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.

Subpart IIII

In a previous blog entry regarding the ZZZZ and JJJJ RICE Rules , we discussed the National Emissions Standards for Hazardous Air Pollutants for Reciprocating Internal Combustions Engines (RICE NESHAP), and the New Source Performance Standards (NSPS) for Spark Ignition RICE Units, more commonly referred to as Subparts ZZZZ and JJJJ, respectively. There is another related rule that bears consideration, and that is Subpart IIII, the NSPS for Compression Ignition Internal Combustion Units (CI ICE).

There are two basic types of Stationary Reciprocating engines: spark ignition and compression ignition. Spark ignition engines use a spark, across a spark plug, to ignite a compressed fuel-air mixture. Typically, fuels for these engines are gasoline and natural gas. Compression ignition engines compress air to a high pressure, heating the air to the ignition temperature of the fuel, which is then injected. The high compression ratio used for compression ignition engines results in a higher efficiency than is possible with spark ignition engines. Diesel fuel oil is normally used in compression ignition engines, although there are dual-fueled varieties, where natural gas is compressed with the combustion air, and diesel oil is injected at the top of the compression stroke to initiate combustion.

The requirements of the Subpart IIII standards, particularly as they are related to performance testing, are dependent on the size of the engine, the manufacture date, the cylinder displacement, and whether it is used for emergency or non-emergency purposes. The EPA defines an emergency engine as one that is used for the purpose of maintenance checks and readiness testing, and is operated less than 100 hours per year. The owner of the emergency engine can NOT connect the engine to the grid under financial incentive and maintain the unit status as an emergency engine. Therefore, a peak shaving engine will not be classified as an emergency unit under the definitions of the Subparts.

For engines that are required to comply with Subpart IIII, including those engines located at Area Sources and engines less than or equal to 500hp located at Major Sources, there are no further requirements under the RICE NESHAP (Subpart ZZZZ). A Major Source is one that has the potential to emit 10 tons per year of any individual Hazardous Air Pollutant (HAP), or 25 tons per year of all HAPs. An Area Source is any source that is not considered a Major Source under this definition.

Regarding stack testing, an owner or operator of a CI ICE non-emergency unit built after 2007 with a displacement of >30L must demonstrate compliance by a performance test (stack test) for emissions of Particulate Matter (PM) and Oxides of Nitrogen (NOx). There are two methods for demonstrating compliance with either pollutant. The first is to show a percent reduction in emissions, and requires sampling for that pollutant at both the inlet and outlet to the control device for the source. Per IIII requirements, NOx must be reduced by 90% and PM by 60%. The second option is to limit the mass emission rate in the exhaust and only requires sampling at the outlet of the unit. The emission limit for NOx is 1.6 g/KW-hr (1.2 g/HP-hr). The emission limit for PM is 0.15g/KW-hr (0.11 g/HP-hr). In addition to the initial compliance performance test, owners of such engines must then perform annual performance tests to prove continued compliance with the standards.

The NESHAP and NSPS rulings can be an impenetrable maze without expert assistance, and the performance testing requirements can have a substantial impact on a facility’s operating budget. It is important to have a partner that is reliable and knowledgeable when approaching the many new emissions requirements being promulgated by the EPA and state governments. For assistance with your compliance needs, and performance testing requirements, ESS is available to help. If you believe you will or may have compliance issues under Subpart IIII, ZZZZ, or JJJJ, give us a call or an email today: 910-799-1055

New Source Performance Standards (NSPS) and Emissions Guidelines for Sewage Sludge Incineration (SSI) Units

Stack Testing for Air Quality ControlHistory of NSPS and Emissions Guidelines for SSI Units

On Feburary 21, 2011, the Environmental Protection Agency finalized new source performance standards (NSPS) and emissions guidelines for new and existing sewage sludge incineration (SSI) units. The rule, per the EPA research is expected to impact 204 units currently in operation. This rule is one of the many new standards for units that emit pollutants under the MACT (Maximum Achievable Control Technology) Standards, and was enacted under Section 129 of the Clean Air Act (See also: New RICE Rules for MACT Standards and Compliance.)

The purpose of the rule is to reduce emissions of a number of toxic air pollutants, also known as hazardous air pollutants, that are known or suspected of causing cancer and other serious health benefits.

