Chandigarh: Patiala Ki Rao and Faidan Choe have recorded high levels of pollution, with several key parameters exceeding permissible limits and dissolved oxygen (DO) falling to nil, says a monitoring study carried out by Chandigarh Pollution Control Committee (CPCC) during the first three months of 2026. The assessment found particularly high organic pollution and suspended solids in the two drains, raising concerns over the quality of water flowing through these channels.The study covered Jan to March 2026 and monitored water quality at several major drains in Chandigarh, including N-Choe/Attawa Choe, Sukhna Choe and Patiala Ki Rao, while Faidan Choe was monitored in Feb. Parameters assessed included pH, dissolved oxygen, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS).Patiala Ki Rao emerged as one of the most polluted drains in the assessment, with COD, BOD and TSS consistently exceeding their prescribed limits in all three months.The permissible limit for COD is 250 mg/l, but Patiala Ki Rao recorded 423 mg/l in Jan, 338 mg/l in Feb and 339 mg/l in March. BOD, against a permissible limit of 30 mg/l, was recorded at 255 mg/l in Jan, 197 mg/l in February and 204 mg/l in March.The most striking finding was the absence of dissolved oxygen. Patiala Ki Rao recorded 0.91 mg/l of DO in Jan, before the level fell to nil in Feb and March. TSS was also substantially above the permissible limit of 100 mg/l, standing at 494 mg/l in Jan, 190 mg/l in Feb and 217 mg/l in March.The pH, however, remained within the permissible range of 5.5 to 9, ranging from 7.2 to 7.6 during the three-month period.Faidan ChoeFaidan Choe, monitored in Feb, also recorded high pollution levels. While its pH was 7, DO was nil. The COD stood at 327 mg/l, exceeding the permissible limit of 250 mg/l, while BOD reached 251 mg/l, more than eight times the permissible limit of 30 mg/l. TSS was recorded at 253 mg/l, against the permissible limit of 100 mg/l.The combination of nil DO and high BOD points to a heavy organic pollution load in the drain. High BOD reflects greater oxygen demand for decomposition of organic matter, leaving less oxygen available in the water.The assessment also monitored Sukhna Choe and N-Choe/Attawa Choe. Sukhna Choe’s COD remained within the permissible limit, though BOD exceeded the limit during all three months. N-Choe/Attawa Choe showed comparatively lower pollution levels, although BOD crossed the permissible limit in Feb and March.The monitoring also highlighted the impact of treatment at Nagar Van. The COD fell from 742 mg/l in untreated water to 130 mg/l after treatment, while BOD declined from 261 mg/l to 26 mg/l and TSS from 219 mg/l to 15 mg/l, demonstrating a substantial reduction in the pollutant load following treatment.Turbid waters–Dissolved oxygen falls to nil in both drains, indicating severe water quality concerns–Patiala Ki Rao’s COD, BOD and TSS exceeded permissible limits in all three months monitored–BOD in Patiala Ki Rao touched 255 mg/l against the permissible limit of 30 mg/l–Faidan Choe recorded BOD of 251 mg/l and nil dissolved oxygen in Feb–High BOD and nil DO point to a heavy organic pollution load in the drains–Patiala Ki Rao’s TSS reached 494 mg/l in Jan against the prescribed limit of 100 mg/l–Sukhna Choe and N-Choe/Attawa Choe showed comparatively lower pollution, though BOD exceeded norms at several points–Nagar Van treatment reduced COD from 742 mg/l to 130 mg/l, showing significant pollutant reduction after treatmentWhat the parameters mean–pH: Measures how acidic or alkaline the water is. A pH of 7 is neutral; the prescribed range in the study is 5.5 to 9–Dissolved oxygen (DO): Measures the amount of oxygen available in water for aquatic life. Very low or nil DO indicates severe pollution and can make it difficult for aquatic organisms to survive–Biochemical oxygen demand (BOD): Measures the oxygen needed by microorganisms to break down organic matter in water. Higher BOD indicates a greater organic pollution load and can result in lower DO–Chemical oxygen demand (COD): Measures the amount of oxygen required to chemically oxidise pollutants in water. Higher COD indicates a higher concentration of oxidisable pollutants–Total suspended solids (TSS): Measures the amount of solid particles suspended in water, such as silt, organic matter and other pollutants. High TSS indicates greater particulate pollution and can affect water quality and aquatic life.
