ISOKINETIC STACK SAMPLING

ISO14001 – TIPS-2: ISOKINETIC STACK SAMPLING

Pursuant to endeavours in complying to one of the elements in ISO14001 that is 'monitoring and measurement' many local have called in or e-mailed me their respective inquiries. In this segment I've compiled and summarized questions pertaining to measuring emissions from stacks or chimneys using the ISOKINETIC Stack Sampling methods. Did The Environmental Quality Act, 1974 specify this method? What do we need to know? How to justify this technique?

1 .Which method to use?

The internationally acceptable most accurate method is the one that is called the Isokinetic Stack Sampling. This one is adopting the USEPA (United States Environmental Protection Agency) Method 1-5,17. This method is officially used by the DOE Malaysia in its enforcement monitoring. Here we'll discuss the following;

• What is the legal requirement on Stack Sampling method?
• How is Stack Sampling being enforced?
• What is CEM.
• What are the restrictions in Stack Sampling methods?
• What to consider?
• What is the role of 3^rd Party Contractors report in the judicial system?
• How to select reliable Stack Sampling Contractors?
• How to establish an objective and cost effective Stack Sampling Programme.

Despite its claim for accuracy, it is also highly susceptible to errors, simply due to its delicate configuration, tedious set-up and specific technical requirements. The most outstanding and user-friendly version of this equipment tested so far is the Anderson AST that reduces pre-sampling calculations by coupling a computer – programmed software as a panel to the sampling probe.

However, this method is applicable when the stack or chimney is large enough in diameter as to maintain its engineered strength to accommodate 2 sampling ports of approximate 3-4 inches in diameter, at right-angled distance apart, and a platform for at least two technicians plus the bulk of equipment.

Isokinetic Stack Sampling Probe and its terrain are delicate precision instrumentation. Handling this equipment with lots of TLC (Tender-Love & Care) would ensure its durability and worthy investment. The glass nozzle could withstand high temperatures of most stacks but vulnerable to the slightest knock on hard surfaces. The entire length from this probe's glass nozzle up to its orifices are assembled with connectors. In other words its assembly must be leak-proof to ensure data precision and acceptability. Various air pollution parameters are measurable using this technique through accessory absorbent media used in its orifice.

So, if you are considering to adapt this technique for your 2 - inch diameter ducting from your ‘wave-solder’ machine – just drop the idea. This method is applicable for larger and stronger stacks such as those erected in the Palm Oil Mills, Steel Factories, Glass Factories, etc. that discharges air emissions at much greater efflux velocities and therefore through bigger stacks.

Hence, when isokinetic method is not feasible, one may choose any other methods that allows justification for data/reading acceptability.

2. What is the legal requirement on Stack Sampling method?

As far as the emission of air impurities are concerned, the law has prescribed several types of air pollutants and their respective emission limits. Although not all of the air pollutants are regulated, the Environmental Quality (Clean Air) Regulations, 1978 has established the triple standards to facilitate compliance.

However, to date, this regulation is still silent on which method to use. Therefore we have the luxury of discretion to select the most applicable method to monitor compliance, not only to the law but also to our own standards if it is more stringent.

3. How is Stack Sampling being enforced?

By virtue of the intent and spirit of the Environmental Quality Act, 1974, we shall comply to the stipulated limits at all times. In other words, the Stack Sampling team of the authority can perform the test on our premise at anytime without prior notice. The results are legal evidence and admissible in our judicial system.

However, the DOE encourages self-regulatory practices and accepts reports from any independent Stack Sampling Contractor. Their report too can play important roles in the court-house, that is, as a documented representation from an expert witness. Apparently, the DOE reserves all rights to regulate sampling frequency and reporting.

4. What is CEM.

The Continuous Emissions Monitoring is an advanced version of environmental monitoring that has eliminated on-site physical/manual sampling. It is an automatic system that links the pollutant sensors, analyzers, transmitters receiver to a monitor that is on-line with observing personnel. Despite heftier financial requirement, this system is much user-friendly and favoured by most environmental authorities around the globe. In some countries, the CEM in a factory is made accessible by their local authorities – on – line.

Chimney or Stack - originating from a Palm Oil Mill.

5. What are the restrictions in Stack Sampling methods?

(a)  The isokinetic method:

ü Human factors: competence and experience – performance accuracy.

ü  Leakage of connectors and seals of sampling apparatus.

ü  Safety of sampling sites (Once, I’ve climbed a 60 feet stack only to find that one of the platform’s welded joints were heavily corroded. Then, for a moment, I wished wasn’t up there! - picture)

ü Fragility and high cost of components/replacement parts.

ü  Parts or replacements are not readily available.

ü Weather and other environmental factors.

ü  Method not standardized in the Malaysian environmental law. (Note: there are a few variations in the Isokinetic methods).

  

b)          The other methods:

ü  Accuracy of sampling is difficult to justify.

ü  Acceptability of report is limited or highly accountable.

ü  Method not standardized in the Malaysian environmental  law.

ü  Human factor : competence, experience and performance.

