Preparing for Your Upcoming Stack Test

Source Emissions testing, or stack testing, is mandated by the Clean Air Act of the U.S. Environmental Protection Agency (EPA), which sets forth guidelines and requirements that must be met to determine a facility’s compliance with emission limits.  Any and all plants, factories, and facilities that utilize a stack as part of manufacturing or production operations are required to undergo stack testing in order to demonstrate compliance with current EPA standards.  There is more to stack testing than simple compliance, however.  A properly-executed testing plan gives you the diagnostic tools to help optimize your operations and improve energy efficiency — quality incentives for voluntary stack testing that is not simply driven by EPA requirements.  With careful preparation for stack-testing compliance and the proper execution of the test plan, a company can save money, protect workers, and effectively streamline their operations.

As a company prepares their facility for an upcoming stack test, reviewing the state-approved test plan is the best way to ensure that you understand all of the testing requirements.  Doing so is your greatest insurance that the stack testing results will show proper compliance with all relevant EPA air emission standards.  However, in many cases technical or legal jargon may make a portion or the entirety of the test plan difficult to understand, and it may not contain all of the required information necessary to conduct a successful test.  To assist you with this, we have put together the following Stack Testing Preparation Checklist to help you make sure that your company is properly prepared for your upcoming testing.  All items on this checklist should be reviewed with your qualified stack-testing team.

  1. What Load you will test at – This information is typically in your air permit, and/or determined by applicable federal/state  regulations.
  2. What Fuel you will burn – Different fuel types can have vastly different emission limits
  3. OSHA compliant platforms – How will the stack test team reach the sampling plane?
  4. Power Requirements – Do you have enough circuits?
  5. Safety/Insurance Concerns- What are your facility requirements?  Does your stack test company meet these requirements?
  6. Are your Test Ports free from blockage and EPA Method 1 Compliant?
  7. What Process Data are you required to document, and how will that data be logged?

Here at Environmental Source Samplers Inc., we’re familiar with the pitfalls a company can experience when faced with an upcoming test.  Advance preparation, with these guidelines in mind, will provide your company the ability to address any issues or questions prior to the stack testing date. Saving your company the time, hassle, and money that late revisions and changes inevitably cause.  These guidelines are also helpful in maintaining high levels of safety and compliance regardless of having a scheduled stack test or not, benefitting the overall operations and their environmental impact.

Choosing a stack testing company that has the appropriate background and experience for your industry will help ensure that your stack test will be successful.  The stack testing company should have the capability to execute the testing types and methodologies that govern your specific operations, while using equipment that is well-maintained and up-to-date.  Just as importantly, they should be current and informed on the changes and revisions to existing testing methodologies, since the EPA air emission limits and standards are subject to change as the Agency sees fit.

Stack testing is required and performed for the health and safety of the plant, the workers, and the environment.   It is also a diagnostic tool that provides insight into the efficiency of your operations.  However, whether you are testing for compliance or diagnostic purposes, careful preparation is the key to ensuring that your stack testing project gives you the data that you can use effectively.

Please contact the experts at Environmental Source Samplers (ESS) to learn more about their stack testing services:

Phone: 910-799-1055
Email: [email protected]

EPA News: For the First Time in 40 Years EPA to Put in Place a Process to Evaluate Chemicals that May Pose Risk

2017-01-13 First Time 40 Years Chemical Review

WASHINGTON–The Environmental Protection Agency (EPA) is moving swiftly to propose how it will prioritize and evaluate chemicals, given that the final processes must be in place within the first year of the new law’s enactment, or before June 22, 2017.

“After 40 years we can finally address chemicals currently in the marketplace,” said Jim Jones, EPA’s Assistant Administrator for the Office of Chemical Safety and Pollution Prevention. “Today’s action will set into motion a process to quickly evaluate chemicals and meet deadlines required under, and essential to, implementing the new law.”

When the Toxic Substances Control Act (TSCA) was enacted in 1976, it grandfathered in thousands of unevaluated chemicals that were in commerce at the time. The old law failed to provide EPA with the tools to evaluate chemicals and to require companies to generate and provide data on chemicals they produced.

