The Oak Ridge National Laboratory, in April 2012, reported the potential new generating capacity of non-powered dams in the United States totaled more than 12-GW of electricity. That is as much power as is produced by 24 large coal power plants.
Of the 50 dams identified as having the most promise to provide energy, 48 are U.S. Army Corps of Engineers (USACE) Civil Works projects. But despite a promise of clean energy, USACE is strained by legislation and funding to develop new hydropower. A potential solution to this problem is private funding.
Mahoning Creek DamOne recently completed, privately developed project on a USACE dam is the Mahoning Creek Hydroelectric Project in western Pennsylvania. Developer Enduring Hydro LLC worked with the design firm of Mead & Hunt and the builder through collaborative project management with federal, state and local agencies to achieve success in a very short timeframe.
NEW PLAN FOR AN OLD IDEA
Mahoning Creek Dam is a concrete gravity dam built in 1941 as a flood control project impounding Mahoning Creek, an Allegheny River tributary. Original plans to include hydropower were postponed by the diversion of raw materials to the World War II effort. The American Recovery and Reinvestment Act of 2009 provided for a public-private partnership of USACE Pittsburgh District and Enduring Hydro to develop hydropower on the dam through the 1603 Grant Program. This funding offered renewable energy project developers payments equivalent to 30 percent of the project’s total eligible cost basis in most cases. Of the 922 awards approved through the 1603 program as of July 2013, however, only 27 were for hydropower—and of those, just seven were for new facilities.
The Mahoning hydropower design focused on durable, low-maintenance systems that were cost-effective to construct:
Steel lining an existing 108-in penetration and adding inlet works consisting of a 9-ft by 13-ft roller gate with trash racks on the upstream dam face.
A 108-in butterfly valve within a caisson supported vault at the downstream end.
A buried steel 1,200-ft-long penstock that runs from the dam to the powerhouse.
A reinforced concrete powerhouse with two vertical generating units (6-MW) linked to two vertical Francis turbines. A two-third/one-third split allows the powerhouse to operate efficiently across a large range of flow levels.
Powerhouse equipment—a prefabricated equipment skid with controls, office, switchgear and a hydraulic power unit.
Power grid connection via a 1.3-mi-long, 25-kV transmission line.
A 0.5-mi-long access road.
Additionally, the project will operate highly automated the majority of time and be monitored 24/7 via the plant supervisory control and data acquisition system.
A key to the project’s success was accounting for the differing goals and focuses of each partner. USACE’s primary objective, for instance, was not compromising dam safety and flood control operations. The project team’s main goals were high quality construction within budget and on time, and minimal maintenance requirements during future years of operation. And within each organization, there were numerous other requirements. Pittsburgh District’s Planning and Environmental Division was very concerned about water quality, erosion and ground cover, while the Operations Division was primarily concerned with the effect of the new hydropower facility on existing operations. Understanding these interests was a start—but the project scope, timing and regulatory aspects called for a high degree of organization, with clear direction to complete each task.
Mahoning Creek Dam hydropwerEnduring Hydro acquired the Mahoning Creek project in August 2012. Design was essentially complete at that point and equipment ordered. However, to receive clearance for construction, the team had to negotiate an independent external peer review, Federal Energy Regulatory Commission (FERC) and USACE reviews, overcome numerous regulatory hurdles and negotiate easements with local landowners. Final clearance for construction was not received until May 2013. To qualify for the 1603 Grant, the work needed to be finished prior to the end of 2013. This left a six-and-a-half-month construction window.
Building any federal project is challenging, especially one that modifies an existing USACE flood control dam. The most significant regulatory hurdle for Mahoning Creek was the Section 408 Permit for the alteration, occupation, or use of public works. Since the 408 is approved by the Assistant Secretary of the Army for Civil Works, ratification was necessary at all levels of USACE’s chain of command.
With a very short timeline, a complex project and numerous levels of review, Enduring Hydro employed a collaborative project management approach. This included weekly working group meetings and monthly executive meetings. All stake¬holders were kept informed of the ongoing progress and potential challenges.
During design and construction, it was common for three to four calls each week between key team members and the government agencies. Protocol included:
SharePoint site for project documents, permits and approvals.
Weekly telecommunications meetings to review design, regulatory approval, construction, schedule and safety.
Monthly executive project team meetings to review quality, schedule and budget.
Use of the USACE DrCHECKS system for design reviews, comments and resolution.
Periodic calls with USACE Pittsburgh District, the USACE Hydroelectric Design Center, and the USACE Risk Management Center.
E-mail to the appropriate entities that clearly addressed issues/requirements.
Through strong communication, it is possible to meet the often varying goals and objectives of multiple agencies and arrive at a shared solution. Both USACE and FERC, for instance, required a primary failure mode analysis (PFMA) of the design. Conducting this at the right point is crucial; the 65 percent design level was ideal for Mahoning Creek. It also is important to clarify who will be involved and at what stages. Peer review is equally valuable. Establishing an acceptable Independent External Peer Review team early in design worked well for Mahoning Creek.Mahoning Creek Dam hydropower
To expedite the approval process, Enduring Hydro coordinated and scheduled two separate PFMA sessions. The second session included a semi-qualified risk assessment required by USACE Risk Management Center. Immediately following, the project team was able to satisfactorily address all remaining open comments, and received final clearance for construction. On Dec. 26, 2013—five days prior to the deadline—the work was done.
The Mahoning Creek Hydroelectric Project is delivering power as expected. The dam remains the responsibility of USACE, with Enduring Hydro operating the powerhouse in close coordination.
Collaborative project management works. Key players come together to solve permitting, design, construction and commissioning challenges. Instead of relying on one person, the entire team is involved and ultimately enjoys an enhanced knowledge base and range of expertise.
On a project with short timelines and several stakeholders, there is no such thing as over-communication. Communicate often, document everything, follow-up meticulously. Meet in person with approving agencies in addition to electronic communication. Do not assume anything or there are bound to be misunderstandings that can negatively impact progress.
Hydropower is a terrific source of clean, renewable energy, and the United States has a vast amount of untapped potential in its existing dams. However, given federal budget constraints, new development will need to rely on private capital and faces many challenges. Enduring Hydro’s project delivery team, working closely with FERC and USACE, was able to overcome the challenges it faced to realize the green energy opportunity at Mahoning Creek.
Through the process, the partnership learned valuable lessons on planning, designing, approving and building these projects quicker and for less cost, while maximizing the interests of all involved.