ü  Environmental factors.

ü  Sampling accessibility.

6. What to consider?

Firstly, in order to justify the sampling parameters that we have to select, the following factors should be considered;

i)                    Origin of emission.

ii)                   Types of emission i.e. environmental parameters.

iii)                 Available legal standards.

iv)                Other international standards.

(Other elements, such as, objective of sampling, sampling personnel, equipment etc. is not discussed here.)

i)              Origin of emission.

Here we have to identify what are the most probable air pollutants (Env. Aspects) that can be emitted from an activity (including process, equipment, etc.)

For example, the emission from a ‘Wave Soldering’ activity. What does it ‘burn’ or ‘heat – up’? Solder Bar, for instance. Next what is ‘Solder Bar’ consists of? At this point, we have to flick the ‘MSDS” of that Solder Bar or Ingots supplied to us. Lets assume – Lead, Copper, Iron and Tin. When the solder bar melts, metallic fumes are emitted. Usually, electrical energy is used to heat-up the solder pot of the Solder Wave machine. In this example, the most probable air pollutants that is released as air impurities are Lead, Copper, Iron and Tin. Is the Solder Pot coated with Hydrofluoric substances or other anti – stick or ‘release agents’? Similarly, check their individual MSDS or CSDS and look for their constituents. At this point, we have at least identified, that, the probable air pollutants emitted from the Solder Wave into the Suction Ducting and finally into the atmosphere are probably consisting of Lead, Copper, Iron, Tin and Hydrofluoric Acid. So, one of the monitoring program that we construct for  our ISO 14001 EMS on this activity shall include these parameters.

ii)             Available Legal Standards

Next, are all the parameters regulated in the Malaysians Environmental Law? Namely, the subsidiary regulation called Environmental Quality (Clean Air) Regulations, 1978. Identify the stipulated discharge limits against each parameter of interest. Beware of the triple standards: A, B and C!

iii)            Other International Standards.

Apparently, there are a number or significant air impurities that are not regulated in our local EQA, 1974. For example; where we are legally adviced by the same law to ‘use best practical means’ – read Regulations 32 (3) (i – vii).

There are other types of air impurities that are not governed here, such as, Dioxin, Formaldehydes, Phenollic cpds, etc. Ironically, these polluting substances were identified and evaluated as Significant Environmental Aspects by many enterprises. So, what to do? Please seek most acceptable international standards, such as those listed by the USEPA, who, etc. – of cause after referring it to the DOE!

7. What is the role of 3^rd Party Contractors report in the judicial system?

In other words, can your sampling contractors’ reports be used against you? My answer shall be based on the constitutional sovereignty – Yes! However, this is an extremely rare case at this point of time! As mentioned earlier the judge reserves the right to call upon your contractor to justify his analytical findings, in this case, his records on your non – compliance. The court shall normally judge his level of competency, experience and professional integrity, etc. (Please ask this to any Panel Discussion member in our Public Seminar on the EQA, 1974)

8. How to select reliable Stack Sampling Contractors?

Stack Sampling, especially, the Isokinetic method is very delicate and vulnerable to errors. In Malaysia, for the moment, there is no requirement of competency in any formal manner by the authority or even the law. You see, as a sampling personnel for Isokinetic Stack Sampling, one should never fail to follow the work instruction given in the operating manual. No compromise. If there exists factors that can limit the accuracy of sampling – the work should be replicated or in worse cases – abandoned. There are other external factors that can influence sampling accuracy such as the factories’ operational fluctuations, weather, sampling facility, etc.

The major problem is that there is no legal standard for Isokinetic Stack Sampling in Malaysia. There are such standards in some other nations.

Look for contractors who;

i)                    Have formal training on the methods used and the law.

ii)                   Adequate experience – sampling various types and origin of air pollutants.

iii)                 Responsible – attitude, punctuality, transparent reporting.

iv)                Able to train internal personnel (clients).

v)                  Good track record with other clients and the DOE.

vi)                Completeness and adequacy – equipment and personnel

vii)               Good after – sales services, especially F.O.C consultation. 

9. How to establish an objective and cost effective Stack Sampling Programme.

For a continuous environmental monitoring programme please follow these steps:

i)                 Conduct a baseline sampling of all parameters stipulated under the law and that you have reason to believe of its existence.

ii)                   Identify parameters that are detected from the baseline sampling and list them out. Ignore the rest that are not detected.

iii)                 Prioritize the list of parameters in accordance to;

(a)    Local legal requirement.

(b)    DOE requirement.

(c)    Significant Environmental Aspects – that is within control.

(d)    Significant Environmental Aspects – that is beyond control but can    

      cause transboundary impact.

(e)    Cost effective vs. regularity.

(f)     Other requirement or criteria-external communication with the authorities, international conventions, local conventions, FMM dialogs, public complaints, national interests, etc.

So, that all folks. Nonetheless, feel free to e-mail any inquiry to my e-mail sgy@streamyx.com for Sekitar Synergy Sdn Bhd (Khalid Mohd Ariff)