[Read more…]

EPA News: EPA Report Shows Air Emissions of Toxic Chemicals from Industrial Facilities Down More Than Half Since 2005

2017-01-13 Toxic Air Emissions Down 56 Percent

WASHINGTON — The U.S. Environmental Protection Agency today released its annual Toxics Release Inventory (TRI) National Analysis, which shows releases of toxic chemicals into the air fell 56% from 2005-2015 at industrial facilities submitting data to the TRI program.

“Today’s report shows action by EPA, state and tribal regulators and the regulated community has helped dramatically lower toxic air emissions over the past 10 years,” said Jim Jones, EPA Assistant Administrator for the Office of Chemical Safety and Pollution Prevention. “The TRI report provides citizens access to information about what toxic chemicals are being released in their neighborhoods and what companies are doing to prevent pollution.”

The report shows an 8% decrease from 2014 to 2015 at facilities reporting to the program contributed to this ten-year decline. Hydrochloric acid, sulfuric acid, toluene and mercury were among chemicals with significantly lower air releases at TRI-covered facilities. Medical professionals have associated these toxic air pollutants with health effects that include damage to developing nervous systems and respiratory irritation.

[Read more…]

OSHA News: US Department of Labor Issues Final Rule to Lower Beryllium Levels

2017-01-06 New OSHA Rule for Beryllium Exposure

WASHINGTON – A new rule issued today by the U.S. Department of Labor’s Occupational Safety and Health Administration dramatically lowers workplace exposure to beryllium, a strategically important material that can cause devastating lung diseases. The new beryllium standards for general industry, construction and shipyards will require employers to take additional, practical measures to protect an estimated 62,000 workers from these serious risks.

Beryllium is a strong, lightweight metal used in the aerospace, electronics, energy, telecommunication, medical and defense industries. However, it is highly toxic when beryllium-containing materials are processed in a way that releases airborne beryllium dust, fume, or mist into the workplace air that can be then inhaled by workers, potentially damaging their lungs.

Recent scientific evidence shows that low-level exposures to beryllium can cause serious lung disease. The new rule revises previous beryllium permissible exposure limits, which were based on decades-old studies.

[Read more…]

EPA News: EPA Names First Chemicals for Review Under New TSCA Legislation

EPA News: 10 Chemicals Under TSCA Review

WASHINGTON – Today, EPA is announcing the first ten chemicals it will evaluate for potential risks to human health and the environment under TSCA reform.

“Under the new law, we now have the power to require safety reviews of all chemicals in the marketplace.” said Jim Jones, assistant administrator of the of Office of Chemical Safety and Pollution Prevention. “We can ensure the public that we will deliver on the promise to better protect public health and the environment.”

The first ten chemicals to be evaluated are:

  • 1,4-Dioxane
  • 1-Bromopropane
  • Asbestos
  • Carbon Tetrachloride
  • Cyclic Aliphatic Bromide Cluster
  • Methylene Chloride
  • N-methylpyrrolidone
  • Pigment Violet 29
  • Tetrachloroethylene, also known as perchloroethylene
  • Trichloroethylene

Toxic Substances Control Act (TSCA) as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act, requires EPA to publish this list by December 19, 2016. These chemicals were drawn from EPA’s 2014 TSCA Work Plan, a list of 90 chemicals selected based on their potential for high hazard and exposure as well as other considerations.

When the list is published in the Federal Register it will trigger a statutory deadline to complete risk evaluations for these chemicals within three years.  This evaluation will determine whether the chemicals present an unreasonable risk to humans and the environment. If it is determined that a chemical presents an unreasonable risk, EPA must mitigate that risk within two years.

Under the newly amended law, EPA must release a scoping document within six months for each chemical. This will include the hazard(s), exposure(s), conditions of use, and the potentially exposed or susceptible subpopulation(s) the agency plans to consider for the evaluation.

Additional chemicals will be designated for evaluation, and all of the remaining Work Plan chemicals will be reviewed for their potential hazard and exposure. For each risk evaluation that EPA completes, TSCA requires that EPA begin another. By the end of 2019, EPA must have at least 20 chemical risk valuations ongoing at any given time.

For more on the chemicals listed and additional information:



Cathy Mibourn

[email protected]



Supreme Court Halts MATS Rule

Late Tuesday it was announced that the U.S. Supreme Court has halted the implementation of the Mercury and Air Toxics (MATS) rule.  This is the first time in recent memory that the U.S. Supreme Court has put a rule on hold before the lower court review.  Rulings from the lower court are expected over the summer.

