Nevco Engineers Private Limited v. Central Pollution Control Board & Anr.

1. This hearing has been done through hybrid mode.

2. The present petition has been filed by the Petitioner–Nevco Engineers Pvt. Ltd., seeking quashing of the letter dated 25th March, 2022 issued by Respondent No. 1–Central Pollution Control Board (‘CPCB’) insofar as it seeks to ban the Petitioner’s technology i.e. Differential Optical Absorption Spectroscopy (DOAS).

3. The grievance of the Petitioner in this case is that the adding of the compliance of standard National Ambient Air Quality Standards, 2009 (‘NAAQS’) has resulted in a situation where the Petitioner's technology is not being accepted.

4. Ld. Counsel for the Respondent No.1 had submitted on the last date i.e. 20th January, 2023 that the review process had not been concluded. ON the said date, Dr. Mukesh Sharma from IIT Kanpur had joined the proceedings and had submitted that the review process is likely to remain pending till 30th April 2023. After hearing the ld. Counsel for the parties and Dr. Mukesh Sharma, the following directions were issued vide order dated 20th January 2023:-

5. Keeping in mind of the above said order, the Review Report on the Differential Optical Absorption Spectroscopy (DOAS) Technology for Measurement of Gaseous Air Pollutants in Ambient Air (‘the Review Report’) has now been submitted by IIT, Kanpur to the CPCB on 15th March 2023 which has been placed before this Court. The said report has concluded as under:- “6.0 Concluding Remarks The DOAS technology is based on sound scientific principles and has been certified by USEPA and a few European agencies for SO[2], NO[2] and O[3]. However, except for the Republic of China, it appears that no other country has included this technology in their NAAQS system or for regulatory requirements. In view of of sound scientific technology, certifications by US and European agency and preliminary data analysis, DOAS technology may be approved for regulatory measurements of SO[2], NO[2] and O[3] in ambient air under NAAQS. It may be stated that while technology is on sound scientific principle, its application in producing accurate and precise measurements will require proper and regular calibration, alignment of laser source and receiver, ensuring its operation and suitability during foggy and varying atmospheric conditions. The Central Pollution Control Board or other suitable agency may develop a certification mechanism for DOAS and other technologies for accurate and precise measurements for producing acceptable air quality data in the country.”

6. A perusal of the submitted Review Report and the conclusion reproduced above clearly shows that IIT, Kanpur has recommended DOAS technologies for regulatory measurements for ambient air quality under NAAQS.

7. Mr. Ramesh Singh, ld. Sr.Counsel for the Petitioner submits that in view of the above Review Report, the ban order dated 25th March 2022 insofar as it seeks to not recognise the DOAS technology for measuring ambient air quality would be liable to be reviewed by Respondents i.e CPCB and the MoEF.

8. Mr. Shekhar, ld. Counsel appearing for Respondent No.1-CPCB submits that the DAOS technology has been approved by the Respondents as per the Guidelines for Continuous Emission Monitoring Systems, 2018 (‘CEMS Guidelines’). “The suitability of the technologies/instrumentation for monitoring the stack emission quality in different matrices, considering the limitations of the technologies, the varying Indian environmental conditions were assessed. Issues related to the utilities and maintenance required, operating costs, etc., wherever available were also considered. The parameters for online monitoring for various sectors of industries are specified at Annexure-I. The comparative chart depicting working limitations, including, specifications of above said technologies for measurement of particulate matter and gaseous pollutant is depicted in Table-4 and 5.” Table 5: Overview on Technical Selection & Suitability for Gaseous CEMS Technology Technique Type Parameter (S) Measured Comments & Limitations Differential Optical Absorption Spectroscopy (DOAS) Open Path cross duct NO, NO[2], SO[2] NH[3], Hg with DOAS- UV CO, CO[2], HCl, CH[4], VOC, H2O, HF etc.

DOAS-IR - Suitable of monitoring of multiple gases. - Suitable for trace measurements - Indirect measurement technique. - Stable, comparatively low calibration requirements. - Measurement of Hg requires its conversion to elemental form for UV DOAS for which the system is required to be equipped with heated gas probe, heated sample transfer line and heated measurement cell. Removal of SO[2] interference is essential in case of UV measurement of mercury.

9. However, the same has not been included in the Guidelines for the Measurement of Ambient Air Pollutants, 2012 issued by the CPCB, as given below.

10. Considering that IIT, Kanpur was the expert body which the CPCB itself had referred the matter to, as per impugned letter dated 25th March 2022, and the Review Report prepared by IIT, Kanpur has recommended the DOAS technology, the matter deserves to be reviewed by the MOEF.

11. Accordingly, it is directed that the Respondent- MoEF shall review the Guidelines for the Measurement of Ambient Air Pollutants, 2012 and consider the Review Report submitted by the IIT Kanpur, and take a decision in respect of approval of DOAS technology for NAAQS, as also for monitoring of Continuous Emission Monitoring Systems (‘CEMS’).

12. The said decision by the Respondent shall be taken within a period of three months. In the meantime, wherever permissible, the Petitioner’s DOAS technology can be implemented in terms of the Review Report submitted by IIT, Kanpur.

13. With these above terms, the present petition with all pending applications, if any, is disposed of.