Greensboro Fire District No. 1 (GFD#1), situated on the Northern portion of the Green Mountains in Vermont, requested assistance with their water distribution and treatment systems due to deficiencies identified in a sanitary survey conducted by the State of Vermont. This contract addresses these deficiencies and provides the District a more robust covered water storage tank, secure buildings that house controls and chemicals and related equipment, emergency power generation, and water metering.
As part of the project, Tata & Howard helped GFD#1 secure funding that included a 45% USDA Grant for the originally planned project with an estimated budget of $2,900,000. During the design phase, the District lost their primary well source due to an extended drought. Tata & Howard engineers worked with the District to secure a 100% USDA grant for the cost of constructing a new municipal well source and associated emergency generator and related appurtenances.
Tata & Howard provided design, construction administration, and resident observation for the water system improvements project. Construction began in the spring of 2015 with the setup of a temporary water storage system and demolition of the existing water storage tank roof structure. Precast planks and a ballasted membrane roof were then installed, providing safe, quality water. Two new small buildings were constructed to house chemicals and water well piping and controls, along with an emergency generator to provide continuous water in case of interruption to electrical power.
THE CHALLENGE: The existing spillway is inadequate to discharge the 100-year spillway design flood, and the existing, aging dam is in very poor condition. The embankments are steep and lack erosion protection, the crest is narrow, and the outlet is in disrepair and inoperable. The reconstruction of Fosters Pond Dam needs to be designed to improve the safety and reliability of the structure, provide an operable outlet, and make the structure easier to maintain.
THE SOLUTION: The reconstruction includes constructing new, higher reinforced concrete spillway training walls, providing upstream riprap erosion protection, constructing a new reinforced concrete gate structure with 24-inch inlet and outlet pipes and sluice gate, widening the embankment crests to 12 feet, flattening the slopes for ease of maintenance, and providing a gravel road to allow access to the left (looking downstream) embankment and gate structure. Riprap erosion protection will be provided on the upstream slopes and in the discharge channel. With these improvements, the dam will be able to safely pass the 100-year spillway design flood with 1.1 feet of freeboard. The level and length of the spillway weir will remain unchanged.
PROJECT: Mountain Street Water Treatment Plant Valve Replacement
THE CHALLENGE: The three check valves on the clarifier influent feed lines were failing and, as a result, the disc was consistently hitting the downstream pipe spool piece, eventually causing each section to develop holes and leaks.
THE SOLUTION: Rather than simply replacing the check valves with the same style valve, we decided to dig deeper. We believed the discs were failing due to turbulence generated by an upstream modulating valve, so we researched alternative valves. We found that most alternative valves required a longer lay length than the existing check valves, which would have required replacement of the influent piping as well as reconfiguration of the valves and flow meters on each of the clarifier influents that feed the three units back to the header.
With additional research, we identified a flanged duckbill check valve that could actually be inserted between two flanges within the pipe, with the flange of the check valve sandwiched between the two flanges of the existing pipe configuration. The valve itself was located within the influent piping and allowed for installation without having to significantly alter the clarifier influent piping. As a result, the Owner saved on the cost of the valve replacement as well as avoided an extended shutdown time, as each clarifier would have been out of service for a far longer duration if extensive influent piping modifications were necessary.
PROGRESS: The project was successfully completed in October of 2014.
This project included construction of a 1.0 million gallon, precast, pre-stressed, wire wound, concrete water storage tank in Marion, Massachusetts, with associated piping and appurtenances, a Tideflex mixing system, and site work. Other work included the decommissioning and demolition of the existing 2.0 million gallon pre-stressed concrete water storage tank at the project site. All work was completed ahead of the August 30, 2015 deadline.
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.
PROJECT: Mountainaire asset management based water distribution system study to assist with prioritizing water system improvements
THE CHALLENGE: Mountainaire is a small water distribution system with limited manpower and revenue resources, and the operation and maintenance of the system is often reactive rather than proactive.
THE SOLUTION: Tata & Howard successfully helped secure WIFA funding for the completion of the study which provides guidance to the PUC on how the system operates, what improvements are needed for efficient operation and continued maintenance of the system, and a prioritized approach to assist in funding and implementation of projects. This asset management based water distribution system study addresses undersized deteriorating water mains, above grade assets, and the energy efficiency of the pumping system. The study evaluates the system as a whole, based on above grade and below grade assets. Above grade assets are evaluated based on remaining useful life expectancy. Water mains are based on hydraulic capacity, criticality, and risk of failure. A hydraulic model was created for the study.
