Successful Coal Ash Pond Management

About the Authors

Mark Johnson, P.G., is a Senior Client Services Manager at TRC. He has 25 years of experience in environmental assessment and remediation.

Kent Nilsson, P.E., is a Senior Engineer at TRC. He has 29 years of experience in geotechnical and environmental engineering with a focus on landfill waste and innovative design.

Coal ash storage ponds would be excavated and closed under new rules from the Environmental Protection Agency. While the EPA has confirmed it will finalize coal ash rules by Dec 19, 2014, it is not clear what those rules will look like. Many questions remain. Successful Photo courtesy: TRC Companies Inc. is advantageous to know and anticipate environmental issues upfront to avoid Coal Ash Pond expensive backtracking and delays. It’s a bit early to know the true im- pact of recent regulatory activity related Management to this issue because much rides on the final rule outcomes for Effluent Limita- BY MARK JOHNSON AND KENT NILSSON, TRC COMPANIES INC. tion Guidelines (ELG) and Coal Com- egulatory requirements, uncertainties. Success requires careful bustion Residuals (CCR), which are not plant retirements, chang- attention to upfront analysis and stra- expected until late 2014. If the regulato- es to facility operational tegic decision making as well as proper ry requirements are what we expect, the profiles, environmental implementation and sequencing of all decision to close ponds may be straight liability management the regulatory, contractual, land use, forward. What may be controversial, andR political and social pressures are and community issues contained in the however, will be how to close the ash among the factors driving utilities to selected solution(s). Facilities will need ponds. Some facilities may want to close or consider closing their coal ash to plan their activities to take into ac- close in‐place, which may be more cost‐ ponds. The process can be time‐in- count operational changes, regulatory effective than other solutions, but these tensive and costly ‐‐ and fraught with impacts and long term land use issues. It facilities may face external pressures from social and political groups to re- regulatory changes while working con- selected strategy and schedule will be move the materials. If a plant is in an currently within facility operations or dictated in part by regulatory require- environmentally sensitive area, owners retirement plans. Successful coal ash ments and timing, future site use (re- should proceed with caution and plan facility closure strategies map out in tirement versus continued operations), for different scenarios. advance the regulatory, financial, so- and site‐specific characteristics. It will cial, political and environmental im- be necessary, at a minimum, to keep RETIRING V. pacts and address future uses. National Pollutant Discharge Elimina- OPERATING PLANTS Data gathering is essential to meeting tion Systems (NPDES) permits in place The process and closure options for schedule requirements and budgeting until facility changes and ash pond clo- ponds will vary based on whether a fa- properly for closure expenditures. One sures are complete. Additionally, design cility will be retired or continue to oper- key strategy component will be to keep and construction specifications and bid ate. Retiring plants will need to clearly abreast of the CCR packages will need define the property end use up front as rule and its ap- “If a plant is in an to be prepared early different pond closure solutions may plicability to your environmentally in anticipation of be required dependent on future site plants/ash ponds, sensitive area, owners meeting deadlines. use. For example, high value properties and evaluate and Owners will also in prime locations for commercial or integrate the po- should proceed with need to ascertain residential redevelopment may require tential benefits of caution and plan for what regulatory ap- stricter clean up and maintenance than plant retirement or different scenarios.” provals are neces- retired sites with little or no redevelop- closing ash ponds sary and factor these ment potential or sites that will con- sooner rather than - TRC into their schedules. tinue to support energy infrastructure. later. In many cases, this may not be Questions to ask at this stage of clo- Site specific conditions and operational feasible due to operational constraints sure planning include: Will the closure outlooks will initially drive and dictate or pond size. In the absence of federal remain in‐place or will dewatered ash the closure strategies. rules, owners/operators will need to be removed; is there a viable market look to state agencies for guidance. for the ponded material and what are STRATEGY Once the decision is made to close the economic constraints; what are the Although regulations are still in flux, ash ponds, a number of factors need long‐term obligations and environ- it’s not too early to plan a course of ac- to be evaluated to determine the best mental liabilities and can and should tion. It is important to develop a proj- and most cost‐efficient closure strategy these be addressed as part of the clo- ect management plan that anticipates to meet schedule requirements. The sure plan; what is the future land use; is the pond’s footprint needed for future operational needs; is there useable borrow material on‐site or will it need to be purchased; are the ponds located within an environmentally sensitive area; are there siting or constructabil- ity constraints for an on‐site landfill or a new, lined ash pond; what are the staffing demands; what are the outside resources needed, will they be avail- able and what do they cost; and im- portantly, what is the price tag for all of the various options and schedules? Part and parcel of a well‐planned pond closure is the quality and detail

