Vikram Nath, J.

At the outset, it may be noted that the present judgment is structured in two parts. The first part addresses the civil appeals arising out of the Special Leave Petitions and examines the legality of the change of Land Use and the impugned judgment of the High Court. The second part separately considers the writ petitions under Article 32 of the Constitution of India, which raise an independent challenge to subsequent regulatory actions taken during the pendency of the appeals.

Part I: For SLP (Civil) No. 8316 of 2024 and SLP (Civil) No. 8495 of 2024

2. Leave granted.

3. The present appeals arise from the common judgment and order dated 29.02.2024 passed by the High Court of Punjab and Haryana at Chandigarh in CWP No. 20134 of 2022 and CWP No. 18676 of 2022. By the impugned judgment, the High Court dismissed the writ petitions and upheld the change of Land Use dated 13.12.2021 granted in favour of 'Shree Cement North Private Limited'. Civil Appeal arising out of SLP (Civil) No. 8316 of 2024 has been filed by the writ petitioners in CWP No. 20134 of 2022. Civil Appeal arising out of SLP (Civil) No. 8495 of 2024 has been filed by Vasant Valley Public School, which was the writ petitioner in CWP No. 18676 of 2022. For ease of reference, the parties shall be referred to as per their status in SLP (Civil) No. 8316 of 2024. Accordingly, Respondent No. 9 is Shree Cement North Private Limited, the main contesting respondent, before this Court.

4. The facts giving rise to the present appeals are as follows:

                   4.1. The Appellant in Civil Appeal arising out of SLP (Civil) No. 8316 of 2024 is a group of agriculturists residing in and around Sangrur, Punjab. The Appellants state that Respondent No. 9 purchased land admeasuring about 47.82 acres for establishing a cement related industrial unit in close proximity to their agricultural lands and residential houses. The Appellant in Civil Appeal arising out of SLP (Civil) No. 8495 of 2024 is Vasant Valley Public School. The School claims that its premises are located in the immediate vicinity of the proposed site and that the proposed activity would adversely affect the health and safety of students and staff.

                   4.2. On 13.12.2021, the Punjab Bureau of Investment Promotion issued a Change of Land Use[In short 'CLU'] in favour of Respondent No. 9 for the proposed unit. On 14.12.2021, consent to establish/No Objection Certificate from the pollution angle was granted under the Single Window mechanism on the basis of Punjab Pollution Control Board's[In short 'PPCB'] consideration. The Appellants contend that the CLU was granted in a manner not contemplated by the Punjab Regional and Town Planning and Development Act, 1995[In short 'PRTPD Act']. The Appellants also contend that the proposed site falls within a rural agricultural zone under the Master Plan for Sangrur and that a red category polluting industry could not have been permitted at the said location.

                   4.3. The agriculturist Appellants, therefore, instituted CWP No. 20134 of 2022 before the High Court challenging the CLU dated 13.12.2021 and the consequent approvals. Vasant Valley Public School instituted CWP No. 18676 of 2022 raising similar objections and specifically relied upon the proximity of the school and other habitations to the proposed site. During the pendency of the writ proceedings, the High Court passed an interim order dated 20.09.2022, and the interim arrangement continued till the writ petitions were finally decided.

                   4.4. By the common judgment and order dated 29.02.2024, the High Court dismissed both writ petitions. The High Court noted that as on 13.12.2021, the CLU did not have statutory backing in the form contemplated by the PRTPD Act. The High Court, however, upheld the CLU on the reasoning that the Punjab Regional and Town Planning and Development Board granted approval in its 43rd meeting dated 05.01.2022. The High Court treated the said approval as curing the defect and accepted the stand that the land use permissibility stood validated thereafter.

                   4.5. The High Court also proceeded on the basis that the decision taken by the Planning Board on 05.01.2022 was relatable to the power of amendment of the Master Plan. The High Court relied upon Section 76 of the PRTPD Act and held that the approval recorded in the 43rd meeting dated 05.01.2022 could operate to support the CLU and to sustain the proposed industrial activity. The High Court further proceeded on the premise that the competent authorities had considered the relevant siting aspects and that the CLU itself contained conditions and restrictions. The High Court observed that if the conditions stipulated in the CLU were violated, the affected persons would be at liberty to pursue appropriate remedies.

5. Aggrieved by the dismissal of their writ petitions and by the upholding of the CLU dated 13.12.2021, the Appellants have preferred the present civil appeals.

6. We have heard the learned counsel for the parties, and we have gone through the comprehensive material on record. In our considered opinion, the following questions arise for determination in the present appeals:

                   I. Whether the CLU dated 13.12.2021 could have been granted for the proposed unit when the land use under the Master Plan for Sangrur treated the site as falling in a rural agricultural zone.

                   II. Whether the 'approval' recorded in the 43rd meeting of the Punjab Regional and Town Planning and Development Board dated 05.01.2022 could lawfully cure the admitted defect in the CLU and whether such approval is capable in law of operating as an alteration or amendment of the Master Plan under the PRTPD Act.

                   III. Whether the siting norms and environmental safeguards, including the PPCB notification dated 02.09.1998 and the relevant regulatory framework, were complied with in relation to the proximity of habitations and the school, and whether the process adopted by the authorities satisfies the requirements of the prevailing legal norms.

7. It is apparent that the controversy before us turns principally on the statutory scheme governing the Master Plan and control of development under the PRTPD Act; and the environmental and siting safeguards applicable to a cement grinding unit as in the present case.

                   A. PRTPD Act, the Master Plan, its binding force, and the procedure for alteration/revision

                   7.1. Chapter X of the PRTPD Act deals with 'Preparation and Approval of Master Plans.' Under the same, Section 70 of the PRTPD Act lays down the foundational statutory scheme for the preparation, approval, and legal operation of a Master Plan. The same has been reproduced hereunder:

                   '70. Outline Master Plan. - (1) As soon as may be after the declaration of a planning area and after the designation of a Planning Agency for that area, the Designated Planning Agency shall, not later than one year after such declaration or within such time as [the State Government may, from time to time, extend, prepare and submit to the State Government for its approval a plan (hereinafter called the "Master Plan")] for the planning area or any of its part and the Master Plan so prepared shall -

                   (a) indicate broadly the manner in which the land in the area should be used;

                   (b) allocate areas or zones of land for use for different purposes;

                   (c) indicate, define and provide the existing and proposed highways, roads, major streets and other lines of communication;

                   [(cc) indicate areas covered under heritage site and the manner in which protection, preservation and conservation of such site including its regulation and control of development, which is either affecting the heritage site or its vicinity, shall be carried out.]

                   (d) include regulations (hereinafter called "Zoning Regulations") to regulate within each zone the location, height, number of storeys and size of buildings and other structures, open spaces and the use of buildings, structures and land.

                   (2) Subject to the provisions of the rules made under this Act for regulating the form and contents of the Master Plan, any such plan shall include such maps and such descriptive matters as may be necessary to explain and illustrate the proposals in the Master Plan.

