“The Washington Department of Fish and Wildlife, in collaboration with the Center for Urban Waters (University of Washington Tacoma), reported detecting contaminants of emerging concern (CECs) in transplanted mussels collected in 2012/2013 from locations near urbanized areas around Puget Sound. In 2018 investigators reanalyzed mussel tissues collected in 2012/2013 and identified over 200 pharmaceuticals, including trace amounts of antidepressants, antibiotics, detergents (synthetic surfactants), cardiac medications, and the chemotherapy drug melphalan, among others. They also found traces of oxycodone in mussels taken at 3 of 18 locations (17%).”
Learn more on the Human Health Implications Following Detection of Oxycodone in Mussels Collected in Washington State (2019) by Yau et al via BCMJ.
Where can I drop off out-dated or leftover medicine or medical sharps in British Columbia?
When you pick up your prescription, ask your pharmacist. You can also visit BC’s Medications Return Program to find a location or click on Returning Medicine or Medical Sharps to learn how and where you can dispose of your prescriptions or call the RCBC Recycling Hotline: 
UBC Family Practice Residency Program: Abbotsford-Mission Site 