Guidelines for Handling, Storage, Management, Utilisation and Disposal of Reject water and Discarded Element Generated from Domestic Water Purification System and Commercial Water Purification System

GUIDELINES FOR HANDLING, STORAGE, MANAGEMENT UTILISATION AND DISPOSAL OF REJECT WATER AND DISCARDED ELEMENT GENERATED FROM DOMESTIC WATER PURIFICATION SYSTEM AND COMMERCIAL WATER PURIFICATION SYSTEM Central Pollution Control Board (CPCB) Ministry of Environment, Forests & Climate Change (MoEF & CC) Parivesh Bhawan, East Arjun Nagar, Delhi – 110032 September, 2026Contents

1.0 BACKGROUND ............................................................................... 3

2.0 WATER PURIFICATION SYSTEM ............................................. 3

2.2QUANTUM OF RO REJECT ....................................................... 4

3.1 Utilization of RO Reject Water ..................................................... 5

3.2 Storage of RO Reject Water .......................................................... 5

3.3 Disposal of RO Reject Water ........................................................ 5

4.0 GUIDELINES FOR HANDLING, STORAGE, MANAGEMENT AND UTILISATION OF DISCARDED ELEMENT ............................................................................................... 5

5.0 ROLES AND RESPONSIBILITIES ............................................ 5

5.1 Role of Manufacturer .................................................................... 5

5.2 Role of User 6 Annexure-I 71.0 BACKGROUND In exercise of the powers conferred by sections 3, 6 and 25 of the Environment (Protection) Act, 1986 (29 of 1986), MoEF&CC notified the “Water Purification System (Regulation of Use) Rules, 2023” vide GSR 833 (E) dated 10.11.2023.

The afore-said Rules define responsibilities of Manufacturer, User, Central Pollution Control Board (CPCB), State Pollution Control Board or Pollution Control Committee and Bureau of Indian Standards (BIS) for Domestic Water Purification System

(DWPS) and Commercial Water Purification System (CWPS).

These guidelines for handling, storage, management and utilisation of reject water and discarded element generated from Domestic Water Purification System (DWPS) and Commercial Water Purification System (CWPS) have been prepared as per the responsibility assigned to CPCB in the afore-said Rules.

“Discarded element” means element which is discarded from the domestic water purification system and commercial water purification system due to manufacturing defect, wear, tear, loss of its utility attributes or achieved its end of life;

“Commercial water purification system” means equipment or device, having reverse osmosis based water treatment system that reduces total dissolved solids, chemical contamination to safe level and removes physical particles including microbiological impurities in water to produce water for human consumption and meeting the required specification of IS 10500: 2012.;

2.0 WATER PURIFICATION SYSTEM Water Treatment System means a system that removes or reduces contaminants from water to produce water that is safe for human consumption.

Water purification systems like Ultra Filtration (UF), Nano Filtration (NF), Reverse Osmosis (RO), Ion Exchange etc. differ in their filtration capabilities, efficiency and the types of impurities they are designed to remove. The general conditions or criteria that determine when and how RO system is suitable for use are given in Annexure I.

Use of RO Based Water Purification systems is increasing in households as an additional precaution for removal of harmful substances that may be present in supplied ground water or surface water by the water supply agency.

Reverse Osmosis based water purification system has reject stream. Characteristics of reject water includes high concentration of suspended solids, elevated level of bacteria, viruses and other organics. Hence, proper guidelines are required for management, storage, utilization and disposal of reject stream.2.1 PROCESS OF REVERSE OSMOSIS BASED WATER PURIFICATION Reverse osmosis is a process of water purification that uses a synthetic lining i.e. semi- permeable membrane to filter out solutes i.e. salts, bacteria, virus, color, unwanted molecules and large particles such as sediments and dirt from drinking water.

It is employed in various applications viz. desalination, treatment of waste water, reclamation of minerals, concentration of whey and other food products, and purification of water. In recent years, RO has been used increasingly in making processed water for dialysis in hospitals and for certain cosmetics and drugs by pharmaceutical manufacturers.

In India, Reverse osmosis is commonly used in drinking water purification systems in households to treat raw water in urban areas and in areas where water has high concentration and dissolved solids or is contaminated with pathogens. Metal and other ions viz. lead, arsenic, sulphate, calcium, magnesium, sodium, potassium, nitrate, fluoride and phosphorus can also be removed through this process.

As raw feed water flows through the reverse osmosis system, feed water is separated in two streams viz. Permeate water and RO Reject. Permeate is the treated low TDS water used for various domestic and industrial purposes including drinking. While, RO reject, which is high in TDS, contains removed salts, dissolved pollutants, minerals etc., is finally discarded.

2.2 QUANTUM OF RO REJECT The RO process employs semi-permeable membranes to separate water into two

streams: permeate, the purified water that passes through the membrane, and concentrate, the portion that contains salts, heavy metals, minerals, and including microorganisms and therefore needs a suitable and environmentally friendly management option. The characteristics and quantum of the reject or waste stream, also termed as concentrate, retentate or brine, are governed mainly by the quality of the feed water, the quality of the produced water. As per Bureau of Indian Standards IS 16240: 2023, the minimum recovery rate shall be equal to or more than 40 percent.

2.3 RULES FOR RO BASED WATER PURIFICATION SYSTEM The MoEF&CC issued notification G.S.R. 833(E) dt 10.11.2023 on “Water Purification System (Regulation of Use) Rules, 2023” for the Domestic Water Purification system (DWPS) and Commercial Water Purification system (CWPS)3.0 GUIDELINES FOR HANDLING, STORAGE, MANAGEMENT AND UTILISATION OF RO REJECT WATER

3.1 Utilization of RO Reject Water Utilization of RO (Reverse Osmosis) reject water is an important step toward water conservation, especially in areas facing water scarcity. RO systems typically waste a significant amount of water while purifying it, but this reject water can still be reused for various non-potable purposes. It can be effectively utilized for cleaning floors, washing vehicles, flushing toilets, and sprinkling in construction activities, as it contains dissolved salts but is not harmful for such activities.

