Cigarette Butt Water Treatment Cost

The calculation has five steps. Percentages are converted to decimals (for example 65% becomes 0.65) before use. No intermediate value is rounded; rounding happens only on screen.

Step	Calculation	Unit
1	Butts littered = annual cigarette sticks × littering rate	butts
2	Butts entering aquatic environments = butts littered × aquatic-entry rate	butts
3	Modelled water volume = butts entering aquatic environments × assumed contamination extent per butt (17, 33 or 67 litres)	litres
4	Modelled water volume in cubic metres = litres ÷ 1,000	m³
5	Estimated treatment cost = cubic metres × treatment cost per cubic metre	selected currency

One cubic metre is exactly 1,000 litres. Each cigarette is assumed to leave one butt. There is no separate treatment-share factor: the model applies the treatment cost to the whole modelled water volume. The modelled volume is a model quantity, not a measurement of water actually treated by a utility.

The cost is calculated in the currency of the cost per m³ (US dollars for the three scenarios). The result is then shown in the country’s local currency and as a US$ equivalent, using the latest World Bank WDI official exchange rate (indicator PA.NUS.FCRF, local currency units per US$, annual average). For comparison with tariffs quoted per 1,000 US gallons, the panel shows the equivalent (1 m³ = 264.172 US gallons; US$1.33 per m³ ≈ US$5.03 per 1,000 US gallons). That equivalent is not used in the calculation.

Input	Default	Classification
Annual cigarette consumption	Country value from the database	Country-specific database value [5]
Littering rate	65%	Evidence-informed default [1]
Aquatic-entry rate	1%	Conservative value based on OECD (2022): about 1.7% of plastic waste entered aquatic environments in 2019 [3]
Treatment cost per cubic metre	US$1.33 (US$0.64 or US$2.03 selectable, or a local cost)	Midpoint of selected published estimates [4]
Assumed contamination extent per butt	33 litres (17 or 67 selectable)	Ecotoxicity-based dilution equivalent [2]

Every step multiplies by its input, so the result changes in direct proportion to each one. Doubling any input doubles the cost; setting any of them to zero gives a cost of zero.

1. [1] Littering rate: 65%

   Used in the rapid assessment tool paper and in a peer-reviewed US modelling study. That study took 65% from an observational US study (Schultz et al., 2013) and reported other published observational estimates of 65–84%. It also ran sensitivity scenarios of 85%, 35% and 10%.

   Limitation: 65% comes from US observations. It is not a global average, and littering behaviour varies by country, setting and enforcement. Replace it with a local estimate where one exists.

   Source: Lowe AT, Maki A, Figueroa C, Venugopal PD. Place-based estimates of cigarette butt litter raise environmental justice concerns in the United States. PLOS ONE. 2024;19(8):e0308930. https://doi.org/10.1371/journal.pone.0308930

2. [2] Assumed contamination extent: 33 litres per butt (mid-range default), 17 or 67 litres

   The calculator uses 33 litres per cigarette butt as its mid-range default assumed extent of water contamination, with selectable alternatives of 17 and 67 litres. These are ecotoxicity-based dilution equivalents, rather than measured volumes physically contaminated by each butt. The 17-litre lower option is rounded from 16.7 litres, calculated as the reciprocal of a published 48-hour immobilization EC50 of 0.06 cigarette-butt equivalents/L for the freshwater invertebrate Ceriodaphnia cf. dubia, reported by Warne et al. and summarized by Slaughter et al. (2011). The 33-litre default is rounded from 33.3 litres, corresponding to the more sensitive end of the freshwater immobilization EC50 range reported by Micevska et al. and summarized in the same paper. EC50 denotes an effect in 50% of tested organisms, not a safe concentration. The 67-litre alternative follows Mandelli et al. (2024), who derived a preliminary marine species-sensitivity threshold of 0.015 cigarette-butt equivalents/L and explicitly estimated an impact equivalent to approximately 67 litres of seawater per butt. The calculator uses 33 litres as the default because it sits in the middle of the three options, between the lower freshwater value (17 litres) and the marine value (67 litres); it is not a scientifically established contamination volume. Users should select between the freshwater and marine scenarios according to the receiving environment. These values describe assumed contamination extent, not toxin content, drinking-water safety thresholds, or demonstrated municipal treatment requirements.

