Compliance with environmental standards is expected to be 100% and on 24×7 basis in most countries including India. This means that if you draw a sample at any time, the concentrations of the specified pollutant must be within the set limits or standards. If not, it becomes a case of violation or non-compliance that the regulator can act upon. Even one single default becomes a case of non-compliance.
This situation is applicable for both emission/effluents as well as for ambient environmental standards. Given this expectation, can any polluter be truly compliant? And when ambient environmental standard gets violated, how do we find the ‘culprit’? And do we act in case of such a violation, against the regulator or against the regional agency responsible?
But I wonder how realistic it is to ask for 100% and 24×7 compliance in the first place. We all know that emissions and effluent streams are to be released after required treatment. The design of treatment and disposal systems is to be done such that compliance can be ensured. The treatment systems however receive variable quantities and sometimes unpredictable characteristics of ‘inputs’. Even given this variability (often beyond the control of the treatment system designer and operator), ‘outputs’ are expected to meet the standard, 100% of the time. Is this reasonable? And isn’t this asking for too much?
On most occasions, the regulators (e.g. Pollution Control Boards in India), use their discretion based on how frequently the emission/effluent concentrations cross the limits? To what extent is the violation? Which are the parameters and how critical are they in positing risks or causing damage to humans and ecosystems? Occasional and marginal ‘defaulters’ are then let go with warning and fines. This can be a subjective process. Most polluters follow this first option of negotiation with the regulator and pay fines especially when the violations or noncompliances come to light.
The second option is to ‘overdesign’ the treatment and disposal systems with a ‘factor of safety’ to handle the input variability. Most industrial effluents today are subjected to flow and load balancing and equalization tanks get added to the ‘process train’. In some cases, additional treatment processes are introduced or the treatment units are oversized. This strategy of ensuring compliance however requires more capital investments.
The third option is to reduce variability of inputs at the source itself by introducing process controls and practising effluent segregation. This option is perhaps most effective and goes well in combination with option 2 stated above.
The fourth option is to frame compliance with the standard in a statistical manner. Here, we accept the fact that 24×7 compliance on 100% basis is just not possible.
For ambient air quality in India, compliance for 98% of the time is acceptable with the annual average standard (See http://cpcb.nic.in/National_Ambient_Air_Quality_Standards.php) To calculate the annual average, the number of samples specified is 104 i.e. two samples drawn every week over 24 hours. The additional condition is that while 2% of samples may be noncompliant, violation of the standard cannot happen on more than two consecutive occasions.
I like this definition of compliance as it recognizes the fact that 24×7 and 100% compliance for ambient air quality is not possible. It then goes on to accept 98% compliance, defines the sample size and stipulates that more than two consecutive violations will not be acceptable in the noncompliance zone of 2%.
Unfortunately, what has been proposed for ambient air quality in India, the same has not been ‘translated’ to air emissions from stacks or to effluents from industries? We do not state, for example, that an effluent treatment plant at an industry will report at least 156 samples in a year (i.e. thrice a week), with samples collected on a composite basis. Out of the 156 samples, at least 95% of the samples must be compliant. Out of the 5% of the violations, non-compliant samples should not be consecutive or over two successive occasions.
Indeed, we need to bring such anomalies to the notice of the regulators and also the judiciaries. We have to be realistic, scientific and practical. Let us not overstate the requirements of environmental compliance. While we may pursue Options 2 and 3 stated above, let us lobby with the regulators to refine environmental compliance in a statistical framework.
(You may like to read report on Environmental Compliance and Enforcement in India: Rapid Assessment -wonder how the various statistics on compliance in this document were reported in light of thoughts expressed above. The picture used in this post is sourced from http://info.era-environmental.com/blog/bid/51852/Don-t-Make-These-7-TRI-Reporting-Mistakes-in-2012)
For students – Take up a research project to review statistical or probabilistic standards – whether these are in vogue and in which countries they exist and what has been the practical experience. Cover ambient as well as emission/effluent standards. See paper “Some Historical Statistics Related to Future Standards” by Paul M. Berthouex, at http://cedb.asce.org/cgi/WWWdisplay.cgi?21665 as a source of inspiration..