Ecology & Waste in West Bengal
River water quality (Hooghly, Damodar, Mahananda, Teesta), district forest cover change, Sundarbans mangroves, municipal solid & plastic waste, e-waste, and noise monitoring across West Bengal.
West Bengal sits at the end of the Ganga, on the edge of the world’s largest mangrove delta, and at the fourth-highest rank of urban waste generation in India. The story is uneven: the Sundarbans cover 42% of the country’s mangroves and the northern hills still have 68-85% forest; yet 17 CPCB-flagged river stretches carry raw sewage, coastal districts are losing mangroves to erosion, and nearly 70% of the state’s solid waste ends up neither treated nor landfilled. This page traces each of those threads to its data source.
Key figures & data tables
The CPCB monitors 15 river stations in West Bengal across the Ganga/Hooghly, Damodar, Mahananda and Teesta (2022). The Class-A drinking-water criteria are dissolved oxygen ≥ 5 mg/L, BOD ≤ 3 mg/L and faecal coliform ≤ 2500 MPN/100 mL. The worst BOD reading is 44 mg/L at Ramghat (D/S). West Bengal carries 17 CPCB-flagged polluted river stretches and has appeared on every biennial list since 2015.
Forest cover is 16,832.33 km², or 18.97% of the state, against 21.76% for India (FSI ISFR 2023). The state gained 50.22 km² against the ISFR 2021 (revised raster-based assessment) baseline. The most forested districts are Kalimpong (85.26%), Darjeeling (68.28%), Alipurduar (55.31%); the largest losses are in South 24 Parganas (-28.21 km²), Purba Medinipur (-16.3 km²), Howrah (-14.36 km²) — coastal erosion and delta dynamics.
The Sundarbans hold 2,119.16 km² of mangrove — 42.45% of India’s total. The headline total looks stable (1.41 km² over two years) but the composition is degrading: very dense mangrove fell -2.02 km² while open mangrove rose 3.13 km². The historical Sundarbans (Indo-Bangladesh) was ~40,000 km² around 1900 vs ~10,200 km² today (WB + Bangladesh combined). The WB-side figure has held near 2,100 km² for two decades — the active loss front is embankment erosion and cyclone damage, not clearance.
West Bengal’s 128 urban local bodies generate 13,469 tonnes of municipal solid waste a day (2022-23). Collection is near-universal at 99.85%, but only 3,053 TPD is treated (22.67%) and 1,187 TPD landfilled — leaving 9,209 TPD unaccounted for. Of 123 legacy dumpsites, 84 have started biomining and 26 are cleared. Plastic waste generation is 1,28,837.03 tonnes a year.
The rows behind the charts above — 8 tables
›River water quality at West Bengal monitoring stations (CPCB)(15 rows)
CPCB Water Quality Data of Rivers 2022 (National Water Quality Monitoring Programme). Each cell is the MIN/MAX of monthly grab-sample measurements across calendar 2022. FC = fecal coliform (MPN/100 mL). Class A = drinking water source after disinfection (strictest). Values far in excess of FC 2,500 flag raw sewage entry.
| River | Station | District | DO min | DO max | BOD min | BOD max | FC min | FC max | pH min | pH max |
|---|---|---|---|---|---|---|---|---|---|---|
| Ganga/Hooghly | Farakka | Murshidabad | 5.3 | 9.4 | 1.1 | 2.9 | 78 | 4,900 | 7.12 | 8.48 |
| Ganga/Hooghly | Baharampore | Murshidabad | 6 | 9 | 1.1 | 2.9 | 490 | 24,000 | 7.69 | 8.28 |
