The water treatment industry in India is well established and has been around since the early 1950s with just a few players at that time, several of them subsidiaries of companies known internationally. The market grew over the last 5 decades and today, there are probably close to a few thousand companies(including many small, local companies) as players now in the market. As the industrialization and development of the country progressed, water use too grew rapidly with water being used with utter profligacy depleting groundwater and polluting surface water with industrial wastewater and enormous quantities of domestic sewage.

As water quality deteriorated, there was a clear opportunity for companies to bring in Reverse Osmosis (RO) technology to cater to the drinking water needs of the country. The standard for drinking water BIS-10500 had also been established in 1991 by the Indian Standards Institution (ISI) now re-named Bureau of Indian Standards (BIS). This standard reflected the deterioration that water quality had undergone, particularly groundwater. BIS-10500 has laid down the desirable quality, the acceptable quality, and lastly the permissible quality for water used for human consumption if no better, alternate source was available. Such a situation was ideal for the growth of the water treatment industry to cater to the domestic segment using RO for drinking water purification since groundwater over much of the country had deteriorated due to exploitation leading to water with dissolved solids content far over the maximum limit specified by BIS-10500. There was enormous growth in the industry that catered to the water demand of the domestic market.

The economic reforms of 1991 too saw accelerated GDP growth. In this scenario, the real estate development industry is too geared up to meet the pent-up demand for housing in the country. If one takes Bangalore as a typical example of this growth, one saw the city of Bangalore growing in size, spreading out, and growing in all directions with a virtual forest of apartment complexes and gated communities springing up in almost no time at all! As much of this growth was in areas to which BWSSB was unable to supply Cauvery Water, the residents of such areas had to make do with groundwater which was mostly hard water and had excess total dissolved solids. Now, this gave birth to Water Treatment Plants in Apartment Complexes and Housing Societies.

Water treatment plants in Apartment Complexes & Housing Societies

Let us first examine in detail the reasons leading to Water Treatment Plants in Housing Societies.

Hard Water

High hardness in water causes the deposit of scales in vessels used for heating water, hot water geysers, and pressure cookers. Hard water causes poor quality of washing in washing machines, increases consumption of detergent, and prevents soap from lathering when having a bath or even when just washing utensils. Hard water prevents dal and rice from cooking, spoils the taste of tea when it is used to make tea, it also ruins the taste of whiskey when it is used to make a drink!! Hard water fails to quench your thirst when you drink it. Hard water also forms scales in the pipes carrying water and can warrant the replacement of all water pipes in the complex after a few years which can be a very huge expense.

Softeners are the answers to such problems. Softeners have therefore become very common in apartment complexes in the form of a large centrally installed system that softens all water used in the premises it is installed in. Sometimes there is no centralized softener in an apartment complex and one finds that some individual apartments have installed small domestic softeners to soften the water for various uses or to soften the water fed to a small domestic RO unit.

Total Dissolved Solids (TDS)

Total dissolved solids are the total of all the minerals present in water including the total hardness. A total dissolved solids content of approximately 300 to 500 ppm (or mg/liter) is acceptable and does not need to be treated by an RO unit. However, in most places well waters often have TDS levels as high as 1000 ppm or more.

This is where an RO system comes in as very useful as it can remove 90 to 95% of the TDS and thus provide good-tasting water. Using an RO unit would produce treated water with TDS as low as 20 to 30 ppm. However, it is important to note that hard water cannot be directly fed into a RO unit as it forms a hardness scale on the RO Membrane. Thus, Soft water is the best kind of water to feed an RO unit. There are apartment complexes where the residents of a complex have shared the cost of installing a central RO system which is used to supply RO water to all the apartments in the complex 

Suspended Impurities

In a majority of cases, softeners need to be protected from the presence of suspended impurities in the feed water. This is done by installing a pressure sand filter and, sometimes by also installing an additional activated carbon filter which protects the softener from the effects of chlorinated water and organic impurities. Such filtration systems are also a must as a pre-treatment for RO systems.

Thus, essentially we need water to pass through filtration plants, followed by softener, and then through RO Unit to get potable water.

