Worcester, Massachusetts Hydraulic Modeling Services and Capital Efficiency Plan™

Tata & Howard completed a hydraulic model update and Capital Efficiency Plan™ for the City of Worcester. As part of the project, Tata & Howard updated and verified the City’s existing hydraulic model, which has over 550 miles of water main.  Work included three days of fire flow tests throughout the City and allocation of demands using up-to-date billing and parcel data.  Phase II of the project, 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, calculating needed storage requirements, 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.

Tata & Howard calibrated the hydraulic model under extended period simulation for an evaluation of the Super High Service Area with the Chester Street Tank off-line due to rehabilitation.  The configuration of the service area included two distinct zones.  The Chester Street Tank is located in one area and the Howland Hill and Apricot Tanks are located in the other area.  To remove the Chester Street Tank from service, an evaluation of supply and pressures needed to be completed.  The results of the analysis included running both zones off the Apricot Tank and utilizing the Chester Street Pump Station to maintain pressures within the vicinity of the Chester Street Tank.

Capital Efficiency Plan™ for Manchester-By-The-Sea, MA

Tata & Howard, Inc. was recently retained by the Town of Manchester-by-the-Sea to complete a Capital Efficiency Plan for the Town’s water system.  The system was evaluated to identify areas of the water distribution system in need of rehabilitation, repair, or replacement, and to prioritize improvements to make the most efficient use of the Town’s capital budget.  The study evaluates the existing water infrastructure including water transmission and distribution piping and appurtenances.  In addition, water storage and supply needs were evaluated and prioritized. The analysis and improvements in this report are based on the Three Circles Approach for optimum capital efficiency, which combines hydraulic and critical component considerations with an asset management rating system to evaluate the condition of the water mains in the distribution system.  Each circle represents a unique set of evaluation criteria for each water main segment.  From each set of criteria, system deficiencies are identified.  System deficiencies from each circle are then compared.  Any deficiency that falls into more than one circle is given higher priority than one that does not.  Using the Three Circle Approach, recommended improvements will result in the most benefit to the system.  In addition, the Three Circle Approach allows us to identify any situations that mitigate a deficiency in one circle and eliminate a deficiency in another circle.  By integrating all three sets of criteria, the infrastructure improvement decision making process and overall capital efficiency are optimized.

Recommendations included a siting study for a second storage tank, Phase I-III distribution system improvements, and the continuance of scheduled maintenance programs such as hydrant flushing, leak detection, and meter testing. The Town’s pavement management plan was also taken into consideration to best prioritize and coordinate utility work with roadway reconstruction.

 

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Capital Efficiency Plan™ and Water Supply Study in Rowley, MA

A Capital Efficiency Plan was completed for the Town of Rowley in May 2017.  The study evaluated the 45 miles of the Town’s water distribution system using the Three Circles Approach, which consists of a system hydraulic evaluation, criticality component assessment, and asset management considerations.  From each set of criteria, system deficiencies were identified and a 20-year recommended improvements plan was provided.  Recommended improvements consisted of water main replacement projects, a pumping capacity evaluation and well redevelopment study, an interconnection analysis, and a distribution static pressure evaluation.

 

Capital Efficiency Plan™ for Avon, MA

Page Street Tank

Tata & Howard recently completed a Capital Efficiency Plan™ for the Town of Avon, MA.  As part of the project, Tata & Howard updated and verified the Town’s existing hydraulic model.  The work included the completion of fire flow tests throughout the Town and allocation of demands using up-to-date billing and parcel data.  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. Recommendations included installation of two replacement wells, conducting an interconnection study, rehabilitation of the Page Street Tank, and phased distribution system improvements.

The hydraulic model was also verified under an Extended Period Simulation (EPS), which considers changes in the distribution system over time.  The EPS will be used to evaluate tank operating ranges and modifications to the well operating conditions.

 

Capital Efficiency Plan™ for Norwalk, CT First Taxing District

Tata & Howard, Inc. was retained by the First District Water Department (FDWD) to complete a Capital Efficiency Plan for the First District water system in the City of Norwalk, CT.  Areas of the water distribution system in need of rehabilitation, repair, or replacement, were identified and improvements were prioritized to make the most efficient use of the FDWD’s capital budget. The study evaluated the existing water infrastructure including water transmission and distribution piping and appurtenances.  In addition, water storage needs were evaluated and prioritized.

Tata & Howard evaluated the water distribution system using the Three Circle Approach, which consists of evaluation criteria including a system hydraulic evaluation, a critical component assessment, and asset management considerations.

