Study/Evaluation Archives - Page 4 of 6

Replacement Wells, Upton, MA

Tata & Howard provided engineering services to the Town of Upton to address a water supply deficit identified in the 1998 Water Distribution System Study and the 2011 Water Master Plan and Capital Efficiency Plan™, both conducted by Tata & Howard. The multi-faceted approach was recommended to mitigate the supply deficit included maximizing their existing supply sources and the development of a new wellfield.

The original Glen Avenue Wellfield consists of two groups of 12 2½-inch diameter tubular wells, pumped through an 8-inch diameter, cast iron main. The original pumping capacity of the Glen Avenue Wellfield is approximately 0.316 million gallons per day (mgd). Recently, the yield of the Glen Avenue Wellfield has declined to approximately 0.08 mgd during the summer months. Due to the decreased yield, the Town did not have adequate supply to meet existing water demands. Replacement wells were recommended by Tata & Howard to regain the permitted capacity of the source.

The project consisted of a test well investigation program to evaluate the feasibility of replacement wells and preliminary permitting with the Massachusetts Department of Environmental Protection (MassDEP). Once the test well program indicated that three 16” x 10” gravel packed wells could replace the yield of the existing tubular wellfield, Tata & Howard met with MassDEP to approve the concept prior to proceeding with the pump test proposal submittal.

The scope of services included conductance of a 48 hour pump test as required by MassDEP, permitting with the MassDEP, Army Corps of Engineers, the Natural Heritage Endangered Species Program and the Upton Conservation Commission. Work also included design of well screens, submersible wells pumps, pitless adapters, variable frequency drives (VFDs), transducers in each well and water main to connect the new wellfield to the existing pump station and electrical and signal wiring. The wellfield was metered with one single meter within the pump station. Tata & Howard provided construction administration services and post construction administration services for the project.

Water System Operations Plan, Falmouth, MA

Tata & Howard, Inc. prepared a Water System Operations Plan for the Falmouth water system. As part of the Settlement Agreement between the Town of Falmouth and the Commonwealth of Massachusetts, the Town agreed to complete a Water System Operations Plan. The purpose of the plan was to evaluate seasonal demands, current source and storage tank operations and identify system and operational changes necessary to address distribution areas with low chlorine residuals.

The Town of Falmouth’s water distribution system consists of approximately 400 miles of water mains of various materials ranging in size from six to 24 inches in diameter. The Town has five active water supply sources including both groundwater and a currently unfiltered surface supply. Each source is treated with sodium hypochlorite for disinfection with the exception of Long Pond, which includes disinfection with chlorine gas. Falmouth’s water distribution system includes four water storage tanks and a Supervisory Control and Data Acquisition (SCADA) system to run and monitor operations.

The Falmouth Water Department faced a number of challenges, including the following:

Maintaining regulatory compliance
Meeting water demands
Peak summer demands could only be met with Long Pond surface supply
Long Pond is an unfiltered surface water supply
Constant struggle to maintain treatment compliance and water quality
Seasonal impacts from turnover or algae growth
Lack of treatment to address taste, odor, and color can require severe curtailment in use of the supply
Excessive source chlorine residuals needed to maintain distribution system residual chlorine concentrations, combined with source water organics results in elevated disinfection by-products (DBP – Total Trihalomethanes and Haloacetic Acids) which are regulated compounds

The study reviewed the challenges above and recommended changes to systems operations procedures to improve water quality. We used a hydraulic model to determine water age and look at its impacts on water quality. The plan was submitted and approved by Mass DEP.

Additionally, Tata & Howard completed the design of a 3.6 mgd treatment facility which utilizes air stripping and pressure filtration technology for the removal of iron, manganese and volatile organic compounds (VOCs). The facility includes an air stripping tower, three greensand filtration units, horizontal carbon contactors, chemical storage and feed facilities, gravel pack supply well, finished water storage, and backwash holding tanks.

Water Treatment Facilities, Canton, MA

The Town of Canton had primarily been relying on water from the Massachusetts Water Resources Authority (MWRA) for a majority of its water supply needs since 2003 due to the poor water quality of their well supplies. In order to reduce the amount of water purchased from MWRA, the Town began investigations of water treatment options for iron and manganese removal. In 2005, Tata & Howard conducted a pilot test using water from Well No. 9 since it represented what was considered the worst water quality particularly with regard to iron concentration. The pilot testing indicated that oxidation with potassium permanganate followed by membrane ultrafiltration would be successful in reducing the elevated levels of iron and manganese to below the Secondary Maximum Contaminant Levels of 0.3 mg/l and 0.05 mg/l, respectively. Based on the results of preliminary pilot testing, a system from Koch Membrane Systems, Inc. (Koch) of Wilmington, Massachusetts was used.

