Landfills close to bodies of water tend to have more gull problems. This particular landfill is near the Mississippi, Black, and La Crosse Rivers, in addition to Lake Onalaska and Lake Neshonoc. Lack of natural food during the cold weather/winter months brings birds to the landfill. My curiosity was piqued after seeing this phenomena. I did some reading on gulls and landfills. A Duke University Study (by R. Scott Winton) finds that gulls' nutrient-rich droppings may cause major water-quality problems in nearby lakes and reservoirs. It's quite a dilemma that affects our environment. Who knew?
Read more at: https://phys.org/news/2017-06-trash-picking-seagulls-poop-tons-nutrients.html#jCp