{"id":383517,"date":"2026-04-05T17:46:23","date_gmt":"2026-04-05T17:46:23","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/383517\/"},"modified":"2026-04-05T17:46:23","modified_gmt":"2026-04-05T17:46:23","slug":"why-you-shouldnt-pour-coffee-down-the-drain","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/383517\/","title":{"rendered":"Why you shouldn&#8217;t pour coffee down the drain"},"content":{"rendered":"<p>Analysis: The coffee dregs we pour down the drain can create a serious pollution problem down the road for rivers and waterways<\/p>\n<p>By <a href=\"https:\/\/theconversation.com\/profiles\/kevin-collins-255350\" rel=\"nofollow noopener\" target=\"_blank\">Kevin Collins<\/a>, <a href=\"https:\/\/theconversation.com\/institutions\/the-open-university-748\" rel=\"nofollow noopener\" target=\"_blank\">The Open University<\/a><\/p>\n<p>A woman was recently <a href=\"http:\/\/www.bbc.co.uk\/news\/articles\/cg435gg66gpo\" target=\"_blank\" rel=\"nofollow noopener\">fined<\/a> \u20ac170 by Richmond council in London for pouring coffee down a drain before getting on a bus. The fine has now been <a href=\"http:\/\/www.bbc.co.uk\/news\/articles\/cg435gg66gpo\" target=\"_blank\" rel=\"nofollow noopener\">rescinded<\/a>, but the incident has prompted many discussions about whether coffee discarded like this could cause environmental damage.<\/p>\n<p><a href=\"https:\/\/en.wikipedia.org\/wiki\/Economics_of_coffee\" target=\"_blank\" rel=\"nofollow noopener\">Over 2 billion cups of coffee<\/a> are consumed every day worldwide. All that liquid has to go somewhere, whether you are at home, at work or running for a bus. While the welcome hit of caffeine is a morning ritual for many, it can be an unwelcome hit for the environment when disposed of.<\/p>\n<p>An individual cup is insignificant, but millions of daily dregs poured down the drain would create a much bigger problem for rivers and watercourses, because we are adding to the caffeine levels already present in sewage from households. The more caffeine that goes in to these pipes, the more that could evade the treatment and reach rivers.<\/p>\n<p alt=\"Could take-away coffee reach \u20ac5 a cup?\" class=\"tpe\" data-description=\"Brian O'Connell, RT\u00c9 reporter \/\/ James Imam Milan based freelance journalist who writes for The Times of London \/\/ Stephen Kennedy, owner of Copper and Straw who operates three coffee shops in Dublin and Wicklow \" data-embed=\"rte-player\" data-id=\"22503324\" data-ot-category=\"C0004\" data-title=\"Brian O'Connell, RT\u00c9 reporter \/\/ James Imam Milan based freelance journalist who writes for The Times of London \/\/ Stephen Kennedy, owner of Copper and Straw who operates three coffee shops in Dublin and Wicklow \">We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.<a class=\"blocked-button\" href=\"https:\/\/www.rte.ie\/brainstorm\/2026\/0402\/1540841-coffee-dregs-drains-wastewater-pollution\/javascript:void(0);\" onclick=\"OneTrust.ToggleInfoDisplay()\" rel=\"nofollow noopener\" target=\"_blank\">Manage Preferences<\/a><\/p>\n<p>From RT\u00c9 Radio 1&#8217;s Today with Claire Byrne, could take-away coffee reach \u20ac5 a cup?<\/p>\n<p>Cups of coffee contain hundreds of chemical compounds. As well as caffeine (assuming you are not drinking decaf), many will include milk and sugar while some also contain cocoa, spices and other ingredients.<\/p>\n<p>Of these, caffeine has the most impact, environmentally speaking. It does not break down quickly or easily, and is considered an emerging contaminant (scientists have only recently started testing for caffeine levels and it is not always monitored). But even back in 2003, caffeine was found to be <a href=\"https:\/\/doi.org\/10.1021\/es020125z\" rel=\"nofollow noopener\" target=\"_blank\">polluting Swiss lakes and rivers<\/a>.<\/p>\n<p>However, don&#8217;t think this means it&#8217;s fine to pour decaf coffee down the drain. All coffee lowers the pH of water, and coffee also contains organic compounds which rob aquatic systems of oxygen as they decompose. The nutrients in coffee also encourage algae growth and may lead to additional oxygen depletion in rivers and lakes, which can stress and potentially reduce the lifespan of marine plants and animals.