--- title: Wood Cleanses Bacteria from Drinking Water, Study Finds description: Scientists discover a sophisticated filtration system underneath the bark of a pine tree canonical: https://time.com/13754/need-clean-drinking-water-just-add-wood/ author: Dan Kedmey article:opinion: false article:content_tier: free article:published_time: 2014-03-06T10:05:56.000Z article:modified_time: 2026-02-21T06:36:40.029Z article:section: Science og:title: Wood Cleanses Bacteria from Drinking Water, Study Finds og:description: Scientists discover a sophisticated filtration system underneath the bark of a pine tree og:url: https://time.com/13754/need-clean-drinking-water-just-add-wood/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt35f8ce52eb03905e/69868422361760510790ac47/476877973.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: A forest and lake og:type: article twitter:card: summary_large_image twitter:title: Wood Cleanses Bacteria from Drinking Water, Study Finds twitter:description: Scientists discover a sophisticated filtration system underneath the bark of a pine tree twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt35f8ce52eb03905e/69868422361760510790ac47/476877973.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # Need Clean Drinking Water? Just Add Wood  by [Dan Kedmey](https://time.com/author/dan-kedmey/)  ## Dan Kedmey Mar 6, 2014 10:05 AM UTC  Austria, Upper Austria, Salzkammergut, Gruenau, Alm valley, Lake Almsee Austria, Upper Austria, Salzkammergut, Gruenau, Alm valley, Lake AlmseeGetty Images  by [Dan Kedmey](https://time.com/author/dan-kedmey/)  ## Dan Kedmey Mar 6, 2014 10:05 AM UTC One way to clean harmful bacteria from river water is to pump it through costly man-made filters. But scientists may have discovered much more affordable technology, fully developed and ready for use, beneath the bark of an ordinary tree. NPR [reports](http://www.npr.org/blogs/health/2014/03/05/286215962/to-clean-drinking-water-all-you-need-is-a-stick?ft=1&f=1007) that MIT scientist Rohit Karnik strained water through the sapwood of a pine branch. The branch’s vascular system contains membranes designed to filter out microscopic air bubbles. Karnik found that those same membranes could filter out harmful bacteria as well, apparently as much as 99.9%. The remaining iota could still pose a serious public health risk, skeptics caution. For the moment, though, it’s an intriguing proof of concept and also evidence that sometimes invention is just catching a ride on nature’s coattails. \[[NPR](http://www.npr.org/blogs/health/2014/03/05/286215962/to-clean-drinking-water-all-you-need-is-a-stick?ft=1&f=1007)\] ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/13754/need-clean-drinking-water-just-add-wood/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/13754/need-clean-drinking-water-just-add-wood/"},"headline":"Need Clean Drinking Water? Just Add Wood","datePublished":"2014-03-06T10:05:56.000Z","dateModified":"2026-02-21T06:36:40.029Z","description":"Scientists discover a sophisticated filtration system underneath the bark of a pine tree","url":"https://time.com/13754/need-clean-drinking-water-just-add-wood/","keywords":["Water","Drink","MIT","drinking"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt35f8ce52eb03905e/69868422361760510790ac47/476877973.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Dan Kedmey","jobTitle":null,"url":"https://time.com/author/dan-kedmey/"}],"articleSection":"Science","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt35f8ce52eb03905e/69868422361760510790ac47/476877973.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"A forest and lake","caption":"A forest and lake","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/science/","name":"Science"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/13754/need-clean-drinking-water-just-add-wood/","name":"Need Clean Drinking Water? Just Add Wood"}}]}] ```