On April 27, 2012, the EPA issued a Denial of Reconsideration Petitions for the Final Rule.

Affected SSI Units

An SSI unit is an incinerator or combustion device that is used to burn dewatered sewage sludge. The units are typically owned by municipalities, and located at wastewater treatment facilities. They come in two primary types. The first – Multiple Hearth – covers over 80 percent of the identified SSI units. The other units are Fluidized Bed combustors. Most of the affected units are in the Eastern parts of the United States, with the largest number of facilities in New York, Pennsylvania, and Michigan. There are a significant number on the West Coast as well. Units incinerating sludge at other types of facilities, such as commercial, industrial, and institutional, will be covered under different air pollution incineration standards.

Sewage Sludge Treatment Plants are regulated under 40 CFR Part 60, Subpart O, as well as 40 CFR Part 61, Subparts C and E. The new source performance standards for these units have been promulgated under Subpart LLLL, and the Emission Guidelines themselves are promulgated under Subpart MMMM. The EPA estimates that of the 204 active SSI units, 155 are currently meeting these emission limits, and forty will need to install one or more air pollution control device.

Regulated Pollutants for SSI

The following table lists the Regulated Pollutant, the unit of measurement for emission limits, and the Emission Limit itself for both Multiple Hearth and Fluidized Bed Incinerators.



Emission Limit for MH Incinerators

Emission Limit for FB Incinerators


mg/DSCM @7% O2



Carbon Monixde

ppmvd @7% O2




ppmvd @7% O2




mg/DSCM @7% O2



Oxides of Nitrogen

ppmvd @7% O2




mg/DSCM @7% O2



Dioxins/Furans, Total Equivalency Quality

ng/dscm @7% O2 (TEQ)



Dioxins/Furans, Total Mass Basis

ng/dscm @7% O2 (TMB)



Particulate Matter

mg/DSCM @7% O2



Sulfur Dioxide

ppmvd @7% O2




Measuring Emissions

To measure and quantify the emission rates for these pollutants, it is typically necessary to do an Emissions Sampling Program, or Stack Test, conducted by a qualified and accredited stack testing organization. The EPA has reference methods for quantifying emissions for each regulated pollutant, and the testing must be done in accordance with those methods. The methods in question can be found on the EPA website.

Mercury Emissions and the Ontario Hydro Method

Mercury (Hg) is one of the strictly regulated pollutants. Mercury has been shown through research to adversely affect developing brains in children, including detrimental effects on IQ, learning, and memory. However, controlling mercury emissions can be tricky, dependent on what form the Mercury takes in the emission from the stack. There are two primary types: Oxidized and Particle-Bound, and the control devices associated with controlling those two types are different. For that reason, during stack testing to determine existing emissions, many owners of SSI units elect to perform a special Mercury Speciation test, utilizing ASTM Ontario Hydro Method. The data taken from this sampling can be used to determine the best approach to further controlling emissions for that specific stack.

Sludge and Scrubber Water Analysis

Many facilities often undertake fuel analysis on the sludge feedstock itself, to determine the base level of pollutants in the sludge prior to being incinerated. These measurements can be utilized to determine the current effectiveness of emissions controls.

About Environmental Source Samplers, Inc. (ESS)

ESS has some of the most experienced SSI test crews in the country. In the last six months, ESS has conducted this nearly identical test series for SSIs at multiple municipal facilities in Virginia, Ohio, and New York.  All test series have been completed on-time and on budget. ESS has a history of working with chief WWTP consultants that extends back to 1990, and has partnered with some of the leading experts on SSI in the nation. Our experience in some of the more exacting methodologies required by the SSI test program is unsurpassed in this industry.

A Guide To Subpart ZZZZ and JJJJ RICE Rules

United States Environmental Protection AgencyRICE NESHAP – Subparts ZZZZ and JJJJ

Several million stationary reciprocating engines are in use throughout the United States. These engines, in general industry use, provide shaft power to drive process equipment, compressors, pumps, standby generator sets and other machinery. The uses are similar in agriculture, with many engines serving the purpose of driving irrigation pumps. Reciprocating engines also find wide application in municipal water supply, wastewater treatment, and in commercial and institutional emergency power and load-managing stations.