   Scenario	Assumed contamination extent	Scientific basis	Interpretation
   Lower freshwater	17 L/butt	Reciprocal of 0.06 butts/L: approximately 16.7 L/butt; freshwater-invertebrate immobilization EC50.	Lower-volume alternative.
   Mid-range freshwater (default)	33 L/butt	Reciprocal of 0.03 butts/L: approximately 33.3 L/butt; more sensitive end of the reported freshwater immobilization EC50 range.	Mid-range default.
   Marine	67 L/butt	Published estimate derived from a preliminary marine species-sensitivity threshold of 0.015 butts/L.	Marine ecological-hazard scenario, not a higher freshwater estimate.

   Note: One cigarette butt can release enough nicotine to exceed an ecological safety benchmark in approximately 1,000 litres of water. That estimate considers nicotine alone; the options above are based on studies of the combined chemicals leaching from cigarette butts. They use different measures of harm, so 1,000 litres does not mean that all this water would kill aquatic life or require treatment.

   Sources: Slaughter E, Gersberg RM, Watanabe K, Rudolph J, Stransky C, Novotny TE. Toxicity of cigarette butts, and their chemical components, to marine and freshwater fish. Tobacco Control. 2011;20(Suppl 1):i25–i29. https://pmc.ncbi.nlm.nih.gov/articles/PMC3088407/. Mandelli WG, Pestana BM, Choueri RB, Abessa DMS, Castro ÍB, Moreira LB. Waterborne toxicity to Neotropical invertebrates and hazard of cigarette butt leachates in marine environments. Environmental Toxicology and Chemistry. 2024;43(2):374–384. https://pubmed.ncbi.nlm.nih.gov/37933775/. Nicotine note: Roder Green AL, Putschew A, Nehls T. Littered cigarette butts as a source of nicotine in urban waters. Journal of Hydrology. 2014;519:3466–3474. FAO AGRIS record

3. [3] Aquatic-entry rate: 1% (conservative value based on OECD, 2022)

   The default is the share of littered butts assumed to enter aquatic environments (rivers, lakes, coastlines and the ocean). It draws on the OECD Global Plastics Outlook, which estimates that in 2019, 6.1 million tonnes of the 353 million tonnes of plastic waste generated worldwide (about 1.7%) leaked into aquatic environments, and 1.7 million tonnes (about 0.5%) flowed into the ocean. The calculator uses 1%, which lies between these two global shares and below the share for all plastic waste entering aquatic environments. Because littered butts have already escaped waste collection, the share of littered butts that reaches water is likely to be higher than the share of all plastic waste, so 1% is a conservative assumption.

   The OECD figures describe plastic waste in general, not cigarette butts. The OECD regional values (Table A.13 of the Outlook) are not applied, so no regional or country mapping is used. Users may enter a local estimate.

   Source: OECD (2022), Global Plastics Outlook: Economic Drivers, Environmental Impacts and Policy Options, OECD Publishing, Paris. https://doi.org/10.1787/de747aef-en

4. [4] Treatment cost: US$1.33 per cubic metre (default), US$0.64 or US$2.03

   The calculator provides lower, midrange, and higher treatment-cost scenarios of US$0.64, US$1.33, and US$2.03 per cubic metre, with US$1.33/m³ selected as the default. The lower endpoint is rounded from Valladares Linares et al. (2016), who estimated US$0.637/m³ of product water for a large-scale membrane-bioreactor–reverse-osmosis–advanced-oxidation treatment train, incorporating modeled capital and operating costs over a 20-year project life at a 6% interest rate. This approximately ten-year-old estimate is retained as a historical lower-cost benchmark. The upper endpoint follows Lugo et al. (2023), whose conventional-system benchmark of US$2.03/m³ encompasses secondary wastewater treatment, advanced purification for potable reuse, and sludge treatment. The default is the arithmetic midpoint of these selected endpoints, (0.637 + 2.03) / 2 = 1.3335, rounded to US$1.33/m³; it is a study-selected scenario value, not a pooled average of comparable studies. Other published estimates provide context: Noibi et al. (2020) reported approximately US$0.93–1.28/m³ for RO-based advanced treatment with different concentrate-management configurations, while Chamaki et al. (2023) estimated US$0.675–1.167/m³ for RO configurations using already-treated wastewater. Because the studies differ in scale, system boundaries, and price bases, the scenarios are presented in their original monetary terms without inflation adjustment and should not be interpreted as universal minimum or maximum costs. Where RO is included, a separate heavy-metal-removal charge is not automatically added, because RO can reject dissolved metals; however, contaminant-specific performance and management of contaminated residuals remain relevant to local costing. None of these cost studies establishes the price of achieving specified removal targets for the complete cigarette-butt contaminant mixture. Users may replace the scenario values with a documented local cost consistent with the model’s treatment boundary.

