Significance and Use
4.1 Purpose—This guide provides a process for reclamation of existing CCPs placed in active and inactive storage areas. The guide includes information on the following activities required for the safe and effective reclamation of CCPs from storage areas: (1) Background Review of CCP Storage Areas; (2) Detailed Characterization of CCP Storage Areas; (3) Harvesting Planning and Scoping of CCP Storage Areas; (4) Harvesting Detailed Design and Approval of CCP Storage Areas; and (5) Harvesting Implementation of CCP Storage Areas. More detailed descriptions of these activities are in Sections through .
4.2 Potential Beneficial Uses of CCPs—There are many CCP storage areas that are potentially harvestable and can provide a functional benefit in a wide variety of beneficial uses. The beneficial use of CCPs contained in these storage areas can have significant environmental and economic benefits for the facility, the facility owner and the local economy, and can significantly reduce disposal operations (. ) Beneficial use of CCPs can provide industry with a safe and responsible way to economically manage the CCPs, while promoting conservation and recycling/reuse, meeting sustainability goals, and addressing the shortage of CCPs in some building product market areas (. , , )CCPs consist of fly ash, bottom ash, boiler slag, fluidized-bed combustion (FBC) ash, economizer ash, and flue gas desulfurization (FGD) material (see Terminology for definitions of CCPs) (. , )
4.2.1 Fly ash is the most abundant CCP in existing storage areas. Its beneficial uses include, but are not limited to: partial replacement for cement in concrete and concrete products – once in concrete, fly ash reacts with Portland cement to create additional reaction products that improve the strength and durability of concrete; raw feed for the production clinker – fly ash can be calcined along with other minerals to produce clinker; blended cements – fly ash can be an important component in the production of blended cement, especially when pozzolanic properties are desired; filler in plastics – fly ash typically increases the stiffness and compressive strength when used as a filler in plastics; controlled low strength materials (CLSM) – CLSM that include fly ash, typically have improved flowability and strength as well as reduced bleeding and shrinkage; as a soil stabilization material; as an aggregate/soil replacement construction material in structural fill and mine reclamation projects; fillers in carpet backing – fly ash is high performance mineral filler; and as a solidification agent within landfills and remediation projects (. )
4.2.2 Bottom ash can be beneficially used as raw feed for the production of clinker, as a component of structural fills, and as aggregate in the manufacturing of masonry products (. , , )
4.2.3 Boiler slag can be used as blasting grits and roofing granules. Other applications include, but are not limited to, as a component of structural fills and mineral filler in asphalt (. , )
4.2.4 Fluidized-bed combustion (FBC) ash can be utilized in various mixtures as a low strength concrete material and soil stabilization agent (. )
4.2.5 Flue gas desulfurization (FGD) gypsum, in its majority, is typically beneficially used in gypsum panel products. Other uses include in agricultural applications to improve soil, as a component in structural fills, and as an important component in the production of cement (. , , )
4.3 Approval Context—This guide does not supersede local, state or country requirements, if applicable. This guide is intended to be used for storage areas that are both within an approval authority program and historic (or unpermitted) storage areas.
4.3.1 For harvesting of CCPs from storage areas within an approval authority program, governing documents should be carefully reviewed and followed to ensure that all requirements relative to design, operations, monitoring, closure, and post-closure are followed, or that agreements are established to ensure compliance and allow for harvesting activities.
4.3.2 For harvesting of CCPs from historic (or unpermitted) storage areas, the project team should engage with the appropriate local, state, province, or country approval, or combination thereof, authorities to determine the appropriate requirements, and should ensure that the appropriate engineering controls and institutional controls are incorporated into the harvesting project.
4.4 Use of Guide—Approval authorities may incorporate this guide, in whole or in part, into general guidance documents or site-specific approval documents.
4.5 Professional Judgment—This guide presumes the active involvement of an environmental professional who is knowledgeable in how to design and construct storage areas and how to identify acceptable site conditions, or when appropriate, satisfy applicable statutory or approval authority limitations on the use of an operating, closed, or historic (unpermitted) storage area.
4.6 Inherent Uncertainty—Professional judgment, interpretation, and some uncertainty are inherent in the processes described herein even when decisions are based upon objective scientific principles and accepted industry practices.
1.1 This guide provides a framework to address critical aspects related to the harvesting of CCPs placed in active (operational) and inactive (closed or no longer receiving CCPs) storage areas. These storage areas may be used for wet or dry material, and may be located at active or inactive facilities (that is, coal-fired electric utilities or independent power producers that are currently generating electricity or have ceased to do so, respectively). Also, CCPs may be harvested from active or inactive storage areas located on-site or off-site of the facility.
1.2 This guide does not include information on how to determine what storage areas or facilities, or both should be selected for potential harvesting of CCPs, as each entity may approach a harvesting program in accordance with their own harvesting pursuits and regulatory requirements. In addition, it does not include information on how an energy company or other interested parties should evaluate inventories to determine the order of their storage areas for potential harvesting, including consideration of risk, performance and cost. This guide is intended to be used to evaluate the potential harvesting of the storage areas once the storage areas are selected for evaluation.
