8.4 mgd Water Treatment Plant Design, Permitting, Construction Administration, Falmouth, MA

8.4 mgd Water Treatment Plant Design, Permitting, Construction Administration, Falmouth, MA

DAF water treatment plant

THE CHALLENGE: More stringent USEPA and MassDEP regulations, including Stage 2 Disinfectants/Disinfection-by-Product Rule (S2 D/DBPR) and the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR), resulted in the Town of Falmouth needing to make a decision on whether to construct a filtration facility in compliance with the SWTR or to upgrade disinfection processes only at the existing Long Pond Water Treatment Facility (LPWTF) to maintain the existing Filtration Waiver.

THE SOLUTION: Because the existing LPWTF utilized no filtration to remove bacteria, organics, and particulates, the water quality entering the distribution system was an ongoing concern with elevated turbidity and organics leading to seasonal color, taste, and odor complaints; elevated bacteria and concentrations; and elevated algae counts. In addition, the high doses of chlorine needed to maintain the disinfection residuals required for an unfiltered supply reacted with the organics in the raw water to form disinfection by-products. Therefore, the only viable option for the Town of Falmouth was a new water treatment plant. After evaluating 22 treatment processes and developing eight treatment alternatives for pilot testing, only one treatment process met all goals: Dissolved Air Flotation (DAF) clarification, intermediate ozone followed by filtration. This alternative also scored favorably on the benefit/cost analysis.

Tata & Howard provided design and construction services for the new Dissolved Air Flotation (DAF) facility with a design capacity of 8.4 million gallons per day (mgd) for the Long Pond surface water supply for the Town of Falmouth, MA. The water treatment plant (WTP) utilizes coagulation, mixing, flocculation, dissolved air flotation (DAF), dual media filtration including granular activated carbon (GAC) above sand, chemical feed systems, and an intermediate ozone feed. Building components include HVAC, plumbing, fire sprinkler, gas and electrical services. Other work included site work with exterior piping systems, exterior above and below ground tanks, sludge holding lagoons, construction of a garage, new raw water intake and pump station, directional drilling of raw water mains, and demolition of equipment and site piping at the existing water treatment facility.

As part of the project, Tata & Howard provided design and permitting of a new 8.4 mgd intake and raw water pump station (RWPS) for the WTP.  The new intake and RWPS were constructed along the eastern shore of Long Pond and replaces the existing intake and Low Lift Pump Station.  The new intake and RWPS includes a two-level intake consisting of two 8.4 mgd rated intake screens installed at elevations -3 feet below mean sea level (MSL) and -13 feet below MSL.  The 36-inch HDPE intake pipeline connects the intake screens to the new RWPS located approximately 150 feet from the eastern shore of Long Pond.  An air burst system was designed in the RWPS to provide a means for routine cleaning of the new intake screens.

An accelerated 11 month design and permitting schedule, followed by contractor prequalification, bidding, and award, were completed in time to qualify the Town for >$3M in principal forgiveness.

Design included the following:
• 300 Drawings
• 1,200 pages of Specifications
• SRF PEF application
• Monthly project meetings
• Coordination with Building Department
• Coordination with Board of Health
• Coordination with Town IT Department
• Coordination with Police and Fire Departments
• Coordination with Gas and Electric Utilities

Permits included the following:
• Wetlands Protection Act-Local Conservation Commission
• Board of Health
• Remediation General Permit (NPDES)
• Massachusetts General Permit
• Environmental Notification Form
• Massachusetts Historical Commission: Intensive Archaeological Survey including 200 test holes
• MassDEP Approval to Construct WTP: BRP WS 24
• DWSRF PAC
• 401 Water Quality Certification
• NHESP – Turtle Protection Plan
• Chapter 91 Waterways License
• U.S. Army Corps of Engineers General Permit

The construction of the Long Pond Water Treatment Plant progressed on schedule and was completed in 2017.  dji_0051The plant included numerous sustainability and energy efficiency initiatives including the following:

