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Power Generation and the Environment

EPA's New Haven accountability project helps community strike a balance.

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It's not often that power companies, residents, and environmental groups can all agree to build new power turbines and an exhaust stack. With the support of EPA research and data, the City of New Haven, Connecticut and community groups worked with the power company Public Service Enterprise Group (PSEG) Exit EPA Disclaimer to develop a plan to offset the emissions from PSEG's new turbines and exhaust stack.

Natural gas-powered turbines, called peaker plants, are meant to help meet energy demands during peak hours. However, building gas-powered peaker plants also means an increase in air pollution—particularly in nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter (PM), which can damage the heart and lungs.

EPA researchers developed an air model of New Haven that estimated air pollution out to 2030 and presented it to city officials and residents. The model showed several air pollution "hotspots," one of which was the location of the proposed peaker plants.

Based on this information, the City of New Haven opposed the plan "unless [PSEG] found a way to ensure that [the peaker plants] would result in no net emissions," says Robert Smuts, Chief Administrative Officer for the city. This meant that the cumulative emissions (total amount of pollution) and acute emissions (emissions at specific times such as peak hours) should be no higher than current levels throughout the city.

To meet the city's wish for no new net emissions, PSEG made modifications to their existing plants to help offset the emissions of NOx and SOx from the new turbines and stack. While this action effectively controlled NOx and SOx emissions, the modifications did not offset PM emissions.

Using EPA air quality and exposure models, local environmental groups, the Environmental Justice Network, neighborhoods, city officials, and PSEG formed a stakeholder group to collaboratively find alternative methods to reduce PM emissions. PSEG provided $500,000 to support the effort.

The stakeholder group used EPA's air quality model AERMOD, which predicts pollutant concentrations from stationary and mobile sources, and the Agency's Community Multi-scale Air Quality (CMAQ) Modeling System, which predicts regional background concentrations in the study area.

Information map of the United States.

Image from EPA's CMAQ program.

The group also used exposure models, including EPA's Stochastic Human Exposure and Dose Simulation model for Air Toxics (SHEDS-Air Toxics), to estimate the human exposure from breathing in the pollutant.

To meet the necessary reductions in PM emissions, the stakeholders group formed a three-part plan:

  1. Retrofit diesel garbage trucks in the area to reduce PM exposures in neighborhoods at the ground level where humans have the most contact with the pollutant.
  2. Add filters to equipment in the port such as cranes and bulldozers to offset PM from the ships coming into the city.
  3. Install power outlets for boats docked in the port as an alternative to using their diesel generators.

According to New Haven's Robert Smuts, all groups supported the three-part plan, and the collaboration and cooperation across groups allowed New Haven and PSEG to "overcome the negative thoughts about putting in new turbines and exhaust stack." Smuts stressed that an agreement was possible due to the company's efforts, the credibility of the EPA data, and trustworthiness of the city officials.

The interactions between PSEG, the city of New Haven, and community groups provide an ideal example of effective collaboration and negotiating that resulted in new construction to meet energy demands with no net increases in emissions. New Haven's efforts to work with the power company now serve as best practice examples for other cities in Connecticut and across the nation.

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