These engines are subject to a number of emissions parameters. Newly constructed engines, in particular, must maintain compliance with two EPA rulings promulgated in the First Quarter of 2008. These are the RICE NESHAP, 40 CFR 63, Subpart ZZZZ, and the New Standards of Performance For Stationary Spark Ignition Internal Combustion Engines (SI ICE NSPS), 40 CFR 63, Subpart JJJJ.

Description of Affected Units

There are two basic types of Stationary Reciprocating engines – spark ignition and compression ignition. Spark ignition engines use a spark, across a spark plug, to ignite a compressed fuel-air mixture. Typically, fuels for these engines are gasoline and natural gas. Compression ignition engines compress air to a high pressure, heating the air to the ignition temperature of the fuel, which is then injected. The high compression ratio used for compression ignition engines results in a higher efficiency than is possible with spark ignition engines. Diesel fuel oil is normally used in compression ignition engines, although there are dual-fueled varieties, where natural gas is compressed with the combustion air, and diesel oil is injected at the top of the compression stroke to initiate combustion.

Summary of Rules and Regulated Pollutants

The JJJJ rule became effective on March 18, 2008, and applies to newly-constructed, modified, or reconstructed Spark units, regardless of size and the fuel that is combusted. This rule does NOT apply to combustion turbines. The emissions are required to be controlled to levels achievable by Best Demonstrated Technology (BDT). The regulated pollutants are Oxides of Nitrogen (NOx), Carbon Monoxide (CO), and Volatile Organic Compounds (VOC). There is a sulfur limit, as well, on the gasoline fired.

The ZZZZ rule also became effective on March 18, 2008, and includes requirements to regulate emissions from new and reconstructed units that are less than or equal to 500 hp, and located at major sources of Hazardous Air Pollutants (HAP), as well as all new and reconstructed units at area sources. A HAP major source is a facility with a potential to emit 10 tons per year of a single HAP, or 25 tons per year of a combination of HAPs. An area source is any source that is not a HAP major source. Typically, the major regulated pollutant is Carbon Monoxide. This ruling was updated on February 25, 2009.

Sources that meet compliance with the emission limits in JJJJ also meet compliance with ZZZZ.

Meeting and Demonstrating Compliance

Newly-constructed, modified, or reconstructed units have 180 days after achieving maximum operating levels to demonstrate compliance with the emission limits in the rules. This can be accomplished in one of two ways. The first is a certificate of compliance from the manufacturer of the unit. For those who do not have the initial certification, compliance must be demonstrated by developing a maintenance plan for the unit, and conducting a performance test for the emission of pollutants from the exhaust of the unit, also known as a stack test.

There are various compliance dates and specific requirements depending on the unit in question, so if you have questions about your applicability and compliance requirements, you can find help using the online tools below from

RICE Rule Quiz for Determining Requirements Under 40 CFR Section 63, Subpart ZZZZ

Stack Testing Compliance Controls Air Emissions and Maintains Air Quality

Stack Testing for Air Quality ControlStack testing for any industry that utilizes a tower for production is a necessary component of the facility operation.  Compliance with Environmental Protection Agency (EPA) regulations on stack testing and air emissions is necessary in order to avoid violations and penalties as well as to aid in the management of environmental health and air quality as put forth in the Clean Air Act, originally enacted in 1970 and improved by amendments over the last forty years.

The EPA states that consistent, complete, and accurate stack test information is critical in managing the national air program.  Stack testing is conducted for purposes of performing routine source maintenance, relative accuracy test audits (RATA tests), linearity checks, and routine calibration of continuous emission monitoring systems (CEMS Testing).  All of these performance tests ultimately help determine compliance with applicable regional, state, or national EPA standards using approved test methodologies.

Stack testing protocols vary according to industry, process, facility, and permit requirements.  Some of the different protocols available for testing emission units include:

  • Manual Emissions Testing – includes EPA test methods and NIOSH/OSHA methods as well as ASTM, CARB, and SW846 test methods.
  • Instrumental Emission Testing – includes CEMS Testing, Performance Specification Testing, CO/CO2/O2/SO2/NOx, and Total Gaseous Organics.
  • Special Emissions Testing – can include Capture Efficiency (CE) determinations, VOC emissions profiling, Thermal Oxidizer Temperatire Optimization, and Mercury speciation determination.
  • Air Pollution Control Equipment Testing and Optimization – facilities can expect on-site inspection, equipment specification data, diagnostic testing, performance data evaluation, adn pilot plant tests.

