Alpha 3 Manages Capping of Three CCR Sites in Maryland

Engagement

As the owner’s representative, Alpha 3 provided project management and project controls support for the capping and closure of three coal combustion residual (CCR) storage facilities located throughout southern Maryland. The facilities are associated with the Chalk Point, Dickerson, and Morgantown power plants, acquired by NRG in 2013 through its acquisition of GenOn. The program was initiated pursuant to a Consent Decree signed by NRG MD Ash Management and Maryland Department of the Environment (MDE) in April 2013.

After investigation and design of remediation measures, construction is now near completion. The Alpha 3 team provided support from conceptual design through project closeout. A total of 250+ acres were capped with geosynthetic liner systems. The construction scope included large-scale earthwork operations, installation of geosynthetic liner systems, installation of temporary and permanent water treatment facilities, and maintenance of erosion and sedimentation controls to ensure CCR containment during construction. As owner's representative, Alpha 3 negotiated and managed contracts for engineering and design services, contracts for capping operations, and contracts for the design and implementation of water treatment facilities. Design and inspection services were provided by Golder Associates and AECOM, and cap construction was performed by CB&I.

(Aerial photo taken at Faulkner site, showing cap vegetation and runoff pond)

Scope Definition Challenges for Large CCR Capping Projects

The boundaries of large-scale, covered CCR facilities are often uncertain due to the potential for underground migration of ash over decades of storage. Thus, the extent of remediation and capping must be adjusted as needed during construction. Alpha 3 managed design and scope change as they frequently arose throughout the program. Alpha 3 personnel worked closely with MDE, project engineers, and contractors to ensure environmental compliance was maintained throughout the project lifecycle. Alpha 3 also worked with NRG’s site operations and maintenance personnel to coordinate ongoing site operations concurrent with construction and to transition the capped sites to operations for long-term oversight.

Alpha 3 provided project controls services throughout the program’s duration, executing on budget and schedule parameters consistent with the environmental liability accounts and consent decree dates required. Unit-price contracts for all three sites required detailed quantity tracking to calculate earned value and validate monthly payment requisitions. Alpha 3 also provided cash flow and budget forecasting on both the project and program levels, maintained estimates at completion, and provided weekly and monthly client reporting to company executives.

Weekly reviews of resource-loaded CPM schedules ensured the constructability of capping work-paths and alignment with site drainage capacity limitations. One of the greatest risks associated with capping CCR sites is the chance of significant rain events on exposed ash. Once cover soil is stripped from an area of the site, an unanticipated rain event can quickly erode large quantities of ash. If the exposed area is not carefully managed, E&S controls can be overwhelmed, resulting in loss of containment, significant extra work for cleanup and repairs, delays, and extra cost. Thus, disturbance limitations must be maintained while carefully monitoring the weather forecast and simultaneously ensuring sufficient open workfronts to keep labor and equipment productive.

Project Management and Controls Highlights

The capping program had high visibility for upper management, focused on completing construction within the allotted consent decree dates while maintaining the program budget. Development and maintenance of the program’s cash flow was one of the early focuses of the project controls effort for such a large, unit-priced program. Alpha 3 provided services to quantity-load and cost-load CPM schedules, in cooperation with the contractor, to provide early and late cash flow curves for management reporting. The program’s cash flow forecast was updated on a monthly basis to provide NRG management with up-to-date spending projections. Alpha 3’s ability to manage and forecast cash flow became a valued skill for both the owner and contractors involved in the program.

Although the initial project design fulfilled all regulatory requirements, field modifications were necessary to achieve and maintain successful erosion and sediment controls in the field. Variables including excessive rainfall, sinkholes, uncharted ash migration, and slope adjustments to maintain the limits of disturbance all contributed to the need for additional measures not fully detailed in the initial designs. To prevent any erosion and sediment control program deficiency, the team implemented additional measures when needed, including rip-rap check dams, grouted rip-rap letdowns, widening and strengthening of perimeter drainage channels, daily hydro-seeding; tackifier application in disturbed areas, and tarp blanketing to manage excess flow volumes. Successful implementation and maintenance of erosion controls is fundamental for the successful capping of CCR sites. If a rain event results in a significant breach of erosion controls and the release of CCR from the site, the cost of remediation can easily exhaust project contingency. After years of work on these sites with several contractors, the Alpha 3 team developed significant experience in using funds to install preventative measures when needed to prevent more costly remediation efforts. The team also developed valuable experience in balancing the effort to minimize the amount of exposed ash on site while maintaining construction momentum.

Construction Challenges

Constructability challenges contributed to some early schedule delays on the program. Specific constructability difficulties included maintaining strict adherence to disturbance limitations, challenges with temporary drainage of work areas after rains, integrating the many required regulatory inspections into the schedule, and sourcing personnel experienced in the operation of specialty equipment used throughout the program. In support of NRG and its various contractors, Alpha 3 provided schedule development, analysis, and resource loading throughout the program, which reflected constructability solutions implemented in the field. Detailed, planning, resource-loading, and re-planning when needed provided up-to-date production rates as operations were adjusted and work paths changed. Alpha 3 takes pride in the ability to successfully plan, schedule, and manage construction on-the-fly, in the field, even with multiple constraints and resource limitations.

Safety

NRG demonstrated its firm commitment to safety as its first requirement for a successful project. Safety concerns with the initial general contractor ultimately led to a termination of the original contracts and a transition to CB&I as prime contractor. Proper execution of the contractor transition process was crucial to maintain the overall program budget, schedule, and environmental compliance. The Alpha 3 personnel on the program management team provided services to spearhead the transition from close-out of the initial contractor, competitive bidding for completion, and acclimation of the new contractor's personnel into the program's continuing requirements. Specific documentation during the transition included bid package materials to support current bid items and quantities, schedules for the remaining scope, and implementation of updates to the contract based on lessons that had been learned during execution.

As the Maryland Ash Program wraps up in 2018, Alpha 3 is proud to have been a part of a successful program to provide a long-term solution for these CCR sites. Through close coordination with all stakeholders, responsible project management, and detailed project controls, Alpha 3 was able to facilitate successful completion of the program for all parties.