| Ganga/Hooghly | Tribeni | Hooghly | 5.1 | 9.1 | 1.4 | 3.2 | 1,100 | 23,000 | 7.6 | 8.51 |
| Ganga/Hooghly | Palta | North 24 Pgs | 5.1 | 8.6 | 1.2 | 3 | 6,800 | 79,000 | 7.79 | 8.4 |
| Ganga/Hooghly | Dakshineswar | North 24 Pgs | 5 | 7.8 | 2 | 4.1 | 33,000 | 1,70,000 | 6.81 | 7.96 |
| Ganga/Hooghly | Howrah-Shivpur | Howrah | 5.2 | 7.7 | 2.1 | 4 | 23,000 | 79,000 | 7.02 | 7.96 |
| Ganga/Hooghly | Garden Reach | Kolkata | 5 | 7.7 | 2 | 4.3 | 23,000 | 1,30,000 | 7.05 | 8.1 |
| Ganga/Hooghly | Uluberia | Howrah | 5 | 7.3 | 2 | 4.9 | 13,000 | 33,000 | 7.1 | 8.1 |
| Ganga/Hooghly | Diamond Harbour | South 24 Pgs | 5.3 | 7 | 2 | 3.7 | 2,300 | 11,000 | 7.2 | 8.2 |
| Damodar | Durgapur U/S | Paschim Bardhaman | 7.4 | 8.6 | 1.8 | 3.3 | 1,400 | 4,700 | 6.84 | 8.21 |
| Damodar | Raniganj D/S | Paschim Bardhaman | 7.3 | 8.8 | 2 | 3 | 1,400 | 7,000 | 7.19 | 8.41 |
| Damodar | Asansol U/S | Paschim Bardhaman | 7.6 | 8.9 | 1.4 | 2 | 1,700 | 3,900 | 7.45 | 8.85 |
| Mahananda | Siliguri | Darjeeling | 6.1 | 8 | 1.1 | 2.8 | 1,300 | 1,10,000 | 6.71 | 7.27 |
| Mahananda | Ramghat (D/S) | Darjeeling | 2.1 | 6.3 | 3.9 | 44 | 50,000 | 50,00,000 | 6.51 | 7.47 |
| Teesta | Sevoke/Siliguri | Darjeeling | 7.1 | 8.7 | 1.1 | 1.8 | 1,700 | 6,000 | 6.89 | 7.6 |
›Forest cover by West Bengal district (FSI ISFR 2023)(23 rows)
FSI India State of Forest Report 2023, Volume II — West Bengal chapter, Table 10.29.3. Change column is km² change w.r.t. revised raster-based ISFR 2021. Purba Medinipur (-16.3) and South 24 Parganas (-28.2) account for the largest losses — coastal erosion + mangrove attrition. Bankura (+41) and Paschim Medinipur (+30) see the largest gains, reflecting plantation drives on mining-belt wasteland. Hill districts (Darjeeling, Kalimpong) already carry the highest % forest cover in WB.
| District | Geographic area (km²) | Very dense | Moderately dense | Open | Total forest (km²) | % of area | Change vs 2021 (km²) |
|---|---|---|---|---|---|---|---|
| Kalimpong | 1,095 | 324.66 | 343.09 | 265.82 | 933.57 | 85.26 | 0.37 |
| Darjeeling | 2,054 | 397.04 | 338.9 | 666.63 | 1,402.57 | 68.28 | -2.82 |
| Alipurduar | 2,801 | 438.92 | 319.19 | 791.26 | 1,549.37 | 55.31 | 12.42 |
| Jalpaiguri | 3,426 | 297.45 | 113.15 | 868.18 | 1,278.78 | 37.33 | 1.35 |
| Jhargram | 3,097 | 126.71 | 310.63 | 445.4 | 882.74 | 28.5 | 12.83 |
| South 24 Parganas | 9,960 | 968.2 | 754.47 | 1,047.39 | 2,770.06 | 27.81 | -28.21 |
| Paschim Medinipur | 6,271 | 135.16 | 319.44 | 857.37 | 1,311.97 | 20.92 | 29.61 |
| Howrah | 1,467 | 0 | 48.04 | 243.57 | 291.61 | 19.88 | -14.36 |
| Bankura | 6,882 | 232.33 | 420.02 | 656.43 | 1,308.78 | 19.02 | 41.18 |
| North 24 Parganas | 4,094 | 13.44 | 179.01 | 509.58 | 702.03 | 17.15 | -5.95 |
| Purba Medinipur | 4,713 | 1.68 | 110.22 | 678.12 | 790.02 | 16.76 | -16.3 |
| Purulia | 6,259 | 40.23 | 311.59 | 582.7 | 934.52 | 14.93 | 3.94 |
| Malda | 3,733 | 0 | 214.56 | 294.4 | 508.96 | 13.63 | 20.87 |
| Nadia | 3,927 | 1.04 | 154.95 | 309.55 | 465.54 | 11.85 | 0.26 |
| Cooch Behar | 3,387 | 0 | 26.88 | 335.96 | 362.84 | 10.71 | -1.39 |
| Paschim Bardhaman | 1,812 | 47.77 | 45.79 | 97.62 | 191.18 | 10.55 | 0.12 |
| Uttar Dinajpur | 3,140 | 0 | 3.62 | 229.1 | 232.72 | 7.41 | -3.64 |