In addition to the pilot study, Tata & Howard performed a feasibility study to determine the best location for a treatment facility for all of their well supplies. The recommended location for a single facility was a Town-owned property between Charles Drive and Pecunit Street adjacent to the Well Nos. 11 and 12 site, requiring the construction of approximately 14,500-feet of transmission main. Due to the significant cost of the transmission mains, the disruption of traffic throughout the Town from road excavation for construction of those mains, and the unknown cost of the required permitting activities for the transmission mains, the Town decided on the construction of two treatment facilities.

Tata & Howard provided engineering design and construction administration services for two water treatment facilities. Piloting for the projects was completed at two well sites. The Neponset Street Water Treatment Facility (WTF) has a design capacity of 2.53 mgd. The facility use ultrafiltration with chlorine dioxide for treatment. The Pecunit Street WTF has a design capacity of 0.95 mgd and uses LayneOx with chlorination for treatment. The two treatment facilities allowed the Town to reduce the volume of water purchased by the MWRA.

Water Treatment Plant Dissolved Air Flotation (DAF) Pilot Study, Norwich, CT

The NPU contracted with Tata & Howard for the design and construction of renovations at the Stony Brook Water Treatment Plant. The NPU was challenged by an apparent and relatively abrupt change in raw water quality as a result of a green algae bloom consisting primarily of chlorophyta beginning in the summer of 2010. The original project requested the replacement of the media in the filter clarifier units with buoyant media. T&H proposed an alternative approach to not replace the media but rather add a new unit operation to the plant. Our belief was that simply changing the media at this plant would not have appreciably changed the treated water quality. T&H recently completed piloting a Dissolved Air Flotation (DAF) system at the plant to improve treated water quality.

Tata & Howard prepared a pilot test plan for DAF Clarifier piloting at the Stony Brook Water Treatment Plant site and conducted one summer season of DAF clarifier and filtration piloting. A pilot study report was prepared, including water quality data, evaluation of the treatment system, chemical dosages, flow rates, conclusions, recommended process, and design criteria. As a part of the pilot study, bench scale testing was performed to examine the performance of coagulants and polymers at various dosages and mix rates for the best removal of disinfection by-product (DBP) precursors. The bench scale testing was performed simultaneously with the pilot test and results were incorporated into the pilot test program.

In addition, T&H prepared design drawings and specifications for a 4.0 mgd capacity DAF clarifier system to be added to the plant to remove algae and to remove a greater level of disinfection by-product precursors. Additionally, we assisted with bidding of the project and provided construction administration and resident observation services.

Capital Efficiency Plan™ including Water System Master Plan, Northampton, MA

Tata & Howard has completed a Water System Capital Efficiency Plan™ for the City of Northampton. The plan includes a comprehensive water system master plan that evaluates the hydraulics of the system as well as critical components and asset management considerations. The hydraulic analysis included completion of fire flow testing and c-factor tests. Tata & Howard developed a hydraulic model from the City’s extensive ArcGIS database and the flow test results were used in verification. Tata & Howard reviewed recommended static pressures and Insurance Service Office recommended fire flows as well as estimated needed residential and commercial fire flows throughout the system.

The Northampton water system has wide range of ground elevations, resulting in extreme high and low static pressures in some areas. To maintain recommended system pressures, a new service zone was recommended to divide the distribution system. The recommendations included a new water storage tank, pressure reducing valves and transmission main improvements. Tata & Howard also developed additional recommended water main improvements to meet fire flow needs.

The asset management portion of the project included a detailed analysis of each segment of pipe in the water system based on age, diameter, material, pressure, soil conditions, break history, and potential water hammer. Each segment of pipe was given a numeric rating based on weighted asset criteria developed in cooperation with the City. This information was used with the hydraulic evaluation and critical component assessment to determine the prioritized improvements for the system.

Tata & Howard is also assisting the City with testing of pipes throughout the system. The work includes visual evaluation of samples and pipe strength testing. An analysis of the estimated service factor of each pipe segment will be provided to the City and used to supplement the information obtained during our asset management analysis.

