Lok Sabha Question No. 1707 (UNSTARRED), answered on 2024-08-01
Subject: Contamination of Ground Water in Chennai
Ministry: JAL SHAKTI
Asked by: Dr. Kalanidhi Veeraswamy

## GOVERNMENT OF INDIA MINISTRY OF JAL SHAKTI DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT & GANGA REJUVENATION

## LOK SABHA UNSTARRED QUESTION NO.1707

ANSWERED ON 01.08.2024

## CONTAMINATION OF GROUND WATER IN CHENNAI

## 1707. DR. KALANIDHI VEERASWAMY

Will the Minister of JAL SHAKTI be pleased to state: (a) whether the Government is aware of the fact that increasing amount of heavy metal contamination in ground water of North Chennai has led to non-usability of water for drinking purpose in the region; (b) if so, the details thereof along with the current level of heavy metal contamination in ground water of North Chennai; (c) the measures taken by the Government to address the issue of heavy metal contamination in ground water of North Chennai; (d)  the  details  of  potential  health  risks  associated  with  consumption  of  heavy  metal  contaminated ground water in North Chennai along with the steps being taken to protect the affected population; (e)  whether  the  Government  identified  the  industries  responsible  for  heavy  metal  contamination  in North Chennai's ground water and if so, the actions taken to hold them accountable; and (f) the steps taken by the Government to provide clean and safe drinking water to the residents of North

Chennai in the light of the ground water contamination issue?

## ANSWER

## THE MINISTER OF STATE FOR JAL SHAKTI ( SHRI RAJ BHUSHAN CHOUDHARY )

(a) & (b) Central Ground Water Board generates ground water quality data on a regional scale during various scientific studies and ground water quality monitoring throughout the country including North Chennai of Tamil Nadu. CGWB had carried out special studies in the industrial cluster of Tamil Nadu during 2011 and 2016. These studies indicate that during July 2011, the concentrations of heavy metals viz. Copper, Lead, Zinc, Nickel, Chromium in North Chennai were found to be within the permissible limit except Manganese and Iron. During May 2016, also the elements were within the permissible limit except Lead. The details are given in Annexure A .

Further,  during  2019,  ground  water  samples  from  National  Hydrograph  Network  stations (NHS) in North Chennai were collected and analyzed for heavy metals including Copper, Lead, Zinc, Nickel, Cadmium, Chromium, Manganese, Iron and Arsenic. All the samples from North Chennai were found  to  be  within  the  permissible  limit  of  BIS  (10500:2012).  The  details  are  given Annexure  B . However, area specific intensive ground water sampling studies will be required to gauge the current trend.

(c) Water being a State subject, sustainable development and management of groundwater resources, including  the  quality  aspect  is  primarily  the  responsibility  of  the  State  Government.  However,  the Central  Government  facilitates  the  efforts  of  the  State  Governments  including  Tamil  Nadu  through technical  and  financial  assistance  through  its  various  schemes  and  projects.  In  this  direction,  the important steps taken by the Ministry of Jal Shakti and other central ministries are given below :-

-  CGWB  has  prepared  the  Master  Plan  for  Artificial  Recharge  to  Groundwater-  2020  in consultation with States/UTs which is a macro level plan indicating various structures for the different  terrain  conditions  of  the  country  including  Tamil  Nadu.  In  Tamil  Nadu,  the  Master Plan envisages construction of about 88 thousand Rain water harvesting and artificial recharge structures  to  harness  about  960  Million  Cubic  Metre  (MCM)  of  monsoon  rainfall.  The management plan has been shared with the state Government which is devising suitable action plan for its implementation in select priority areas.
-  CPCB has made a comprehensive programme on water pollution for controlling point sources the main components of which are developing industry specific standards and general standards for discharge of effluents notified under the Environment (Protection) Act, 1986 by Ministry of Environment, Forest and Climate Change, Govt. of India to be enforced by the SPCBs / PCCs through consent mechanism; Establishment of Common Effluent Treatment Plants (CETPs) for cluster  of  Small  Scale  Industries;  Installation  of  Online  Continuous  Effluent  Monitoring Systems  (OCEMS)  by  Grossly  Polluting  Industries  for  getting  real  time  information  on  the effluent quality etc.
-  Awareness  generation  programs/  workshop  on  various  aspects  of  ground  water  including preventing ground water pollution and safe use of contaminated water are being conducted by CGWB periodically.
-  Since ground water is the predominant source used for drinking and since its quality is found to deteriorate when drawn from greater depths, Ministry of Jal Shakti and other central ministries are  implementing  several  programmes  for  recharging  ground  water  and  water  conservation which  are  expected  to  improve  the  underground  water  table,  thus  improving  the  quality  of ground  water.  Some  of  such  programmes  are  Jal  Shakti  Abhiyan,  AmrutSarovar  Mission, MNREGS, PMKSY-WDC etc.
-  CGWB constructs wells for Exploration of Ground Water. Successful contamination- free wells are handed over to the State Governments for gainful utilization.
-  Data  on  ground  water  quality  available  with  CGWB  are  made  available  in  public  domain through  reports  as  well  as  through  the  web  site  (http://www.cgwb.gov.in)  for  use  by  various stakeholders. The data is also shared with concerned State Governments for taking necessary remedial measures.

