By Don Fuller, PE
|Photo courtesy: Stantec|
On Oct. 19, 2015, the Environmental Protection Agency (EPA) Coal Combustion Residuals (CCR) Rule took effect. The long-anticipated and much discussed rule establishes comprehensive regulatory siting, design, and operating environmental performance criteria for both CCR impoundments and landfills for the coal-fired power industry. And, while it covers a multitude of CCR management issues, the October date sets in motion the first of several required compliance deadlines that extend through Oct. 17, 2018.
The core logic behind the rule stems from a phased EPA CCR Risk Assessment Program which took a broad look at U.S. coal-fired power CCR management methodology beginning shortly after the 2008 Kingston Dredge Cell failure. According to EPA, the CCR rule directly relied on the Assessment Program to identify areas of concern to be addressed by the rule. The hazard assessment program included key elements relating to:
- CCR unit structural integrity
- Impoundment breach hazard classifications
- Impoundment hydrologic and hydraulic capacity
- Liner systems
- Evaluation of available CCR and groundwater analytical data
- Various human and ecological impact pathways and receptors
The final CCR rule appears to have distilled the risk assessment findings into three primary focus areas:
- Structural integrity (global slope stability and varying operational conditions)
- Unlined surface impoundments
- Site-specific risk conditions
Structural integrity is addressed through multiple rule compliance criteria, ranging from global and veneer-type slope stability, to structural evaluation of impoundment pool control and discharge structures. Because the EPA considers structural factors as a primary trigger for closure, impoundments that fail to demonstrate compliance with structural factors of safety will be marked for mandatory closure by April 2017, with no time extensions allowed. Mandatory closure “triggers” appear to be aligned with EPA’s conclusions on primary risk elements. It is anticipated that non-compliance for rule elements that are not subject to mandatory closure triggers will be addressed through mitigation measures.
The distinction between lined and unlined impoundments relates to another mandatory path to closure. All CCR units are subject to groundwater monitoring for a variety of monitoring parameters. However, an unlined impoundment that exceeds the defined groundwater protection standard will be subject to mandatory closure. EPA’s sensitivity analyses on liner types concluded that unlined impoundments presented the greatest risks to human health and the environment, while clay-lined units posed lower risks. And finally, composite liners were the only liner types shown to effectively reduce risks from all pathways and constituents far below human health and ecological criteria. Lined impoundments that exceed a groundwater protection standard are not required to close; they simply must comply with the groundwater corrective action program.
Site-specific risk conditions are largely addressed under the rule’s facility location restriction criteria. Siting criteria includes the assessment of unstable ground conditions, CCR to groundwater vertical separation buffers, proximity of wetlands to surface water discharge flows, and site-specific seismic risk considerations. Failure to comply with location restriction standards is also a mandatory closure trigger.
Compliance Activity Observations
To date, utility industry compliance activities center around three primary elements:
- Fleet-wide planning (decision tools)
- Operations data collection program
- Web-based data portals
Fleet planning activities include integrating projected compliance cost, schedules, and risks within a comprehensive planning matrix that includes all existing fleet management metrics. Ultimately, this planning tool is used by a utility’s leadership team to determine its path forward for the coal-fired generation fleet. Although there are a myriad of operational variables that ultimately come into play, the CCR elements include engineering assessment of the byproduct management systems with a focus on associated future cost and risk in maintaining environmental compliance.
EPA requires utilities to reflect available CCR unit operational documentation within a formal operational record. Inherent with the historical environmental permitting standards for impoundments typically permitted under NPDES as a water treatment unit, the level of existing documentation is limited. The industry must now locate available information, compile documentation and establish structured documentation programs looking forward. The required compliance documentation is to be published on a publicly accessible web site required to go live on October 19, 2015.
In discussions with industry leaders, long-term compliance elements showing the most intensive activity include:
- Groundwater monitoring
- Facility design compliance
- Cost-effective pond closure
- Pending regulation compliance planning
While groundwater monitoring protocols vary widely from state to state, the majority of existing impoundments are not subject to any groundwater monitoring program or federal oversight. Impoundments or landfills that have established monitoring systems, likely do not have a network of wells that meet the CCR rule requirements. Therefore a key CCR rule requirement- that down gradient wells be positioned at the waste boundaries-has ignited a flurry of industry activity.
In terms of compliant facility design, the industry is largely ahead of the curve. Many, if not most, issues related to core slope stability or hydraulic and hydrologic design conditions have already been addressed. However, the CCR rule requires that specific structural integrity evaluations and seismic loading conditions relating to the pool control and outlet structures for impoundments be performed and documented. This new requirement is spurring significant demand for engineering assessments.
Today, utilities must inevitably prepare for impoundment closures. Major CCR impoundment closure involves a significant cost, often exceeding $20 million. Significant planning, engineering, and project management resources are needed throughout this complex closure process. Some of the required steps include uncoupling related water operations and eliminating or re-routing a multitude of plant outlet flows, impoundment drawdown water management, and residual sediment stabilization. Given the high stakes nature of pond closure, many industry players are engaging specialized engineering expertise to develop critical compliant and cost effective designs and overall implementation plans.
Some proactive owners are also integrating pending environmental regulations (such as the Clean Water Act 316b and pending Effluent Limitation Guidelines) into their overall CCR compliance planning. Utilities are seeing considerable efficiency in this process by leveraging their existing CCR compliance planning tools as the framework for expanded regulatory compliance planning.
