Tata & Howard provided the design of a 1.44 million gallon per day (mgd) water treatment plant to treat water from the Whitinsville Water Company’s Whitin Wellfield. The existing facilities consisted of a chemical injection facility and pump station, and historical high levels of iron and manganese led to water discoloration issues in the distribution system.
The new treatment facility for the Whitin Wellfield utilizes chlorine oxidation and GreensandPlus™ media filtration to remove iron and manganese from the raw water to concentrations below Secondary Maximum Contaminant Levels. The installation of 16-inch pipe between the existing facility and the water treatment facility is utilized in combination with filtration to provide contact time to achieve log removal of Giardia Lamblia (Giardia), Cryptosporidium, and viruses, if it becomes necessary in the future.
The treatment plant components include a three cell horizontal pressure filter vessel, a backwash water tank, and backwash pumping systems. The design also included a dehumidification system and the installation of crushed stone below the filter vessel and spent backwash tank. This allows for water to infiltrate into the ground and prevent puddling on the concrete floor in the event that condensation does occur on the equipment.
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
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.
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.
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.
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.
Prepared tank sub-gradeCompleted leveling base for tankTank floor/footing reinforcing steel and seismic cables prior to concrete pourCompleted tank floor/footingFinished tank
PROJECT: Mission critical storage tank systems for Southeast Louisiana Veterans Health Care System (SLVHCS)
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 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.
PROJECT: Chester Street 0.5 million gallon water storage tank painting, cleaning, and rehabilitation
THE CHALLENGE: The Chester Street water storage tank required evaluation, repair, cleaning, and painting of both the interior and the exterior. The tank is located in a heavily populated residential neighborhood and the exterior surface had high levels of lead in the paint. Therefore, special attention to lead contamination, noise, and construction debris was required. In addition, determination of the effects of taking the tank offline were required before any work could be started.
THE SOLUTION: Analysis of the Super High Service Area using the verified hydraulic model was conducted, and the model was run under extended period simulation (EPS) to evaluate the potential pressure problems within the service area. As a result, operational modifications to the existing pump stations and service zones were recommended. Working only during daylight hours while keeping noise and debris to a bare minimum, construction crews completed miscellaneous repairs including replacing the anchor bolts, installation of overflow support brackets, modification of the access ladder, modification of the roof ladder, repair of the upper level sway rod, extension of the balcony handrail, installation of a roof handrail, and replacement of the roof finial vent. During the exterior abrasive cleaning, a containment system was utilized to prevent lead from getting into the air and soil. Once all repairs and cleaning were completed, the interior and exterior of the elevated tank were painted.
PROGRESS: Two years later, the tank is still in pristine condition, as shown in the photo above.
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.
CLIENT: Town of Auburn, Massachusetts Department of Public Works
PROJECT: Replacement of three existing wastewater pump stations
The buildings are situated on very small sites
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.
An existing building is inspected during the design phase
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.
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