                   (3) [As soon as after the Master Plan has been prepared under sub - section (1) ,by the Designated Planning Agency, the State Government, not later than such time, as may be prescribed, shall direct the Designated Planning Agency to publish the existing land use plan and master plan and the place or places, where the copies of the same may be inspected, for inviting objections in writing from any person with respect to the existing land use plan and master plan within a period of thirty days from the date of publication.]

                   (4) [The State Government, after considering the objections and in consultation with the Board, may, direct the Designated Planning Agency to modify the Master Plan or approve it as such.]

                   (5) [The Designated Planning Agency, after approval of the State Government, shall publish the final Master Plan in the Official Gazette, after carrying out the modifications if any, under intimation to the State Government within a period of thirty days from the date of according approval by the State Government.]'

                   7.2. The provision makes it clear that the Master Plan is not a mere policy document or an internal administrative guideline. It is a statutory instrument which governs how land in the planning area is to be used and regulated. The Act places the primary responsibility for preparing the Master Plan upon the Designated Planning Agency, which is required to prepare the plan and submit it to the State Government for approval. The contents of the Master Plan, as reflected in the statutory scheme, include the identification and allocation of land into different zones for specified purposes and the regulatory norms that will govern development and land use within those zones. Equally significant is the procedure that Section 70 mandates before a Master Plan can acquire enforceable effect. The Act requires that the proposed Master Plan be brought into the public domain, that the public be afforded an opportunity to submit objections and suggestions within the prescribed period, and that such objections and suggestions be considered by the Designated Planning Agency before the plan is placed for approval. This is not a procedural formality. It is a statutory safeguard intended to ensure transparency, participatory planning, and reasoned decision making, particularly because zoning and land use decisions have a direct bearing on property rights, local habitations, public amenities, and environmental and health concerns.

                   7.3. The Act then ties enforceability to publication in the Official Gazette. In other words, the Master Plan becomes operational, and thereby binding for land use regulation, only upon its publication in the Official Gazette in the manner contemplated by the statute. Section 75 of the PRTPD Act reinforces this principle by reiterating that the Master Plan comes into operation from the date of such publication, and the same reads as follows:

                   '75. [Coming into operation of Master Plan,-The Master Plan come into operation from the date of publication, referred in sub-section(5) of section 70.]'

                   The combined statutory scheme indicates that once the Master Plan is published and comes into operation, it binds both the authorities and the public, and land use permissibility is to be determined with reference to its zoning prescriptions unless the statute is duly followed to alter or revise the plan.

                   7.4. The same statutory discipline governs review and revision. Section 76 of the PRTPD Act contemplates periodic review of the Master Plan, and it permits revision where the statutory authority considers it necessary. Section 76 reads as follows:

                   '76(1) At any after time after the date on which the Master Plan for an area comes into operation, and atleast once after every ten years, after that date, the Designated Planning Agency shall after carrying out such fresh surveys as may be considered necessary or as directed by the [State Government], prepare and submit to the Board, a Master Plan after making alterations or additions as it considers necessary.

                   (2) The provisions of [Sections 70 and 75] shall mutatis mutandis as for as may be possible, apply to the Master Plan submitted under sub-section (1).'

                   However, the Act does not treat review as a mechanism by which land use norms can be altered informally or on a case by case basis. The provision expressly applies the publication, objection, consideration, and gazette publication requirements to a revised Master Plan as well. This legislative design ensures that revision of the Master Plan, even when undertaken as part of a periodic review cycle, remains subject to the same safeguards of notice, participation, and formal publication which give the Master Plan its legal force in the first place.

                   7.5. The Act also provides for the making of minor changes, but even that power is not arbitrary. Where changes are proposed to the Master Plan, including changes described as minor, the statutory scheme requires that the State Government's direction and the fact of change be brought to the notice of the public in the manner contemplated by the Act. The underlying principle is that a change in zoning or land use permissibility cannot rest only upon internal file notings, minutes, or administrative approvals. Where the change alters the operative land use framework that binds the public and the authorities, the statute insists upon transparency and public notice so that the Master Plan continues to remain a legally certain and publicly knowable instrument of planning regulation.

                   B. Control of development and 'change of land use' permissions

                   7.6. Once a Master Plan has come into operation in the manner contemplated by the PRTPD Act, the statutory command is that land use and development within the planning area must conform to the zoning and regulatory prescriptions of the Plan. Section 79 to 81 in Chapter XI of the PRTPD Act provides for the same and has been reproduced hereunder:

                   79. After the coming into operation of any Master Plan in any area, no person shall use or permit to be used any land or carry out any development in that area otherwise than in conformity with such Master Plan:

                   Provided that the Competent Authority may allow the continuance of any use of any land, for a period not exceeding ten year, upon such terms and conditions as may be provided by regulations made in this behalf for the purpose and to the extent, for and to which it was being used on the date on which such a Master Plan came into operation.

                   80. After coming into operation of any Master Plan in any area and subject to the other provisions of this Act, no development in respect of, or change of use of, any land shall be undertaken or carried out, in that area -

                   (a) without obtaining the permission in writing as provided for hereafter; and

                   (b) without obtaining a certificate from the Competent Authority certifying that the development charge or betterment charge as leviable under this Act has been paid or that no such charges are leviable:

                   [Provided that except in the case of development, affecting heritage site or its vicinity, no such permission shall be necessary-]

                   (i) for operational constructions and constructions in the area comprised in the abadi-deh of any village falling inside its Lal Lakir or Phirni ;

                   (ii) for carrying out such works for the maintenance, improvement or other alteration of any building which affect only its interior or which do not materially affect the external appearance of the building ;

                   (iii) [....] for the carrying out by the Central Government or the State Government or any local authority of,-

                   (a) any work required for the maintenance or improvement of a high way, road or public street, being work carried out on land within the boundaries of such highway, road or public street;

                   (b) any work for the purpose of inspecting, repairing or renewing any drains, sewers, mains, pipes, cables or other apparatus including the breaking open of any street or other land for that purpose ;

                   (iv) for the excavations (including wells and tubewells) made in the ordinary course of agricultural operation or for such constructions which are made for agricultural purposes subservient to agriculture :

                   Provided that such excavation or constructions are situated in the areas in which agriculture is permitted land use as per the Master Plan ;

                   (v) for the construction of unmetalled roads intended to give access to land solely meant for agricultural purpose.

                   81.(1) Any person intending to carry out any development in respect of, or a change of use of any land or intending to sub-divide his plot or to layout a private street shall make an application in writing to the Competent Authority for permission in such form and containing such particulars and accompanied by such documents and plans as may be prescribed.

                   (2)(a) In the case of a Department of the State Government or the Central Government or a local authority intending to carry out any development in respect of, or, change of use of, any land, the concerned Department or the local authority, as the case may be, shall notify in writing to the Competent Authority of its intention to do so giving full particulars thereof and accompanied by such documents and plans as may be prescribed, at least, two months prior to the undertaking of such development or change, as the case may be.

