威斯康星州的大肠菌群总阳性率在夏末秋初出现了无法解释的峰值，这导致了一系列“沸水”指令和其他监管活动。这项研究收集了数据来帮助解释这一现象。一年内，每月对威斯康星州各地约65口非社区公共供水井进行采样。为了更好地了解分配系统中的生物膜、季节性和大肠菌群再生和定植之间的关系，对水样进行了大肠菌群以及铁细菌、异养平板计数细菌和水温等生物膜指标的测试。对整组样本的分析表明，高温和总大肠菌群阳性率之间存在高度相关性。 分析生物膜的存在对总大肠菌群阳性率的影响表明，两者之间存在密切联系。夏末水温升高时，存在生物膜的小型井水系统比不存在生物膜的井水具有更高的大肠菌群阳性可能性。

Wisconsin experiences unexplained peaks in total coliform positivity in the late summer and early fall which results in a rash of "boil water" orders and other regulatory activities. This study gathered data to help explain this phenomenon. Approximately sixty-five, non-community public water supply wells located throughout Wisconsin were sampled monthly for one year. Water samples were tested for coliform bacteria as well as biofilm indicators such as iron bacteria, heterotrophic plate count bacteria and water temperature in an attempt to better understand the relationship between biofilms in distribution systems, seasonaltiy and coliform regrowth and colonization. Analysis of the entire set indicates a high correlation between elevated temperatures and total coliform positivity. Analysis of the influence of the presence of biofilms on total coliform positivity indicates a strong connection. Small well water systems with biofilms present have a much higher likelihood of coliform positivity when water temperatures rise in late summer than wells where biofilm were not present.