Assessing the impact of wastewater treatment plant upgrades on fish health

人口的持续城市化对加拿大有限的水资源提出了越来越大的需求。尽管废水处理在减少急性毒性和富营养化方面是有效的，但废水中释放的新的新化学物质引起了人们的关注。这些化学品可通过许多相互关联的机制与生物体相互作用，对包括鱼类种群在内的生态系统健康造成不利后果。废水公用事业面临着相当大的不确定性，涉及这些变化的潜在生态意义以及有效消除这些变化的现有选择。新的《污水处理系统条例》(《渔业法》)要求加拿大所有污水处理系统达到选定污水参数的最低基线。然而，这不包括新出现的污染物的多样性，如环境雌激素，这些污染物存在于对鱼类繁殖有重要影响的流出物中。随着废水公用事业公司投资于处理过程升级，以满足法规和保护接收环境，确定这些污染物如何受到影响以及生态系统如何反应将是重要的。在安大略省南部的格兰德河流域，与两个主要废水处理厂有关的鱼类受到了许多影响。然而，这些设施目前正在进行重大流程升级(2012-2020年)。这些地点的分水岭研究已经进行了十多年，因此创造了一个独特的机会来跟踪生态系统(即鱼类)对这些重大投资的反应。过去的数据集，以及存档的和新收集的样本，将被用来评估生物反应(对种群的基因)是如何在哨鱼物种(彩虹飞镖、蓝斑鱼)中改变的。这将得到分析化学和实验室生物分析的支持，以更好地了解暴露和风险随时间的变化。该项目将加强公用事业公司评估保护环境的努力并指导未来投资决策的能力。

Continued urbanization of human populations has put increasing demands on the limited water resources available in Canada. Although wastewater treatment has been effective in reducing acute toxicity and eutrophication, new emerging chemicals released in the effluents are raising concerns. These chemicals can interact with organisms through numerous interlinked mechanisms to cause adverse outcomes on ecosystem health, including fish populations. Wastewater utilities face considerable uncertainty related to the potential ecological significance of these changes and the options available to effectively remove them. The new Wastewater Effluent Systems Regulations (Fisheries Act) require all Canadian wastewater systems to achieve minimum baselines for selected effluent parameters. However, these do not include the diversity of emerging contaminants, such as environmental estrogens, that are present in effluents that can have important effects on reproduction in fish. As wastewater utilities invest in treatment process upgrades to meet the regulation and protect receiving environments, it will be important to determine how these contaminants are affected and how ecosystems respond. In the Grand River watershed, in southern Ontario, many effects have been documented in fish associated with the two major wastewater treatment plants. However, these facilities are currently undergoing major process upgrades (2012-2020). Research has been ongoing in the watershed for more than a decade at these sites and therefore has created a unique opportunity to follow the response of the ecosystem (i.e., fish) to these major investments. Past data sets, along with archived and newly collected samples, will be used to assess how biological responses (genes to populations) are altered in a sentinel fish species (rainbow darter, Etheostoma caeruleum). This will be supported with analytical chemistry and laboratory bioassays to better understand changes in exposure and risk over time. The project will strengthen the utilities' ability to assess efforts to protect the environment and guide future investment decisions.