                   (b) Where the Competent Authority has raised any objection in respect of the conformity or the proposed development either to any Master Plan under preparation or to any rules in force at that time, or due to any other material consideration, the Department of the State Government or the Central Government or the local authority, as the case may be, shall either make necessary modifications in the proposals for such development or change of use to meet the objections raised by the Competent Authority or submit *[to the State Government the proposal for such development or change of use together with the objections raised by the Competent Authority for decision.]

                   (c) The [State Government] on receipt of such proposal together with the objections of the Competent Authority shall either approve the proposals with or without modifications or direct the Department of the State Government or the Central Government or the local authority, as the case may be, to make such modifications in the proposals as it considers necessary in the circumstances.

                   (3) Every application under sub-section (1) shall be accompanied by such fee as may be prescribed:

                   Provided that no fee shall be payable in the case of an application made by a Department of the State Government or the Central Government.

                   (4) On an application having being duly made under sub-section (1) and on payment of the development charge or betterment charges if any, as may be assessed under Chapter XIII, the Competent Authority may,-(a) pass an order -

                   (i) granting permission unconditionally ; or (ii) granting permission subject to such conditions as it may think necessary to impose ; or

                   (iii) refusing permission ;

                   (b) without prejudice to the generality of clause (a) impose conditions -

                   (i) to the effect that the permission granted is only for a specified period and after the expiry of that period, the land shall be restored to its previous condition or the use of the land so permitted shall be discontinued ; or

                   (ii) for regulating the development or use of any land under control of the applicant or for the carrying out of works on any such land as may appear to the Competent Authority expedient.

                   (5) The Competent Authority in considering the application for permission shall ensure that it is in conformity with the provisions of the Master Plan prepared or under preparation under this Act and where the development or change or use of any land is likely in the opinion of the Competent Authority to interfere with the operation of the Master Plan or to be prejudicial to planned development, or any plan for development of the Authority, the Competent Authority may refuse such permission.

                   (6) Where permission is granted subject to conditions or is refused, the grounds of imposing such conditions or such refusal shall be recorded in the order and such order shall be communicated to the applicant in the prescribed manner.

                   (7) [If the Competent Authority does not communicate its decision to grant or refuse permission to the applicant within a period of sixty days from the date of receipt of his application in case other than the heritage site, and within a period of one hundred twenty days in the case of heritage site and development affecting such site, or within a period of sixty days from the date of receipt of reply from the applicant in respect of any requisition made by the Competent Authority, whichever is later, then such permission shall be deemed to have been granted to the applicant on the date immediately following the date of expiry of the later date without prejudice to the provisions of this Act, rules and regulations made thereunder:

                   Provided that any development carried out in pursuance of such deemed permission, which is in contravention of the provisions of the Act, rules and regulations made thereunder, shall be deemed to be an unauthorised development for the purposes of sections 86, 87, 88, 89 and 90.]'

                   7.7. Section 79 is a prohibition in mandatory terms. It does not leave the matter to administrative discretion on a case to case basis. It interdicts the use of land and the carrying out of development in a manner inconsistent with the operative Master Plan. The legislative intent is to ensure certainty, uniformity, and enforceability in planning control, so that the zoning framework is not diluted by ad hoc departures that would defeat the Plan's public purpose.

                   7.8. Section 80 then provides the complementary statutory control. Even where a proposed activity is otherwise permissible under the Plan, the statute mandates that development or change of use can be undertaken only upon written permission of the competent authority. This written permission is not conceived as a substitute for, or an override of, the Master Plan. It is a regulatory permission which must operate within the discipline of the Plan and the statute. In other words, Section 80 does not create a untrammelled executive power to authorise land use contrary to the Master Plan. It creates a permission regime which presupposes conformity with the planning framework, and which is intended to regulate the manner, conditions, and safeguards subject to which permissible development may proceed.

                   7.9. Section 81 sets out the structured decision-making process for grant or refusal of permission. The provision contemplates an application by the person intending to carry out development, a time bound decision by the competent authority, the power to impose conditions while granting permission, and an obligation to record reasons where permission is refused. The scheme is designed to ensure that permissions are granted on relevant considerations, that the decision is not arbitrary, and that the affected party is informed of the basis of refusal. The deemed permission clause is also part of this discipline. It operates as a statutory consequence where the authority fails to act within the prescribed period. It does not dispense with the substantive requirements of conformity with the Master Plan or compliance with other applicable laws.

                   7.10. The appellate remedy is similarly part of the statutory architecture. It provides a supervisory forum within the executive framework, but it does not dilute the binding force of the Master Plan or the mandatory nature of the statutory controls in Sections 79 and 80.

                   C. Environmental clearance and siting safeguards

                   7.11. Environmental clearance and siting safeguards stand on a distinct but overlapping legal plane. Under the Environment (Protection) Act, 1986 and the Environment (Protection) Rules, 1986, the EIA Notification dated 14.09.2006 (hereinafter referred to as the EIA Notification, 2006) is a delegated legislation which creates a regime of prior environmental clearance for specified projects and activities. The requirement of prior environmental clearance is triggered before commencement of construction activity or preparation of land at the site. The statutory design is preventive. It ensures that environmental impacts, mitigation measures, and site-specific concerns are assessed at a stage when the project can still be meaningfully evaluated, conditioned, modified, or declined.

                   7.12. The EIA Notification, 2006 also prescribes a stage wise process which includes screening, scoping, public consultation, and appraisal. These stages are not interchangeable. Each stage serves a distinct function within the regulatory design, and public consultation has a specific role in ensuring that persons likely to be affected can place their concerns on record and that the appraisal is informed by local conditions and stakeholder inputs. Where the project is treated as falling within Category 'B' under the relevant schedule entry, the appraisal is at the State level through the institutional mechanism of the State Level Environment Impact Assessment Authority[In short 'SEIAA'] and the State Expert Appraisal Committee[In short 'SEAC']. This classification determines the forum and the process for appraisal. It does not dilute the core requirement that the environmental clearance must be prior and must be obtained before construction or preparation of land.

                   7.13. Siting and proximity norms operate as an additional layer of safeguards, particularly where habitations and sensitive receptors such as educational institutions are involved. The PPCB notification dated 02.09.1998 prescribes minimum siting distances for cement plants and grinding units, including minimum buffers from residential clusters and educational institutions, and it also requires development of a green belt along the boundary. These norms reflect a regulatory framework prescribing that certain minimum separations and buffers are required to reduce risk of exposure and nuisance from dust, emissions, noise, and traffic. They function as minimum protective standards for the purpose of grant of consent and related pollution control permissions. Compliance with these standards is relevant to evaluate whether the regulatory authorities have applied the correct yardsticks and whether the safeguards imposed are adequate having regard to the site conditions and the proximity of habitations and the school.

8. Having set out the statutory scheme governing planning control and the environmental and siting safeguards, we now turn to the three issues that arise for determination in these appeals as framed in the earlier part of this judgment.

Issue I: Whether the CLU dated 13.12.2021 could have been granted when the site fell in a rural agricultural zone under the Master Plan for Sangrur.

