Lok Sabha Question No. 2853 (UNSTARRED), answered on 2024-08-08
Subject: Usage of Treated Sewage Water
Ministry: JAL SHAKTI
Asked by: Dr. K Sudhakar

## 2853.

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

## LOK SABHA

## UNSTARRED QUESTION NO.2853

ANSWERED ON 08.08.2024

## USAGE OF TREATED SEWAGE WATER DR. K SUDHAKAR

Will the Minister of JAL SHAKTI be pleased to state:

(a) whether the Government has conducted any scientific study on usage of secondary treated domestic sewage water being used for ground water recharge through tanks and reservoirs at Chikkaballapur, Kolar and Bangalore rural districts in Karnataka and if so, the details thereof;

(b) whether the usage of such treated domestic sewage water could be hazardous once percolated down to the ground water and if so, the details thereof;

(c) whether there are any such models working successfully and found to be not harmful for ground water levels at International levels and if so, the details thereof; and

(d) whether the Government has data regarding the method of domestic sewage water treatment being done  at  Chikkaballapur,  Kolar  and  Bangalore  rural  district  and  if  so,  the  details  of  the  waste  water treatment mechanism adopted?

## ANSWER

## THE MINISTER OF STATE FOR JAL SHAKTI

## ( SHRI RAJ BHUSHAN CHOUDHARY )

(a) As  per  the  information  received  from  the  Minor  Irrigation  &  Ground  water  Development Department  of  the  Government  of  Karnataka  (GoK),  they  have  engaged  a  team  of  scientists  from Indian  Institute  of  Science  (IISc),  Bangalore  to  study  the  groundwater  quality  following  the  use  of indirect ground water recharge through filling the local irrigation tanks with treated recycled water and the ability of the tank water as well as the groundwater to remain fresh and usable for long periods. Further, IISc was also requested to study the potential environmental and socio-economic implications of this project. As per information the finding of the study have shown significant positive impact.

(b) As reported by the GoK, no hazardous signals/signs have been noticed over the past five years due to usage of treated domestic sewage for groundwater recharge. GoK has also reported that since Indian laws  do  not  permit  a  mix  up  of  domestic  sewage  with  industrial  wastewater,  domestic  wastewater collected  by  municipalities  is  expected  to  be  free  of  any  industrial  wastewater  contamination  and therefore simplifies the acceptance of treated wastewater.

(c) Reportedly,  there  are  several  international  projects  of  recharging  ground  water  with  treated domestic  sewage  which  are  working  successfully.  However,  while  taking  up  such  projects  due  care must  be  placed  on  comprehensive  treatment  of  sewage  water  to  meet  the  accepted  standards  before using them for recharge. Further, continuous monitoring to maintain safety standards and mitigate any risks to groundwater quality or public health is also necessary in such projects.

(d) As  reported,  Bangalore  Water  Supply  and  Sewerage  Board  (BWSSB)  is  the  nodal  body  that collects, treats and disposes treated domestic sewage using the two types of sewage treatment plants (STP)  which  work  under  the  operational  principles  either  of  sequential  batch  reactors  (SBR)  or  the activated sludge process (ASP) based technologies in combination with Biological Nutrient Removal (BNR), disc filtration and disinfection by chlorination in order to achieve treated water quality meeting NGT 2019 standards or near  tertiary  treated  water  quality.   The  resulting  treated  water  delivered  to Kolar, Chikkaballapur and Bangalore rural districts from Bangalore STPs, meets the NGT norms for discharge of secondary treated water to surface water bodies.

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