Additionally, in commercial settings, this water can be treated further and reused in processes like cooling or landscaping. By adopting simple reuse practices, individuals and organizations can contribute to sustainable water management and reduce unnecessary depletion of freshwater resources.

3.2 Storage of RO Reject Water In order to utilize the reject water, it is important to have adequate storage facility for reject water so that it can be used for options mentioned above. User of purifier shall arrange the container as per their requirement to hold reject water.

3.3 Disposal of RO Reject Water If the RO reject is not utilized for above mentioned options then the unutilized RO reject shall be disposed of into sewerage system leading to terminal STPs.

4.0 GUIDELINES FOR HANDLING, STORAGE, MANAGEMENT AND UTILISATION OF DISCARDED ELEMENT The manufacturers of water purifiers shall adopt a policy of maximizing use of raw materials having high recycling rate for manufacturing the water purifiers. Use of halogenated plastics shall be avoided.

The discarded elements of water purification system shall be managed as per the provisions of the Plastic Waste Management Rules, 2016, the E-Waste

(Management) Rules, 2022 and the Hazardous and Other Waste (Management and Transboundary Movement) Rules, 2016 as amended from time to time.

5.0 ROLES AND RESPONSIBILITIES

5.1 Role of Manufacturer1. The manufacturer shall obtain Standard Mark under a license from the Bureau of Indian Standards as per the Indian Standard IS 16240 (as amended from time to time) under Scheme –I, Schedule- II of Bureau of Indian Standards (Conformity Assessment) Regulations,2018.

2. Manufacturer shall mention about utilization of RO Reject Water in their Product's manual and promote reuse of RO reject water.

3. The manufacturers of water purifiers shall adopt a policy of maximizing use of raw materials having high recycling rate for manufacturing water purifiers. Use of halogenated plastics shall be avoided.

4. The discarded elements of water purification system shall be managed as per the provisions of the Plastic Waste Management Rules, 2016, the E-Waste

(Management) Rules, 2022 and the Hazardous and Other Waste (Management and Transboundary Movement) Rules, 2016 as amended from time to time.

5.2 Role of User The user of domestic or commercial water purifier shall explore and adopt use of RO reject to the maximum possible extent at the point of use as per options mentioned at Point 3.1. If the RO reject is not utilized for above mentioned options then the unutilized RO reject shall be disposed of into sewerage system leading to terminal STPs.

***Annexure-I CONDITIONS THAT DETERMINE WHEN AND HOW RO SYSTEM IS SUITABLE FOR USE Type of Purpose Conditions treatment Particle Contaminant Water Pre-treatment Pressure Applications size Quality requirements removal Ultra-filtration UF is primarily Typically Effective for Suitable for UF may be Operates at low Domestic drinking water used for removing removes reducing bacteria, use when the used as a pre- pressures (1-10 purification, wastewater

(UF) larger suspended particles in viruses, feed water treatment for bar), making it treatment, and industrial solids, colloids, the range of suspended solids, contains high RO or other energy efficient applications where only bacteria, viruses, 0.01 to 0.1 and certain levels of systems, but suitable for biological and particulate and some microns. organic materials, turbidity, especially in applications filtration is needed.

macromolecules but not effective particulates, or cases where where minimal from water for dissolved biological the water has a dissolved salts, minerals, or contaminants. high fouling impurities need heavy metals. potential. to be removed.

Nanofiltration NF is used for NF Removes larger Suitable for - Operates at Water softening, partial

(NF) softening hard membranes organic water sources moderate desalination, and water, reducing can remove molecules, that have high pressures (4-8 wastewater treatment, organic particles multivalent ions hardness or bar), requiring especially for reducing compounds, and down to (e.g., calcium, organic more energy hardness and certain removing divalent 0.001 magnesium), and content but do than UF but less organic compounds in ions like calcium microns. some bacteria and not require than RO. water.

and magnesium viruses but allows complete while allowing monovalent ions desalination. some monovalent (e.g., sodium, ions like sodium chloride) to pass and chloride to pass through. through.Reverse RO is used for Removes Highly effective Suitable for Requires pre- Requires high Seawater desalination, Osmosis (RO) comprehensive particles for removing use when the treatment pressures (15-70 wastewater treatment, and water purification, down to dissolved salts feed water (such as UF or bar) depending production of ultrapure including the 0.0001 (desalination), contains high sediment on the system, water for industrial or removal of microns, heavy metals levels of filtration) to especially for laboratory applications.

dissolved salts, which (e.g., lead, dissolved salts, prevent seawater heavy metals, and includes arsenic), nitrates, heavy metals, fouling of the desalination, virtually all types almost all fluoride, or other RO membrane which increases of contaminants. dissolved pharmaceuticals, dissolved by suspended energy solids, and other contaminants solids or consumption.

bacteria, impurities. that UF or NF biological viruses, and cannot contaminants. organic remove. molecules.

Ion Exchange Ion exchange is - Effective for Suitable for Requires - Water softening in used for removing removing use when the relatively domestic systems, specific ions from dissolved ions, primary clean feed deionization for industrial water, particularly including concern is the water, free processes, and heavy metal for water softening hardness ions removal of from removal in wastewater (removing calcium (calcium, specific ions, particulates treatment and magnesium) magnesium), especially in and organic and deionization heavy metals industrial matter, to (removing all ions (e.g., lead, applications prevent for ultrapure water copper), and for where fouling of the production). demineralization deionized or resin bed.

in some cases. softened water is required.