Project Scope of Work

Project Scope of Work 2003

Biscayne Bay Coastal Wetlands Well-Site Data Acquisition

Biscayne Coastal Wetlands Groundwater Monitoring Well Locations
Figure 1. Location of monitor-well sites for the Biscayne Bay Coastal Wetlands Project that include monitor-well sites 0009AB and 0011AB. [larger image]

1. Background. The goal of the Comprehensive Everglades Restoration Plan Biscayne Bay Coastal Wetlands Project (BBCWP) is to rehydrate wetlands and reduce point-source discharge to Biscayne Bay. The BBCWP will replace lost overland flow and partially compensate for the reduction in ground-water seepage by redistributing, through a spreader system, available surface water entering the area from regional canals. The proposed redistribution of freshwater flow across a broad front is expected to restore or enhance freshwater wetlands, tidal wetlands, and near shore bay habitat. A critical component of the BBCWP is the development of a realistic representation of ground-water flow within the karst Biscayne aquifer. Recently, Cunningham and others (USGS-WRIR 2004) have demonstrated that a dual-porosity conceptual model is appropriate for this karst aquifer system with a series interlayered diffuse-carbonate and conduit flow zones that are vertically arranged within the context of a high frequency sequence stratigraphy. Mapping these ground-water flow units is key to the development of models that simulate ground-water flow from the Everglades and urban areas through the coastal wetlands to Biscayne Bay. As participants in this pilot project, the South Florida Water Management District (SFWMD), the US Army Corps of Engineers (Corps), and the United States Geological Survey (USGS) are working together to better understand the hydrogeologic framework of the Surficial aquifer in the Biscayne Bay Coastal Wetlands in Miami-Dade County. Because there is little detailed hydrogeologic data of the Surficial aquifer (to depth) in this area, the Biscayne Bay Coastal Wetlands Project Delivery Team (PDT) proposes to install two monitor-well sites (Figure 1) and collect the necessary detailed hydrogeologic data.

2. Objective. The objectives of this data acquisition project are to complete the downhole geophysical logging including video and flowmeter logging of two core holes (9A and 11A, Fig. 1), which are the deepest wells at monitor well sites 0009AB and 0011AB (Fig. 1). The USGS staff will provide and run gamma ray, fluid conductivity and temperature, EM-induction, 3-arm caliper, full wave form sonic tools, a heat-pulse flow meter, spinner flowmeter, an OBI-40 Mark III digital optical tool, the Laval video tool, and a computed vuggy porosity log. This data will be a benefit to the USGS and the BBCWP as data to fill a regional concept of the Biscayne aquifer.

3. Scope. The Corps will contract with a licensed drilling contractor to install two continuously cored monitor ground water wells in April-May 2004. Prior to completion of the wells, the USGS will complete geophysical logging of these wells. Drilling of the wells is expected to be complete within 2 months after initiation of well drilling. The USGS geophysical logging, processing nad and delivery of the data are expected to be complete within 1 month after the logging has been completed.

The purpose is to provide the Biscayne Bay Coastal Wetlands PDT with knowledgeable hydrogeologic staff with experience in the general area that will provide borehole geophysical and hydraulic data to be used by PDT decision makers in construction of monitor wells and an advanced suite of borehole logs for interpretation of the hydraulics and geology of coastal Biscayne Bay.

The USGS hydrogeologist will be on site while the drill crew develops monitor wells 9A and 11A (Figure 1) for logging and during geophysical borehole logging of the deepest well at each of the two monitor well sites. The site USGS hydrogeologist will: 1) Monitor the drilling contractor for adherence to correct borehole development and preparation for geophysical borehole logging, 2) Run geophysical logs, digital-image logs, video logs, flowmeter measurements, and 3) provide calculated computed vuggy-porosity logs.

USGS staff will run USGS geophysical tools, flow meters, and video tools to log the four core holes and deepest well at each monitor wells 9A and 11A (Figure 1).

The USGS will collect geophysical logs, digital-image and video logs, and flowmeter measurements at wells 9A and 11A.

4. Work Responsibilities of the Parties:

Corps responsibilities:

1. Contract with licensed drilling contractor to install continuously cored monitor wells,
2. Coordinate schedule with drilling contractor and the USGS staff,
3. Provide borehole conditions appropriate for geophysical, optical and flowmeter logging,
4. To be available to meet with or talk with USGS hydrogeologists to discuss the new data and select well screen intervals, and
5. Provide timely review and comments/approval of deliverables.