Swimming pool purification process

In apartments/societies where Swimming Pools are present, swimming pool purification plants need to be present to take care of the clarity of pool water and need to be used well in advance to ‘turn over’ the entire contents of the pool before swimmers can use it. Pools need clear water, have an almost neutral pH, and are free from any bacteria. This involves having to dose a variety of chemicals into the pool water daily. This ends up increasing the chemical content of the pool water which then needs to be brought down by diluting the pool with fresh water after the pool filter has been backwash(cleaned). The backwashing process reduces the quantity of pool water and which is made up of fresh water to dilute the concentration of chemicals in the water.

Now comes the question – with every step of water treatment, there is bound to be wastewater getting generated. How much is this quantity and can anything be done about this ‘wastewater?

Waste Water Generated by each treatment process

In such a scenario, it is essential to take a good look at the wastewater generated by each treatment process which is given below:

1. Filters: Water lost due to backwash to clean filters is between 10 to 15%. This means that for every 100 liters of filtered water, a filter needs 110 to 115 liters of feed water. This applies to swimming pool filters too.
2. Softeners: Water lost due to ‘regeneration’ or ‘ recharge’ is as much as 30% if inlet hardness is around 300 to 350 ppm as CaCo3 and increases as the inlet hardness increases. The feed water needed will be 130 liters or more for every 100 liters of soft water or depending on higher hardness values.
3. RO plants: Small, domestic units used in individual households are the most wasteful, and the waste can be as high as 90% in small units and lower if the RO system is of large capacity, and waste in such systems would be around 50 to 30% of feed water.

Need to Reduce Waste Water from the Purification/treatment methods

Hardly any housing society or apartment residents’ association or its plant operating personnel know or bother to monitor the wastewater that is created by any of the treatment systems used in an apartment complex. Worse still I have yet to see any plant installed which has a water meter fitted at the inlet that can help to monitor the amount of water treated and wasted during the regeneration of softeners, the backwash of filters, and during normal operations of RO systems which have a steady flow of ‘ reject’ water going to waste during operation. In a majority of the places, they do not even have an accurate figure of the total water coming into the property particularly if they have yielding bore wells. As most parts of Bangalore now have dry bore wells and get water in tankers, some vague figure based on the number of tankers supplied is available. Tanker volumes are notoriously unreliable and they seldom supply what they claim as the tanker capacity.

Need to have better operations and maintenance of WTPs

I have seen numerous WTPs (filters, softeners, RO plants & swimming pool purification). Most of them ( close to 95%) are badly operated or not operated. Maintenance is seldom done as per schedule(actually, I have yet to see a maintenance schedule!). This is a wasteful practice and results in the unnecessary waste of water that could otherwise have been used in some apartments.

Proper treatment of wastewater

Regeneration/rejection waste and filtration waste waters in any property usually go as a mixture clandestinely to stormwater drains. The quality of this wastewater is such that pollution control laws do not permit such disposal and it would normally have to be sent to the STP for treatment, as, normally STP treated water is usually re-cycled and not (can not be) discharged.

Bleak future

If this is the state of affairs with WTPs, I question the need to even install such systems as they do not meet the objective of producing treated water. The main point that needs to be kept in mind is that the increasing scarcity of fresh water will make the use of WTPs unviable as there will not be enough fresh water (from bore wells/tankers) for both use and regeneration/re-charge of WTPs. I also predict that swimming pools will soon become unviable for swimming pool use, but could be used as storage whenever a sizeable volume of water becomes available.

Why Facilus? Facilus Facility Management Pvt Ltd

• Realtime water monitoring 

• Automated System for Motors, Blowers 

• Water leakage and wastage arrest

• Save Energy and Improve the Efficiency of STP

• Facilitate Solar Grid setup for STP & Street lights

• Pollution control board-approved lab reports

• Plant Preventive maintenance

• Plant revamp support

• Daily reports

• Back-End SME Support 24*7

• Core Team PhD. Holders of Chemistry to solve your problems.

Contact Us.

Jagadeesh P

CEO, Founder & FMS Auditor @ Facilus Facility Management Pvt Ltd.

Mail ID: jagadeesh.p@facilusfms.com

Mobile No: +91 87470 78508

Website: www.facilusfms.com

Address: 20/1, 2nd Floor, 14th Cross Rd, opp. to SBI Bank ATM, 1st Block, Rajajinagar, Bengaluru, Karnataka 560010