Wastewater Treatment Plant Evaluation, Manchester-By-The-Sea, MA

Tata & Howard completed a comprehensive evaluation of the Manchester-by-the-Sea wastewater treatment plant (WWTP).

The Manchester-the-Sea WWTP was originally constructed in 1998. The plant is designed to treat an average daily flow (ADF) of 1.20 mgd. The plant includes the following treatment processes: influent pumping, influent sewage grinding, manual bar rack, grit removal equipment, aeration tanks and blowers, clarifiers, chlorine disinfection, and sludge thickening.  The treated effluent is discharged into the ocean with effluent pumps through an ocean outfall pipe.

The treatment plant evaluation included a comprehensive assessment of the physical condition of the plant to provide an additional 20-year life for the facility.  The evaluation included all mechanical systems and equipment, electrical systems and controls, buildings, and structures.  The study included an evaluation of energy usage at the plant and developed recommendations to improve energy efficiency including replacement of influent and effluent pumps, and aeration blowers to better match plant flow requirements and system demands.

The final report includes an evaluation of existing conditions and proposed recommendations to improve current operations, upgrade aging equipment and facilities, improve energy efficiency,  and provide plant hardening against potential climate change and sea level rise.

 

Canaan, VT and Stewartstown, NH Energy Efficient Wastewater Treatment Plant Upgrades

The Towns of Canaan, Vermont and Stewartstown, New Hampshire operate a shared wastewater treatment facility, which required significant upgrades. The existing facilities were 40 years old and although a few upgrades were performed in the 90s, the facilities were not performing well, did not meet Life Safety codes, and required significant maintenance. The upgrade met all of the goals of the Client by providing for simple operation and maintenance requirements, meeting the Life Safety codes, eliminating confined spaces, lowering of electrical power costs, and meeting discharge parameters through production of high quality effluent. The solutions developed for the upgrade to this facility were also economical.

Control building insulated concrete forms

One of the primary elements of the design was the consideration of the economics of energy reduction.  The design incorporated insulated concrete form construction for the building walls with R-49 insulation rating in the ceilings.  The design also included a wood pellet boiler with a pellet silo and hot water heating system, which allowed for reduction of explosion proof heaters in the headworks building.  All of the windows were low-E and highly insulated, and an outer glassed-in entry way increased the solar gain retention of the building and reduced heat loss.  The process headworks and operations buildings were constructed as single story structures, increasing operator safety.  The lagoon aeration system is now a fine bubble, highly efficient process with additional mixing provided by solar powered mixers that help reduce aeration requirements, improve treatment, and allows for the addition of septage, all at no cost due to solar power.  The pump station upgrades were designed to eliminate daily confined space entry by the operator by the conversion to submersible pumps.  For sludge removal, a unique and simple “Sludge Sled” system was incorporated, which allows the operators to easily remove the sludge at their convenience. Sludge treatment is accomplished with a geo-bag system that allows the sludge to be freeze dried, reducing the volume by almost 50% with no energy consumption. The influent pump station was designed with three pumps instead of the normal two-pump system in order to meet both present and future design flows, allow for lower horsepower pumps, improve flexibility, reduce replacement costs, and reduce energy costs.   The other four deep dry pit pump stations were converted to wet wells and submersible pumps, eliminating confined spaces, and are equipped with emergency generators, eliminating the need for operator attention when power is lost.

Solar mixers for lagoons

The incorporation of highly energy efficient building components resulted in reducing annual operation and maintenance costs, which resulted in lower user rates and a more sustainable facility.  All building components are virtually maintenance free.  All of the equipment and processes were selected to reduce both annual and future replacement costs.

The treatment system is a 3-cell aerated lagoon system, and the solar powered mixers were installed to enable reduction of the aeration needs and horsepower during the summer months when septage is added.  The aeration blowers, which are housed in insulated enclosures, reduce noise and were sized to allow for the addition of septage to the lagoons, which is not common in Vermont.  The aeration blowers are controlled with Variable Frequency Drives (VFDs), which allow for greater operator control of aeration and provide energy cost savings. The operation is simple and safe for operators and others who need to maintain the facility and equipment.  The design has provided flexibility to the operators and has resulted in an energy efficient, sustainable solution for this community.


 

 

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Funding Assistance for WWTF Upgrade in Lyndon, VT

Upgrade for a 750,000 gallon per day extended aeration wastewater treatment facility to an A/O biological facility.  Assistance included acquiring State CWSRF planning grants and USDA Rural Development grant for extensive improvements including separation of combined sewer/stormwater collection systems (CSO), advanced Class A sludge treatment, and reconstruction of original 1970’s treatment facility to new Anoxic/Oxic Treatment System.  Total grant funds were $7,275,000.

Business Practice Evaluation (BPE), North Texas Municipal Water District

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North Texas Municipal Water District (NTMWD) Wylie Treatment Plant, courtesy of NTMWD

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.

 

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Odor Control at Wastewater Treatment Plant, Lyndon, VT

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.

lyndonvt_odorcontrol_wwtf_interior

Interceptor Sewer, Danbury, CT

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Jacking a 48-inch steel casing under I-84 in Danbury, CT

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.

Infiltration/Inflow Investigations in Milford, MA

Milford, MA wastewater treatment plant
Milford, MA wastewater treatment plant

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.

CHALLENGE: Critical Wastewater Treatment Facility Upgrade Needed, Limited Funds Available

Wastewater treatment plant that serves the Towns of Canaan, VT and Stewartstown, NH
Wastewater treatment facility that serves the Towns of Canaan, VT and Stewartstown, NH

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.

CHALLENGE: Mission Critical Storage Tanks, Southeast Louisiana Veterans Health Care System, New Orleans, LA

hospital new orleans
State-of-the-art SLVHCS in New Orleans, LA, is on track for silver LEED certification

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 atrium of Southeast Louisiana Veterans Health Care System
The atrium of SLVHCS

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.

CMOM Requirements in NPDES General Permit, Winchester, NH

Board of Sewer Commissioners, Winchester, NH

WinchesterNH_WWTP_watershotTata & 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.