CERP Hillsboro Aquifer Storage and Recovery Pilot - PROJ 34

The objective of the Western Hillsboro ASR Pilot Project is to test the feasibility of utilizing ASR technology for storage at this site and other sites identified in the CERP. Information gained from the pilot project will be used to develop an operating plan for the system, to refine the long-term operational goals of these and other ASR wells at the site, and to provide insight for future ASR projects, which may be constructed for similar purposes. Results from the pilot project will also be useful in determining the feasibility of utilizing ASR technology at other locations, especially within the SFWMD's Lower East Coast Planning Region. Information to be collected and analyzed during construction and testing of the ASR wells will include:
• Hydrogeologic data from potential storage intervals and confining layers
• Recommendation of the most suitable ASR storage interval(s)
• Quantification of recharge and recovery rates
• Recovery efficiency and delivery potential of the ASR system under differing operating conditions
• Water quality of the source water (surficial aquifer and surface water)
• Water quality of the upper FAS
• Water quality changes in the upper FAS due to ASR storage
• Water quality of the recovered water after storage
• Optimization of techniques to maintain water quality via groundwater collection designs

The Western Hillsboro ASR Pilot Project is located along the Hillsboro Canal in southern Palm Beach County. More specifically, it is located at the southern end of the Loxahatchee National Wildlife Refuge (LNWR), also known as Water Conservation Area (WCA) No.1, where it intersects with the northeastern comer of WCA No.2 (Figure 1). The 1,660-acre tract north of the Hillsboro Canal is SFWMD-owned, and has been used for improved pasture, nursery stock and aggregate mining. The majority of the site, with the exception of the western-most comer, is currently leased. The leased activities include cattle grazing, and may be expanded to include outdoor entertainment (e.g., skeet shooting, fly-fishing, etc.).

In the CERP, the Western Hillsboro site is ultimately planned to contain a 2,460-acre surface water impoundment (by addition of 800 acres south of the Hillsboro Canal) as shown in Figure 2. The completed ASR pilot project is anticipated to consist of the following components:
• Three ASR wells completed into the upper FAS, each with an anticipated capacity of 5 million gallons per day (mgd).
• A surface water collection system that will supply water to the ASR system. The source of the surface water (e.g., Hillsboro Canal) will depend on water quality testing.
• A 50-acre pilot impoundment that will be constructed and tested in conjunction with the ASR pilot project.
• A groundwater collection system consisting of horizontal wells constructed along the perimeter and underneath the pilot impoundment. The horizontal wells will supply water to the ASR system. The water will be a combination of seepage from the pilot impoundment and groundwater from the Surficial Aquifer System (SAS).
• A pre-recharge water treatment facility, if deemed necessary based on water quality testing
• A pre-discharge water treatment facility (for water recovered from the ASR wells, prior to discharge into a canal or impoundment).
• Piping between the source water collection system, the ASR wells, and discharge point(s)
• Surface facilities (e.g., pumps, valves, meters, instrumentation, etc.) to operate and monitor the system.
• Associated monitor wells (FAS and SAS)

A proposed layout of the Western Hillsboro ASR Pilot Project is shallow horizontal wells, in association with a pilot impoundment, as the source water to the ASR wells for storage. Surface water may also be used as a source instead of, or in addition to, the horizontal wells. In this case, a surface water collection facility will be located at the most-appropriate location based on water quality. Locations of the ASR wells, monitor wells, and placement of the horizontal wells are conceptual. The actual locations of these features will be determined through the project formulation process. The ultimate layout of the pilot project features will also need to consider the ultimate designof the full-scale impoundment and ASR system at the site.

西希尔斯伯勒含水层储回（Aquifer Storage and Recovery，ASR）试点项目的目标，是验证在该场址及《综合大沼泽地恢复计划》（Comprehensive Everglades Restoration Plan, CERP）中确定的其他场址应用ASR技术开展储水作业的可行性。本试点项目获取的信息，将用于制定该系统的运行方案、优化本场址及其他ASR井的长期运行目标，并为其他同类用途的ASR项目提供决策参考。试点项目的成果还有助于判定在其他区域，尤其是南佛罗里达水利管理区（South Florida Water Management District, SFWMD）东海岸下游规划区域内，应用ASR技术的可行性。

在ASR井的施工与测试阶段，需收集并分析的信息包括：
• 潜在储水层与隔水层的水文地质数据
• 最优ASR储水层推荐方案
• 补给与回采速率量化分析
• 不同运行工况下ASR系统的回采效率与输水潜力
• 原水（表层含水层与地表水）水质
• 上层佛罗里达含水层（Floridan Aquifer System, FAS）水质
• 因ASR储水导致的上层FAS水质变化
• 储水后回采水的水质
• 基于地下水集水设计维持水质的工艺优化方案

西希尔斯伯勒ASR试点项目位于棕榈滩县南部的希尔斯伯勒运河沿岸，具体坐落于洛克斯哈奇国家野生动物保护区（Loxahatchee National Wildlife Refuge, LNWR，又称第一水保护区WCA No.1）的南端，与第二水保护区（WCA No.2）东北角接壤（见图1）。希尔斯伯勒运河以北的1660英亩土地归SFWMD所有，曾被用于改良牧场、苗木种植与集料开采。除最西侧区域外，该场址大部分区域目前处于租赁状态，租赁用途包括畜牧放牧，未来还可能拓展至户外娱乐项目（如飞碟射击、飞蝇钓等）。

在CERP框架下，西希尔斯伯勒场址最终规划建设2460英亩的地表水蓄滞区（在希尔斯伯勒运河以南新增800英亩区域），详见图2。完工后的ASR试点项目预计包含以下组成部分：
• 3口钻入上层FAS的ASR井，单井设计处理能力为每日5百万加仑（million gallons per day, mgd）
• 为ASR系统供水的地表水集水系统，地表水水源（如希尔斯伯勒运河）的选择将取决于水质检测结果
• 与ASR试点项目同步施工并测试的50英亩试点蓄滞区
• 沿试点蓄滞区周边及底部布设的水平井组成的地下水集水系统，该系统将为ASR系统供水，水源包括试点蓄滞区的渗漏水与表层含水层系统（Surficial Aquifer System, SAS）地下水的混合水
• 前置补水水处理设施（需根据水质检测结果确定是否设置）
• 前置排放水处理设施（用于对ASR井回采的水进行处理后，再排入运河或蓄滞区）
• 连接原水集水系统、ASR井与排放点的输水管道
• 用于系统运行与监控的地面设施（如泵组、阀门、计量设备、监测仪表等）
• 配套监测井（上层FAS与SAS监测井）

西希尔斯伯勒ASR试点项目的拟议布局为：以与试点蓄滞区配套的浅层水平井作为ASR井的储水原水水源，也可采用地表水替代或补充水平井作为水源。若采用地表水作为水源，将根据水质检测结果选定最适宜的地表水集水设施位置。ASR井、监测井及水平井的布设位置均为概念性方案，实际位置将在项目规划阶段确定。试点项目的最终布局还需兼顾本场址全规模蓄滞区与ASR系统的最终设计要求。