Convincing neighbors to switch fertilizer?

Hi! I have been doing undergrad research w/ a professor on a local polluted pond that drains into the Atlantic ocean. For the last three years it has grown higher in P, N, and E. coli and lower in DO, basically oligotrophic at this point. A lot of this is contributed to fertilizer and stormdrains leading into the pond. Any tips on how to influence community members to change their fertilizer/lawn care products to be more nature-friendly? I know most people don't like to go out of their way to change things that aren't broken, so I'd appreciate tips.