VEO Form Instructions

VEO Form Instructions

Use the tabs above to learn more about how to fill out the VEO form.


VEO Form - 30 minute
VEO Form - 60 minute
Federal Method

Company Identification

company contact information
Reference Instructions: QA/QC Procedure
The LEGAL Name of the Company as it appears on the Permit. Be careful to not abbreviate in an inappropriate way. Is the company an LLC, Inc, or Corp? E. I. du Pont de Nemours and Company is often known as DuPont but this is not the LEGAL name and this may vary for some companies by State. Include the Complete name for positive identification of the company: Parent Company name, Division, and/or subsidiary should be included.
E.I du Pont de Nemours and Company, Fiber Division, Charleston, SC Facility

Street Address
Indicate the street address of the facility i.e. physical location address (NOT the mailing address or the home office) not the main office of the site but the site address itself. The exact physical location of the source should be documented (verifiable by GPS coordinates). If necessary the mailing address and/or home office address may be listed on the back of the form or in the comments section.

Phone (key contact)
List the phone number of the appropriate contact at the facility such as the plant manager or Environmental Officer.

Source ID Number
This space is provided for the use of agency personnel and may be used to enter the number the agency uses to identify that particular source, such as the State file number, Compliance Data System Number or National Emission Data System number --- with the inception of Title V Permitting program under the Clean Air Act of 1990 this number would be the identification number in the Title V permit (synthetic minor or minor source permit) for the source of emissions.

Emission Description

Includes information that definitely establishes what was observed while making the visible determinations (observations). Note: Items called for in this section may change a number of times during the observation period. It is recommended that these changes be noted in the comment space beside the appropriate opacity readings (for each minute) and reference (letter a, b, c, etc. …..) to this be made in the corresponding space in this section.

Describe Emissions

Include the physical characteristics and behavior of the plume (not addressed elsewhere on this form ) and the distance it is visible. Physical descriptions may include such things as texture, graduation, and contents; examples are "lacy", "fluffy" "copious". "mushrooming" (this would indicate poor engineering design on the fan selection), "puffing", "wisping" , "spreading over the horizon" and "detached non-water vapor condensibles." The Standard Plume Terminology illustrated on the bottom of page 46 may be used to describe plume behavior. The behavior is generally used to determine the atmospheric stability on the day of the opacity observations.

Emission Color

Note the color of the emissions. The plume color can sometimes be useful in determining the composition of the emissions and also serves to document the total contrast between the plume and its background as seen by the opacity observer. For emissions that change color a number of times during the observation period (such as those from a basic oxygen furnace), the color changes should be noted in the comments space next to the opacity readings themselves.


There are no emissions, but the subpart OOO source (limestone crusher and screening facility) has only a potential to emit emissions of a white or light gray emissions. What is the emission color? After emission color write -"Potential - White", at beginning and end put -"NONE".

The emission color changes during the reading? Do I need to change locations/backgrounds? How do I document this? You do not necessarily need to change position but you can. Use a superscript a to denote a footnote or reference to a comment, this may include that the emission color changed so you stopped reading at a certain time and resumed reading at a specific time or may simply denote the color change and now the lack of contrast may under-report the actual opacity, allowing a continual reading without change of location.

I cannot get a contrasting background - can I still read? Yes. Documenting the color and the background will pour meaning into your readings by clearly delineating the degree of contrast or lack thereof.

If water droplets plume: This box is only completed if visible water droplets are present (see Water Vapor Plume Video). Check "attached" if condensation of the moisture contained in the plume occurs within the stack and the water droplet plume is visible at the stack exit. Check "detached" if condensation occurs some distance downwind of the stack exit and the water droplet plume and the stack appear to be unconnected.

Plumes containing condensed water vapor ("water droplet plumes" or "steam Plumes") are usually very white and billowy (like white clouds) and then wispy at the point of dissipation, where the opacity decreases from a high value (usually 100%) to zero if there is no residual opacity contributed by contaminate in the plume. Water Vapor collapses upon itself as it evaporates back in the atmosphere, more quickly in low humidity conditions.

To document the presence or absence of condensed water vapor in the plume two points must be addressed.

First - Is sufficient moisture present (condensed or uncondensed) in the effluent to produce water droplets at in-stack or ambient conditions?

