Projects Archive - Page 9 of 16

Dam Reconstruction, Meriden, CT

The Fosters Pond Dam reconstruction project presented several challenges. The existing spillway was inadequate to discharge the 100-year spillway design flood, and the existing dam was in extremely poor condition. The embankments lacked erosion protection and were very steep, the crest was narrow, and the outlet had fallen into disrepair, rendering it inoperable. Therefore, it was imperative that the reconstruction design of Fosters Pond Dam be designed to improve both safety and reliability, provide a functional and operable outlet, and provide ease of maintenance.

The reconstruction included the construction of new and higher reinforced concrete spillway training walls, upstream riprap erosion protection, a new reinforced concrete gate structure with 24″ inlet and outlet pipes and sluice gate, widened embankment crests to 12′, flattened slopes for ease of maintenance, and a gravel road to allow access to the embankment and gate structure. Riprap erosion protection is now provided on the upstream slopes as well as in the discharge channel. Because of these improvements, the dam can safely pass the 100-year spillway design flood with over a foot of freeboard. The length and level of the spillway weir remains unchanged.

Dam Gate Chamber Repairs, Weston, CT

Saugatuck Dam is a concrete water supply dam in Weston, CT built in 1940, now owned by Aquarion Water Company. The majority of this project included repairs and modification to the gatehouse and gate chambers at the dam. Repairs included rebuilding the gatehouse walls, cleaning and painting the intake and outlet valves, and removing and replacing the stems and valve operators. Modifications included installing platforms made of steel beams and fiberglass in the gate chambers to provide safer access the valves in the chambers, and the interconnection of the 36” supply main and the 48” diversion main at the toe of the dam to provide greater flexibility for releasing water from the reservoir.

Treating Arsenic in Water in Arizona

The Shangri La Ranch water supply, located in New River, Arizona, exceeded the running annual average maximum contaminant level (MCL) for arsenic. For the first quarter of 2015, the running annual average (RAA) was 0.0107 mg/L, and the RAA for the second quarter of 2015 was 0.0106 mg/L. The MCL for arsenic is 0.01 mg/L. Arsenic contamination within aquifers is not uncommon and is generally from natural mineral deposits. Arsenic in high enough concentrations can result in skin legions and damage to the circulatory system and cancer; therefore, it is important to monitor and minimize this contaminant from drinking water.

The Shangri La Ranch is a non-transient, non-community water system that services approximately 240 customers. The actual number of customers served varies and is dependent on the number of people that are visiting the resort during a given period of time. Tata & Howard prepared an Arsenic Treatment Report for the Arizona Department of Environmental Quality (ADEQ) to address arsenic levels in the Shangri La Ranch’s water supply. It included a summary of the existing layout and operation of the water supply wells, representative treatment provided, and recommendations for additional treatment to meet the State and Federal MCL for arsenic.

The results of the study indicated that the arsenic concentrations in Well No. 1 was low enough that blending from the existing wells would adequately reduce the arsenic concentration to below the MCL. It was also recommended that the system install two ISOLUX® cartridges, in parallel, to reduce the arsenic level in Well No. 4 to levels below the MCL prior to blending with the remaining water supplies. ISOLUX® utilizes a zirconium adsorption system to remove arsenic from water

Water System Improvements and Funding Assistance, VT

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.

Fosters Pond Dam Reconstruction

CLIENT: City of Meriden, CT

PROJECT: Fosters Pond Dam Reconstruction

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.

Water Mains, Milford Water Company, MA

Tata & Howard was contracted to design approximately 2,000 linear feet of new 12-inch diameter ductile iron water main on Congress Street and West Fountain Street (High Service Area). The work included borings, survey, preparation of plans and specifications, and bidding. Construction of the High Service Area Water Mains took place over the summer, and was recently completed. Tata & Howard provided construction administration and resident observation services.

In addition, Tata & Howard was contracted to design approximately 2,400 linear feet of new 12-inch diameter ductile iron water main on East Main Street (Route 16). The work included survey, wetlands delineation, MassDOT permitting, completion of a Notice of Intent, preparation of plans and specifications, bidding, construction administration, and resident observation services.

Mountain Street Water Treatment Plant Valve Replacement

CLIENT: Northampton, Massachusetts

PROJECT: Mountain Street Water Treatment Plant Valve Replacement

Hole in clarifier pipe caused by failed check valve

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.

Great Hill Water Tank Construction, Marion, Massachusetts

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.

Tank floor/footing reinforcing steel and seismic cables prior to concrete pour

Shared Wastewater Treatment Facility, VT

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.

Mission Critical Storage Tanks, SLVHCS, New Orleans, LA

CLIENT: NBBJ, Columbus, Ohio

PROJECT: Mission critical storage tank systems for Southeast Louisiana Veterans Health Care System (SLVHCS)

hospital new orleans — SLVHCS in New Orleans, LA

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.

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