Tata & Howard Provided management consulting and leadership skill building for the North Texas Municipal Water District. Project included meeting with each of the nine wastewater treatment plant Superintendents and Chief Operators and wastewater collection system management one-on-one as well as meeting with supervisors and managers. Two briefing workshops were conducted to discuss the findings, overall observations and potential opportunities for improvement that benefits the treatment and collection system facilities. In addition, a management, operation and maintenance (MOM) workshop was conducted that discussed effective business practices that were compared to industry standards.
The wastewater treatment plant in Lyndon, Vermont was experiencing excessive odor issues. The existing odor control system relied primarily on chemical treatment, which was difficult for the operators to manage. Tata & Howard’s project design consisted of a bio-filter with root mulch to remove the odors, which are primarily ammonia, that are generated from the Auto Thermophilic Aerobic Digestion (ATAD) sludge treatment vessels. The ATAD system is a system that results in class A sludge that can be spread anywhere as a fertilizer, and it reduced the annual volume of sludge produced at this facility by 65%. The new system includes fans that pull the air off the top of the ATAD unit vessels through a cool down water wash tank, which knocks down the ammonia, and then pushes the air through PVC piping up through the root bio-filter shown in the picture. The total cost was under $300,000, for which Tata & Howard procured the Town a 100% grant.
The second part of the design project included a nitrogen reduction system for the secondary aeration process that may be necessary in the near future. The design includes a recirculation pump system from the Anoxic zone back to the Oxic zone. The Contractor was T. Buck Construction of Maine.
The Oakland Avenue sanitary sewer project consists of jacking a 48-inch steel casing pipe through the Interstate-84 embankment in Danbury, CT and installing a new 24-inch sanitary sewer to replace the existing 16-inch sewer that is undersized. The project will alleviate the restriction that is causing sewer overflows. Services included surveys and mapping, review of easements, review and updating of original design, preparation of plans and specifications, bidding, construction administration, and resident observation. Construction is currently underway and the project is expected to be completed by the end of this October. The new sewer line installation will complete an interceptor project that was constructed in 1994.
Tata & Howard has been conducting Infiltration/Inflow (I/I) investigations for The Town of Milford, Massachusetts for the past several years within their collection system, which consists of approximately 90 miles of 4-inch diameter to 36-inch diameter gravity sewers and force main, ten pump stations and a 4.3 million gallon per day (MGD) advanced wastewater treatment facility. Throughout the investigations, I/I sources such as broken service connections, broken pipes, cracks, roots, and illegal connections have been identified. The I/I ranged from 144 gallons per day (gpd) to in excess of 400,000 gpd. Based on the results of previous I/I investigations, the Sewer Department was able to remove a direct connection from the street drainage system to the sewer system that resulted in the removal of an estimated 450,000 gpd of extraneous water from the sewer system, therefore regaining 10 percent of available capacity at the treatment facility.
As a result of conducting these I/I investigations, the Town has the ability significantly reduce the amount of extraneous water entering the collection system, as well as free up capacity at the treatment facility. The Town of Milford has also incorporated a 5:1 removal policy within the Town Bylaws, which requires Contractors/Builders to remove 5 gpd of I/I from the system for each gallon of wastewater proposed to be discharged, which minimizes repair costs for the Town and their residents.
CLIENT: The Towns of Canaan, VT and Stewartstown, NH
PROJECT: Shared Wastewater Treatment Facility
THE CHALLENGE: The existing wastewater treatment facility was 40 years old, costly to operate, and did not meet state and federal water quality standards. In addition, the Towns had very limited funds with which to upgrade the treatment facility.
THE SOLUTION: Tata & Howard helped the Towns secure a $2.412 million low-interest, long-term loan and $1.69 million in grant funds from the U.S. Department of Agriculture (USDA) Rural Development in order to build the new facility.
Tata & Howard, Inc. provided complete consulting engineering services for the construction of the wastewater treatment facility project which included the complete upgrade of four pump stations as well as the upgraded 0.185 mgd, 3-cell lagoon wastewater treatment facility. In addition, Tata & Howard’s St. Johnsbury, Vermont office, formerly Leach Engineering Consultants, provided full design services for all of the upgrades. The Towns now enjoy a state-of-the-art, reliable wastewater treatment facility that meets the Effluent Discharge limits to the Connecticut River and provides for a more efficient treatment process. The new influent screening and grit removal processes extend the life of the treatment facility components. In addition, septage receiving provides for additional income and also provides service to the residents of the Towns that are not on public sewer. The design included numerous energy-efficient features such as variable-frequency drives (VFDs) on aeration blowers, solar-powered lagoon mixers, a wood pellet boiler for heat, energy-efficient windows, and insulated concrete form (ICF) walls, resulting in a reduction in annual operation and maintenance costs. The pump stations were upgraded to eliminate operators entering below grade structures and to allow for future pump replacement that would be lower cost with it would be with the original centrifugal pumps.
PROGRESS: The project is complete, and the Towns celebrated the completion of their shared $4.12 million wastewater treatment facility with a ribbon-cutting ceremony in Canaan, VT.
CLIENT: NBBJ, Columbus, Ohio
PROJECT: Mission critical storage tank systems for Southeast Louisiana Veterans Health Care System (SLVHCS)
THE CHALLENGE: SLVHCS is the successor to the VA Medical Center, which was decimated by Hurricane Katrina in 2005. The new hospital requirements included green building practices and resiliency during natural disasters, including the ability to remain operational for at least five days with enough provisions and accommodations for up to 1,000 staff and patients in case of a major disaster.