<\/p>\n<p alt=\"What wastewater samples tell us about cocaine use in Co Kildare\" class=\"tpe\" data-description=\"The latest statistics show that nearly four in ten people in drug treatment centres require help with cocaine addiction. But how do we quantify cocaine use in Ireland? Dr Se\u00e1n McDermott from the School of Chemical &amp; BioPharmaceutical Sciences at TU Dublin has come up with a way by analysing wastewater samples in Kildare!&#10;\" data-embed=\"rte-player\" data-id=\"22423070\" data-ot-category=\"C0004\" data-title=\"The latest statistics show that nearly four in ten people in drug treatment centres require help with cocaine addiction. But how do we quantify cocaine use in Ireland? Dr Se\u00e1n McDermott from the School of Chemical &amp; BioPharmaceutical Sciences at TU Dublin has come up with a way by analysing wastewater samples in Kildare!&#10;\">We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.<a class=\"blocked-button\" href=\"https:\/\/www.rte.ie\/brainstorm\/2026\/0402\/1540841-coffee-dregs-drains-wastewater-pollution\/javascript:void(0);\" onclick=\"OneTrust.ToggleInfoDisplay()\" rel=\"nofollow noopener\" target=\"_blank\">Manage Preferences<\/a><\/p>\n<p>From RT\u00c9 Radio 1&#8217;s Drivetime, what wastewater samples tell us about cocaine use in Co Kildare<\/p>\n<p>Why is caffeine such a problem?<\/p>\n<p>Wastewater treatment plants vary in their ability and capacity to treat and remove caffeine \u2013 ranging from 60-100% depending on <a href=\"https:\/\/doi.org\/10.1007\/s11356-024-32918-6\" rel=\"nofollow noopener\" target=\"_blank\">treatment types, plant design, season, temperature and other elements<\/a>. This means even treated water can contain caffeine when it is returned to <a href=\"https:\/\/doi.org\/10.1016\/j.envpol.2020.114371\" rel=\"nofollow noopener\" target=\"_blank\">rivers<\/a> and <a href=\"https:\/\/doi.org\/10.1016\/j.chemosphere.2021.131675\" rel=\"nofollow noopener\" target=\"_blank\">seas<\/a>.<\/p>\n<p>Heavy rains add to the problem if the capacity of sewage pipes is exceeded. When this happens, untreated wastewater is designed to divert directly into rivers and water courses to prevent sewage flooding of homes, businesses and treatment plants.<\/p>\n<p>Whether from a street drain or toilets, some of the caffeine that we have consumed will eventually make its way into our rivers and aquatic environments. This is a problem in every part of the world, <a href=\"https:\/\/doi.org\/10.1016\/j.envpol.2017.05.060\" rel=\"nofollow noopener\" target=\"_blank\">including in Antarctica<\/a>. One study of <a href=\"https:\/\/doi.org\/10.1073\/pnas.2113947119\" rel=\"nofollow noopener\" target=\"_blank\">258 rivers in 104 countries<\/a> found caffeine in over 50% of sites sampled.<\/p>\n<p>Recent studies show that <a href=\"https:\/\/doi.org\/10.3390\/jox15030086\" rel=\"nofollow noopener\" target=\"_blank\">caffeine has an impact on the metabolism<\/a>, growth and mobility of some freshwater algae, plants and aquatic fly larvae, potentially leading to their death. <a href=\"https:\/\/doi.org\/10.3390\/toxics12010029\" rel=\"nofollow noopener\" target=\"_blank\">Caffeine can affect marine and plant life<\/a> even in small amounts.<\/p>\n<p alt=\"What happens to the stuff that goes down the drain? \" class=\"tpe\" data-description=\"Every single day, we deal with wastewater, human waste, grease and chemicals by putting it out of sight, but it still has to be processed and dealt with. In the latest Brainstorm show, Ella McSweeney and guests - Jean O'Dwyer and Tom Curran - look at what happens to the stuff that goes down the drain in your kitchen and bathroom.\" data-embed=\"rte-player\" data-id=\"21807307\" data-ot-category=\"C0004\" data-title=\"Every single day, we deal with wastewater, human waste, grease and chemicals by putting it out of sight, but it still has to be processed and dealt with. In the latest Brainstorm show, Ella McSweeney and guests - Jean O'Dwyer and Tom Curran - look at what happens to the stuff that goes down the drain in your kitchen and bathroom.\">We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.<a class=\"blocked-button\" href=\"https:\/\/www.rte.ie\/brainstorm\/2026\/0402\/1540841-coffee-dregs-drains-wastewater-pollution\/javascript:void(0);\" onclick=\"OneTrust.ToggleInfoDisplay()\" rel=\"nofollow noopener\" target=\"_blank\">Manage Preferences<\/a><\/p>\n<p>From RT\u00c9 Brainstorm, what happens to the stuff that goes down the drain in your home?