The challenge that we took to revitalize 
 Hussain Sagar Lake, Hyderabad, India
Hussainsagar is a 400-year-old water body.
.                                                                                             Area: 4.7 km² (1.8 Sq. mi.)
In the past years:
The Hussain Sagar Lake suffered continuously for decades from the sewage flowing from four nalas being dumped into it and the fear has been that one day the lake will end up as a large sewage effluent tank in the heart of Hyderabad.

''By 2010, pollution in the lake would be a thing of the past''. That did not happen, and worse, the project in fact encroached into the lake area, with a sewage treatment plant (STP) being built on the lake bed.:There are four storm water drains from which sewage entered the lake.
Max depth: 9.754 m (32 feet), Area: 4.7 km² (1.8 Mi ²), Length: 3.2 km (1.9 miles), shoreline length: 14 Km

March 03, 2016 - 17:51
Residents raise a stink about the stench.

A series of measures have been taken to clean the lake, 
but these have been ineffective,and the foul smell still continues
to annoy tourists and nearby residents
A Clean Hussain Sagar Campaign has been launched in November 2013 
Apr 14, 2016, 06.57 PM IST 
It’s a stinky mess!                      

Hyderabad: Thousands of people living around Hussainsagar may have to stock up on air fresheners to ward off the stench emanating from the lake.With temperature soaring and water stagnating, the lake is spewing large quantities of highly toxic and stomach-churning Hydrogen Sulphide. The gas has already resulted in residents of colonies surrounding the lake complaining of the stink.

NOTE: . Oxygen level is 2 oe 3 mg/L  (should be 7)
           .  Biologivcal Oxygen demand is 25 mg/L  ( should be 3)
           .  Some aerators which are fixed at some places in the lake
 Dec 22, 2016, 10.35 AM IST
Toxins scrape bedrock of Hussainsagar

Heavy metals trickled 3 metres into lakebed, aquatic life choking, say scientists in study.
Rising level of pollution in Hussainsagar Lake over the years has been a raging issue for Hyderbadis, given the iconic status of the water body. Confirming fears of green activists, researchers now warn that the level of pollution has assumed such monstrous proportions that heavy metals have seeped up to three metres into the lake bed.

The lake's water scored very low in all these tests forcing the researchers to describe the lake as a `virtual garbage bin'.
NOTE: . Dissolved oxygen: 3 & 7.2  -  . Chemical Oxygen Demand  (COD) = 289  - Turbidity = 72
           . Dissolved solids = 1126  -  PH = 8.1 to 9
Pollution in Hussain Sagar Lake Hyderabad

Among the above mentioned nallas, the Balkapur nalla and the Banjara nalla enters the Hussain Sagar Lake with domestic sewage from the northwest as well as western side. But the Picket nalla that enters this artificial lake carries the domestic sewage from residential areas of north eastern side and the Kukatpally nalla deposits domestic as well as industrial effluents. 
On September 2011, 7 high jet aeration fountains with led lights were installed at the Hussain Sagar Lake Andhra Pradesh in order to enhance the dissolved oxygen level and at the same time to improve the water quality of the lake

Feb 8, 2017, 10.38 AM IST
Death knell: 
Hussainsagar raises stink even in spring

If you happen to take a morning or evening stroll along the picturesque Tank Bund or Necklace Road or pass by Hussainsagar Lake at this time of the year, you will be choking on stench. Though the historic lake is synonymous with stink and pollution, this is the first time Hussainsagar is plagued by bad odour so early in the year.

 Published: 17th March 2017 02:
Canadian technology to rejuvenate

HYDERABAD: Hussainsagar is polluted. And nothing is being done about it. However, with a Hyderbad-based company now coming forward with a Canadian technology to take up the challenge of cleaning the lake, things are set to change, or so it seems.

Matrix Environment, having expertise in removing pollutants and sediments from water bodies through Ezox system, will make efforts to clean up the lake on a pilot basis.
90 % of the bad odour was reduced in 10 days
The status of the  lake on March 27th 
Dissolved Oxygen :  0.0 during the day / Max  0.17
Conductivity :          1616.70 avg
PH:                              7.2 avg
TSS avg:                   36.9
BOD avg:                  41.8
COD avg:                122.8

FIRST FIFTEEN DAYS dissolved oxygen
Water taken from the four separate locations in the lake - one week apart
Minimum DO has always been '' 0 ''
The other 10% is the occasional temporary smell located in small 
areas. This is caused by the normal process of the lake’s recuperation.

The first 35 days of revitalizing the lake - 55 days to go
When you see an area of the water turning green, it’s a very good sign since it means that the phosphorus is being eliminated and that the dying algae is surfacing. The natural process should take care of that. Also the bottom sludge is decomposing and the light part is surfacing. It’s the biological processes necessary to jump start nitrification and sludge digestion.

Water samples taken on June 6 at four different locations and at depths up to 17 feet






Satelite map of Hussain Sagar Lake 
We started on march 27th 2017
Every expert will tell you that the bottom of a lake controls the quality of the water. We know that Hussain Sagar Lake’s bottom is composed of a very thick black, sticky, smelly muck from dark brown to light brown granular sludge, and that we have unwanted contaminants including micro-organisms and heavy metals. Therefore, since we have done most of the work on the surface of the lake, we must continue the restoration in order to show a positive impact in the bottom (benthic zone) and to really show an improvement.

This activity in the sludge layers leads to rapid degradation of the organic fractions and the worsening of the water clarity. This is a natural process and it may go on for months until the organic matter is aerobically digested and then the bottom will become ‘’aerobic’’.

 This is a first-of-its-kind project not only in India but Asia as well.
 07th July 2017 08:53 AM  

HMDA had expressed satisfaction with the implementation 
of the free pilot project for improvement of quality of the lake
water with Canadian innovative technology.

The results showed improvement in the water quality, specifically in respect of enhancement in the levels of dissolved oxygen (DO) and reduction in biochemical oxygen demand (BOD), besides a change in the colour and turbidity of the water.

September 2017