Why KSPCB’s real-time probe for STPs is ridiculous

New guidelines for STP design - Part 1

Sewage Treatment Plant (STP) of an apartment. Pic credit: Dr Ananth S Kodavasal

On March 1, 2021, the Karnataka State Pollution Control Board (KSPCB) issued a new guideline for Sewage Treatment Plant (STP) design and location. It will have a major impact on all STPs, including those of the Bangalore Water Supply and Sewerage Board (BWSSB), municipalities, Urban Local Bodies (ULBs), residential apartments, commercial complexes, IT parks, educational institutions, railway stations, airports, etc.

Although the document is a guideline, some aspects are mandatory. We will be analysing these new guidelines in a three-part series. This first part analyses real-time probes, which requires installation of sensors for all STPs.

Here are eight compelling reasons why the KSPCB’s real-time probes idea is bad:

1. Violates cost minimisation principle

Note that the principle of cost minimisation is enshrined in our National Environmental Policy. The public is entitled to challenge any measure imposed by the KSPCB where costs cannot justify the results. The RT probe is one such measure. It is not worth the massive amount of money needed to set up the RT probes. Here are the reasons:

The RT probe is supposed to keep a tight watch on an STP that may malfunction sometime during its life. But as the following points show, a malfunctioning STP poses a negligible threat to the environment (and it is least hazardous to public health).

The KSPCB has simply ignored far larger threats to the environment and public health and focused on a trivial issue.

  • The highest threat to our water system comes from industries because they do not have effluent treatment plants (ETP). Industrial effluent has chemicals and heavy metals. Yet the KSPCB has not done anything to address this threat.
  • The next threat comes from untreated domestic pollution. According to official estimates, only 40% of Bengaluru’s sewage is treated. Neither BWSSB nor KSPCB has done anything to address this pollution.
    Thus a majority of the population is allowed to spoil the environment without paying any penalties, or monthly service charges or annual fees. Such buildings do not have Occupancy Certificate (OC), and people live there illegally. KSPCB is supposed to take immediate action to get such buildings vacated, which they have not done.
  • Instead, KSPCB wants to focus on the “threat” of a malfunctioning STP. Well, when an STP malfunctions, it does not release totally raw sewage but has some “out-of-limit” parameters. Such malfunctioning does not pose any significant threat to the environment or public health.

2. Violates “polluter pays” principle

As described in the previous topic, KSPCB has let off the largest polluters whose impact on the environment and public health is the highest. Instead, it seeks to impose a huge financial burden on minor potential polluters (who are NOT polluting at present but may have a problem later). This violates the “polluter pays” principle. 

3. RT probe is overkill

RT probes are meant for a process where even a momentary lapse results in a disaster. For example, the Union Carbide Plant in Bhopal, or the Chernobyl Nuclear plant, etc.

Read more: Why Bhopal gas leak survivors find themselves in double jeopardy

But if any of the water quality parameters are out of limit in a domestic STP, there is no impact on public safety or environment whatsoever. In such a low-threat situation, periodic checks are enough to monitor the health of STPs. Therefore the RT probe is overkill, and serves no purpose.

4. Real-time monitoring unwarranted for bio process of STPs

In process measurement theory, the measurement period is tied to the temporal variability of the process. The STP is a biological process, where the parameters do not change fast. Even the characteristics of the incoming sewage do not change for days altogether. Therefore, monthly water quality checks are quite sufficient.

Given this, why do we need to measure the parameters in real time? The very idea of “real time” (vs “periodic”) is ridiculous! 

An apartment STP. Pic credit: Dr Ananth S Kodavasal

5. Why not make CFE-CFO process stringent?

If KSPCB insists that domestic STPs are critical and dangerous plants, then this should reflect in a stringent process for CFE-CFO (Consent for Establishment and Consent for Operation), so that STPs are designed and fabricated to meet the process control, stability and safety aspects. But KSPCB issues CFE and CFO without such stringent checks:

  1. It does not check the STP’s process capability
  2. It does not check whether the I&C subsystem matches the process capability of the STP

So, such an STP is likely to produce substandard sewage from day one, and likely to exceed the pollution limits in an unpredictable manner. Fitting RT probes to such a sick STP is not the answer. The real remedy is to build a robust plant that works consistently, and meets the limits with a good margin.

Read more: A must-have checklist for apartment buyers as cities run dry

If the STP is robust, just the monthly water quality checks and the annual inspections are enough.

To conclude, KSPCB’s lackadaisical CFE-CFO approach produces sick STPs that are perennially in intensive care. And now it proposes to attach an ICU to each patient at a greater cost. Why should the user pay the cost of this dereliction of duty by KSPCB?

6. If RT probe detects fault, can KSPCB handle it?

For a moment, let us assume that RT probes are installed in all STPs in the city, and KSPCB is getting “out-of-limit” triggers. What are we supposed to do after this? KSPCB has no plan to handle this scenario.

Rather than blame the builder or the RWA, the KSPCB must make a systematic arrangement to support such STPs, not only with expert technical support, but also in managing sewage while the STP is faulty. For the latter, one solution is to allow STPs to avail of the UGD network at no cost (or nominal cost) so that the STP operator is not forced to dump raw sewage while he repairs the STP.

For that matter, each and every STP needs a major scheduled shut-down maintenance (and tank-cleaning) once a year. KSPCB has not applied its mind to that either. This scenario also requires the same support from BWSSB and KSPCB.

Read more: How a Bengaluru apartment fixed its sewage treatment process

Currently, faulty STPs are not given UGD access. They are forced to hire honeysuckers for the entire period. This “solution” is too costly, typically Rs 7000 per household. And even after this huge spending, we do not achieve a clean environment because many honeysuckers just dump the sewage close-by.

Many STP operators avoid these high costs by just bypassing the STP and dumping raw sewage in SWDs.

Rather than trying to catch them using RT probes, it would be more fruitful to provide faecal management support to the STPs. This will develop an open and trustful relationship between the STP operators and KSPCB.

7. Dumping data generated by RT probes

If KSPCB’s proposal is accepted, each STP will generate a massive amount of data. However, most of these multi-dimensional data is of no use, and cannot be used for diagnostics. Like the lake data, this too would be stored without any purpose. This does not justify a large amount of public investment to create junk data.

8. RT probe technology in state of flux

The RT probes are very expensive, and currently, the probe technology and the data-transmission technology are in a high flux; which means they will change rapidly, and make any investment obsolete.

Internet of Things (IoT) is making rapid progress, and the competition between 5G and LoRAWAN is only beginning. It would be best to see how this scenario develops, and not rush into adopting a particular approach.


This looks like a solution in search of a problem.

KSPCB is rushing to adopt a glittering high-tech solution prematurely, without setting up the support system first. Clearly, this is overkill, expensive and serves no purpose at all.

KSPCB has failed to create a system that ensures that all STPs are built with proper process capability. It has also failed to ensure that the STPs get an emergency sludge management service during shutdown maintenance. As a result, the user would be burdened with huge bills without any benefit.  

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[Disclaimer: This article is a citizen contribution. The views expressed here are those of the individual writer(s) and do not reflect the position of Citizen Matters.]

About Nagesh Aras 23 Articles
Nagesh Aras is a resident of Bellandur. He works on urban governance issues like mobility, lake and water management, and STPs.

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