PROGRESS: Using the findings of the study, we are currently providing engineering services to evaluate flow and pressure requirements for the existing Kiowa Site booster pump station in order to construct a constant pressure pumping system to replace the existing booster pump and hydropnematic tank system that is old and failing.
The Long Pond Water Treatment Plant project consists of an 8.4 mgd DAF treatment plant, ozone contractors, and raw water pump station with intakes. The site stormwater management part of the project was separated into two designs: the parts of the site under the Conservation Commission’s jurisdiction and those that are not.
The majority of the site from the entrance along the access road and around the main treatment plant building did not fall under the Conservation Commission’s jurisdiction, and therefore did not require stormwater treatment. However, we did not want to ignore the potential impacts of stormwater, so this portion of the site was designed to allow for 100 percent infiltration. Along the access road, grading allowed for water to discharge and infiltrate in undeveloped areas where it will not impact the site. The area around the main building flows over land to an infiltration basin that is designed to collect, store, and infiltrate most storm events. There is an overflow in the case that the infiltration basin is overwhelmed during a large storm event.
The construction of the raw water pump station and intakes fell within the Conservation Commission’s and other agencies’ jurisdiction. Since the only impervious area was the building, and the building did not have a metal roof, MassDEP guidelines allowed for direct infiltration. The guidelines usually require the infiltration to occur in drywells in this situation, but the local Conservation Commission agreed that having an infiltration basin with an overflow would require fewer man-made structures and therefore have less impact on the surrounding environment. The infiltration was designed to store and infiltrate the raw water pump station roof runoff, and included an overflow for large storms.
CLIENT: Town of Auburn, Massachusetts Department of Public Works
PROJECT: Replacement of three existing wastewater pump stations
THE CHALLENGE: The sites were very small and restricted with high groundwater levels, and there were adjacent wetlands and private property. All three buildings were also very small and had other issues such as asbestos.
THE SOLUTION: We determined that the best course of action would be to demolish the buildings and convert the concrete dry pit that housed the pumping equipment into a wetwell for new, submersible pumps. The solution saved the Town hundreds of thousands of dollars.
PROGRESS: Tata & Howard provided the project design and will be putting the project out to bid this summer. We will also provide construction administration when construction begins in the fall.
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. The 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:
NPDES Phase II Small MS4 General Permit Annual Report Services
The purpose of the MS4 annual report is to document the status of NPDES Storm Water Management Program (SWMP) implementation with information including the following:
A self-assessment review of compliance with the permit conditions;
An assessment of the appropriateness of the selected BMPs;
An assessment of the progress towards achieving the measurable goals;
A summary of results of any information that has been collected and analyzed;
A discussion of activities for the next reporting cycle;
A discussion of any changes in identified BMPs or measurable goals; and
Reference to any reliance on another entity for achieving any measurable goal.
Tata & Howard has provided MS4 Annual Report services to the following municipalities:
Dover, Massachusetts
Tata & Howard assists the Town of Dover, MA with MS4 compliance. Services have included completion of the annual report, facilitation of an educational training session with municipal leaders, review and updating of stormwater infrastructure, and education on the upcoming MS4 Permit. We are currently assisting them with preparing the Notice of Intent required for coverage under the new 2016 Massachusetts MS4 General Permit.
Manchester-by-the-Sea, Massachusetts
Tata & Howard reviewed stormwater information and provided a Year 11 annual report to the Town of Manchester-by-the-Sea, MA.
Leicester, Massachusetts
Tata & Howard assists the Town of Leicester, MA with MS4 compliance. Services have included creation of an IDDE program including written statement of IDDE responsibilities, outfall inspection and mapping, and educational presentation to Town leaders on illicit connections. In addition, Tata & Howard helped the Town create and pass a bylaw related to illicit connections required by the MS4 Permit and produced the MS4 Annual Report for the Town. We are currently assisting them with preparing the Notice of Intent required for coverage under the new 2016 Massachusetts MS4 General Permit. Moving forward, we will be assisting the Town with additional mapping and catchment area identification.
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