Hussainsagar’s water quality deteriorated during Hyderabad’s Ganesh idol immersion period, with pollution indicators rising at all six monitoring locations and several remaining above pre-immersion levels afterwards, according to Telangana Pollution Control Board (TGPCB) monitoring findings reported by The Hindu.
The board collected samples before, during and after the immersion period under a monitoring exercise prescribed by the Central Pollution Control Board. Samples were taken on September 11 before immersion, on September 17, 19, 21 and 23 during the immersion period, and on September 28 after immersion.
Turbidity, total suspended solids, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) increased across all six monitoring points during the immersion period. The highest turbidity reading was 200 NTU at Necklace Road, where COD also reached 164 mg/L. Total suspended solids peaked at 99 mg/L at Platform No. 1 opposite NTR Park.
The monitoring locations covered two points opposite NTR Park, Lumbini Park, Necklace Road, the immersion point near Lepakshi Handicrafts and the Buddha statue area. The Buddha statue area served as the control point for the exercise.
The board found that turbidity, suspended solids and COD declined after the immersion period but did not return to their pre-immersion levels by the time of the September 28 sampling. BOD increased at all six locations during and after immersion, indicating that the change in water quality persisted beyond the main period of idol immersion.
Bacterial contamination also rose during the immersion period. Total coliform levels increased at all monitoring points. Although the levels declined at some locations afterwards, they remained elevated at the two platforms opposite NTR Park. Faecal coliform levels increased at four locations during immersion and continued to remain above pre-immersion levels after the festival. At Lumbini Park, faecal coliform levels increased further after immersion.
The TGPCB did not find significant changes in dissolved oxygen levels in the lake. This means the monitoring exercise recorded deterioration in several water-quality indicators without a corresponding significant change in dissolved oxygen during the period covered by the samples.
The board also noted that rainfall affected the readings. Rain fell on September 14, 19, 20 and 22, and runoff from surrounding catchment areas entered Hussainsagar. According to the monitoring findings, this contributed to variations in parameters including COD, BOD and hardness.
The sampling sequence provides a before-during-after comparison of the lake’s condition, while the spread of monitoring points captures locations near immersion activity as well as public-facing areas around NTR Park, Lumbini Park and Necklace Road. The September 28 results show that some pollution indicators had begun to decline, but the lake had not fully returned to its pre-immersion readings within the monitoring period.
The findings place the management of festival-related immersion within the wider operational challenge of protecting Hussainsagar while accommodating large public and religious gatherings. The monitoring exercise was conducted under the Central Pollution Control Board’s prescribed framework, with the TGPCB responsible for collecting and assessing samples at the identified locations.