9. At the outset, it is necessary to notice the legal character of the Master Plan for Sangrur and the zoning prescription governing the site in question. The material on record, including the reports and communications relied upon by the parties, proceeds on the consistent premise that the land purchased by Respondent No. 9 fell in a rural agricultural zone under the notified Master Plan for Sangrur. It is also not in dispute that, as per the zoning permissibility then prevailing, a red category industry was not permissible at the said site.

10. In this backdrop, the CLU dated 13.12.2021 has to be tested on its own legal footing. This Court has consistently held that a statutory development plan is not a mere policy statement. It has binding force and regulates land use in the larger public interest. Any development contrary to the operative plan is impermissible unless the plan itself is altered in the manner known to law. The principle has been reiterated in decisions of this Court in K. Ramadas Shenoy v. Town Municipal Council, Udipi[(1974) 2 SCC 506, para nos.26-30] and Bangalore Medical Trust v. B.S. Muddappa[(1991) 4 SCC 54], where this Court emphasised that zoning and planned development norms cannot be diluted by ad hoc departures at the cost of public interest. The relevant portion from Bangalore Medical Trust (supra) is reproduced hereunder:

                   '48. Much was attempted to be made out of exercise of discretion in converting a site reserved for amenity as a civic amenity. Discretion is an effective tool in administration. But wrong notions about it results in ill-conceived consequences. In law it provides an option to the authority concerned to adopt one or the other alternative. But a better, proper and legal exercise of discretion is one where the authority examines the fact, is aware of law and then decides objectively and rationally what serves the interest better. When a statute either provides guidance or rules or regulations are framed for exercise of discretion then the action should be in accordance with it. Even where statutes are silent and only power is conferred to act in one or the other manner, the Authority cannot act whimsically or arbitrarily. It should be guided by reasonableness and fairness. The legislature never intends its authorities to abuse the law or use it unfairly. When legislature enacted subsection (4) it unequivocally declared its intention of making any alteration in the scheme by the Authority, that is, BDA and not the State Government. It further permitted interference with the scheme sanctioned by it only if it appeared to be improvement. The facts, therefore, that were to be found by the Authority were that the conversion of public park into private nursing home would be an improvement in the scheme. Neither the Authority nor the State Government undertook any such exercise. Power of conversion or alteration in scheme was taken for granted. Amenity was defined in Section 2(b) of the Act to include road, street, lighting, drainage, public works and such other conveniences as the government may, by notification, specify to be an amenity for the purposes of this Act. The Division Bench found that before any other facility could be considered amenity it was necessary for State Government to issue a notification. And since no notification was issued including private nursing home as amenity it could not be deemed to be included in it. That apart the definition indicates that the convenience or facility should have had public characteristic. Even if it is assumed that the definition of amenity being inclusive it should be given a wider meaning so as to include hospital added in clause 2(bb) as a civic amenity with effect from 1984 a private nursing home unlike a hospital run by government or local authority did not satisfy that characteristic which was necessary in the absence of which it could not be held to be amenity or civic amenity. In any case a private nursing home could not be considered to be an improvement in the scheme and, therefore, the power under Section 19(4) could not have been exercised.

                   49. Manner in which power was exercised fell below even the minimum requirement of taking action on relevant considerations. A scheme could be altered by the Authority as defined under Section 3 of the Act. It is a body corporate under Section 3 consisting of the Chairman and experts on various aspects, namely, a finance member, an engineer, a town planner, an architect, the ex-officio members such as Commissioner of Corporation of the City of Bangalore, officer of the Secretariat and elected members for instance, two persons of the State legislature, one a woman and other a scheduled caste and scheduled tribe member, representative of labour, representative of water supply, sewerage board, electricity board, State Road Transport Corporation, two elected councillors etc. and the Commissioner. This authority functions through committees and meetings as provided under Sections 8 and 9. There is no section either in the Act nor any rule was placed to demonstrate that the Chairman alone, as such, could exercise the power of the Authority. There is no whisper nor there is any record to establish that any meeting of the Authority was held regarding alteration of the scheme. In any case the power does not vest in the State Government or the Chief Minister of the State. The exercise of power is further hedged by use of the expression, if 'it appears to the Authority'. In legal terminology it visualises prior consideration and objective decision. And all this must have resulted in conclusion that the alteration would have been improvement. Not even one was followed. The Chairman could not have acted on his own. Yet without calling any meeting of the Authority or any committee he sent the letter for converting the site. How did it appear to him that it was necessary, is mentioned in the letter dated April 21, because the Chief Minister desired so. The purpose of the Authority taking such a decision is their knowledge of local conditions and what was better for them. That is why participatory exercise is contemplated. If any alteration in scheme could be done by the Chairman and the Chief Minister then sub-section (4) of Section 19 is rendered otiose. There is no provision in the Act for alteration in a scheme by converting one site to another, except, of course if it appeared to be improvement. But even that power vested in the Authority not the government. What should have happened was that the Authority should have applied its mind and must have come to the conclusion that conversion of the site reserved for public park into a private nursing home amounted to an improvement; then only it could have exercised the power. But what happened in fact was that the application for allotment of the site was accepted first and the procedural requirements were attempted to be gone through later and that too by the State Government which was not authorised to do so. Not only that the Authority did not apply its mind and take any decision if there was any necessity to alter the scheme but even if it is assumed that the State Government could have any role to play, the entire exercise instead of proceeding from below, that is, from the BDA to State Government proceeded in reverse direction, that is, from the State Government to the BDA. Every order, namely, converting the site from public park to private nursing home and even allotment to BMT was passed by State Government and the BDA acting like a true subservient body obeyed faithfully by adopting and confirming the directions. It was complete abdication of power by the BDA. The legislature entrusted the responsibility to alter and approve the scheme to the BDA but the BDA in complete breach of faith reposed in it, preferred to take directions issued on command of the Chief Executive of the State. This resulted not only in error of law but much beyond it. In fact the only role which the State Government could play in a scheme altered by the BDA is specified in sub-sections (5) and (6) of Section 19 of the Act. The former requires previous sanction of the government if the estimated cost of executing the altered scheme exceeds by a greater sum than five per cent of the cost of executing the scheme as sanctioned. And later if the 'scheme as altered involved the acquisition otherwise than by agreement'. In other words the State Government could be concerned or involved with an altered scheme either because of financial considerations or when additional land was to be acquired, an exercise which could not be undertaken by the BDA. A development scheme, therefore, sanctioned and published in the gazette could not be altered by the government.'

11. Once a Master Plan has come into operation under Section 70(5) of the PRTPD Act read with Section 75 of the PRTPD Act, the statutory scheme does not contemplate a permission regime where land use contrary to the operative zoning can be authorised merely by issuance of a CLU. The prohibition contained in Section 79 of the PRTPD Act, read with the written permission requirement in Section 80 of the PRTPD Act and the structured decision-making framework in Section 81 of the PRTPD Act, makes it clear that a CLU is not a source of power to override the Master Plan. A CLU operates as a regulatory permission within the statutory discipline of the Master Plan. It presupposes that the proposed use is permissible under the operative planning framework, or that the framework has already been altered or revised in accordance with the procedure prescribed by the PRTPD Act. The binding character of the Master Plan under Sections 70 and 75 of the PRTPD Act, read with the control on development and land use under Sections 79 to 81 of the PRTPD Act, requires that land use permissibility be determined with reference to the operative zoning prescription. It cannot be displaced by ad hoc permissions.

