You can just type "birth control pollution" into Google, there are a shitload of outlets that have talked about it. The thing is that, by using birth control, women subject themselves to hormones, these hormones are generally in fairly large dose and thus a lot leaves the body through urine. This contaminated urine travels through the sewage system and eventually accumulates within the environment. And that is just the sewage system feeding into the environment, there have also been reports of people having it bleed into their water supply. It isn't a very widely discussed topic because of people responding with "lol you believe frogs can turn gay?" and "b-but it's muh vagina" to any mention of saying women should stop using birth control 24/7 regarding this. But sure, here's a few I got:>birth control affecting fishhttps://www.lunduniversity.lu.se/article/oestrogen-in-birth-control-pills-has-a-negative-impact-on-fish>medicines and birth control bleeding into people's tap water, also fucking over fish and frogs (article mentions using filters)https://www.scientificamerican.com/article/birth-control-in-water-supply/>United Kingdom putting massive funding into getting rid of these chemicals, turning the fish into trannies is mentionedhttps://www.theguardian.com/environment/2012/jun/02/water-system-toxic-contraceptive-pill
Some people try to downplay it saying that it's not going to affect healthy adults therefore it is a non-issue, in reality it is going to fuck over a substantial number of people over time. People getting hundreds of different type of medications through their water supply in trace amounts can be negligible in the short-term, but it also means pregnant women (and thus also the child they have) can get fucked up by knock-on effect. People with specific illnesses or already on significant amounts of medication are also likely to get screwed.