Little Patuxent Water Reclamation Plant Addition No. 7
The Little Patuxent Water Reclamation Plant Addition No. 7 helps protect water quality in the Chesapeake Bay by removing excess nutrients, allowing Howard County to meet its wastewater treatment demands through 2030. The main upgrade included design and construction of new denitrification filters to reduce excessive nitrogen in the wastewater discharges. Additional improvements included new influent multi-rake screens and screening compactors.
The Little Patuxent Water Reclamation Plant was expanded to include new facilities for state-of-the-art equipment that will remove greater amounts of nitrogen and phosphorus from wastewater. After the Addition No. 7 was completed in 2012, the Plant could remove 37,000 pounds of suspended solids, 4,730 pounds of nitrogen, and 965 pounds of phosphorus every day. It’s capacity increased to 29 million gallons of water per day.
The project affected every treatment process at the plant, and maintenance of plant operations (MOPO) procedures had to be considered throughout design and construction to prevent permit violations. The team developed detailed MOPO plans for all portions of work to orchestrate shutdowns of and tie-ins to the existing facilities. Plant staff reviewed these plans and provided input on process limitations. The final plans were then included in the contract documents for implementation during construction.
Operating under a Construction Manager (CM)-at-risk delivery method allowed early stages of work to start even while later activities were being formalized. The team delivered the denitrification filter facilities in February 2012, allowing them to operate nearly four months before the enhanced nutrient-removal permit limits went into effect.