General Operational Industry Trends
Utility companies have responded to the CCR rule with a range of reactions – from addressing each implementation deadline individually “as they come” to initiating fleet-wide assessment programs that proactively address all of the rule’s technical compliance elements ahead of pending deadlines. Proactively planning for rule implementation is the way to go because it allows utilities to assess compliance risk, define the preferred path forward, and refine pertinent plant operational plans accordingly.
At the highest planning level, rule conditions will likely require the coal-fired power industry to choose one of the following CCR operational paths:
- Manage compliance risk under current CCR operational conditions
- Adjust operations to maintain compliance (e.g., wet-to-dry conversion, new or retrofitted CCR storage methodology)
- Switch to non-coal fuel operations
- Plant closure and decommissioning
Few utilities are in a position to quickly transition out of active impoundment operations to maintain CCR Rule compliance. The same applies to impoundments left in service as part of plant process water management following the end of their capacity to store additional CCRs. Regardless of the impoundment’s history, most existing impoundments continue to act as a critical cog in the overall plant water treatment process.
One path forward involves moving existing CCR surface impoundments to an “inactive” classification, which avoids many of the long-term CCR rule requirements. Inactive CCR surface impoundments are those that contain both CCR and liquids on or after October 14, 2015, but no longer receive CCR on or after that date. Should an inactive impoundment complete closure in accordance with the CCR regulations (i.e., either clean closure or closure in place) by April 17, 2018, it will be exempt from all other requirements of the CCR rule, including groundwater monitoring and post-closure care. As a pre-condition to obtaining this exemption, a notification of the facility’s intent to initiate closure of the CCR impoundment must be placed in the facility’s operating record by December 17, 2015. Failing to close the unit by the April 17, 2018 deadline will subject it to all requirements applicable to ‘existing’ surface impoundments.
Contrary to popular belief, the rule allows for continued wet handling and impoundment storage, provided the applicable rule requirements are met. This applies to existing and new CCR units. In reality however, retrofitting an existing impoundment with a CCR-compliant liner within an active plant environment is a very challenging proposition. U.S. plant infrastructure rarely provides the luxury of redundant pond systems that divert the active plant byproduct sluice flow away from liner construction activities.
One of the most pressing challenges for the industry is navigating compliance under the dual regulatory drivers represented by state regulations and the CCR rule. With few exceptions, most states don’t appear to be moving toward adopting CCR guidance or overseeing CCR rule implementation. In order to reconcile the plant-specific environmental performance standards related to CCR management in the future, utilities must establish which regulatory driver has the most restrictive or “controlling” condition. This requires a careful side-by-side review of the applicable state regulations as compared to the CCR rule. As with any industry facing dual regulatory authorities over one operation, reconciliation is a tedious process. However, once the hybrid regulatory framework is established, the path toward compliance becomes much clearer.
Another foreseen challenge is: how will the industry and state regulatory authorities network to document CCR rule compliance elements and provide a smooth transition for operational changes; should state regulatory permitting be required for pond closure and new landfill permitting?
A primary example is the closure of an existing state-administered NPDES permitted ash impoundment. Regardless of CCR rule timelines and technical requirements, this facility is not recognized as “closed” until all state requirements are met. In many states, this process includes effectively transitioning the NPDES pond into the state solid waste program as a permitted, closed unit. There are no current scenarios where state permitting timelines line-up directly with the CCR rule milestones. In short, there is little indication state regulatory authorities are going to grant closure status based solely on EPA CCR rule closure requirements.
Another fundamental concern is that state agencies will not have the resources or plans to facilitate timely processing of the short-term surge in regulatory permitting activity triggered by the CCR rule. As referenced previously, to maintain compliance with the rule, a utility must post the specific CCR compliance documentation both publicly, and according to strict timelines. To date, there is no CCR Rule provision for reconciling state regulatory activity lead times with the defined CCR compliance schedule milestones.
In order to successfully close or open new CCR facilities, permitting strategies will require significant communication between the utilities and State regulatory authorities to ensure critical path planning elements are met.
The EPA appears to have recognized that the coal-fire industry cannot change operations overnight. Mandatory closures of both (1) unlined impoundments that exceed a groundwater protection standard and (2) units that fail to demonstrate compliance with a required location restriction standard, may be postponed and the units could continue operations for up to five years, or until alternative disposal capacity is available. Should the facility agree to cease its coal-fired boiler operations by a certain date, further deadline extensions are available. By providing adequate deadlines for operational compliance, the EPA allows for the considered design, development, and scheduling of various scenarios to maintain CCR rule compliance. However, failure to meet a structural factor of safety is a strict compliance hammer with a stated deadline and no available time extensions.
In the matter of CCR impoundments and landfills, existing state frameworks governing technical requirements and permitting processes vary widely. A “playbook” for the engineering design and operational requirements for these facilities does not exist. What is clear, however, is that the CCR rule and state regulations operate in parallel, meaning that industry activities should consider both sets of requirements as the industry moves forward.
At this point, there is no consensus on how the CCR rule will ultimately impact the coal-fired generation industry. Existing ponds that aren’t critical to plant operations will likely close. The number of remaining plants that will continue coal-fired operations under wet handling versus dry handling has yet to be determined. The remaining active pond operations will take one of the tracks previously outlined, which is driven by a multitude of plant-specific considerations. In other words, the only certainty is change.
Don Fuller is Stantec’s National Program Manager for coal combustion residual management services. In his role as CCR Program Manager, Don coordinates Stantec’s Water, Power, and Environmental Services Business Lines to provide full service solutions to the power sector.