USGS Responsibilities:

1. Provide personnel and equipment, including geophysical tools, video tools, and flowmeters required to complete the project,
2. Monitor the performance of the drilling contractor to assure adherence to the established scope of work during well development and geophysical borehole logging,
3. Use USGS geophysical tools, video tools, and flowmeters to log monitor wells 9A and 11A (Fig. 1),
4. Provide geophysical borehole data and other information to the PDT geotechnical sub-team for their use in selection of well-screen interval depths and for making other geotechnical decisions during construction of monitor wells 9A and 11A,
5. Provide deliverables including electronic files of digital logs, MPG file (mini-movie of borehole video), and excel file of computed vuggy porosity logs, WellCad and pdf file of all logs on one single 36-inch wide log display or log montage, and two paper copies of the log montage as scheduled, and
6. Meet with BBCWP PDT geotechnical sub-team to discuss findings, if requested.

5. Schedule. Oversight of the drilling contractor during development of the well and geophysical logging of the wells will begin shortly after drilling commences at wells 9A and 11A (Fig. 1). It is expected that this will occur prior to May 30, 2004. All deliverables will be available to the PDT within one month of completion of geophysical logging of wells 9A and 11A (Figure 1). The schedule for collecting field data and providing all deliverables included in this scope of work is contingent on the actual start date of the project and drilling contractor's ability to provide borehole conditions that will allow collection of all geophysical logs, digital-image and video logs, and flowmeter measurements.

MODIFICATION #1

Statement of Work for Amended Work in support of L-31 North Canal Seepage Management Pilot Project

Downhole Geophysical Logging Support

1. Introduction. The L-31 North Canal Seepage Management Pilot Project is intended to curtail easterly seepage emanating from within Everglades National Park (ENP). The pilot project is examining various seepage management technologies as well as operational changes that could be implemented to reduce the water losses from ENP. This project is in close proximity to Biscayne Bay so an effort has been made to combine ongoing work efforts at the two project areas.

The project objective as developed by the L-31 North Project Delivery Team is:

"The purpose of this project is to determine the appropriate technology needed to control seepage from the Everglades National Park and provide the appropriate amount of wet season groundwater flow that will minimize potential impacts to the Miami-Dade County's West Wellfield and freshwater flows to Biscayne Bay."

Seepage emanating from ENP and traveling east is discharged to multiple sinks. First, a large percentage of seepage is discharged into the L-31 North Canal. Historical estimates and recent estimates prepared for the Seepage Management project suggest that total seepage into the L-31N Canal between Tamiami Trail and the G-211 structure amounts to a daily average of 250 to 500 cubic feet per second (cfs) (COE, 1952; Klein and Sherwood, 1961; Klein and Hampton, 1971; SFWMD, 1991; COE, 1999; USGS, 2002; COE, 2003). Second, seepage not captured by the L-31N Canal flows beneath the L-31 N Canal toward the east. The West Miami-Dade well field collects a portion of this seepage while the rest flows further toward the east to be discharged into local Miami-Dade County canals and Biscayne Bay. The distribution of seepage into the L-31 North Canal and beneath it is not known with any degree of certainty today. A canal draw down experiment is proposed to provide additional field data that will be utilized to refine seepage estimates in the study area as well as determine aquifer parameters in the study area. The canal drawdown experiment will be completed in two phases. First, a dry-season test would be conducted toward the end of May 2004. Second, a wet-season test would be conducted in late July 2004. Both portions of the test are envisioned to be at least four days in duration. During the test multiple sets of hydrologic instrumentation would be monitored on a continual basis. In addition, during the dry-season test, downhole flow logging would be completed in two open-hole interval wells adjacent to the L-31N Canal. It is envisioned that the United States Geological Survey (USGS), Miami Field office would provide the expertise and equipment to perform the required down-hole logging.

2. Scope. The USGS will acquire geophysical logs using the fluid conductivity and temperature probes, and heat-pulse and spinner flowmeters at two coreholes specified by the USACE and funded by the L-31N Seepage Management Pilot project. Two coreholes will be logged during the second day of the 48-hour duration of the drawdown test. The drawdown test will be conducted by USACE and South Florida Water Management District personnel in late May or early June 2004, during dry season conditions. The well location and schedule will be coordinated with the USACE POC, Chris Brown, 904-232-1008.

Project schedule for the modification is as follows:

Conduct initial geophysical logging of coreholes	late May 2004
Processing of geophysical log data complete	1 months after last log collected
Deliverables provided	3 months after last log collected

Deliverables: The deliverables will include:

• Electronic files of digital logs for fluid conductivity and temperature, and heat-pulse and spinner flowmeters in the form of WellCad and pdf electronic files of all logs on one single 36-inch wide log display or log montage for each well. Four paper copies of the log montage for each well will be provided.
• Meet with the L31N Seepage Management Pilot project PDT to discuss finding, if requested.