Here are some other articles discussing the Supreme Court’s decision to put the MATS rule on hold:

Supreme Court To EPA: Fool Me Once

Carbon pollution controls put on hold

Supreme Court Puts White House’s Carbon Pollution Limits On Hold


Sample Port Installation, EPA Method 1, and Successful Testing

Too often the installation of sampling/testing ports is an afterthought in the process of stack construction.  However, sampling ports are essential to the stack testing process which is a requirement for demonstrating compliance.  In fact, the EPA goes so far as to state outright that Method 1 should be taken into consideration before stack construction begins.

Having a better understanding of EPA Method 1 can reduce or eliminate the need for excess modifications on an existing source.  That means knowing the optimum location for sampling ports can save money in your compliance testing budget.

So what is EPA Method 1 exactly and how can it be helpful to the pre-construction design and post-construction installation of sampling ports?

Simply stated, EPA Method 1 is a way to determine sampling port locations that are free from swirling air, or cyclonic flow.

What causes Cyclonic Flow?

Cyclonic Flow occurs when the sampling plane is too close to a disturbance (vane straighteners, fans, control equipment, etc.) or any duct configuration that causes a disturbance in the air flow causing the air to swirl rather than travel on a linear path.

Determining Placement of Sampling Ports

EPA Method 1 provides two options for sample port installation, as follows:

Simplified – Used most often and applies to most stacks

Alternative – Used for smaller stacks with a diameter less than 12 inches

The majority of our clients have larger stacks, so we’ll overview the Simplified Port Installation guidelines, but don’t hesitate to call us at 1-888-363-0039 if you need assistance understanding Alternative Port Installation.

Three Conditions for Simplified Port Installation

  1. The flow through the stack at the port location must be minimally cyclonic.

Following Method 1 procedures as detailed by the EPA prevents issues with cyclonic flow for most stationary sources.  Cyclonic flow at a sampling plane will skew results which becomes an expensive issue if it causes compliance failure, that’s why ESS conducts EPA Method 1 with all stack testing.

  1. The stack diameter must be 12 inches or greater or 113 square inches in a cross-sectional area.

When the stack diameter is less than 12 inches, Alternative Port Installation must be used.

  1. The sampling plane must be located more than two stack diameters from the nearest upstream disturbance and more than half a stack diameter from the stack exit or next downstream disturbance.  (See Diagram 1).

    Diagram 1 Sample Port Placement

A disturbance is anything that interrupts or alters the flow of air and gas through the stack.  Examples of disturbances include: fans, duct bends, stack exits and vane straighteners.

Upstream measurement is the distance between the test ports and the nearest upstream disturbance.

Conversely, downstream measurement is the distance between the test ports and the stack exit.

To calculate the equivalent diameter of a rectangular duct use the equation:
De= 2(LxW) / (L+W)

While those three items cover the requirements for Method 1 Simplified Port Installation, there are still other sampling port factors to consider for a smooth test day.

Port Size and Pollutants Tested

Particulate, metals, dioxin/furans, flowrate or other manual method tests require a minimum of two (2) 4”-diameter ports located 90 degrees from each other.  PM10 and PM2.5 require at least two (2) 6”-inch ports.  It is common to install four (4) of these test ports 90 degrees apart from each other so that more testing can be conducted simultaneously.  The distance of 90 degrees apart is a requirement whether two (2) or four (4) ports are installed.

Sampling ports for gases should be greater than one-quarter-inches in diameter and installed directly above one of the manual method ports.

Port Access

OSHA-compliant platforms are required for the testing team to access the sampling plane safely and effectively.  All installed platforms should be a minimum of 48 inches wide from stack wall to handrail.  If a temporary platform must be erected, then OSHA-compliant scaffolding is preferred, but man lifts are also acceptable.  Scaffolding should be constructed directly in front of each sample port with enough room for the sampling equipment to access the ports (see diagram 2).

Diagram 2 Scaffolding Placement

Diagram 2 Scaffolding Placement

The safety of our crew is of utmost concern, so OSHA-compliant structures are mandatory for testing.

When test day arrives, be sure that sample ports are clean and free from debris.  Sample port condition is regularly monitored by state regulators.

