Bowie

Delaware County, New York

As part of Delaware County’s goal to continue to utilize their existing landfill site, they embarked on extensive efforts to redefine their solid waste management goals and objectives. In order to do so, the County assembled a team of planning specialists who focused on centralized and integrated solid waste management and watershed planning issues.

As part of the overall strategy to fully utilize the existing landfill property, Stearns & Wheler successfully identified a solution to continue development of solid waste disposal and processing facilities at the County’s Solid Waste Management Center that satisfied environmental, regulatory, and watershed management standards. These efforts included:  solid waste management planning; development of aggressive recycling and landfill diversion strategies; integration of multiple town transfer stations; biosolids management; wetlands evaluation; landfill siting study and permitting; landfill design and construction services; and municipal solid waste (MSW) co-composting facility development.

Components of the fully enclosed MSW Co-composting facility include:

• A waste recovery area for MSW, biosolids, and liquid waste
• A design capacity of 35,000 tons per year (TPY) for MSW and 6,500 TPY for biosolids
• 48-meter rotating drum bioreactor
• Primary refining and sorting area
• Maturation area for 56 days of compost processing
• Fully enclosed secondary refining system to remove inorganic matter
• Compost storage and curing area for 90 days of compost
• Biofilter and complete odor control system

The Solid Waste Management Center is now home to a state-of-the-art solid waste landfill, a materials recovery facility, a construction and demolition landfill, and a municipal solid waste co-composting facility.

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Cox Creek Water Reclamation Facility
Anne Arundel County, Maryland

The 15.0 mgd Cox Creek Water Reclamation Facility (WRF) is the largest wastewater treatment facility in Anne Arundel County and is also the County’s largest single contributor of nitrogen to the Chesapeake Bay. The County targeted the ENR upgrade of the Cox Creek WRF as the first step in a plan to upgrade all of their wastewater treatment facilities for ENR.

In consultation with the client, Stearns & Wheler used a two-step approach to select three ENR alternatives for detailed evaluation. During the first step, the ENR Evaluation Matrix Criteria established during a chartering meeting were used to score five general ENR categories:

1. Single-Stage Activated Sludge Process;
2. Two-Stage Process;
3. Parallel Suspended Growth Systems;
4. Single-Stage Membrane Bioreactor (MBR); and,
5. Three-Stage Process.

The three categories with the highest score - 1, 3, and 4 – were carried forward to the second step of the process. For each category alternative process configurations were developed and scored using the same Evaluation Matrix. The highest scoring process configuration in each category was selected for the detailed evaluation as follows:

1. Integrated Fixed-Film Activated Sludge (IFAS) Process Retrofit in Existing Aeration Tanks;
2. Oxidation Ditches in Parallel with Upgrade of Existing Biological Process; and,
3. Membrane Bioreactors (MBR) Retrofit Using Existing Aeration Tanks.

For each alternative, calculations were developed for preliminary hydraulics and unit process sizing, summary tables were prepared for design criteria and parameters, process flow diagrams and layouts were developed, and capital and operations cost estimates were compiled.

Membrane bioreactors were selected as the best solution due to the facility’s very tight site constraints, inadequate existing reactor volume to fully nitrify year round, inadequate existing secondary clarification facilities, limited hydraulic head available for process modifications, and the County’s desire to produce the highest quality effluent as possible with the maximum degree of reliability.

The facility is now in the design phase.

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Stearns & Wheler provided evaluation, design, and construction services for comprehensive improvements to the City of Binghamton’s water filtration facilities and Water and Sewer Department offices.

The facility is a 20 mgd/76 mld conventional filtration plant, including: a raw water pumping station and intake on the Susquehanna River; chemical feed building housing alum, chlorine dioxide, sodium chlorite, powder-activated carbon, acid, caustic and polymer; 4 flocculation/sedimentation basins; and, 10 rapid sand filters, chlorination, corrosion control and fluoridation.

The site contains separate office and maintenance facilities for water treatment and water distribution, and sewer collection operations for the City.

The improvement program provided upgrades to the treatment plant to comply with current and proposed drinking water regulations to improve the reliability of the process, and to address the rehabilitation needs of a 40-year-old facility.

The project also included major upgrade and expansion of the office/maintenance space and Information Technology improvements to link the communication and maintenance between common staff across two City departments, including a water and sewer system-wide SCADA system. Other plant improvements included:

• Chemical feed systems replacement
• Conversion from chlorine gas to sodium hypochlorite
• A silo for powder-activated carbon storage and feed
• Exterior masonry and roof replacement of all buildings
• Expansion of residuals pumping capacity
• HVAC replacement for all buildings
• Structural improvements to process tanks
• Replacement of major electrical components
• Replacement of raw, finished water and backwash pumping systems

Stearns & Wheler services included: evaluation, design, bidding, construction engineering, permitting, bench-scale treatment studies, SCADA and PLC programming, computerized maintenance management, and computerized O&M manuals.  A detailed construction sequence was developed and communicated to the contractor to allow continuous production during the upgrade, even while major process systems were being interrupted. The upgrade was completed without impact to the City’s supply needs and met all water quality standards.

The water plant improvements provided $15.5 million in upgrades and the project is the largest single public works project undertaken by the City. The project benefits include: a considerable reduction in power consumption due to higher-efficiency pumping equipment and the availability of distribution system storage information through SCADA to time pumping for off-peak electrical demand periods; a reduction in chemical costs due to online analyzer control and flow pacing; and, a significant improvement in process reliability.  In fact, the plant was able to maintain production and meet all drinking water quality standards during the worst flood of record on the Susquehanna River.

The project, funded through the New York State Revolving Loan Fund, received the Environmental Project of The Year Award from the New York State American Public Works Association.

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