(d) As per information received from Ministry of Health & Family Welfare, heavy metal contamination in groundwater can lead to neurological impairment, developmental delays in children, renal impairment, increased risk of cancer, etc.

(e) Heavy metal contamination can occur due to multiple reasons owing to factors which are geogenic and anthropogenic, or a combination of both. Ascertaining the true nature of contamination and actual factors responsible for it is possible only with detailed area specific studies.

(f) Water being a State Subject, providing clean and safe drinking water to the residents of including North Chennai part of Tamil Nadu is the responsibility of the concerned State Government. As per the information available from the Chennai Metropolitan Water Supply and Sewerage Board (CMWS&SB), the drinking water is being supplied to the Chennai city from both ground water based and surface water based sources. The problem of contamination, if any, is taken care of by treating the water thoroughly in the designated water treatment plants of CMWS&SB prior to distribution to households.

ANNEXURE REFERRED TO IN REPLY TO PART (a) & (b) OF UNSTARRED QUESTION NO. 1707 TO BE ANSWERED IN LOK SABHA ON 01.08.2024 REGARDING 'CONTAMINATION OF GROUND WATER IN CHENNAI'.

The details of the special studies carried out by CGWB in Industrial Cluster in North Chennai

| S. No.   | Heavy Metals   | Range (mg/l)                    | Range (mg/l)                    | Permissible limit of BIS in mg/l   | %of Samples Exceed Permissible Limit   | %of Samples Exceed Permissible Limit   |
|----------|----------------|---------------------------------|---------------------------------|------------------------------------|----------------------------------------|----------------------------------------|
| S. No.   |                | July 2011(n=12)*May 2016 (n=12) | July 2011(n=12)*May 2016 (n=12) |                                    | July 2011                              | May 2016                               |
| 1        | Copper         | ND - 2.06                       | ND**                            | 1.5                                | 17                                     | Nil                                    |
| 2        | Lead           | ND                              | ND-0.078                        | 0.01                               | Nil                                    | 25                                     |
| 3        | Zinc           | 0.03 - 4.89                     | ND                              | 15.0                               | Nil                                    | Nil                                    |
| 4        | Nickel         | ND                              | ND                              | 0.02                               | Nil                                    | Nil                                    |
| 4        | Chromium       | ND                              | ND                              | 0.05                               | Nil                                    | Nil                                    |
| 5        | Manganese      | 0.19 - 1.57                     | 0.012 - 0.24                    | 0.3                                | 50                                     | Nil                                    |
| 6        | Iron           | 0.09 - 11.83                    | ND-0.74                         | 1.0                                | 42                                     | Nil                                    |

ANNEXURE-B The details of Heavy metal in Ground Water samples collected from the NHS in North Chennai

| S. No.   | Location     | Cr in mg/l                                  | Fe in mg/l                                  | Mnin mg/l                                   | Cu in mg/l                                  | Zn in mg/l                                  | As in mg/lPb                                | in mg/lU                                    | in mg/l                                     |
|----------|--------------|---------------------------------------------|---------------------------------------------|---------------------------------------------|---------------------------------------------|---------------------------------------------|---------------------------------------------|---------------------------------------------|---------------------------------------------|
|          |              | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water | Permissible limit of BIS for drinking water |
|          |              | 0.05 mg/l                                   | 1.0 mg/l                                    | 0.3 mg/l                                    | 1.5 mg/l                                    | 15.0 mg/l                                   | 0.01 mg/l                                   | 0.01 mg/l                                   | 0.03 mg/l                                   |
| 1        | Tondiarpet   | 0.00014                                     | 0.02                                        | 0.33                                        | 0.00                                        | 0.08                                        | 0.00438                                     | 0.00098                                     | 0.00179                                     |
| 2        | Tiruvottiyur | 0.00573                                     | 0.46                                        | 0.09                                        | 0.00                                        | 0.16                                        | 0.0097                                      | 0.00222                                     | 0.00034                                     |
| 3        | Vyasarpadi   | 0.00005                                     | 0.03                                        | 0.00                                        | 0.00                                        | 0.07                                        | 0.00665                                     | 0.00065                                     | 0.00026                                     |

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