Stack pressure and stack temperature can also affect sampling plane design—call us if you have questions on this point.

There are many issues to consider for an emissions test.  Being prepared with the knowledge to properly construct sample ports will save money by preventing excessive stack modification.  Furthermore, understanding and adhering to the guidelines of EPA Method 1 will ensure that sample port, size, placement, and access are not an issue on test day.

For assistance in determining your specific sampling port needs, questions about EPA Method 1, or any other stack testing issues feel free to call Environmental Source Samplers at 1-888-363-0039.  It would be our pleasure to assist you.

Download a PDF version of this article.

Copyright © 2018 by Environmental Source Samplers, Inc.  All rights reserved.

Understanding Upstream and Downstream

The terms “upstream” and “downstream” are frequently used in the stack testing industry to describe direction within a stack.  However, these terms are often confused and used opposite of their intended meaning.

The key to remembering upstream and downstream when talking about flow is to think about another flowing object—a river!

Rivers generally flow from a source, like a mountain lake, to an outlet, like the ocean where the freshwater disperses into the saltwater.  In terms of stack air flow, the air emissions originate from an emissions source and travel through the stack to the stack exit where they disperse into the atmosphere.

The direction of travel from a source to an outlet is with the current, or downstream.  Conversely, the direction of travel from an outlet to a source is against the current, or upstream.

There are two simple mnemonic devices which can help you to remember the difference between upstream and downstream.

“Up the Creek Without a Paddle”

Imagine you are in a canoe enjoying a peaceful trip down the river when you hear the sound of a waterfall ahead.  You look around for your oars, but there are none in sight.  Frantically, you use your arms to try to paddle further upstream to safety, but it is very difficult because you are fighting the current.  This is a situation of being up the creek without a paddle.

Upstream is the direction toward the source and also against the current.

Upstream Downstream Diagram

Diagram Showing Upstream and Downstream in Relation to Current


“Gently Down the Stream”

Now imagine that you made it safely to the river bank and carried your canoe to bypass the waterfall on foot.  You put the canoe back into the river where you can lay back and relax because the current is carrying you gently down the stream to your destination.

Downstream is the direction away from the source and also with the current.

The diagram above is a visual aid demonstrating the relationship between current and upstream/downstream direction.

If you have questions about this topic, or any other emissions testing question, please call Environmental Source Samplers at 1-888-363-0039 and we will be happy to help you.

Download a PDF version of this article.

Copyright © 2015 by Environmental Source Samplers, Inc.  All rights reserved.

Sulfuric Acid Mist Sampling and Controlled Condensate (NCASI Method 8a) Testing

Criteria Pollutants and MACT related air toxics such as Mercury and HCl get a lot of attention in the field of air-quality analysis and emissions testing (stack testing), but other, less-known pollutants can and do cause issues for facilities. Sulfuric Acid Mist (H2SO4) is one such pollutant.


Sulfuric acid emissions

Sulfuric acid emissions have traditionally been measured using EPA Method 8. This method utilizes the principle of selective solvent absorption (SSA) and captures sulfur trioxide (SO3) and H2SO4 in an isopropyl alcohol (IPA) solution, and SO3 in a low concentration of hydrogen peroxide. A drawback to this method, however, is that it was developed and originally promulgated to determine SO3/H2SO4 emissions from stationary sources in the absence of other particulate matter. The principal drawback is the absence of a filter to effectively remove PM and other pollutants prior to the capture of H2SO4 in IPA. This can lead to interference from a number of filterable particulates and other pollutants, such as ammonia, and may result in emissions reading much higher than expected, making it difficult to achieve compliance with the emissions standards.


NCASI Method 8a

NCASI Method 8a, originally Conditional Test Method (CTM)-013, was developed as an alternative to EPA Method 8, and uses a heated quartz filter for capturing particulates, thereby eliminating the potential for interference from particulate sulfate and other interference. For sources that are having trouble with obtaining low emissions of H2SO4, and particularly those that have been using ammonia-injection control technology, the use of this method can result in a significant reduction in reported emissions from the source, by removing these varying interferences.