Distribution System Water Quality Study, Norwich, CT

Tata & Howard, Inc. was retained by the Norwich Public Utilities (NPU) in Norwich, Connecticut to perform a distribution system water quality study to evaluate the water age, water quality, and hydraulic gradient in the Taftville/Occum Service Area. The Taftville/Occum Service Area has high water age, due primarily to the large volume of the Occum Tank. In addition, high levels of total trihalomethanes (TTHM) are observed throughout the Taftville/Occum Service Area.

This study examined the TTHM concentrations and high water age in the Taftville/Occum Service Area and presents various options to help mitigate these issues.

During the course of this study the following tasks were completed:

Updated the existing WaterGEMS hydraulic model using recent system data
Collected water distribution system data on current operating conditions,
historical and current disinfection by-product samples, water age, pressures, flows, and tank levels and supply and demand data for the entire NPU system
Conducted a gradient evaluation of the affected service area and investigated potential alternatives to improve the current conditions, including making short and long term capital improvements to provide improved tank level fluctuation and improved customer pressure ranges
Performed water age modeling of the existing service area and for potential
alternatives that improve the current conditions and graphed the results
Provided information and costs for alternatives to the tank passive mixing system
Provided recommendations for improving the service area gradient(s), water age, and water quality
To evaluate the Taftville/Occum Service Area, the entire NPU distribution system needed to be examined to determine the quality of the water as it enters the service area.

The key finding from this study related to the TTHM levels in the Taftville/Occum Service Area was that the formation potential in the effluent water from both of NPU’s surface water treatment plants was high enough for the TTHMs to exceed 80 µg/L at the entry point to the service area.

Based on this study, NPU has decided to add dissolved air flotation (DAF) to its Stony Brook water treatment plant. Tata & Howard designed the DAF system and other related improvements.

On-Call Water Engineering Services, Franklin, NH

Tata & Howard has been assisting the City of Franklin, New Hampshire with general water engineering services since 2009. The Tata & Howard team has managed several phases of work, including the design and construction of the water treatment plant and distribution system improvements.

The first phase was the design and construction of 2,500 linear feet of water main on Hill Road to connect a new water treatment plant to the City’s distribution system. This project also involved use of four bioretention systems to treat and manage stormwater from the roadway, and was constructed in 2010.

The second phase of our work with the City included the design and construction of two parallel 2,500 LF sections of 12-inch diameter HDPE crossings beneath the Pemigewasset River using horizontal directional drilling to transport water from the City’s Franklin Falls Well to the water treatment plant site.

Tata & Howard managed the survey and geophysical studies and prepared a Preliminary Design Report and Environmental Review documents for several phases of work. The City’s wells are surrounded by lands controlled by the US Army Corps of Engineers, which required that we complete an extensive permitting process to secure permissions for the final design of the project.

Tata & Howard completed design, construction, permitting, and funding applications for a 1,000 gallons per minute groundwater treatment plant to remove iron and manganese from three of the City’s wells. The plant has four pressure filters containing Greensand Plus media and using sodium hypochlorite for oxidation and sodium carbonate (soda ash) for pH adjustment. This plant went online July 9, 2012.

Tata & Howard provided design services for the construction of a new prestressed concrete tank at the site of an existing tank. The existing tank was in poor condition and due to the site characteristics, it was determined that construction of the new tank on the existing foundation of the old tank would be the best option. A second tank on the site was demolished in 2013 and a new prestressed concrete tank will be constructed in its place.

Tata & Howard also conducted a full water system analysis for the City of Franklin, New Hampshire by utilizing our proprietary Capital Efficiency Plan™ methodology. Our CEP involved creating a model of all water infrastructure in the City including sources, pump stations, treatment facilities, storage facilities, transmission, and distribution lines. Using our GIS modeling software, the system was calibrated based on fire flows in an attempt to accurately replicate the existing system. We then pinpointed deficiencies within the system based on a custom rating scale given to multiple criteria such as age, break history, material type, criticality and size. Recommendations were made for improvements in order of need. The study renewed both above ground and below ground assets. Funding for this study was in part from an Asset Management Planning Grant from NHDES.

SaveSave

Hospital Water Audit, Framingham, MA

Tata & Howard conducted a hospital water audit for the MetroWest Medical Center in Framingham, Massachusetts. The project was divided into two phases. The first phase involved data collection and a review of all water use devices at the MetroWest Medical Center (MWMC) campus. Inventory of all items was taken over a two day period. Items were categorized by their use including: toilet, faucet, shower, cooling units, and more. Tata & Howard performed an analysis of the water and dollar savings if the older models were replaced by newer, more efficient models. This analysis did not take into consideration the usage per day of the fixtures.