The Environmental Protection Agency is expected to release a final rule for handling coal combustion residuals later this year. of the schedule. • Will all coal ash regardless of use construction engineering. Though Coordination and timing of the var- or disposal require more toxicity quite obvious, the collection and eval- ied steps requires close attention, skill testing and pose a greater virtual uation of data is one of the first and and some pliability. You don’t want liability risk to utilities? most important steps for successful to employ a work schedule that is so • Will there be limitations on ben- closure and compliance. rigid that it will hamper closure should eficial reuse? The evaluation of potential environ- a proverbial “monkey wrench” get • Will these materials be so stigma- mental liabilities associated with the thrown into the mix. Creating a sched- tized that builders will not accept it? historical pond use is critical. Due to ule that anticipates complications and • Will financial assurance be required? their age, some ash ponds were con- provides alternative glide paths will re- • Is the time for closure sufficient to structed without regulatory oversight, duce cost and delays. address CCR units? liners, leachate collection and control, Customization is also pertinent to While we await the answers, facil- or they may be located in environmen- the plan. What works for one facility ity owners must plan for the different tally sensitive areas (e.g. adjacent to may not work for the next. scenarios. surface water bodies). A good closure strategy will be site‐ It is important to define closure op- If not already done, a groundwater and pond‐specific. If the plant is go- tions early on, including the potential assessment will likely be necessary to ing to be retired, when it will be re- beneficial reuse of pond materials, ascertain whether environmental im- tired is a key early decision. For those which is getting increased attention. pacts exist. The need and timing of facilities continuing to operate, neces- In some cases, traditional in‐place clo- additional investigations (such as sedi- sary decisions include whether ponds sure plans are being publically chal- ment, soil and surface water) should are to be closed, cleaned out and used lenged and facilities are implementing be evaluated on a case‐by‐case basis for other wastewater streams, or con- alternate solutions, including ben- and guided by regulatory require- verted into landfills. eficial reuse, potentially lengthening ments (federal and/or state) and future Other planning factors include their closure process and increasing site use. thoughtful consideration of the envi- the cost. At a minimum, a groundwater in- ronmental setting, potential impacts, It is prudent to evaluate and incor- vestigation plan should take into con- the future use, remaining life and the porate potential beneficial reuse strat- sideration the point of compliance ELG strategy. egies (as well as other alternatives) determination issues (locations and upfront to avoid delay and budget potential aggregation of the ponds as REGULATORY PLANNING overruns, especially for those facilities a single unit), constituents of potential AND BENEFICIAL REUSE that may be within environmentally concern, well placement and construc- Different regulatory frameworks im- sensitive areas. tion (including potential use of wells pact closure planning and implemen- Constructing cost‐benefit analyses for post‐closure monitoring activities), tation. Understanding the federal and and return on investment scenarios sampling protocol, quality assurance/ state specific requirements is crucial, per site‐specific factors and timelines, quality control measures, statistical and the potential beneficial reuse of and vigilantly tracking state and fed- protocol, and determination of back- coal ash byproducts is an important eral activities that will affect ash pond ground conditions. part of the overall evaluation. Suc- decisions will be critical for successful Care should be taken when determin- cessful closures integrate designs with closure planning. ing groundwater background conditions regulatory obligations, permitting con- because pond hydrology may influence straints, beneficial reuse opportunities, ENVIRONMENTAL or mask true background. Groundwater and construction considerations. INVESTIGATION AND flow models may need to be constructed While the EPA has recently con- RISK ASSESSMENT to determine groundwater flow rate and firmed it will finalize coal ash rules Coal ash facility closure plans must concentration gradients. by Dec. 19, 2014, it is not clear what assess and address potential risks and Finally, if any environmental im- those rules will be. While the current liabilities as well as future area use. pacts are identified, a risk assessment general consensus is that EPA is lean- This requires a host of specialized is necessary to identify not only po- ing toward a Subtitle D determination planning skills including geotechni- tential receptors but also the potential for CCR’s, many questions remain: cal evaluation, environmental assess- for adverse risk. This risk evaluation • Will coal ash be classified as a ment, landfill and pond closure de- should also include background deter- hazardous waste or a solid waste? sign, environmental permitting, and mination and consideration. Coal-fired power plants in the U.S. will be forced to close their coal-ash surface impoundments under new rules from the Environmental Protection Agency.

Data to support the proposed closure options and alternatives, as well as data to support potential remedial alternatives for impacted media (e.g. groundwater) should be collected in conjunction with the environmental investigation, especially if a remedial design will be incorporated into the overall closure plan.

POND CLOSURE Closure and remediation solutions vary greatly from facility to facility. Op- tions are plentiful and include capping, schedules and increasing costs. are more structurally robust, requiring dewatering and/or stabilizing, consoli- Hauling ash materials for off‐site stabilization/removal of ash solids, a dating into a new landfill, disposing disposal or importing fill materials reinforced cover, or other accommoda- off‐site, converting to wetlands, benefi- from off‐site sources for inplace clo- tions beyond a typical closure. cial reuse, or a combination of these. sure must also be a consideration in At the completion of closure, final The ash pond closure design (closure a suburban area. Heavy truck traffic documentation should include regu- plan) and construction will require may be more limited. latory approval, close‐out of permits, close coordination with ongoing facil- For such a condition, an in‐place clo- and development and approval of ity operations, especially if it is at an sure may be better suited than a “clean a long‐term monitoring and main- operating plant. closure” with its removal of all pond sol- tenance plan (PostClosure Plan), to Trade‐offs and ids, since total haul include cap maintenance, long term competing priori- “Groundwater flow volumes (and cor- groundwater monitoring, and remedi- ties create complex- models may need responding truck ation system operation, as warranted. ities for even a sim- traffic) would like- ple pond closure. to be constructed ly be less. PREPARE NOW Closures near to determine Real estate val- As industry awaits for the final ELG residences for ex- groundwater flow rate ues for property and CCR regulations, closure activities ample are more occupied by a pond can commence. likely to have re- and concentration in a suburban loca- Planning for different outcomes, stricted site access gradients.” tion may be higher while they may seem like an extra step, imposed by fenc- - TRC than the value of is prudent. es, utilities, and pond property in a Gathering data to understand the adjacent structures than closures in a rural setting. An operating plant at a sub- complexity of the environmental condi- non‐populated area. This may constrain urban site may be property constrained, tions and inform the solution‐making the type and size of construction equip- and the facility could potentially use process is undeniably the first order of ment that can safely operate. Operating a closed pond area for vehicle parking, business. With sound, strategic guidance and working hours may also be limited plant expansion, material staging, etc. based in research and the willingness to when closing a pond in a suburban These considerations may drive the be flexible, long‐term success in coal ash area due to noise impacts, extending final closure toward conditions that pond closures is within reach.