CIB committee looks at fly ash, wastewater treatment options
The Science and Technical Advisory Committee (STAC) of the Delaware Center for Inland Bays met on Friday, Dec. 5, in Lewes. The committee and members of the public heard from Scott Andres of the Delaware Geological Survey; David Goss, executive director of the American Coal Ash Association (ACAA); and the Delaware Department of Natural Resources and Environmental Control’s Ron Graber.
One of the subjects last Friday was coal fly ash – the waste product of coal-fired power plants, such as the Indian River Power Plant, and a major concern as a source of pollution for the inland bays.
Discussion of the topic was aimed to inform STAC members and the public about the issues related to storage and disposal of coal fly ash, in the wake of the controversial decision in September by state natural resources officials to approve expansion of the IR power plant’s coal ash storage next to the power plant and over clean-up of the existing storage sites there.
Executive Director of the American Coal Ash Association David Gross spoke about the possibility of either selling or giving away coal combustion products, or fly ash, created by the coal-fired power plants in the area.
The CCPs, he said, can be used in everything from Portland cement and wallboard manufacturing to green roofs and countertops. He mentioned that LEED and other “green” building councils award points for CCPs’ use in construction projects.
According to the Center for Inland Bays, this is a local issue of great significance.
“The management and reuse of coal combustion products is an important issue for the Inland Bays watershed. Three fly ash landfills have been permitted in sensitive areas around Indian River Bay, and one of the three, the Burtons Island landfill, appears to be contaminating sediments nearby.”
According to Gross, the mission of the ACAA is to advance the management and use of coal combustion products in ways that are environmentally responsible, technically sound, commercially competitive and more supportive of a sustainable global community. Members include coal-fired power utilities, non-utility CCP producers, marketing firms and other organizations worldwide, as well as individuals with commercial, academic and research interests.
He said that with each ton of fly ash used instead of Portland cement, release of one ton of CO2 can be avoided or postponed. He stressed that fly ash is non-hazardous, locally available and economical.
“When properly managed and engineered, CCPs do not have a negative impact on public health or the environment,” said Gross. “However, it has to be looked at on a case by case basis. The potential for leeching needs to be mitigated, the climatology, geology and water sources among other factors need to be looked at. Local, state, and federal regulations may apply as well as engineering standards. What works in Colorado might not work in Delaware.”
The fly ash has to have a low concentration of carbon to be viable for sale. Gross did mention that some plants give away their fly ash that has too high a carbon content to sell and that others subsidize companies removing their fly ash which is still a savings over land-filling it.
Other types of pollutants that can endanger the inland bays were also up for discussion on Dec. 5.
In his presentation, “There’s Wastewater in the Geology,” Andres gave a technical overview of how rapid infiltration basins, or RIBs, work to manage wastewater.
He said centralized wastewater treatment and disposal systems offer more control over output of pollutants, have many complex interrelated issues and are often a long-term source of revenue for the government. Private wastewater utilities, on the other hand, he said, have the ability to be bought and sold as a private commodity, and some of the infrastructure costs shift from the public to private sector.
RIBs are of special interest in this area, because they need less space than other wastewater treatment systems. They are high-loading, so they have smaller land requirements. Because land prices got so high in the past decade, developers started to look at different ways to manage wastewater, including RIBs
Andres said there are many misconceptions about RIBs and they are not to be looked at as being without risks. He said treated sewage can seep into the ground at high rates. He also said that, with their research, DGS learned that other states have adapted engineering regulations and policy, and he said Delaware needs to look into specific public and environmental issues that pertain to this area.
Because hydraulic failure can occur – a common but avoidable situation where the RIB is already dysfunctional before it meets its capacity – Andres said much research and planning is needed before Delaware adopts any type of regulation regarding the systems.
“A low-risk design will take extensive work, but a no-risk design is impossible,” he said.
Andres was asked if RIBs didn’t seem like they had the potential to be worse than septic systems for the inland bays and its watershed and also if a moratorium might be a good idea while more research was done.
“There is that potential,” he said of them being worse then individual septic systems. He also emphasized that he was pointing out the faults and risks of RIBs to show that careful research and regulations would be needed if Delaware wanted to entertain the idea of them on a large scale. He said that Kent County did put a moratorium on them, but in Sussex it was always about “property rights, property rights.”
Ron Graber of DNREC spoke about what Delaware has currently in terms of RIB guidelines. He said that, starting in 2003, DNREC started to see a big interest in them because land prices had gotten so high. He said the department started a process to revise the regulations and as a “stop-gap measure during the interim,” they have guidelines they have developed.
“Because of our shallow water table, all wastewater systems have to meet drinking-water standards. Also, they have to be disinfected of pathogens, and we require a very detailed soil/hydrological report. It would be premature to recommend a ban on RIBs,” said Graber.
He also said that the guidelines would be further extended, but, for now, they have the guidelines to go by and they are backed by existing regulations.
“We are not asking simply people to abide by the guidelines — they are backed by current regulations,” he emphasized. He noted that the limit of total nitrogen levels allowable were 5 miligrams per liter, but as for phosphorous, no regulations beyond monitoring exist.
For more information on using fly ash in road construction projects, visit www.greenhighways.org. For more information on the American Coal Ash Association, visit www.acaa-usa.org. For more information on the center for the Inland Bays, or to view the presentations from the Dec. 5 STAC meeting in full, visit www.inlandbays.org.