12. It must be emphasized that when a statute prescribes a particular manner for doing an act, it must be done in that manner and in no other manner. In the present case, where the Master Plan is the governing statutory instrument for land use, a departure which effectively changes land use permissibility must satisfy the statutory procedure for alteration, amendment, or revision contemplated by the PRTPD Act. It cannot rest on internal approvals or administrative convenience. This is also why the High Court's recording that, as on 13.12.2021, the CLU did not have statutory backing, assumes decisive significance. If on the date of its issuance the CLU lacked statutory support to permit the proposed use in the relevant zone, the defect is not a mere irregularity. It goes to the root of jurisdiction. A permission must be lawful when it is granted. It cannot be rendered lawful by a later event unless the PRTPD Act itself so provides.

13. The CLU dated 13.12.2021 also proceeds on the footing that the site falls within the notified Master Plan and is treated as a non-conforming land use zone. In such a situation, a conditional permission issued in the course of the Section 80 of the PRTPD Act and Section 81 of the PRTPD Act framework cannot be used to invert the statutory order by first granting a CLU in a zone where the use is not permissible under Section 79 of the PRTPD Act and then seeking to sustain it on the basis of subsequent approvals.

14. We may also note, in this context, that the reliance placed upon conditions contained in the CLU, and the observation that affected persons may pursue remedies if such conditions are violated, cannot answer the foundational objection. Conditions may regulate the manner in which a permission that is otherwise lawful may be implemented; they cannot supply jurisdiction where the proposed land use is impermissible under the operative Master Plan. To accept conditions as a substitute for conformity with the Plan would invert the statutory order by permitting what is prohibited under Section 79 of the PRTPD Act first, and leaving compliance with the Master Plan to future contingencies.

15. It was also urged that the proposed unit would advance industrial development and employment and that the CLU was processed under a single window mechanism. Such considerations cannot dilute the binding force of the operative Master Plan or the statutory prohibitions governing land use. Administrative facilitation, however efficient, must operate within the four corners of the PRTPD Act, and cannot legitimise a land use that is impermissible under the Plan.

16. The objection founded on alternate remedy or disputed questions of fact does not carry the matter further. The challenge in the present appeals goes to the root of statutory competence and legality, namely, whether a change of land use contrary to the operative Master Plan could be granted at all. Where jurisdictional legality is in issue, the matter cannot be non-suited on the plea that factual aspects may be disputed.

17. For these reasons, we are of the view that the CLU dated 13.12.2021 could not have been granted for the proposed unit when, under the operative Master Plan for Sangrur, the site fell in a rural agricultural zone where the proposed activity was not permissible.

Issue II: Whether the 'approval' recorded in the 43rd meeting dated 05.01.2022 could lawfully cure the admitted defect in the CLU and whether such approval is capable in law of operating as an alteration or amendment of the Master Plan under the PRTPD Act

18. We now turn to the reliance placed on the 'approval' recorded in the 43rd meeting of the Punjab Regional and Town Planning and Development Board dated 05.01.2022. The record indicates that the item placed before the Planning Board itself described the proposal as requiring ex post facto approval, and the minutes record that such ex post facto approval was granted. The crucial question, however, is not the label applied by the administration, nor the form in which the approval is described. The determinative question is whether the decision recorded on 05.01.2022 is capable, in law, of operating as an alteration or amendment of the Master Plan so as to retrospectively validate and cure the admitted defect in the CLU dated 13.12.2021.

19. In our considered view, it is not. Once a Master Plan has come into operation under Section 70(5) of the PRTPD Act read with Section 75 of the PRTPD Act, it acquires statutory force and becomes the governing instrument for land use and development within the planning area. Any change which has the effect of altering land use permissibility, whether described as an amendment, modification, or revision, can be brought about only by following the procedure expressly prescribed by the statute. The review and revision mechanism under Section 76 of the PRTPD Act does not operate in isolation. It expressly attracts, by legislative design, the procedural discipline embodied in Sections 70 and 75, including publication, invitation and consideration of objections and suggestions, and formal bringing into operation of the revised position through publication in the Official Gazette.

20. A decision recorded in the minutes of a meeting, or an internal approval accorded by an executive or statutory body, does not by itself amount to an alteration or amendment that has been brought into legal operation as part of the Master Plan framework. Section 76 empowers the initiation of a revisionary process. It does not dispense with the mandatory steps that alone give legal efficacy to a change in the Master Plan. To treat minutes of a meeting as the functional equivalent of a statutory amendment would be to collapse the distinction between a proposal to revise and a revision that has acquired legal force, and would render the procedural safeguards built into the PRTPD Act otiose.

21. This conclusion becomes inescapable where, as in the present case, the asserted 'approval' has the effect of permitting an otherwise impermissible industrial activity in a rural agricultural zone, with direct consequences for residents, habitations, and a functioning educational institution. Zoning prescriptions under a Master Plan are not mere internal guidelines. They represent a considered legislative balance between competing land uses and are intended to protect public interest. Any departure which dilutes that balance must satisfy the full statutory process prescribed for altering the Plan itself. Executive convenience or post facto endorsement cannot be a substitute for statutory compliance.

22. Equally, the statutory scheme does not contemplate the curing of a jurisdictional defect by retrospective administrative approval. A CLU which is unlawful on the date of its grant for want of statutory authority does not become lawful merely because a later decision purports to validate it, unless the statute expressly confers such a power of retrospective validation. The PRTPD Act contains no such provision. The legality of the CLU must therefore be tested with reference to the law and the operative planning framework as they stood on the date the CLU was granted.

23. Therefore, we hold that where the PRTPD Act occupies the field and prescribes the manner in which an operative planning instrument is to be revised or altered, that manner cannot be substituted by executive decision-making or by treating minutes of a meeting as the equivalent of an amendment brought into operation under the Act. The approach adopted by the High Court, which treats the subsequent approval as curing the illegality of the CLU, cannot be accepted when the statutory structure does not permit legality to be supplied to an act which was unlawful when done, by a later administrative approval which does not itself satisfy the mandatory requirements governing alteration or revision of the Master Plan. The High Court's approach, which proceeds on the premise that an act lacking statutory backing on the date of its issuance may nonetheless be sustained by a subsequent ex post facto approval, is inconsistent with this statutory structure.

24. It was lastly urged that substantial financial investment has been made pursuant to the CLU and that interference at this stage would cause prejudice. We are unable to accept this submission.

Expenditure incurred or steps taken in furtherance of a permission that is unlawful or without statutory authority cannot confer legitimacy upon the underlying action. No amount of financial investment can justify the continuation of an illegal project that operates in derogation of the statutory planning framework and directly impacts the rights of civilians living in the region.

