The humble cotton tampon, coupled with a black light flashlight, reveals the presence of raw sewage in waterways through a technique known as “tampling.” Scout troops and community groups are tampling their streams to monitor bacteria levels and track down sewage leaks. Learn how you can tample at https://scistarter.org/tampling-optical-brightener-water-quality-sampling

NOTE: When tampling, use organic cotton tampons that don’t themselves contain optical brighteners. You can test one with the black light flashlight; if they glow blue right out of the package, they already have optical brighteners present and can’t be used for tampling.