Second - If enough moisture is present, are the in-stack or ambient conditions such that it will condense either before exiting the stack or after exiting (when it meets ambient air)?

The first question can be answered by examining the process type and/or the treatment of the effluent gas after the process. Some common sources of moisture in plumes are:

    Water produced by combustion of fuels
    Water from dryers
    Water introduced by wet scrubbers
    Water Introduced for gas cooling prior to an electrostatic precipitator or other control device
    Water used to control the temperature of chemical reactions (cooling water)

If water is present in the plume, data from a sling psychrometer, which can be used to determine the relative humidity, in combination with the moisture content and temperature of the effluent gas can be used to predict whether the formation of a steam plume is probable .

Prior Source Test data can be used for the determination of the process effluent condition (Moisture and Temperature) and the referenced relative humidity from the nearest airport ( or other site) can be used to make the ambient condition determination.

Emission Point Identification

Emission point identification for VEO form
Reference Instructions: QA/QC Procedure

Contains information uniquely identifying the emission point and its spatial relationship with the observer's position. It is recommended that distances and heights in this section be noted in consistent units.
Photographs are useful references in this section providing secondary evidence about the source of emission being investigated and allowing verification with those knowledgeable of the process. Photographs are useful as secondary evidence to show the source, and context of the readings.

Describe the Emission Point

Describe the type and physical characteristics of the emission point. The descriptions should be specific enough so that the emission outlet can be distinguished from all others at the source (facility). The description of the type of emission point should address whether it is (1) a specifically designed outlet such as a stack, vent or roof monitor (having confined emissions) or (2) an emission source having unconfined emissions such as a storage pile, chemical tank, non-ducted material handling operations. Description of the physical characteristics of the emission point should include the appearance (such as color, texture, etc) and geometry (size, shape, etc) of the stack or outlet, and it's location (if applicable) in relation to other recognizable facility landmarks.

Any special identification codes the agency or source uses to identify a particular stack ( #3 boiler, round Red Brick stack, 70 feet high and 10 feet in diameter) or outlet should be noted along with a description; the source of the code should also be noted (side of stack, facility designation, agency). Don't use the same code used in section A where the Source ID number is provided. Careful examination of this document will show how all the information provided can be used to self-verify the form. Therefore it is important that this section contain information which could be separately referenced to confirm the stack/source has been correctly identified. A special identification code should not be used alone (#3 boiler) to describe the emission point, since they are at times incorrect and also require a secondary reference. The observer must be certain of the source of the emissions being read (the observer must have a clear and unobstructed view). A description of the emission point coupled with the identification of the process equipment and control equipment should accomplish that purpose. If including the height be consistent with the height above ground level. Information should be consistent with and verifiable by the applicable permit information.

Height Above Ground Level

Indicate the height of the stack or other emission outlet from it's foundation base. This information is usually available from agency files, engineering drawings, or computers printouts (such as the NEDS printouts). The information may be obtained using a combination of a rangefinder and an Abney Level or inclinometer. The height may also be estimated. However be careful not to carry your estimation errors - such as I am 3 stack heights away and the rangefinder gives me 300 feet therefore it is 100 feet.

Height Relative to Observer

Indicate an estimate of the height of the stack outlet (or other type of emission outlet) above the position of the observer. This measurement indicates the observer's position in relation to the stack base (i.e. higher or lower than the base) and is necessary if slant angle calculations are performed. It is expected to confirm that slant angle calculations are not necessary.

Distance from the Observer

Record the distance from the point of observation to the emission outlet. This measurement may be made using a rangefinder. A map (or GPS) may also be used to estimate the distance. This measurement must be reasonably accurate when the observer is close to the stack (within three stack heights). Accuracy is important because this may be used in conjunction with the outlet height relative to the observer to determine the slant angle at which the observations were made (see Fig 2). A precise determination of the slant angle becomes important in calculating the precise bias inherent in opacity readings made when the observer is within three stack heights of the stack. Small sources which are accessible may be measured using a measuring tape, roller/counter or paced off by the observer.

Process and Control Equipment

Process and control equipment for VEO


Include a several word description of the process and control device, indication of the current process operating capacity or mode, and the operational status of the control equipment. Note: This section in particular contains information that will probably have to be obtained from a plant official. EPA personnel asking a plant official for information requires the approval of OMB, an active case investigation, or a prominent disclaimer that the official is under no obligation to answer. Since a facility may consider their production rate or other process information proprietary, the inspector shall specifically inform them that they have a right to request that this information be submitted subject to the confidential business information provisions of 40 CFR 2, subpart 8.