  • Recycling spent backwash water to head of plant and back into the treatment process, after it passes through a plate settler to remove solids.
  • Recycling laboratory analyzer and filter influent piping gallery analyzer discharges back into the treatment process.
  • Using filter-to-waste water after a filter backwash sequence as supply water for the next backwash, instead of using finished water for backwashing.
  • Discharging cleaner supernatant water off the top of the lined lagoons to an unlined infiltration lagoon and back into the ground to minimize residuals.
  • Use of local/native plants for landscaping, including an irrigation system using collected rainwater from roof drainage.
  • Interior and exterior LED lighting fixtures.
  • Variable Frequency Drives (VFDs) on HVAC equipment and process equipment motors.

The plant went online on October 18, 2017. The work was funded under the SRF program. The Long Pond Water Treatment Plant received an ENR New England 2017 Best Project Award in the Water/Environment category, and an Associated Builders & Contractors of Massachusetts Eagle Award in the Public Works – Environmental category. For a drone video of the new water treatment plant taken by the general contractor, Methuen Construction, please see below:

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Pump Stations, Wastewater Treatment Facility, and Force Main Design and Construction, Troy and Jay, VT

Pump Stations, Wastewater Treatment Facility, and Force Main Design and Construction

troy jay vermont wastewater engineeringTata & 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.

District Water Treatment Facility, Transmission Mains, and Metering Station, Mattapoisett, MA

District Water Treatment Facility, Transmission Mains, and Metering Station, Mattapoisett, MA

MRVWD_water treatment facilityThe MRVWD water treatment facility project was designed to treat water from eight wells belonging to the Towns of Fairhaven, Marion and Mattapoisett.  The MRVWD facilities also include approximately 5 miles of raw water transmission mains between the wells and the water treatment facility, finished water transmission mains from the water treatment facility to the existing town transmission mains, six new 100 HP high lift pumps and control/metering stations.  The existing pump stations were upgraded to pump water to the water treatment facility but operation of the pump stations will remain the responsibility of the individual towns.  The total cost of all project components was approximately $16.5 million, which was partially funded with a low interest SRF loan.  By constructing a regional facility, the towns were able to save over $4.9 million in design and construction costs in comparison to individual treatment facilities.

Progressive Cavity Pump Stations, Ludlow, VT

Progressive Cavity Pump Stations, Ludlow, VT

okemoTata & Howard team members designed two high head progressive cavity pump stations for the Jackson Gore expansion project at Okemo Mountain. Each pump station was designed to fit in with the landscape and each had muffin monster grinders in front of the triplex pump arrangement.  All process piping was stainless steel.

 

 

Industrial Park Interceptor Sewer and Pump Station, Medway, MA

Industrial Park Interceptor Sewer and Pump Station, Medway, MA

Medway_MA_interceptor_sewerTata & Howard conducted an alternatives analysis for the collection and disposal of the 80,000 gpd of wastewater anticipated from the Medway Industrial Park at full build out. The study included investigations of on site treatment and subsurface effluent disposal, intermunicipal connections, and/or a pump station with force main and gravity sewer to provide sewers to the Industrial Park. Upon completion of the study, Tata & Howard was retained to design a new sewer interceptor and pump station to service the industrial park.

Tata & Howard completed the design of 18,000 linear feet of 8-inch and 18-inch diameter gravity interceptor sewer and a dedicated pump station with force main to service the Medway Industrial Park. The pump station is a wet well mounted suction lift pump station with a capacity of 500 gallons per minute and it includes a dedicated standby generator with automatic transfer switch.

