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2009 E3 Design Grand Prize
Broad Run Water Reclamation Facility
ENTRANT: CH2M Hill
ENGINEER IN CHARGE: Daniel P. Lynch, P.E.
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Entrant Profile
The result of a 10 year partnership with CH2M HILL and its client Loudoun Water, the Broad Run Water Reclamation Facility is a new water reuse facility with an average 11 million gallon per day (mgd) flow that is expandable to 22 mgd with an ultimate planned build out to 33 mgd. The facility's membrane bioreactor, carbon absorption, and ultraviolet disinfection liquid treatment process represents the latest technology for treating wastewater to reuse standards. Broad Run WRF is the first large-scale application of this technology in the world and the first MBR facility to meet extremely stringent nutrient limits. Designed to protect public health and completely control noise and odors, the facility offers a context-sensitive solution that protects the neighboring Broad Run tributary in a campus-like setting that is shared with the community.
Achieving the vision for the Broad Run WRF brought together a multi-disciplinary design team led by CH2M HILL. CH2M HILL was retained as the engineer for a conceptual study, pilot plant, treatment plant design and construction management. Construction management included resident engineering, inspection, control system software design, operations and maintenance (O&M) manual, treatment plant start-up, and treatment plant optimization. Complementing the CH2M HILL team were design firms Black and Veatch, who designed the influent pump station; and Patton, Harris, Rust, and Associates, who provided final design and permitting for the site and civil design.
Project Description
Introduction
The 10-year partnership between Loudoun Water and CH2M HILL successfully implemented the vision of the Broad Run Water Reclamation Facility as a facility that sets a new world-wide technology standard for water reclamation and also provides a community amenity that will have long-lasting educational, aesthetic, and recreational value.
Comprehensive, Integrated Approach That Considers All Environmental Media
The new water reclamation treatment train of MBR-GAC-UV disinfection improves on previous treatment processes by producing fewer solids in a smaller footprint, with fewer unit processes, resulting in less environmental impact and a more cost-effective process with simpler operation.
Membrane Bioreactor (MBR) technology provides inherent pubic health advantages because the membrane component is uniquely capable of removing a wide range of pathogens. The Broad Run treatment process which includes granular activated carbon (GAC) also incorporates biological and chemical nutrient removal to never before achieved levels resulting in reclaimed water which protects receiving waters from the damaging effects of eutrophication. The evolving costeffectiveness of membrane technology allows these combined benefits to be achieved at lower cost than conventional technology, thus redefi ning viable approaches to water reclamation.
All treatment processes are enclosed in buildings for complete noise and odor control. All odorous air is collected in a buried HDPE pipe system and conveyed to a central biofilter system for treatment; no chemicals are used to remove odors. Although the WRF is currently discharging to the Broad Run, Loudoun Water has plans underway to utilize its reclaimed water in the local area for irrigation and cooling water for neighboring properties. The facility also features stormwater treatment using bioretention and rain gardens that further protect the water quality in Broad Run, the Potomac River, and the Chesapeake Bay. Anaerobic digestion of all solids is used to produce methane gas which heats biosolids for digestion and also provides heat to four buildings onsite. Biosolids are dewatered after digestion and hauled to land application sites.
Quality As Evidenced By the Degree of User Satisfaction and Proven Performance
Implementation of the Broad Run WRF vision exceeded owner expectations for budget, schedule, plant performance and acceptance by the community.
The project met schedule requirements by constructing $190 million of complex treatment plant construction in 46 months to achieve liquid treatment discharge in May of 2008, meeting Loudoun Water's requirement to begin discharge by the Spring of 2008. Errors and omissions change order rate of 2% was signifi cantly under the industry average. Total changes to the contract were 4.5%, which includes a 1% performance incentive fee to the construction contractors-significantly below the industry overall change order rate of 7%. The Broad Run plant startup was completed with no permit violations and no odor complaints. The facility has met all permit requirements since inception in May 2008.
Originality and Innovation
The Broad Run WRF represents a bold step forward in wastewater treatment, by providing a large scale demonstration of MBR technology used in a new way for low-level nutrient removal and combined with GAC.
Through piloting the unique use of MBR for nutrient removal and GAC, Loudoun Water has been successful in determining that MBR and GAC will provide cost-effective process solutions. By demonstrating these results in a large full-scale plant, the Broad Run WRF sets the stage for further advancement of MBR technology, both through focused research and the technological advances that occur through continued application in new plants.
Complexity of Problem/Situation
The Broad Run WRF combines $190 million of complex treatment plant construction into an automated operation that produces the highest quality reclaimed water in the world.
By the mid-1990s, Loudoun Water, the public utility providing water and wastewater services to eastern Loudoun County, Virginia, was faced with growth projections indicating a need for additional wastewater treatment capacity by 2008. The location of the facility, upstream of the water supply for Fairfax County, Virginia, required stringent discharge limits in accordance with the Dulles Area Watershed Policy.
The Broad Run WRF involved the study, pilot plant, design and construction of a new water reclamation plant. The 11-mgd facility uses MBR technology followed by GAC and UV disinfection to produce the highest quality reclaimed water in the world. Broad Run WRF is the first large-scale application of this technology in the world and the fi rst MBR facility to meet extremely stringent nutrient limits.
Broad Run WRF's permit requirements are among the most stringent in the world. The Broad Run WRF is also the first treatment plant in Virginia to meet Enhanced Nutrient Requirements of 3.0 mg/L TN on an annual load basis for further protection of the Chesapeake Bay. The facility consistently produces effl uent with turbidity levels well below State permit limits for drinking water.
Contributes to Social and Economic Advancement
Facility design protects our most valuable resource -WATER- and provides a community learning center for water conservation and reclamation.
The Broad Run facility brings educational and recreational value to its Eastern Loudoun County community. The facility's effluent discharges through a constructed, natural-looking stream to two effl uent display ponds. A portion of the reclaimed water is also diverted to a fountain at the campus entrance. Loudoun Water has developed a public education area coined the "Aquiary" which takes advantage of the outdoor features and space within its new administration building to deliver a message of water stewardship. It is open to the public and includes trails and interpretative stations. It assists the public's understanding of the water cycle, wastewater treatment's role in our quality of life, and the immense potential of water reuse in economically meeting future water demands.
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