<\/p>\n<p>What should and shouldn&#8217;t you put in a drain?<\/p>\n<p>Street drains are part of our water system. Don&#8217;t put anything into a drain that you don&#8217;t want to see ending up in a river, lake, on a beach or in the sea.<\/p>\n<p>This means no coffee or coffee grounds, food-based liquids, oils, paint or hot fats, detergents, bleaches, liquids from building work and so on. All these should be disposed of via the appropriate household bins or waste collection centres. Leave the street drains to do their single, simple job: collecting rainwater not wastewater. What&#8217;s good for your street drain is also good for your kitchen sink and good for the environment. If nothing else, be pragmatic: coffee grounds can easily block your kitchen sink.<\/p>\n<p>So, what should you do with your coffee?<\/p>\n<p>If you are constantly throwing away coffee water, perhaps try making less coffee. At home, you can dilute coffee water for use as a plant tonic. Coffee liquid and grounds can also be disposed of on gardens or any plant beds in <a href=\"https:\/\/www.youtube.com\/watch?v=JLUvaBIMDOw\" rel=\"nofollow noopener\" target=\"_blank\">small amounts with care<\/a>.<\/p>\n<p>While coffee grounds could add to the <a href=\"https:\/\/doi.org\/10.3390\/waste1010002\" rel=\"nofollow noopener\" target=\"_blank\">organic content of the soil<\/a>, regularly adding grounds to the same patch of earth can cause a build up of caffeine and solids, which will be harmful to plants and soil function.<\/p>\n<p>Otherwise, the best place for waste coffee is a compost heap or food waste recycling. If you don&#8217;t have access to these options, then put liquids or grounds into a container and put them in your bin.<\/p>\n<p>A recent UK government inquiry <a href=\"http:\/\/www.gov.uk\/government\/publications\/independent-water-commission-review-of-the-water-sector\" target=\"_blank\" rel=\"nofollow noopener\">concluded<\/a> that improving the poor status of rivers and coasts requires major reform, policy changes and investment. But we, as individuals, are also part of how the water system works. We can help it by keeping coffee out of drains, out of our rivers and out of our environment.<img decoding=\"async\" alt=\"The Conversation\" src=\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/04\/1775411183_211_count.gif\"\/><\/p>\n<p>Follow RT\u00c9 Brainstorm on <a href=\"https:\/\/www.whatsapp.com\/channel\/0029VaJ6ugQ1HsptikZkfS1f\" target=\"_blank\" rel=\"nofollow noopener\">WhatsApp<\/a> and <a href=\"https:\/\/www.instagram.com\/rte_brainstorm\" target=\"_blank\" rel=\"nofollow noopener\">Instagram<\/a> for more stories and updates<\/p>\n<p><a href=\"https:\/\/theconversation.com\/profiles\/kevin-collins-255350\" rel=\"nofollow noopener\" target=\"_blank\">Kevin Collins<\/a> is a Senior Lecturer in Environment &amp; Systems at <a href=\"https:\/\/theconversation.com\/institutions\/the-open-university-748\" rel=\"nofollow noopener\" target=\"_blank\">The Open University<\/a>. This article was originally published by <a href=\"https:\/\/theconversation.com\" rel=\"nofollow noopener\" target=\"_blank\">The Conversation<\/a>.<\/p>\n<p>The views expressed here are those of the author and do not represent or reflect the views of RT\u00c9<\/p>\n<p>                    <script async src=\"\/\/www.instagram.com\/embed.js\"><\/script><\/p>\n","protected":false},"excerpt":{"rendered":"Analysis: The coffee dregs we pour down the drain can create a serious pollution problem down the road&hellip;\n","protected":false},"author":2,"featured_media":383518,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[246,61,60,82],"class_list":["post-383517","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/383517","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=383517"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/383517\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/383518"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=383517"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=383517"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=383517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}