1.3 This guide is comprised of the following sections: Scope, Section ; Referenced Documents, Section ; Terminology, Section ; Significance and Use, Section ; Project Planning and Scoping, Section : Background Review of CCP Storage Areas, Section ; Detailed Characterization of CCP Storage Areas, Section ; Harvesting Planning and Scoping of CCP Storage Areas, Section ; Harvesting Detailed Design and Approval (as applicable) of CCP Storage Areas, Section ; and Harvesting Implementation of CCP Storage Areas, Section . Not all information within this guide will be necessary for each harvesting project, and the user should determine the applicability of each section.
1.3.1 Section , Scope, includes information related to contents of this guide, as well as what is not included in this guide.
1.3.2 Section , Referenced Documents, includes published documents referenced within this guide.
1.3.3 Section , Terminology, includes definitions for terms as they relate to this guide.
1.3.4 Section , Significance and Use, describes the beneficial use of CCPs stored within active and inactive storage areas, including each CCP potential beneficial use; the context of the guide and its use; the professional judgment that is appropriate for use of the guide; and the inherent uncertainty with the processes described within the guide.
1.3.5 Section , Project Planning and Scoping, describes the steps needed prior to implementing this guide, including: establishing a project team; determining what storage areas within the facility should be evaluated for potential harvesting of CCPs; determining the potential materials to be harvested; compiling existing land use, environmental compliance, geologic/hydrogeologic, topographic, design and construction information; estimating potential project costs and project schedule with contingencies (if feasible); and identifying factors that may impact the ability to harvest the CCPs.
1.3.6 Section , Site Background Review of CCP Storage Areas, describes the steps for evaluating the attributes of storage areas at the facility relative to harvesting CCPs.
1.3.7 Section , Detailed Characterization of CCP Storage Areas, describes the steps for developing and implementing the CCP characterization sampling and analysis plan that will evaluate the chemical and physical characteristics of the CCPs within the storage areas, and determining if amendments to the CCPs will be needed for beneficial use.
1.3.8 Section , Harvesting Planning and Scoping of CCP Storage Areas, describes the steps necessary to evaluate the approval status of the storage areas and develop a conceptual harvesting strategy and approval approach for the project. Considerations are given for both active and inactive storage areas.
1.3.9 Section , Harvesting Detailed Design and Approval (as applicable) of CCP Storage Areas, describes the steps needed to prepare the detailed design and approval documents (as applicable) for the CCP storage area harvesting and receive the appropriate approval (as applicable).
1.3.10 Section , Harvesting Implementation of CCP Storage Areas, describes the steps needed to implement the storage area harvesting plans from installation of the appropriate pre-harvesting components and harvesting the CCPs in accordance with the approval requirements, to completing the post-harvesting monitoring and inspections.
1.3.11 Sections through provide the five phases (Phase I through V) of the harvesting process that follow once storage areas are selected for harvesting evaluation. Information related to Phase I through V is located on Table 1.
1.4 This guide does not include information on the processing of harvested CCPs, and therefore, additional approvals not discussed within this guide may be needed (for example, residual waste processing approvals, air approvals specific to processing, water control approvals, storage system approvals, etc.).
1.5 As CCPs are produced, they may be sent off-site directly to beneficial use applications, such as concrete, wallboard and controlled or structural fills, while the alternative is to direct them to dry or wet storage areas. Although many CCPs were placed in storage due to not meeting applicable specifications for use, many other CCPs were stored for lack of market. In either case, the CCPs retain the ability to be considered a wanted material that provides a functional benefit and a benefit to the environment. They can be harvested and lightly processed, if necessary, to meet relevant product specifications and substitute for the raw materials. Depending on the type and homogeneity of CCPs and the type of storage area from which the materials are being harvested (that is, dry or wet storage areas), this harvesting and processing may include, but is not limited to, excavating or dewatering/dredging, drying, milling, classifying and storing or transporting the material before they are beneficially used.
1.6 The CCPs that may be harvested include: fly ash, bottom ash and economizer ash generated by powdered carbon boilers; boiler slag; flue gas desulfurization material; fluidized-bed combustion products as defined in Terminology ; cenospheres; or other materials suitable for beneficial use.
1.7 Laws and approval requirements governing the use of CCPs vary by locality, state and country and generally do not yet include provisions for CCP harvesting as described herein. The user of this guide is responsible for determining and complying with the applicable approval requirements, which may extend beyond harvesting to include approval requirements or guidance on issues such as storage, transportation, end use and other concepts. This guide complements approval programs where guidance on harvesting is unavailable or insufficient, thereby improving the chance that such storage areas may be repurposed for public or private benefit, or both. It is important to engage and educate the approval authority early and often throughout the planning, design and implementation of the harvesting activities. The project team may also consider affording an opportunity to solicit input from other stakeholders.
1.8 This guide should not be used as a justification to avoid, minimize or delay implementation of specific management, operation, closure, or remediation activities, or both as appropriate by law or directive, unless the harvesting activities are conducted in conjunction with such strategies to maintain or achieve compliance with the approval requirements or as otherwise agreed upon with the appropriate authorizing agencies.
1.9 This guide should not be used to characterize (that is, environmentally assess) a storage area for ownership transfer although portions of such information may supplement other environmental assessments that are used in such a transfer.
1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.11 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.