CDM worked with the Greater Lawrence Sanitary District (GLSD) to develop state-of-the-art, environmentally friendly biosolids management facilities to process sludge from its 52-million-gallons-per-day (mgd) wastewater treatment facility. The innovative system incorporates beneficial use technologies, a unique energy recovery system—one of the first of its kind in the U.S.—and system-wide odor controls.
GLSD's biosolids undergo sufficient treatment to meet the U.S. EPA Class A standards, and because processed biosolids are considered exceptional quality, they can be sold as a soil amendment for agricultural and horticultural operations, or to the general public. The unique energy sharing between digestion and drying systems—recovered digester gas provides the primary fuel for the thermal process, and waste heat from dryer condensers aids anaerobic digestion—reduces auxiliary fuel costs by up to $600,000 per year. Also, hybrid project delivery, combining design-build-operate and traditional methods, enabled GLSD to save substantial capital investment costs.
CLIENT: Greater Lawrence Sanitary District
LOCATION: Lawrence, Massachusetts