25. For these reasons, we hold that the 'approval' recorded on 05.01.2022 could not lawfully cure the defect in the CLU dated 13.12.2021, and it is not capable, in law, of operating as an alteration or amendment of the Master Plan under the PRTPD Act.

Issue III: Whether the siting norms and environmental safeguards applicable to the proposed unit were complied with in the manner required by law.

26. The present issue arises at the intersection of two distinct, but complementary, safeguards. The first is the requirement of prior environmental clearance under the EIA Notification, 2006 before commencement of construction activity or preparation of land at the site. The second is the siting and proximity discipline applied at the level of pollution control permissions, including the siting distances prescribed by the PPCB notification dated 02.09.1998 for cement plants and grinding units. These safeguards are intended to operate in advance. They are designed to prevent avoidable risk to habitations and sensitive receptors, including educational institutions, and to ensure that regulatory satisfaction is reached on objective material and not on assumption.

27. The record indicates that Respondent No. 9 applied for Terms of Reference with the SEIAA, Punjab, and that Terms of Reference were granted on 28.09.2021 and amended on 25.11.2021. The record also indicates that a public hearing was conducted on 19.04.2022 in connection with the process for environmental clearance, and that environmental clearance has not been granted, with the parties attributing the pendency to interim orders operating in the writ proceedings and thereafter in these appeals. These steps, however, do not dilute the basic position that the requirement of prior environmental clearance under the EIA Notification, 2006 is not a post facto formality. The statutory scheme proceeds on the basis that assessment, public consultation, and appraisal must precede the commencement of construction activity or preparation of land at the site.

28. Equally, so far as siting is concerned, the PPCB notification dated 02.09.1998 prescribes minimum distances for cement plants and grinding units, including 300 metres from an educational institution and 300 metres from a residential area described as a cluster of 15 pucca houses, apart from other siting parameters. On the material placed before us, Respondent No. 6 has sought to justify the grant of the No Objection Certificate dated 14.12.2021 by stating that it was based on the SDM certification and a site visit dated 17.11.2021. Respondent No. 9 relies upon material which states that the school is beyond the prescribed distance when measured from the periphery of the proposed site and that there is no residential cluster of 15 pucca houses within the prescribed radius. The Appellants, on the other hand, dispute this position and rely upon material to contend that the school and residential habitations are in closer proximity to the proposed site and that the prescribed siting safeguards are attracted. The record also refers to nearby habitations and other establishments in the vicinity. This material, taken as a whole, indicates that the site is not isolated and that the proposed unit is in the vicinity of habitations and an educational institution, which are precisely the kinds of receptors for which siting safeguards exist.

29. A further difficulty arises from the manner in which compliance with distance is sought to be established on the material relied upon by the authorities. Respondent No. 6 acknowledges that the measurement was carried out from the boundary shown by the project proponent and then asserts that the distance would increase if measured from the source of pollution. This approach does not satisfy the minimum regulatory discipline. Siting norms are not satisfied by an assumption that the distance may be more when measured differently. They require demonstrable compliance on the basis of identified emission sources and verified measurements. This is more so when, at the relevant stage, the material placed for consideration did not demonstrably crystallise the emission sources and their configuration in a manner that would permit verified assessment of siting compliance on objective parameters. When the emission sources and their configuration are not crystallised and verified, a conclusion on siting compliance based on boundary measurements cannot be treated as a conclusive regulatory satisfaction, particularly where the school and habitations are close to the margin.

30. Respondent No. 9 has also sought to contend that the proposed unit is a clinker grinding unit, that it is assessed at the State level as a Category 'B' project, and that it proposes the use of fly ash and control systems such as bag filters. These submissions do not answer the core concern we have. Classification for the purposes of appraisal under the EIA Notification, 2006 does not displace the obligation to comply with siting safeguards. Proposed mitigation measures and conditions in a consent to establish do not substitute the minimum siting standards, nor do they permit the regulator to postpone demonstrable compliance to a later stage. In environmental matters, where a school is in close proximity and where there is material indicating nearby habitations, the decision-maker must proceed on the precautionary approach and must demonstrate, on objective material, that the applicable safeguards have been complied with. This approach is consistent with the principles reiterated by various landmark decisions of this Court in Vellore Citizens' Welfare Forum v. Union of India[(1996) 5 SCC 647], M. C. Mehta v. Union of India[(1997) 3 SCC 715] and Hospitality Assn. of Mudumalai v. In Defence of Environment & Animals[(2020) 10 SCC 589], among others.

31. The submissions advanced on behalf of Respondent No. 6 (PPCB), that the consent to establish/No Objection Certificate was granted on the basis of the SDM's report and a site visit, and that compliance with the siting guidelines can be verified at a later stage while considering consent to operate, do not meet the legal requirement of demonstrable compliance at the threshold. Preventive safeguards, by their very design, cannot be treated as matters to be tested only after permissions have been granted or after the project has advanced. Where the regulatory framework prescribes minimum buffers from habitations and educational institutions, the satisfaction recorded by the authority must be founded on objective and verifiable measurements, and not on an assumption that compliance can be ensured later.

32. Likewise, Respondent No. 9's reliance on the grant/amendment of Terms of Reference, the conduct of public hearing, and proposed mitigation measures, does not dilute the requirement that statutory safeguards must operate in advance. Proposed control systems and future-stage compliances cannot substitute the obligation to satisfy siting norms and the discipline underlying prior environmental clearance at the relevant time. Nor can subsequent material or later regulatory developments be invoked to retrospectively validate the legality of permissions already found to be without statutory foundation.

33. For these reasons, we are not satisfied that the siting norms and safeguards, including the PPCB notification dated 02.09.1998 and the regulatory discipline underlying prior environmental clearance under the EIA Notification, 2006, were complied with in the manner required by law on the material presently relied upon. Issue III is accordingly answered in favour of the Appellants.

34. In view of the discussion above, the appeals are allowed.

35. The common judgment and order dated 29.02.2024 passed by the High Court of Punjab and Haryana at Chandigarh in CWP No. 20134 of 2022 and CWP No. 18676 of 2022 is set aside.

36. The Change of Land Use dated 13.12.2021 granted in favour of Respondent No. 9 is quashed. Consequently, the No Objection Certificate/Consent to Establish dated 14.12.2021 issued from the pollution angle in favour of Respondent No. 9, insofar as it proceeds on the basis of the said CLU, is also set aside.

37. Pending applications, if any, shall stand disposed of. No order as to costs.

Part II: For Writ Petition (C) 481 of 2025 and Writ Petition (C) 551 of 2025

38. The appellants in the above civil appeals have also filed the present writ petitions under Article 32 of the Constitution of India. The appellants in Civil Appeal arising out of SLP (Civil) No. 8316 of 2024 has instituted WP(C) No. 481 of 2025 and the appellant in Civil Appeal arising out of SLP (Civil) No. 8495 of 2024 have instituted WP(C) No. 551 of 2025, inter alia, assailing the revised list of industrial sector categorization issued by the CPCB in January, 2025 and the consequential notifications issued by the Ministry of Environment, Forest[MoEF] and Climate Change[Climate Change].

