Climate change was the top environmental focus during Biden's 2020 presidential campaign, so it is reasonable to assume that is where his administration's environmental efforts will be focused initially. In fact, at the time of this writing, the lead candidates for heading up the US Environmental Protection Agency (USEPA) all work in positions that champion ambitious climate policies.

However, with coal‐state senators Shelley Moore Capito (R‐WV) and John Barrasso (R‐WY) chairing the Committee on Environment and Public Works and the Committee on Natural Resources, respectively, the Biden administration's clean energy efforts will move more slowly and rely more on regulatory options than if he had his own party controlling both bodies of Congress. For example, he will have more regulatory options than legislative options available to address greenhouse gases and vehicle efficiency standards. And while presidents do have the power of executive orders at their disposal, they have limited authority and—as we've seen the past few years—can get easily hung up in court unless very carefully crafted.

Specific to water, if the Senate remains in Republican control after January's Georgia runoff elections, it is not likely we will see a major rewrite of the Safe Drinking Water Act to make it easier for USEPA to write new regulations. Either way, don't be surprised if some Republicans support efforts to streamline rule‐writing to a degree. There are plenty of Republicans with contamination from per‐ and polyfluoroalkyl substances (PFAS) or lead service line issues in their states or districts, and those issues have their attention.

It is likely we will see drinking water regulations issued for a handful of chemicals within the PFAS family, but probably not for the whole class of PFAS compounds. Biden is a centrist by nature, and because PFAS are used in everything from medical devices to semiconductor chips to cables, it is likely his administration will take these uses into account. The administration could require Clean Water Act permits to list PFAS releases and volumes, halt approvals of the use of new PFAS compounds, and close loopholes in existing reporting requirements. Environmental justice has been an ongoing cause for incoming vice president Senator Kamala Harris (D‐CA), so expect that to get a higher profile in this administration. Enforcement of environmental regulations will also get a renewed emphasis.

As for the ongoing saga of the Waters of the United States rule, the Trump administration issued a narrower definition of regulated wetlands than its predecessor, but that is hung up in court. If the Biden administration moves to change that newest definition, expect more action in the courts. This could go on for a while until the issue reaches the Supreme Court again; the court's decision in 2006, Rapanos vs. United States, opened the door to more litigation on the matter. The Trump administration also attempted to streamline the environmental permitting process by issuing new regulations under the National Environmental Policy Act. That has attracted five lawsuits so far. Since there is not time for these new regulations to take effect, the Biden administration will have the opportunity to reconsider these actions.

Infrastructure spending is often seen as a tool to boost economic growth and get people employed again. A big uncertainty is the length and depth of the current economic downturn that the country is experiencing because of coronavirus impacts. If Congress feels a need to step in again this spring, infrastructure spending could be wielded as it was in the American Recovery and Reinvestment Act (ARRA) of 2009. If this is the case, then the question will be whether to put more federal money into existing tools, such as the Water Infrastructure Finance and Innovation Act program and the state revolving loan fund programs, or to also create new financial tools like ARRA did with Build America Bonds. The most likely course is for Congress and the administration to focus on those existing finance tools and possibly existing grant programs, such as those for lead service line removal and PFAS remediation.

The past decade has not been kind to forecasters of political trends, so be prepared for developments beyond those described here.

气候变化是拜登2020年总统竞选期间最关注环境的问题，因此可以合理地假设这是他的政府最初致力于环境工作的地方。实际上，在撰写本文时，领导美国环境保护署（USEPA）的主要候选人都在拥护雄心勃勃的气候政策的职位上工作。

但是，由煤炭州参议员Shelley Moore Capito（R‐WV）和John Barrasso（R‐WY）分别担任环境和公共工程委员会和自然资源委员会主席，拜登政府的清洁能源工作将更加缓慢比他拥有自己的政党控制国会两个机构的情况更多地依赖于监管选择。例如，与解决温室气体和车辆效率标准的立法选择相比，他将拥有更多的管理选择。尽管总统确实拥有执行命令的权力，但他们的权力有限，而且，正如我们过去几年所看到的那样，除非精心设计，否则很容易在法庭上被吊销。

对于水而言，如果参议院在一月份的佐治亚州决选之后仍由共和党控制，那么我们不太可能会对《安全饮水法》进行重大改写，以使USEPA更容易编写新法规。无论哪种方式，如果一些共和党人支持在一定程度上简化规则制定的努力，请不要感到惊讶。在他们所在的州或地区，许多共和党人都受到过全氟烷基和多氟烷基物质（PFAS）或主要服务线问题的污染，这些问题引起了他们的注意。

我们很可能会看到针对PFAS系列中的少数化学品发布了饮用水法规，但可能不是针对整个PFAS化合物类别。拜登从本质上说是一个中间派，并且由于从医疗设备到半导体芯片再到电缆，PFAS被用于所有领域，因此他的政府很可能会考虑这些用途。政府可能会要求《清洁水法》许可证列出PFAS的释放量和数量，暂停使用新的PFAS化合物的批准，并消除现有报告要求中的漏洞。环境正义一直是新任副总统卡马拉·哈里斯（D-CA）参议员的原因，因此希望在本届政府中获得更高的知名度。环保法规的执行也将重新受到重视。

至于美国水域统治的持续传奇，特朗普政府对受管制的湿地的定义比其前任更为狭窄，但这是在法庭上悬而未决的。如果拜登政府打算改变这一最新定义，请期待法院采取更多行动。这可能会持续一段时间，直到问题再次提交最高法院。法院2006年的判决，拉帕诺斯诉美国，打开了进一步提起诉讼的大门。特朗普政府还试图通过根据《国家环境政策法》发布新法规来简化环境许可程序。到目前为止，已经吸引了五起诉讼。由于这些新法规没有时间生效，因此拜登政府将有机会重新考虑这些措施。

人们通常将基础设施支出视为促进经济增长和重新就业的工具。一个很大的不确定性是该国由于冠状病毒的影响正在经历的当前经济衰退的持续时间和深度。如果国会认为有必要在今年春季再次介入，可以像2009年《美国复苏和再投资法案》（ARRA）那样动用基础设施支出。如果是这样，那么问题将是是否要投入更多的联邦资金。纳入现有工具，例如《水基础设施金融与创新法》计划和州循环贷款基金计划，或者创建ARRA与Build America Bonds合作创建的新金融工具。对于国会和政府来说，最可能的路线是专注于那些现有的财务工具以及可能的现有赠款计划，

过去十年对政治趋势的预测者并不友好，因此请为此处所述之外的发展做好准备。