Delaware Department of Natural Resources and Environmental Control Acting Secretary David S. Small has issued a Notice of Conciliation and Secretary’s Order to Delaware Solid Waste Authority and Ameresco Delaware Energy LLC for violations of Delaware laws and regulations governing the control of air pollution.


The Delaware Solid Waste Authority and Ameresco Delaware Energy LLC have 30 days to request a public hearing.


Delaware Department of Natural Resources and Environmental Control Acting Secretary David S. Small has issued a Notice of Conciliation and Secretary’s Order to Delaware Solid Waste Authority and Ameresco Delaware Energy LLC for violations of Delaware laws and regulations governing the control of air pollution.

The Order includes requirements for enhanced treatment of landfill gas, a payment of $60,000 for an environmental improvement project and $29,074 as cost recovery reimbursement to the Department for expenses associated with its investigation.

In 2005, DSWA/Ameresco requested a permit to construct a landfill gas recovery facility  at DSWA’s Southern Solid Waste Management Center in Georgetown, Del. One candlestick flare and four generators would be used to consume landfill gas and produce electric energy for sale to the power grid as opposed to flaring all of the landfill gas.

The generators are subject to Delaware’s regulation for stationary generator emissions (1144) including a 170 parts per million (ppm) total sulfur limit. However, the regulation allows for a case b case determination for alternative total sulfur limits and the department approved DSWA/Ameresco’s request for a 900 ppm limit.

Although a higher alternative limit was approved, DSWA/Amereso’s permit included a study followed by corrective actions to be implemented should the total sulfur content reach 200 ppm; a requirement to submit an application to install sulfur abatement equipment to reduce the sulfur content of the landfill gas if it reached 750 ppm; and a requirement to cease operation if the levels exceeded 900 ppm.

In addition, DSWA/Ameresco was required to conduct analyses of the hydrogen sulfide concentration of the landfill gas and submit a report to the department on a monthly basis.

Since issuance of the operating permit, the hydrogen sulfide concentration of the landfill gas has been consistently high, from 800 ppm to 1400 ppm. DSWA/Ameresco failed to adhere to numerous permit requirements including undertaking the corrective actions triggered by the high total sulfur levels and various testing and reporting requirements. The high sulfur content resulted in the exceedence of permitted sulfur oxides limits.

Under the conciliation order, DSWA/Ameresco will undertake actions to achieve compliance including using the hydrogen sulfide pretreatment system to treat all gas collected and sent to the Ameresco generators and flare located in Georgetown to prescribed levels; using the DSWA flare only as a backup flare; and documenting every instance the DSWA flare is used.

The environmental improvement project funding will be used by the Delaware Center for Horticulture for enhancement projects such as a proposed project for a tree planting in the 12th Street area from the railroad bridge to Railcar Avenue in Wilmington near DSWA’s Cherry island Landfill.

The Delaware Solid Waste Authority and Ameresco Delaware Energy LLC have 30 days to request a public hearing.