Consider the external effects of soft-drink packaging on UK beaches, according to this article:

https://www.theguardian.com/environment/2019/may/14/coca-cola-packaging-pollution-on-uk-beaches-surfers-against-sewage-study

Based on this discussion and economic theory, draw an appropriate diagram to illustrate and explain this specific type of externality (assume the market is competitive). Demonstrate on your diagram and evaluate what it would be a suitable government policy to help solve the market failure in this case.