The second phase of the project included a cost/benefit analysis for replacing each fixture throughout the hospital. Usage was estimated for each fixture throughout the hospital and a payback period was calculated based on replacing the fixture with a like modeled unit that meets the EPA’s minimum water efficiency standards. A six year Prioritization Plan was then completed for the campus. Using a budget of approximately $5,000 per year, an annual savings of approximately $29,000 per year is expected upon completion of the six year plan. Savings could increase if more efficient fixtures are purchased instead of standard efficiency units. In addition to the Prioritization Plan, the MWMC was provided a spreadsheet detailing their fixtures throughout the campus which can be updated when an item is replaced.

For more information on water audits, please click here.

Service Area Improvements Study; 50-Year Population and Water Use Study; Capital Efficiency Plan™, SCCRWA

Tata & Howard provided engineering services and completed numerous studies for the South Central Regional Water Authority (SCCRWA) headquartered in New Haven, Connecticut, serving 17 Cities and Towns and serving a population of over 400,000 people. Phase 1 of the New Haven Service Area Improvements Study was completed in 2009. The purpose of the study was to determine the lowest cost set of recommended capital and operational improvements to incorporate additional service areas into the New Haven Service Area. Our services included evaluating potential improvements to the distribution system to meet SCCRWA’s pressure, tank fluctuation, and fire flow criteria, and recommending a conceptual baseline solution, which was optimized during Phase 2 of the study. Phase 3, which completed the study, included a Preliminary Design Report with our final recommendations.

A 50-Year Population and Water Use Study was completed for SCCRWA in 2009. The study examined trends in water use and population growth in each of the towns and service areas served by SCCRWA and projected future water use for average day, maximum day, and maximum month demand throughout the distribution system. The projections were completed in accordance with guidelines from the Connecticut Department of Public Health and were involved in SCCRWA’s 2009 water supply plan.

In 2008, SCCRWA purchased a water distribution system with approximately 125 miles of water mains and customers located in Ansonia, Derby and Seymour, Connecticut. Tata & Howard was contracted to complete a Capital Efficiency Plan™ of the new system. Our services included updating and verifying the existing hydraulic model, evaluating the condition of the existing distribution system infrastructure to determine the adequacy of meeting present and future demands, calculating needed storage requirements, assess and prioritizing system improvements, reviewing and evaluating typical fire flows throughout the system, creating a pipe asset management rating system, and recommending improvements to the distribution system. Following the success of this effort, Tata & Howard completed Capital Efficiency Plans for the
remainder of the distribution system in 2011 and 2012.

Unidirectional Flushing Program, Capital Efficiency Plan™, and Water Main Design, Melrose, MA

Tata & Howard provided assistance during the City’s unidirectional flushing program. As part of the work, Tata & Howard recorded the flow from the hydrants, noted any changes in the plan, and noted any defective hydrants or valves. When completed, a summary report outlining the total usage of water and recommended improvements to the flushing program was provided.

Water Mains and Capital Efficiency Plan™

Tata & Howard also provided design and construction services for approximately 5,600 feet of new 8-inch water main and approximately 950 feet of new 12-inch water main throughout the City. Plans were created using available GIS data from the City and field verification. These water mains also included crossing two MWRA transmission mains and crossing the Lynn Fells Parkway. The Lynn Fells Parkway crossing required permitting with the Department of Conservation and Recreation and a traffic management plan.

This work was funded through the MWRA. As part of the project, Tata & Howard updated and verified the City’s existing hydraulic model, which has over 80 miles of water main. Work included two days of fire flow tests throughout the City and allocation of demands using up-to-date billing and parcel data. The locations of the new water mains were selected based on preliminary recommendations identified in the Capital Efficiency Plan™ that was prepared by Tata & Howard. The Capital Efficiency Plan™ identified and prioritized areas for improvement within the distribution system. Our services included evaluating the condition of the existing distribution system infrastructure to determine the adequacy of meeting present and future demands, assessing and prioritizing system improvements, reviewing and evaluating typical fire flows throughout the system, creating a pipe asset management rating system, and recommending improvements to the distribution system.

Download a whitepaper detailing a comprehensive summary of the UDF by clicking the link below:

Services: Study/Evaluation