Balogh Stephen, Mulvaney Kate, Merrill Nathaniel, Piscopo Amy
U.S. Environmental Protection Agency, Office of Research and Development, Atlantic Coastal Environmental Sciences Division, Narragansett, RI 02882, USA.
Water (Basel). 2022 May 10;14(10):1-23. doi: 10.3390/w14101529.
Solving estuarine water quality problems on Cape Cod, Massachusetts, or elsewhere, is difficult. Nitrogen from septic systems takes years to decades to travel by groundwater to estuaries, depending on local hydrogeology, meaning that nitrogen loading in future years may exceed current conditions. We created a dynamic nitrogen model of Cape Cod's 54 estuaries to better understand 1. how past and present conditions, including legacy nitrogen in groundwater, influence future nitrogen loading, and 2. how different development and nitrogen abatement scenarios could have additional effects. We find that 43 of 54 estuaries are not in equilibrium with current watershed nitrogen loading levels; this increases to 52 of 54 under a buildout scenario. Watersheds contain up to 1000 tons of legacy nitrogen in groundwater; yet, we find that a rapid investment in source control successfully reduces nitrogen loading, revealing a wide range of potential outcomes that depend ultimately on the resources and attention invested in the problem.
解决马萨诸塞州科德角或其他地方的河口水质问题很困难。来自化粪池系统的氮通过地下水输送到河口需要数年到数十年的时间，这取决于当地的水文地质情况，这意味着未来几年的氮负荷可能会超过当前状况。我们创建了一个科德角54个河口的动态氮模型，以更好地理解：1. 过去和现在的状况，包括地下水中的遗留氮，如何影响未来的氮负荷；2. 不同的开发和氮减排情景如何产生额外影响。我们发现，54个河口中有43个与当前流域氮负荷水平不平衡；在全面建设情景下，这一数字增加到54个中的52个。流域地下水中含有多达1000吨的遗留氮；然而，我们发现对源头控制的快速投资成功降低了氮负荷，揭示了一系列最终取决于投入该问题的资源和关注度的潜在结果。