The quartz filter is maintained at temperatures above 500 degrees F, allowing the gaseous SO3/H2SO4 to pass through and be selectively condensed in a temperature-controlled condenser. The condenser cools the flue gases below the dew point of the SO3/H2SO4, but above the dew point of water, eliminating the potential for interference from SO2. The method was developed and validated as an alternative for determining sulfuric acid emissions from combination boilers and recovery furnaces equipped with dry particulate control devices, and tested extensively on kraft recovery furnaces. It was specifically approved by the EPA for use on recovery furnaces in 1996.


Potential Issues

There are two potential issues with utilizing this method. The first is that it utilizes special equipment that not many testing firms have. The equipment costs several thousand dollars, which creates a large up-front cost to conducting tests using this method. The second is that the method is not specifically approved for any units other than recovery furnaces, and compliance tests performed by this method must be approved by state regulators on a case-by-case basis.


Call in the Professionals

ESS, an air-testing firm out of Wilmington, North Carolina, has the equipment and experience to conduct this test method for facilities that are currently or potentially regulated for H2SO4. ESS has requested and received variances from state regulators for use on biomass boilers, paper mills, and ceramic kilns for compliance-level testing. In all cases so far, the use of this alternative method has greatly improved the reported emissions of H2SO4, and helped our clients achieve compliance with the emissions standards their units are subject to.

If your facility is expected to be regulated for sulfuric acid mist, you need a testing partner that can achieve the best results. Give ESS a call today at  (910) 799-1055.

ESS Closing 2013 In a Strong Business Position

ESS Stays Busy in 2013As 2013 moves towards its close, Environmental Source Samplers, Inc. (ESS) continues to complete projects domestically and abroad, finishing strong with one of the busiest years in the company’s 35 year history. ESS attributes this large workload both to increased demand for stack testing service, and to excellent service that has attracted and maintained a consistently growing base of dedicated clients. ESS strives first and foremost to provide quality service to their clients, with projects completed on time, within budget, and acceptable to both facility personnel and state and federal governing bodies. ESS offers expertise on current rulings as well as new and upcoming standards, and has the tools to assist facilities in achieving compliance with them.

ESS continues to conduct many projects related to the MACT standards, including the RICE NESHAP and Boiler MACT. ESS has partnered with PowerSecure and Governor Control Systems (GCS), for the refitting and testing of hundreds of stationary RICE Units in 2013, for demonstration of compliance with the RICE NESHAP, 40 CFR Subpart ZZZZ. In addition, ESS has been assisting many of their industrial clients with engineering testing for metals, particulate matter, HCl, and criteria gases as part of compliance strategies with the Boiler MACT standards. A large, challenging testing project on a Thermal Desorption Unit at the US Ecology of Texas site has rounded out the Fall and early Winter months for ESS USA operations.

Internationally, the ESS office established this year in Hanoi, Vietnam, is also completing projects for both new and repeat clients. In addition to the Hong Kong Environmental Protection Department (HKEPD ) particulate study project, completed during the summer months, ESS Asia, located in Hanoi, Vietnam, has been obtaining new clients every month, often in partnership with Berkman Systems, one of the largest environmental consulting companies in the Philippines. ESS is in the midst of a commissioning project for Foster Wheeler at their Facility in Nghi Son, south of Hanoi. The project involves comprehensive air sampling, boiler tuning; steam-flow measurements; coal, fly, and bottom ash analysis; and other parameters. ESS has recently completed a number of other projects, including an ambient-air study at the location of the new Green building for the United Nations Development Programme in Hanoi, as well as a comprehensive emissions test series for Massan Mining. Both projects involved the measurement of Particulate and gaseous emissions, in the air and in exhaust emissions, and both are continuing projects, expected to involve retests and further analysis over the next few years.

Looking ahead to 2014 indicates a continuation of this trend. Through the acquisition of new clients and the retaining of current ones, ESS is already scheduling projects into late Quarter 1 of 2014, and anticipates more to come before the year closes out. ESS expects to continue to leverage their customer service, stack testing expertise, and project execution to satisfy its current and future client base in 2014, and on into the future.

To learn more about ESS and to inquire about air quality and environmental testing,  please visit the website at or call (800) 245-3778.



Brian Mellor
Sales Manager
Environmental Source Samplers, Inc.
436 Raleigh Street
Wilmington, NC 28412
Phone: 910-799-1055
[email protected]