39. During the pendency of the above appeals, the CPCB, in January, 2025, issued a revised list of industrial sector categorisation. Under the revised list, the activity described as 'stand-alone grinding unit without CPP (Captive Power Plant)' was reclassified from the 'Red' category to the 'Orange' category. Shortly thereafter, the MoEF & CC issued Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025, namely the Control of Air Pollution (Grant, Refusal Or Cancellation Of Consent) Guidelines, 2025 and the Control of Water Pollution (Grant, Refusal or Cancellation of Consent) Guidelines, 2025. The Appellants have accordingly instituted WP(C) No. 481 of 2025 and WP(C) No. 551 of 2025 seeking, inter alia, quashing of the revised categorisation and the aforesaid notifications to the extent they relax the applicable regulatory safeguards for such units.

40. We have gone through the material placed on record in the writ petitions, including the revised industrial sector categorisation issued by the Central Pollution Control Board in January, 2025, the Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025 issued by the MoEF & CC, and the submissions advanced by learned counsel for the parties.

41. In our considered opinion, the question that arises for determination in these two Writ Petitions is whether the revised industrial sector categorisation issued by the CPCB in January, 2025, insofar as it reclassifies the activity described as 'stand-alone grinding unit without CPP' from the 'Red' category to the 'Orange' category, together with the consequential relaxation of siting and regulatory safeguards brought about by Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025, can be sustained in law having regard to the constitutional mandate under Articles 14 and 21 of the Constitution of India and the governing principles of environmental jurisprudence.

Rationale advanced by the CPCB for the revised categorisation

42. The determination of the above issue necessarily requires an examination of the rationale offered by the Central Pollution Control Board for the revised categorisation, the implications of such reclassification on preventive environmental safeguards including siting norms, and the balance that constitutional and environmental law requires to be maintained between developmental considerations and the protection of life, health, and the environment.

43. The CPCB has relied upon a revised classification methodology based on a modified Pollution Index framework, under which industrial activities are assessed on the basis of their potential to cause air pollution, water pollution, and waste generation, and are thereafter assigned a cumulative pollution index. The stated justification for revisiting the 2016 classification is the experience gained over time, increased use of cleaner fuels, adoption of cleaner technologies, and the need to differentiate between integrated industrial operations and standalone units.

44. A central premise of the CPCB's reasoning is that a stand-alone cement grinding unit without a captive power plant has a lower pollution potential than an integrated cement plant involving clinker manufacturing and kiln operations. On this basis, the CPCB has treated such units as a distinct subcategory within the cement sector and has placed them in the 'Orange' category upon application of the revised scoring methodology. The CPCB has also stated that the revised methodology was placed in the public domain, representations were invited, and the final framework was adopted after examination by a duly constituted committee.

45. The CPCB has further asserted that the revised categorisation continues to be guided by the precautionary principle and is intended to function as a regulatory tool for consent management, inspection frequency, siting decisions, and environmental oversight, while also incentivising adoption of cleaner fuels and technologies. The PPCB has substantially adopted this position and has stated that it has implemented the revised categorisation in terms of the directions issued by the CPCB.

46. This, in essence, is the rationale advanced by the regulatory authorities in support of the revised categorisation. The validity of this rationale, when tested against constitutional requirements and the governing principles of environmental jurisprudence, now falls for consideration.

Assessment of the CPCB's rationale and its legal sustainability

47. Having considered the rationale advanced by the CPCB, we are unable to accept that the reclassification of a 'stand-alone grinding unit without CPP' from the 'Red' category to the 'Orange' category, together with the consequential relaxation of regulatory and siting safeguards, can be sustained in law.

48. The revised categorisation proceeds on a sector-level assessment based on a Pollution Index methodology. While such a framework may serve as a regulatory tool for consent management and inspection frequency, it cannot be treated as determinative where the consequence of reclassification is dilution of preventive safeguards, particularly siting norms intended to protect habitations and sensitive receptors such as educational institutions.

49. The CPCB's principal justification rests on a comparative distinction between integrated cement plants and stand-alone grinding units, on the premise that absence of clinker manufacturing and captive power generation necessarily results in lower pollution potential. This approach, however, does not address the core concern. The relevant question is not whether a stand-alone grinding unit is less polluting than an integrated plant in relative terms, but whether its pollution potential is sufficiently low to justify a regulatory downgrade that materially relaxes safeguards governing proximity to civilian habitations.

50. It must be noted that cement grinding units, even without CPP, involve extensive handling and processing of powdered material, which inherently gives rise to particulate emissions and fugitive dust. These emissions have direct public health implications, particularly where units are located near residential areas and schools. The revised categorisation does not demonstrate, on objective and publicly disclosed material, that such exposure risks have diminished to an extent that warrants dilution of the precautionary standards earlier applied.

51. The reliance on adoption of cleaner fuels and technologies is equally unpersuasive. The revised framework proceeds on generic, sector-level assumptions rather than on demonstrated, site specific performance. Preventive environmental regulation does not permit safeguards to be relaxed on the assumption that mitigation will suffice at a later stage. Where the risk to life and health is foreseeable, safeguards must operate at the threshold.

52. Notably, the CPCB itself recognises that the precautionary principle governs categorisation and that deviation from a mechanical application of methodology is warranted where activities pose a high risk of environmental or ecological harm. This recognition undermines the argument that a uniform application of the revised methodology can justify dilution of siting norms in sensitive contexts. The relaxation of minimum siting distances under Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025 further aggravates the concern. Permitting activities with known particulate emission profiles to be located closer to habitations and educational institutions, without a sector specific justification demonstrating redundancy of earlier safeguards, cannot be regarded as reasonable or proportionate.

53. We are therefore of the view that the revised categorisation and the consequential regulatory relaxations elevate a generic classification methodology to a position where it overrides preventive environmental safeguards, without adequate regard to exposure risks, local conditions, or the constitutional obligation to protect life and health. Such an approach is inconsistent with the precautionary principle, the doctrine of sustainable development, and the content of Article 21 of the Constitution of India.

Constitutional threshold for interference with regulatory classification

54. As a general rule, this Court exercises circumspection in interfering with technical classifications and regulatory frameworks formulated by expert bodies. Matters such as industrial categorisation and pollution indices ordinarily fall within the domain of specialised authorities, and judicial review is not invoked merely because a different regulatory choice is possible. Intervention is confined to cases where the decision-making process or its consequences transgress constitutional limits.

55. However, this principle of restraint cannot apply where a regulatory classification has the direct and foreseeable effect of diluting safeguards that protect fundamental rights. When a classification decision results in a blatant erosion of preventive protections governing exposure to environmental hazards, the issue ceases to be a matter of technical regulation alone and assumes constitutional significance.