While environmental regulations seem to be ever-changing, stack testing equipment and technology must keep pace with industry developments affecting air quality.  Environmental consulting firms and stack testing agencies are challenged to remain on the cusp of new and revamped air quality regulations.  Routine testing and maintenance programs help compliance efforts as well as reliance on a qualified and reputable stack testing company.

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

Phone: 910-799-1055

12 Things to Look for in a Stack Testing Company

Stack Testing SpecialistStack testing companies specialize in air emissions testing for compliance with standards and test methodologies set out by the Environmental Protection Agency (EPA).  Manufacturing and processing industries such as Pulp and Paper, Cement, Pharmaceutical, and Petrochemical, use a large variety of air emissions sources — like baghouses, boilers, engines, heaters, incinerators, lime kilns, regenerative thermal oxidizers, turbines, and many more — all of which require testing for air quality compliance.

While these industries must comply with the government standards for air testing, they do have options when it comes to choosing a stack testing company.  There are many factors to consider when choosing a stack testing company, and we’ve set out to bring you the Top 12 Things To Look For in a Stack Testing Company.

  1. QSTI Certified – The Source Evaluation Society (SES) has developed the Qualified Source Testing Individual (QSTI) program to ensure that stack testing companies can demonstrate knowledge and the ability to apply source testing methods as well as fundamental engineering and chemistry principles in a consistent and professional manner.
  2. ISO Compliant (QA Program) – Compliance with the Source Emission Testing Quality Assurance Program helps ensure the validity of the data generated in the course of operations.
  3. NELAC Accredited – Accreditation with the National Environmental Laboratory Accreditation (NELAC) Institute (TNI) ensures that the stack testing company meets the national standard for generating environmental data.
  4. Experience in Your Industry – Check the references and background of a stack testing company to be sure that they have experience in your specific industry and equipment can ensure a more timely and cost effective result as their testing and reporting process will likely be more streamlined.
  5. A Record of Success – Researching how long the stack testing company has been in operation builds confidence that you can rely on them as your go-to source emission testing partner.
  6. Familiarity with Your State Regulations – Specific State regulations in the field of environmental air quality are different from one state to the next and are subject to change at any time.  Make sure that your stack testing company is up-to-date on the current regulations for your particular State.
  7. Cost Competitive Pricing – Compare the quotes from different stack testing companies not only on pricing, but also the comprehensive methods of analysis and data acquisition.  Cost is an important consideration, but before you go with the lowest bidder review the proposals to make sure that the low cost does not mean that you sacrifice quality of service.
  8. Safety Record – Safety is an issue and responsibility for both the stack testing company and the client themselves.  Check the safety record of the company you’re researching so you can be confident in the quality and safety of your operation.
  9. Rapid Mobilizations – How accessible is your stack testing company?  Make sure they can get to your site as quickly as possible when needed.
  10. Turn-around time on Results – Look for safe and reliable on-site labs and mobile data analysis to be sure that you’re getting the best turnaround time on your air testing results.
  11. Clear, Concise, Correct Reporting – Accurate and reliable test reports are crucial, so you can understand, evaluate, and process the data results in a manner relevant to your particular company and industry.
  12. Familiarity with EPA Electronic Reporting – Electronic reporting that can be uploaded, downloaded, and updated is more than a convenience in this era of air quality compliance.  Your business depends on the data contained in these reports and accessing it in an electronic format is critical to your business operations.

As you can see, there are many elements involved in choosing the right stack testing company for your needs.  We’ve highlighted some of the most important factors that you want to consider in your research.  These factors affect the success of your business, the safety and reliability of your operation, and the health of our environment.  Stack testing may be a requirement, but the quality of service and the results you receive are factors well within your control.

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

Phone: 910-799-1055

Ways to Prepare for your Upcoming Stack Test

Stack Testing ServicesSource 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
  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?

This checklist is compiled by an experienced stack testing company 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 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 a scheduled stack test, benefitting 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, and they should be 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.  But whether you test for compliance or diagnostic purposes, careful preparation is the key to ensuring that your stack testing project gives you 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