Laurel RT. 13 Water & Sewer Extension

GMB was hired in 2010 by the Town of Laurel, DE to provide full-scale services including coordination with the funding agency, design, bidding, contract administration, inspection, and 1^st year services for the extension of sewer and water services to the intersections of Route 13 / Route 9 and Route 13 / 468 for commercial and residential properties within or surrounding the existing Town corporate boundaries.  Funding for this project was attained through pursuing grant and loan assistance from USDA Rural Development (RD).  As part of the funding qualifications, GMB applied for and received a Preliminary Planning Grant (PPG) from USDA-RD to complete a Preliminary Engineering Report (PER) and Environmental Report (ER) on the proposed project.  Review and approval of the PER and ER was completed by December 2010 and design of the Laurel Highway Corridor Water and Sewer Extension project began in January 2011.  The project was divided into two phases; Phase 1 and Phase 2.  The projects were 100% USDA-RD in the amount of $13,601,000.  Construction of Phase 1 ($6,022,286) was completed in 2014 and construction of Phase 2, $4,390,881, was completed in 2017.

The Laurel Highway Corridor Water and Sewer Extension- Phase 1 design consists of a new regional pump station and a 500,000-gallon elevated water storage tank located on Route 9 east of Route 13.  In addition, the project comprised of 6,030 ft. gravity sewer, extension of 9,360 ft. water main (8” and 16”), 4,460 ft. of 8-inch force main, and installation of a low-pressure sewer system to serve surrounding Town parcels which could not be reached by extending the existing gravity sewer.  The pump station consists of a ten (10) ft. square precast wet well with two (2) 25 Hp submersible pumps on variable frequency drives, flow meter, comminutor, bypass connection, hoist, emergency generator, wet well supply fan and a carbon odor control unit.  A precast valve vault houses the check valves, gate valves, and flow meter.  The odor control unit and electrical controls are housed in an onsite building.   The design also consisted of several directional drill and jack and bore pipe installations under Route 13 and along Georgetown Rd and Route 9.

The elevated water tower was designed to provide the Town with additional volume and fire storage to serve the future service area.  Altitude valves were implemented to control the pressure difference between the existing Town water towers and proposed tower.  Both the pump station and water tower are controlled by a Remote Terminal Unit (RTU) connected to a SCADA system for monitoring and control.

The Laurel Highway Corridor Water and Sewer Extension- Phase 2 project consisted of a new 525 gpm production well and a 1,000 GPM Water Treatment Facility.  In addition, the Town’s water distribution and gravity sewer collection system was extended to the Route 13 / Discount Land Road intersection to provide economic growth to the Town.

The Water Treatment Facility (WTF) was designed for iron removal for a system design flow of 1,000 GPM utilizing three (3), ten (10) ft. diameter pressure filters.  In addition, the chemical feed system included Sodium Hypochlorite for disinfection, Sodium Hydroxide for pH adjustment, and Calciquest a corrosion inhibitor.  Water is introduced to the new WTF via a new production well that draws from a confined aquifer, as it will be less susceptible to nitrate contamination, and has a 12-inch diameter casing along with a 50 Hp submersible pump. The WTF is equipped with a small lab, office space, control room, emergency generator, and is fully integrated with the Town’s SCADA.

The gravity collection system was extended to the outer boundaries of the corporate limit in the Rt 13 / Discount Land Rd area.  An existing pump station was upgraded to include new pumps, controls, valve vault, and SCADA.  The water distribution system was extended to this same intersection consisting of 16, 12, and 10-inch water mains.  Construction for these utilities utilizes both open cut and trenchless construction.  GMB provided full engineering services, full contract administration and contract inspection services, and will be providing start-up services and 1^st year services.  The construction cost was $4,603,986, and the project was completed in 2017.