As shallow aquifers become depleted or contaminated worldwide, use of deep aquifers will likely increase to meet growing water demands despite expensive drilling costs and well maintenance, and limited recharge to many of these deep systems. We discuss depletion of the Cambrian‐Ordovician sandstone aquifer, a deep bedrock aquifer that has been a major source of water in the Midwestern US for over 150 years. Using a participatory groundwater modeling approach with active stakeholder engagement, we developed a conceptual framework to assess risk to different sandstone units of the aquifer based on simulated heads and production well behavior (pumping levels and specific capacities). Over 320 m of static head decline has occurred since predevelopment in the deepest sandstone unit. Shallower units are actively being dewatered. Drawdown and head separation between sandstone units is even greater under pumping conditions and is most acute near a regional fault zone. Current depletion is prompting massive infrastructure changes to mitigate anticipated water supply shortages. Our results show that even with a substantial reduction in water use by 35% in 2030, many areas of the aquifer remain at High or Severe risk out to 2070. Head decline, as opposed to storage loss, is a critical metric for understanding depletion of deep bedrock aquifers. The participatory modeling process made clear that pumping levels at production wells should not be ignored in evaluations of aquifer sustainability and risk. Our conceptual risk framework could be applied to other deep bedrock aquifers undergoing depletion.

中文翻译：

---

利用生产井行为评估美国中西部寒武纪-奥陶纪砂岩含水层系统中的风险

随着浅层含水层在世界范围内的枯竭或污染，尽管钻井成本和井维护费用昂贵，而且许多深层系统的补给量有限，但深层含水层的使用仍可能会增加，以满足日益增长的水需求。我们讨论了寒武纪-奥陶纪砂岩含水层的枯竭，这是一种深基岩含水层，在美国中西部地区已有150多年的历史了，该含水层一直是主要的水源。我们通过参与性的地下水建模方法和利益相关者的积极参与，建立了一个概念框架，根据模拟压头和生产井的行为（抽水量和比容量）评估了含水层不同砂岩单元的风险。自最深砂岩单元进行预开发以来，已经发生了超过320 m的静压头下降。浅层单元正在积极脱水。在抽水条件下，砂岩单元之间的水位下降和压头分离甚至更大，并且在区域断层带附近最为严重。当前的消耗正在促使大规模的基础设施改变，以减轻预期的供水短缺。我们的结果表明，即使到2030年用水量大幅减少35％，到2070年，含水层的许多区域仍将处于高风险或严峻风险。头数下降（而不是储水量损失）是理解水库枯竭的关键指标。深基岩含水层。参与式建模过程明确指出，在评估含水层的可持续性和风险时，不应忽略生产井的抽水水平。我们的概念风险框架可以应用于其他正在消耗的深层基岩含水层。