The information required differs based upon the purpose for which the information is to be utilized. The comments above for the regulators apply when this is to be used for enforcement action and legal proceedings for which the regulator needs to be certain that the correct procedures for obtaining evidence are followed. Likely within the required report (NSPS or Title V submission) you will desire to exercise your rights under 40 CFR 2, subpart 8, such that all of this information is kept proprietary.

For NSPS purposes, it is important to completely document the make, model, and serial number of the equipment. The operating mode refers to the production capacity. For NSPS purposes, you must reach 90% of your desired operating limit to prove that the equipment meets the environmental requirements at the desired operating limit (i.e. if the operation is designed to produce 1000 widgets per hour the NSPS compliance test must be conducted at least at 900 widgets per hour in order to not have a de-rated production limit applied to the operation). You will be allowed to operate 10% over the name-plate (or proposed) limit or up to 1100 widgets per hour without proving compliance at the higher rate. Achieving a greater than nameplate operational capacity Likely within the required report you will desire to exercise your rights under 40 CFR 2, subpart 8, such that all of this information is kept proprietary.

Title V purposes are different. These are daily, weekly, monthly, at times only annual or less requirements. The make, model, and serial number does not need to be verified daily, but you do need to be sure you are looking at the correct stack (especially consultants need to verify the stack - photographs help).

Process Equipment

Enter a description which clearly identifies the process equipment and the type of facility that emits (or has the potential to emit) the plume or emissions to be read. The description should be brief but should include as much information as possible (complete yet concise), as indicated in the following examples.

Coal Fired Blr-#4 /Power Plt #2 Oil-Fired Blr / Chemical Plt Wood Waste Conical Incinerator
Paint Spray Booth/ Auto Plant Primary Crusher #1 at Rock Qry  Primary Crusher #2 at Rock Qry
Primary Crusher at Rock Quarry Fiberglass Curing oven Reverb Furnace/Copper Smelter
Basic Oxygen Furnace/Steel Mill  Ball Mill / Cement Plant Cement Plant Kiln

If the reading is for a NSPT(New Source Performance Test), attach documentation that provides a complete process description including make, model, and serial number on the equipment. If a new unit (same make and model) replaces an old unit then the NSPT must be performed for the new unit.

Operating Mode

Depending on the type of process equipment and specific situation this information may vary from a quantification of the current operating rate to a description of the portion of a batch-type process form which the opacity is being read, to an explanation of how the equipment is currently operating such as "upset condition," "start-up" or "shutdown." For NSPT purposes these "conditions" would be excluded as well as any down-time. Read and report only upon the operating time and the actual operating rate which can be documented. Other Examples include "90 percent capacity" for a boiler or "85% production rate (assumes name plate production rate previously reported to EPA as the NSPT rate) for the shake-out area of a grey iron foundry. For a steel making facility entries should include the exact part of the process cycle for which the readings are being made, such as "charging", or "tapping". In most case this information will have to be obtained from a plant official. Often this may be coordinated with the reading time in advance or after the exact timing of records will need to be matched. There may also be a delay between a process step and the actual emission occurrence.

Control Equipment

Specify the types of control equipment being used in the process system after the process equipment in question (e.g. "hot-side electrostatic precipitator"). This may entail several steps as a modern clean-coal power plant will included an electrostatic precipitator and a wet (or dry) scrubber.

Operating Mode

Indicate the manner in which the control equipment is being utilized at the time of the opacity observations (e.g. 1 field of 8 tripped on ESP, scrubber operating without water - or at flow and pH of, shutdown, offline) and the operating mode (e.g. automatic, manual, bypass). This information should be obtained from a plant official (because otherwise it is proprietary and an illegal search and potentially would not be admissible into any proceedings - SEE 40 CFR 2, subpart 8)

When performing a new source performance test the make, model, and serial number of the control equipment, as well as a complete operational description should be included. Operating mode should include all parameters applicable to that type of control equipment such as: for a scrubber the air flow, pressure drop, water flow and pH or a bag-house - the pressure drop and air flow or for a primary crusher at a quarry the water flow rate (gallons per minute).