Main Wastewater Pump Station Rehabilitation, Ayer, MA

Main Wastewater Pump Station Rehabilitation, Ayer, MA

Ayer_wastewater_pump_station_rehabilitationTata & Howard prepared a wastewater treatment and disposal alternative analysis for the Town of Ayer. The analysis evaluated alternative plans for treatment and disposal of wastewater utilizing the Town’s existing wastewater treatment facility, a proposed regional wastewater treatment facility, or a combination of both facilities. The alternative analysis estimated the wastewater flows and loadings, assessed the condition and capacity of the existing plant unit processes, and recommended improvements to meet the future service needs over the next 20 years. Tata & Howard designed upgrades to the existing main wastewater pump station which pumps the entire volume of wastewater generated in Ayer. In addition to the overall rehabilitation of the pump station, Tata & Howard designed the addition of new pumping facilities to divert wastewater to the nearby regional wastewater treatment facility at the former Fort Devens, now managed by Mass Development. The main wastewater pump station has a peak capacity of 4.0 mgd and includes four wastewater pumps with a capacity of 2,800 gpm. The upgrades included new variable frequency drives for the pumps and new SCADA.

Pump Station Design and Wastewater Treatment Facility Upgrades, Barre, MA

Pump Station Design and Wastewater Treatment Facility Upgrades, Barre, MA

Barre wastewater treatment facilityThe Town of Barre retained Tata & Howard to evaluate their existing wastewater treatment facility. Tata & Howard recommended a three phase upgrade program in order to reduce the initial impact of the construction cost on the sewer use rates. Included in the upgrade program was the design and construction of a submersible pump station that lifts the raw wastewater from an equalization tank to the biological treatment process. The pump station has a capacity of 1.2 mgd and includes variable frequency drives. The pumping station is controlled by a new SCADA system at the wastewater treatment facility. Tata & Howard also designed 8,000 linear feet of collection system sewers in the Worcester Road area of town. The project also included 500 linear feet of force main and a wet well mounted pump station. The pump station has a capacity of 200 gpm.

Wastewater Pump Station Rehabilitation, Milford, MA

Wastewater Pump Station Rehabilitation, Milford, MA

MilfordMA_wastewater_treatment_plant_aerialTata & Howard provided all design and construction services related to a treated wastewater pump station at the Town’s advanced wastewater treatment facility.  This station has a capacity in excess of 1 mgd and is used to pump treated wastewater to a gas turbine power generation facility where it is used for cooling water.  Included in this project was the preparation of plans and specifications and the monitoring of water quality effects on the Charles River.

The Birch Street Pump Station is a submersible pump station consisting of two 700 gallons per minute pumps. Under maximum day flow conditions, the station has operated well above its current capacity and pump run times of 24 hours have been recorded. Therefore, prior to accepting additional flows would require upgrades to be completed. In 2013, Tata & Howard worked with the Town of Milford and was retained by a developer to design proposed upgrades for the Birch Street Pump Station rehabilitation which included upgrades to the existing submersible pumps, electrical and instrumentation, and controls.

Sewer Improvements and Wastewater Pump Stations, Bingham, ME

Sewer Improvements and Wastewater Pump Stations, Bingham, ME

Bingham ME wastewater pump stationTata & Howard provided engineering services associated with sewer improvements including evaluation, design, and construction of 3,500 linear feet of interceptor sewer, 2,500 linear feet of force mains, and three pump stations. In addition, Tata & Howard provided design and construction of 5,000 linear feet of interceptor sewer, 4,000 linear feet of gravity sewer including a river crossing, and a pump station. Tata & Howard also provided design and construction services for three new wastewater pump stations. The pump station scope included upgrading of one pump station and the design of two other pump stations. One of the pump stations is a suction lift station while the other two are submersible stations.

Wastewater Pump Station, Franklin, MA

Wastewater Pump Station, Franklin, MA

FranklinMA_wastewater treatment facility interiorTata & Howard was retained by the Town of Franklin to evaluate the wastewater pump station that serves the Franklin Industrial Park. The pump station had been experiencing capacity issues and periodic overflows. The design by Tata & Howard included the replacement of two existing wastewater pumps with 350 new gpm capacity pumps with variable frequency drives. The project also included a substantial increase in the volume of the station’s wet well through the construction of additional precast concrete tanks. The work also included upgrades to the existing alarm and communications systems.