Steven T. Moon
Rogers Townsend & Thomas, PC, Columbia

On May 4, 2010, the Environmental Protection Agency issued a proposed rule (RIN-2050-AE81) designed to regulate coal combustion products (CCP), including fly ash, bottom ash, slag, flue gas desulfurization or other products. This is the first time EPA has proposed regulations of CCPs. Many of these products have safe and beneficial uses and have long been components of building products specifically including road paving materials in South Carolina and other jurisdictions.

Coal combustion products are the result of burning coal (usually pulverized) in the electric generation industry. The CCP can have concentrations of certain constituent metals, which are listed in the EPA proposals. Detection monitoring of the CCP is required under the new EPA proposals for boron, chloride, fluoride, sulphate and sulfide. Additionally, under the proposals, the CCP would need to be monitored for conductivity, pH and total dissolved solids. Beyond that, the CCP must be assessed for aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, copper, iron, lead, manganese, mercury, molybdenum, selenium and thallium in addition to the previously listed metals under detection monitoring. The concern of the EPA is that under certain situations and conditions, the CCP can leach these elements of concern into the environment, particularly the groundwater or surface water, and that this will have a polluting effect on the nearby locations.

While the EPA proposal totals more than 560 pages, one of the principal issues on the beneficial use of CCP can be divided into two categories: encapsulated and unencapsulated. To simplify, the new EPA proposal would seem to allow for CCP use where the end product is some type of a concrete or similarly hardened material. Any other use, such as large construction fill or similar matter, would not be allowed under the two alternative regulatory schemes proposed.

For many years State Department of Transportation offices have allowed, within some wide variations, the use of CCP in materials for state jobs. South Carolina has its own set of standards, which includes use of slag or fly ash in cement construction projects (see, SCDOT Qualified Product Listing 3). Like many other states, the South Carolina standards follow or refer to either the AASHTO standards or the ASTM standards. Most of the state designed standards are what might be considered "prescriptive" standards, which is to say there is a design mix of proportions that would meet the allowable usage standards. The standards for the SCDOT, found in the SCDOT 2007 Standard Specifications for Highway Construction, are prescriptive standards. Although these standards do not use the CCP designation, the standards do refer to fly ash and slag in various places, including Section 501, Concrete Pavement and Section 701, Structures. These standards detail the use of the CCP and the quantity that can be used in the construction project. The use is in terms of weight (number of pounds per unit) and do not address the structural specifics of the use of CCP. There are a number of research studies that show increased durability and workability of concrete products with increased amounts of the proper mix of CCP. Generally, the industry would prefer that there be "performance" standards such that the value and addition of the CCP are more readily apparent and would likely result in a combination of a more economical product, an environmentally beneficial product, a more durable product and a qualitative foundation for the use of the product. The composition and constituents of the CCP will vary depending on the nature of the coal burned and the burning process itself.

It seems the EPA proposals will permit the continued use of CCP in state projects. The deeper issue might become whether the state needs to re-visit its requirements to determine a performance standard for use of CCP and move beyond the prescriptive standard which is based solely upon a formula for a design mix.