Lok Sabha Question No. 1335 (UNSTARRED), answered on 2025-07-28
Subject: Discharge of Industrial Effluents into the Rivers
Ministry: ENVIRONMENT, FOREST AND CLIMATE CHANGE
Asked by: Shri T R Baalu

## GOVERNMENT OF INDIA

## MINISTRY OF ENVIRONMENT, FOREST AND CLIMATE CHANGE

## LOK SABHA UNSTARRED QUESTION NO. 1335

TO BE ANSWERED ON 28.07.2025

## Discharge of Industrial Effluents into the Rivers

## 1335.   SHRI T R BAALU:

Will the Minister of ENVIRONMENT, FOREST AND CLIMATE CHANGE be pleased to state:

- (a) whether the Government is aware that the down stream stretches of many Inter State rivers  like  Thenpennai  in  Tamil  Nadu  are  being  heavily  polluted  by  the  industrial effluents locate in upstream stretches; and
- (b) if so, the details of deterrent and punitive actions taken by the Central Pollution Control Board and various Environment Tribunals during the last two years and the current year?

## ANSWER

MINISTER  OF  STATE  IN  THE  MINISTRY  OF  ENVIRONMENT,  FOREST  AND CLIMATE CHANGE (SHRI KIRTI VARDHAN SINGH)

## (a) & (b)

To monitor the pollution of water bodies in the country, Central Pollution Control Board (CPCB) in association with State Pollution Control Boards (SPCBs) and Pollution Control Committees  (PCCs)  has  established  a  Water  Quality  Monitoring  Network  under  the National  Water  Quality  Monitoring  Programme  (NWMP).  Currently,  water  quality monitoring is carried out at 4736 locations in the country.

The discharge of sewage from cities and towns and industrial effluent is the main source of pollution  of  rivers.  The  Central  Government  has  laid down  standards for  the  quality of treated  sewage  and  treated  industrial  effluent  to  be  discharged  into  rivers  and  these standards are enforced by SPCBs.

The water quality data under NWMP is utilized by CPCB for identification of the polluted river  stretches  (PRS)  based  on  the  level  of  pollution  in  terms  of  the  most  significant pollutant - the organic matter content, which is measured in terms of biochemical oxygen demand  (BOD)  concentration  in  the  water.  All  locations/stretches  of  rivers  which  are exceeding the BOD limit (3 mg/L) in the Primary Water Quality Criterion for Outdoor Bathing are identified as polluted location/ stretches. The PRS are classified from Priority Class I to Priority Class V, Priority I being most polluted with BOD value of more than 30 mg/L and Priority V being least polluted with BOD ranging between 3 - 6 mg/L.

Based on the above identification and priority classification criteria, CPCB identified 311 PRS in the country during the year 2022 based on water quality data of year 2019 & 2021. Out of these PRS's, the Polluted River Stretch/ Polluted River location of Thenpennai river at  Chokkarasanapalli Bridge  (Bangalore)  in  Karnataka  was identified as  Priority-I  with maximum BOD value of 72 mg/L and PRS of Dakshinak Pinakini river along Mugalur was identified as Priority-I with maximum BOD value of 111 mg/L.

CPCB - Regional Directorate, Bengaluru monitors water quality of river Thenpennaiyar at Chokkarasanapalli  Bridge  at  Karnataka-Tamil  Nadu  inter-state  location  under  National Water  Quality  Monitoring  Programme  (NWMP)  on  quarterly  basis.  The  assessment  of water quality data for the year 2024 indicates that Dissolved Oxygen (DO) is observed as Below Detection Limit (BDL) (0.3 mg/ L), pH in the range of 7.24 - 8.1, Bio-chemical Oxygen Demand (BOD) in the range of 17 - 52.4 mg/ L, Fecal Coliform in the range of 2,80,000  -  79,00,000  MPN/  100  mL  and  Total  Coliform  in  the  range  of  16,00,000  35,000,000 MPN/ 100 mL.

With respect to the action taken, it is submitted that CPCB in OA No. 1374/2025 before the  National  Green  Tribunal,  New  Delhi  has  communicated  to  KSPCB  to  address  the discharge of sewage/wastewater in river Thenpennai from the Bengaluru city and other significant sources to improve the water quality of Thenpennai river.

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