| Murshidabad | 5,324 | 0 | 52.21 | 287.8 | 340.01 | 6.39 | -2.86 |
| Hooghly | 3,149 | 0 | 13.36 | 142.17 | 155.53 | 4.94 | -1.54 |
| Birbhum | 4,545 | 0.54 | 39.29 | 146.71 | 186.54 | 4.1 | 2.34 |
| Dakshin Dinajpur | 2,219 | 0 | 5.17 | 76.77 | 81.94 | 3.69 | -0.06 |
| Purba Bardhaman | 5,212 | 11.93 | 51.75 | 85.53 | 149.21 | 2.86 | 1.51 |
| Kolkata | 185 | 0 | 0.05 | 1.79 | 1.84 | 0.99 | 0.55 |
›Sundarbans mangrove cover over time (km²)(10 rows)
FSI India State of Forest Report 2023, Volume I, Chapter 3 — Mangrove Cover, Table 3.3
| Year | Mangrove cover (km²) | Source |
|---|---|---|
| 1,987 | 2,076 | FSI SFR 1987 |
| 2,001 | 2,125 | FSI SFR 2001 |
| 2,009 | 2,152 | FSI SFR 2009 |
| 2,011 | 2,155 | FSI SFR 2011 |
| 2,013 | 2,097 | FSI SFR 2013 |
| 2,015 | 2,106 | FSI SFR 2015 |
| 2,017 | 2,114 | FSI SFR 2017 |
| 2,019 | 2,112 | FSI SFR 2019 |
| 2,021 | 2,118 | FSI SFR 2021 (revised raster) |
| 2,023 | 2,119 | FSI ISFR 2023 |
›Mangrove composition in West Bengal, 2023 vs 2021(4 rows)
The state total looks flat (+1.4 km² over two years) but within that total, Very Dense Mangrove has declined (-2.0 km²) while Open Mangrove has grown (+3.1 km²) — a quiet degradation of canopy density that does not show up in the headline number.
| Class | 2023 (km²) | Change vs 2021 (km²) |
|---|---|---|
| Very dense mangrove | 981.63 | -2.02 |
| Moderately dense mangrove | 703.79 | 0.3 |
| Open mangrove | 433.74 | 3.13 |
| Total | 2,119.16 | 1.41 |
›Municipal solid waste in West Bengal (2022-23)(13 rows)
CPCB Annual Report on Implementation of SWM Rules 2022-23 — §3.36 West Bengal. CPCB publishes MSW at state level only. District/ULB-level generation figures for WB are compiled by individual ULBs under the WBPCB. A consolidated district map is not published annually by either agency. The Class I / Class II town counts are the closest proxy for district urban waste load.
| Measure | Value |
|---|---|
| Urban local bodies | 128 |
| Generation (TPD) | 13,469 |
| Collected (TPD) | 13,449 |
| Treated (TPD) | 3,053 |
| Landfilled (TPD) | 1,187 |
| Unaccounted gap (TPD) | 9,209 |
| Treatment rate (%) | 22.67 |
| Collection rate (%) | 99.85 |
| Compost plants | 62 |
| Compost capacity (TPD) | 3,029.8 |
| Legacy dumpsites | 123 |
| Dumpsites with biomining started | 84 |
| Dumpsites cleared | 26 |
›Municipal solid waste generation — state comparison (TPD)(8 rows)
| State | Generation (TPD) |
|---|---|
| Maharashtra | 22,877 |
| Tamil Nadu | 16,066 |
| Uttar Pradesh | 14,710 |
| West Bengal | 13,469 |
| Karnataka | 11,868 |
| Telangana | 11,394 |
| Delhi | 11,272 |
| Gujarat | 10,785 |
›E-waste generation and recycling in India(5 rows)
CPCB publishes only national-level e-waste figures; state-wise generation is not routinely disaggregated, because EPR registration sits with producers (who are HQ-registered) rather than with the generating state.
| Year | Generation (lakh MT) |
|---|---|
| 2019-20 | 10.14 |
| 2020-21 | 13.46 |
| 2021-22 | 16.01 |
| 2022-23 | 17.25 |
| 2023-24 | 17.78 |
›Ambient noise standards by zone (CPCB)(4 rows)
| Zone | Day limit (dBA) | Night limit (dBA) |
|---|---|---|
| Industrial | 75 | 70 |
| Commercial | 65 | 55 |
| Residential | 55 | 45 |
| Silence | 50 | 40 |