Home > News > Archive > News Item
RI Department of Environmental Management
DEM APPROVES PERMIT FOR PROPOSED RELIANT ENERGY FACILITY
PROVIDENCE - The Department of Environmental Management has issued a permit to Reliant Energy Hope, L.P. for an electric power generating facility in Johnston. The new facility will use the cleanest fuel available - natural gas - and state-of-the-art equipment to generate power and control air pollution. The application was approved under DEM's strict air pollution control regulations, which require offsets of emissions and a net benefit to the region's air quality. The decision comes after a public hearing on the draft permit held in February, a 30-day public comment period, and evaluation by DEM of the comments it received.
Reliant is the fifth plant of its type in Rhode Island for which DEM has issued a permit. Other facilities include Ocean State Power in Burrillville, Pawtucket Power, the Manchester Street Station in Providence, and Tiverton Power, which is nearing completion. The proposed 540-megawatt Reliant plant would be similar in size to the Ocean State Power and Manchester Street Station facilities.
"DEM reviewed this application very carefully," said DEM Director Jan H. Reitsma. "We wanted to conduct a thorough analysis of the potential impacts from the proposed plant, given its location near the Central Landfill and other waste management facilities in the Johnston area. We paid particular attention to the public's concern that this proposed power plant could exacerbate air quality problems the community has been experiencing. Based on our evaluation of the proposed design, and with the stringent limits this permit imposes, we believe the new facility will not cause or contribute to any additional air quality problems."
DEM's evaluation of Reliant's permit request took into consideration the full range of potential air quality concerns - air toxics, odors, ozone precursers and the use of treated effluent from the Cranston wastewater treatment facility for the cooling system. The burning of natural gas does not produce air toxics, but DEM did evaluate concerns some commenters expressed about the possible presence of toxic chemicals in treated effluent. The Department modeled potential emissions from the cooling system and found they would not exceed any air quality standard.
With respect to odors, DEM generally does not expect natural gas fired power plants to be a source of odors. Three plants similar to the one proposed by Reliant have been operating in Rhode Island since the early 1990s, and there is no history of odor problems related to these facilities. DEM nonetheless reviewed the specific details of Reliant's application to evaluate the potential for odors and determined that this facility should not be a source of odors.
With respect to nitrogen oxide (NOx) emissions, the final permit sets an emission limitation for NOx at 2.0 parts per million (ppm), a reduction from 2.5 ppm included in the draft permit. The Department conducted modeling of combined emissions from the proposed plant and other sources in the region. The results indicate that the facility will not cause or contribute any exceedance of the air quality standard. In addition, the permit includes limitations on NOx emissions from a glass plant in Dayville, CT, as a 120% offset for the emissions from the Reliant facility, which amounts to a regional net benefit for air quality. It is DEM's policy and practice to reduce NOx emissions to the greatest extent possible. NOx emissions contribute to the formation of ground-level ozone. High ozone concentrations can cause irritation of the eyes, nose and throat, coughing, chest pain, shortness of breath, headache and fatigue.
A number of residents were specifically concerned about potential impacts from the facility's cooling tower, because of the proposed use of effluent from the Cranston wastewater treatment plant. The use of treated effluent for cooling water is a technique that is commonly employed throughout the country, and is often preferred over the use of drinking water or withdrawals from streams or aquifers. The permit includes conditions used in other states to minimize air pollution impacts. The effluent will be treated with liquid sodium hypochlorite before it can be reused, and a residual level of chlorine will be maintained in the wastewater to maximize the effectiveness of disinfection. The effluent will be chlorinated primarily at the Cranston facility and piped directly to the Reliant facility in Johnston. The additional treatment is intended to kill any bacteria, spores and viruses. To the extent the emissions might contain byproducts from chlorination, modeling results indicates they will be below the applicable air quality standards. The permit does, however, call for monitoring of emissions from the cooling tower for at least one year. Another concerns, that moisture from the cooling tower will exacerbate problems at nearby solid waste facilities, is being addressed with high efficiency drift eliminators that will minimize the amount of moisture that is discharged into the air.