONTROL DISTRICT

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minutes per pile, or Ringelmann 2 for no more than 4 minutes per pile if

operating on kerosene, smoke suppressing additives and synthetic

lubricating oil.

3.2.5 Federally Regulated Industries

In addition to the general visible emission limits of Section 3.1 above,

industries subject to any visible emission limit codified in 40 CFR Part

60, 40 CFR Part 61, or 40 CFR Part 63 shall comply with those limits. 

For reference, District Rules 423 (New Source Performance Standards)

and 424 (National Emission Standards for Hazardous Air Pollutants)

include lists of the industry-specific standards which have been

promulgated in 40 CFR Parts 60 and 61 respectively.

PART 4 ADMINISTRATIVE REQUIREMENTS

4.1 Test Methods

4.1.1 Except for any visible emission limits codified in 40 CFR Part 60, 40 CFR

Part 61, or 40 CFR Part 63, all visible emissions determinations shall be in

accordance with EPA Method 9 (Visual Determination of the Opacity of

Emissions from Stationary Sources) except for the data reduction procedures. 

Data reduction shall consist of counting the number of observations above the

applicable standard and multiplying that number by 0.25 to determine the

minutes of emissions above an applicable standard.

4.1.2 Visible emissions for any visible emission limit codified in 40 CFR Part 60,

40 CFR Part 61, or 40 CFR Part 63 shall be observed in accordance with the

observation procedure contained within EPA Method 9 or Method 22 (Visual

Determination of Fugitive Emissions from Material Sources and Smoke

Emissions from Flares), as applicable, codified as Appendix A of 40 CFR Part

60.

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