   Study or calculator value	Cost per m³	Coverage and role in the calculator
   Valladares Linares et al. (2016)	US$0.637	Integrated MBR–RO–AOP; modeled capital and operating costs. Historical lower endpoint, displayed as US$0.64.
   Noibi et al. (2020)	Approximately US$0.93–1.28	RO-based advanced treatment with different concentrate-management configurations; amortized capital and operating costs. Supporting comparison, not an additional charge.
   Chamaki et al. (2023)	US$0.675–1.167	RO configurations using purchased, already-treated wastewater; estimates in 2022 prices. Not the complete cost of treating raw wastewater. Supporting comparison.
   Lugo et al. (2023)	US$2.03	Conventional benchmark covering secondary treatment, advanced potable-water purification, and sludge treatment. Selected higher endpoint.
   Calculator midrange default	US$1.33	Arithmetic midpoint of US$0.637 and US$2.03. Derived scenario value, not a separately published estimate or cross-study average.

   Treatment functions of the integrated train used for the lower endpoint, matched to the principal contaminant groups released by cigarette butts:

   Contaminant released by cigarette butts	Treatment stage	How it is removed
   Nicotine	Biological treatment (membrane bioreactor)	Degraded by acclimated microorganisms
   Heavy metals (e.g. lead, cadmium)	Membrane separation (reverse osmosis)	Dissolved metals rejected by the membrane
   Microplastics	Membrane separation (membrane filtration)	Particles retained by the membrane
   PAHs and other organic pollutants	Advanced oxidation (UV/hydrogen peroxide)	Broken down by oxidation, including what passes reverse osmosis

   Sources: Valladares Linares R, Li Z, Yangali-Quintanilla V, Ghaffour N, Amy G, Leiknes T, Vrouwenvelder JS. Water Research. 2016;88:225–234. https://doi.org/10.1016/j.watres.2015.10.017 (publicly accessible manuscript). Noibi M, Hooper J, Bell K, Funk D. Direct potable reuse using full advanced treatment versus ozone biofiltration: a cost comparison. AWWA Water Science. 2020;2(6):e1210. https://doi.org/10.1002/aws2.1210 (FAO abstract record). Chamaki FN, Jenkins GP, Hashemipour M. Financial, economic, and environmental analyses of upgrading reverse osmosis plant fed with treated wastewater. Energies. 2023;16(7):3292. https://doi.org/10.3390/en16073292. Lugo et al. (2023), original abstract and cost estimates: https://pubmed.ncbi.nlm.nih.gov/36634420/. RO removal of heavy metals, 2024 review: Frontiers in Chemical Engineering.

5. [5] Annual cigarette consumption

   Source: Tobacco Atlas 2016 or later.

• This is a scenario calculator. It is not an engineering model and does not measure environmental damage or actual treatment expenditure.
• The modelled water volume is a model quantity. It is not a measured volume of polluted water, and water reached by litter is not necessarily water that a utility treats.
• The 1% aquatic-entry default is a conservative value based on OECD (2022) global figures for plastic waste in general, not a measurement for cigarette butts; regional values (OECD Table A.13) are not applied.
• The 65% littering rate comes from US observations, and the treatment-cost scenarios (US$0.64, US$1.33 and US$2.03 per m³) come from studies of different treatment systems that did not test cigarette-butt leachate; none is country-specific.
• The 1,000-litre nicotine finding is context only and is not used in the calculation. The calculator uses 33 litres per butt by default (17 or 67 litres selectable), based on studies of the combined chemicals leaching from butts.
• The result is an estimated cost under the selected assumptions. It does not establish that water utilities treat the calculated volume or incur that cost because of cigarette butts.
• The model excludes clean-up, ecological, health and other costs, so it is not the total cost of cigarette butt pollution.
• Database consumption figures come from different sources and years and may be out of date.
• Each input changes the result proportionally, so results should be reported together with the inputs used.