THE SOLUTION: Tata & Howard provided design and construction administration services on specific components of the mission critical storage tanks, which include a domestic water tank, sewage holding tank, cooling tower process and bleed water tank, and fire protection water tank. Our design of specific components of the mission critical tanks included coating, waterproofing, mixing, pumping, bacteria control, odor control, venting, piping to five feet outside the tanks, and instrumentation and control. Specific design elements for resiliency and green design included the following:
- Domestic Water Tank system instrumentation/controls include storage tank level measurement and control of inlet/outlet valves. The system also includes ultraviolet disinfection of all potable water pumped from the storage tank into the hospital.
- Sewage Holding Tank is waterproof and its control system to provide automated response to an event using electrically actuated valves that direct the sewage from the gravity system to the holding tank. After the event, the system will turn the pumps on and transfer the sewage to the City’s system. A water spray system will automatically wash down the empty tank.
- Cooling Tower Make-up Water Tank is waterproof and its control system design provides electrically actuated valves to receive rainwater from the building roof drains, condensate from the buildings, and potable water from the City’s water system. The Cooling Tower Make-up system instrumentation/controls include tank level measurement and control of inlet/outlet valves.
- Cooling Tower Bleedwater Tank is waterproof and its control systems design provides electrically actuated valves to accept water from the cooling towers, recycles water to the cooling towers, and pumps it into the municipal sewer system. The Cooling Tower Bleedwater Tank system instrumentation/controls will include tank level measurement and control of inlet/outlet valves.
- Fire Protection Water Tank is waterproof and its control system design provides electrically actuated valves to automate control of receipt of water from the CEP/Warehouse roof drains and the City’s water system.
- The instrumentation and controls for all of the above elements are capable of communicating with the facility ‘s SCADA system.
PROGRESS: The new state-of-the-art facility opened on August 1, 2015, and the building is on track to receive LEED silver certification. For comprehensive information on the new hospital, please click here.
Board of Sewer Commissioners, Winchester, NH
Tata & Howard is assisting the Town of Winchester to meet the Collection, Management, Operation, and Maintenance (CMOM) requirements in the Town’s NPDES General Permit. To date, the work has consisted of the preparation of an outline for the Full Collection System Operation and Maintenance Plan, which includes descriptions of staffing, management goals, information management, condition assessment, recent studies, and construction activities. Tata & Howard has been retained to prepare the Full Collection System Operation and Maintenance Manual, which includes updating the outline, preparing a preventative maintenance and monitoring program, identifying sources of suspected overflows and back-ups, preparing a program for preventing I/I related effluent violations, and a public outreach program regarding I/I control.
Additionally, Tata & Howard has assisted the Town of Winchester with three phases of improvements to the Winchester Wastewater Treatment Facility (WWTF), I/I investigations, repair and rehabilitation of the sewer collection system to remove I/I, and securing funding to upgrade the WWTF and sewer collection system.
Troy and Jay, VT
Tata & Howard provided engineering services for the evaluation, design, and construction of approximately five miles of pressure and gravity sewer to serve the mountain resort community of Jay, Vermont. The design also included the upgrade to air release structures for 4.5 miles of force main and upgrade of two pump stations, one a progressive cavity station. In addition, Tata & Howard provided engineering services including planning, evaluation, design, permitting and construction services for the Troy-Jay wastewater treatment facility upgrade. The new headworks facility included screening and aerated grit removal and influent design for the force main/pressure sewer from the two towns and mountain resort. The treatment process was an SBR facility with tertiary filtration and UV disinfection for phosphorus removal.
Board of Sewer Commissioners, Milford, MA
Tata & Howard is providing all engineering support services related to the operation of and modifications to the Town’s wastewater collection, pumping, and treatment systems including preparation of a Comprehensive Wastewater Management Plan (CWMP) and preparation of a comprehensive Infiltration/Inflow (I/I) Evaluation. In addition, we are providing all ongoing support services related to the preparation of a Capacity, Management, Operations, and Maintenance (CMOM) program to meet US EPA’s regulations as well as technical assistance on the renewal of the Town’s NPDES permit. Included in this project is the preparation of the Town’s I/I control plan and all annual updates, preparation of the Town’s sewer use regulations and standard specifications for sewer construction, review of plans for all private developments, and review of all applications for industrial wastewater connection permits and pretreatment reports.
All services related to I/I identification, evaluation, and removal performed on the Milford’s sewer system, which consists of approximately 100 miles of interceptor sewers and mains, including an innovative sump pump removal program, has resulted in a dramatic reduction in extraneous flow to the system.
Tata & Howard conducted an energy efficiency study on the aeration blowers and pumps at the Rio and Wildcat Hill treatment plants. The testing showed that modifications to these systems have the potential to save the City approximately $250,000 in annual electrical costs and $445,000 in APS rebate funds for the modifications. Pumping systems had efficiencies as low as 20%. Pumps and blowers were oversized to meet peak and future demands but not efficient at low flows or off peak flows. Energy usage per million gallons treated of 2,170 KWH/MG with cogeneration and 2,804 KWH/MG at the Rio plant, with national average usage of 1,750 KWH/MG.
The project included the testing of blowers and pumps at two reclaimed water plants; review of all the wells, pressure reducing valves, boosters, and splits for energy savings; further evaluation of the turbo blowers and barscreens; and an evaluation of the replacement of the biogas piping for use in cogeneration.
Abstract: In Arizona, the Arizona Public Service (APS) estimates that water systems use 1/7th of all the power used in the State. From the APS testing program, it is estimated that 60 to 70 percent of all pumps have tested below industry standards or changes in operations are needed to operate more efficient. This presentation discusses the findings associated with energy studies completed for a small water supply system (Kachina Village Improvement District) and for a large system (City of Flagstaff, Arizona). The studies show that any water and/or wastewater system, regardless of size can benefit from an energy audit. The studies resulted in significant annual savings, potential rebates from APS to offset replacement costs, high return on investments, while promoting green initiatives.
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