56. This Court has repeatedly recognised that while judicial restraint is the norm in matters involving policy choices and expert regulation, environmental adjudication occupies a distinct constitutional space. Where executive or regulatory action has the effect of exposing communities to foreseeable environmental harm or diluting preventive safeguards that protect life and health, judicial intervention is not an act of activism but a discharge of constitutional duty. This position has been consistently affirmed in landmark decisions such as Vellore Citizens' Welfare Forum v. Union of India (supra), M.C. Mehta v. Union of India (Shriram - Oleum Gas)[(1987) 1 SCC 395], Indian Council for Enviro-Legal Action v. Union of India[(1996) 3 SCC 212], and A.P. Pollution Control Board v. Prof. M.V. Nayudu[(1999) 2 SCC 718], where this Court held that when scientific uncertainty coexists with a credible risk to human health or the environment, courts must err on the side of protection. These decisions underscore that environmental governance is not immune from constitutional scrutiny, and that judicial intervention becomes imperative where regulatory choices undermine the fundamental right to a clean and healthy environment guaranteed under Article 21 of the Constitution of India.

57. In the present case, the revised categorisation and the consequential relaxation of siting safeguards materially affect the level of protection available to civilians, including residents and school-going children, against exposure to industrial pollution. By lowering the regulatory threshold applicable to an activity with known particulate emission characteristics, the revised framework permits such units to be located closer to habitations and educational institutions. The impact is not speculative. It directly implicates public health and safety.

58. The right to life under Article 21 of the Constitution of India encompasses the right to a clean and healthy environment. Preventive environmental safeguards, including siting norms, are the means by which this right is protected. Where such safeguards are relaxed without a demonstrable and reasoned basis showing that the underlying risk has been materially reduced, the resulting action infringes the substantive content of Article 21. Further, Article 14 of the Constitution of India also comes into the picture. A regulatory downgrade that weakens environmental protection must bear a rational nexus to the object of safeguarding life and health. In the absence of a proportionate and scientifically substantiated justification, such dilution is arbitrary. Arbitrariness that impacts life and health cannot be sustained under constitutional scrutiny.

59. The precautionary principle which was recognized as the law of the land by this Court under Article 21 of the Constitution of India in Vellore Citizens' Welfare Forum v. Union of India (supra), and which underlines environmental governance in this country, mandates that where there is a plausible risk of harm, regulatory frameworks must err on the side of protection. In the present case, the revised categorisation prioritises sectoral differentiation over preventive protection, without adequately addressing exposure risks in sensitive contexts. This Court does not interfere with classification merely because it concerns industrial activity. The present intervention is warranted because the impugned actions have the effect of lowering the constitutional minimum of protection guaranteed to affected communities. Where regulatory action compromises fundamental rights under Articles 14 and 21 of the Constitution of India, judicial review becomes a constitutional necessity rather than an intrusion into policy.

Concluding Remarks and Operative Directions

60. Before we proceed to the operative directions, it is necessary to underscore, in clear terms, the constitutional balance that must govern questions of development and environmental protection. Economic development and industrial growth are legitimate and important objectives of the State. However, in a constitutional framework founded on the rule of law, development is not an abstract or absolute goal. It is conditioned by the non-derogable obligation to protect life, health, and environmental integrity. Development that undermines these foundational values ceases to be constitutionally permissible development.

61. We believe that the doctrine of sustainable development is not a slogan of compromise but a principle of prioritisation. It requires that when developmental activity poses a credible risk to human health or environmental safety, regulatory frameworks must err on the side of protection. The Constitution does not permit a trade-off where civilian life and health are exposed to foreseeable harm on the assumption that economic benefit or industrial facilitation justifies such exposure. Articles 14 and 21 of the Constitution of India do not tolerate a regulatory calculus that treats environmental safety as negotiable.

62. If regulatory dilution of the kind impugned in the present case were to be accepted, it would mark a fundamental shift in environmental governance. Sector-level reclassification, divorced from exposure realities and local sensitivities, would become a ready instrument to justify siting of polluting activities in close proximity to habitations, schools, and other sensitive receptors. Such an approach would not remain confined to the present case. It would operate as a precedent, enabling progressive erosion of preventive safeguards across regions, with cumulative and irreversible consequences. The law does not permit environmental protection to be weakened incrementally until harm becomes inevitable.

63. Equally important is the recognition that environmental harm, once caused, is often irreversible or incapable of full remediation. Public health consequences, degradation of air quality, and long-term ecological damage cannot be undone by subsequent regulatory correction. It is for this reason that environmental regulation is designed to be preventive rather than reactive. A regulatory framework that allows risk to materialise first and seeks to address consequences later is fundamentally incompatible with constitutional environmental jurisprudence.

64. At the same time, we reiterate that this Court does not ordinarily interfere with technical classifications or policy determinations made by expert bodies. Judicial restraint in matters of regulatory policy remains a settled principle. However, restraint cannot extend to abdication. Where regulatory action results in a lowering of the constitutional minimum of protection guaranteed to citizens, particularly in matters affecting life and health, judicial intervention becomes a constitutional obligation. The present case falls squarely within that exceptional category.

65. For the reasons recorded above, we are of the considered view that the revised industrial sector categorisation issued by the CPCB in January, 2025, insofar as it reclassifies the activity described as a 'stand-alone grinding unit without CPP' from the 'Red' category to the 'Orange' category, cannot be sustained in law. The said reclassification, read together with the consequential relaxation of siting and regulatory safeguards brought about by Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025, has the effect of diluting preventive environmental protections in a manner that infringes the constitutional guarantees under Articles 14 and 21 of the Constitution of India.

66. Accordingly, Writ Petition (Civil) No. 481 of 2025 and Writ Petition (Civil) No. 551 of 2025 are allowed to the following extent:

                   I. The revised industrial sector categorisation issued by the CPCB in January, 2025 is quashed insofar as it reclassifies the activity described as a 'stand-alone grinding unit without CPP' from the 'Red' category to the 'Orange' category.

                   II. Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025 issued by the MoEF&CC are quashed insofar as they relax the applicable siting and regulatory safeguards for such units on the basis of the aforesaid reclassification.

67. Consequently, any consent, approval or permission that has been granted solely on the basis of the aforesaid reclassification of 'stand-alone grinding unit without CPP' as an 'Orange' category activity or on the basis of the relaxed siting and regulatory safeguards introduced by Notifications GSR 84E dated 29.01.2025 and GSR 85E dated 30.01.2025 shall not survive and shall stand withdrawn, and the concerned authorities shall take all consequential steps in accordance with law.

68. We clarify that this judgment shall not preclude the CPCB or the MoEF & CC from undertaking a fresh exercise of classification or regulatory review in accordance with law, provided that any such exercise is supported by a reasoned, transparent, and scientifically substantiated assessment, and is consistent with the precautionary principle and the constitutional mandate to protect life, health, and the environment.

69. With the above directions, Writ Petition (Civil) No. 481 of 2025 and Writ Petition (Civil) No. 551 of 2025 stand disposed of.

70. Pending applications, if any, shall also stand disposed of.