Little Patuxent Water Reclamation Plant Biosolids Addition
Award of Merit
OWNER: Howard County
LEAD DESIGN FIRM, CIVIL, STRUCTURAL AND MEP ENGINEERS: HDR
GENERAL CONTRACTOR: Clark Construction Group
ELECTRICAL ENGINEER: Shah & Associates
SITE DEVELOPMENT: Gutschick, Little and Weber PA
SUBCONTRACTORS: Clark Water (Site Civil, Process Mechanical, Miscellaneous Metals); Singleton Electric; Bowen Engineering (Site Civil, Process Mechanical); Sherwood-Logan & Associates (Instrumentation and Controls); Dutchland Inc. (Precast Concrete Structures); Haarslev Inc. (Belt Dryer System)
The $92-million, eight-year project used cutting-edge wastewater treatment technology and facilities within a constrained footprint, all while maintaining plant operations within strict discharge quality standards throughout construction. The 1980s facility was upgraded with several systems never before used in the U.S. Because of the treatment systems’ highly technical nature and supply chain concerns, the team was in constant contact with manufacturers to install the equipment, troubleshoot issues and order parts.
To accommodate the project’s geometry and space limitations, two of the three 80-ft by 45-ft digestion tanks and the control building were constructed before the slab for the third digester was poured. The original vision of a sprawling biosolids campus was revised to a dewatering and drying building that was built into the same locations as the existing processing equipment. More than 90% of excavated material was reused on site, eliminating the need to bring in backfill. Another challenge was safeguarding the environmentally sensitive Little Patuxent River from construction-related stormwater runoff, chemicals and other pollutants. The site was divided into individual areas to incorporate runoff controls and spill-prevention measures, such as containment dikes. The enhanced treatment technology produces a substantially lower volume of biosolids, which reduces the number of trucks transporting material from the plant.