Hydraulic improvements included recommendations that would strengthen the transmission capabilities of the system or provide an ISO recommended fire flow to a certain area.  Priority 2 recommendations were identified as part of a system-wide evaluation to improve estimated needed fire flows and system looping.

A critical component assessment was performed for the water distribution system to evaluate the impact of potential water main failures on the system.  The critical component assessment includes identification of critical areas served, critical water mains, and the need for redundant mains.  Critical areas served were identified by the FDWD and include water department facilities, medical facilities, schools, and business districts.  Critical water mains include primary transmission lines as well as water mains that cross over major highways, rivers, and railroad tracks. Factors that affected the decision to replace or rehabilitate a water main include break history, material, age, diameter, soil conditions, water quality, and pressure.

An asset management assessment was completed for the system.  A number of factors are considered in the ratings including break history, material, age, diameter, soil conditions, water quality, and pressure, and these factors affect the decision to replace or rehabilitate a water main.

Utilizing the Three Circle Approach, improvements were recommended and prioritized based on the aforementioned criteria.  Phase I improvements include any recommended improvements that fall into all three circles and are therefore hydraulically deficient, critical, and have a high asset management score.  There are approximately 16,300 linear feet of new main in the Phase I recommended improvements.  Phase II improvements include any recommended improvements that fall into two of the circles.  There are approximately 81,400 linear feet of new main in the Phase IIa and Phase IIb recommended improvements. Phase III recommendations include any recommended improvements that are needed hydraulically or that have a high asset management score indicating poor condition.  The Phase IIIa and Phase IIIb include approximately 157,000 linear feet of new main.  In addition, recommendations included soil testing for corrosivity prior to ductile water main installation, implementation of a unidirectional flushing program, and annual updating of the hydraulic model.

Capital Efficiency Plan™ and Water System Master Plan, Attleboro, MA

Tata & Howard, Inc. was retained by the City of Attleboro to complete a Capital Efficiency Plan and Water System Master Plan for the Attleboro water system.  The purpose of the Capital Efficiency Plan portion of the project was to identify areas of the water distribution system in need of rehabilitation, repair, or replacement, and to prioritize improvements to make the most efficient use of the City’s capital budget.  The Water System Master Plan portion of the project created an inventory of the existing above ground water infrastructure assets including wells, pumping and treatment facilities, and water storage tanks.  The inventory can be used to track maintenance, repair, and replacement work.  Basin safe yields were reviewed and compared to projected demands to evaluate the adequacy of sources of supply. In addition, the project included creation of an extended period simulation (EPS) hydraulic model which can be used to analyze the system and account for changes over time.

An asset management assessment was completed for the system.  Several factors are considered in the assessment including age, material, diameter, break history, soil conditions, water quality, pressure, and whether the main was installed poorly.  These factors affect the decision to replace or rehabilitate a water main.  Using our asset management rating approach, each water main in the system was assigned a rating based on these factors. Utilizing the Three Circles Approach, improvements were recommended and prioritized based on the aforementioned criteria. Recommended improvements include the following:

  • Three phases of water main replacement projects;
  • A Water Quality and System Optimization Study to evaluate ways the City can lower the water age in the storage tank;
  • A study to evaluate improvements to maximize available yield;
  • Collection and maintenance of data on water main failures as well as pipe crushing results from water mains that have failed;
  • Testing of soil for corrosivity prior to installation of new ductile iron water mains;
  • Implementation of a Unidirectional Flushing Program; and
  • Minor repairs and security improvements to address deficiencies in the City’s above ground assets.

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Southern Maine Regional Water Council (SMRWC) Regional System Study

SMRWC graphicv1 - Dist-Flows

Tata & Howard was retained by the Southern Maine Regional Water Council (SMRWC) to complete a Regional System Study for the Portland Water District (PWD), Maine Water Company – Biddeford & Saco (MWCB&S), Kennebunk, Kennebunkport, Wells Water District (KKWWD), Sanford Water District (SWD), South Berwick Water District (SBWD), York Water District (YWD), and Kittery Water District (KWD). The purpose of the study was to provide a detailed update to their 2008 Regional Water System Master Plan Study, which studied possible interconnections between the water systems within the SMRWC.  A combined water distribution system regional hydraulic model was developed using the hydraulic models of each individual water system. The regional hydraulic model was used to evaluate the hydraulic feasibility and impacts of the proposed interconnections as well as the potential of transferring water from northern systems to southern systems through a completely connected and open system.  The PWD and MWCB&S have large water sources and are interested in exploring the option of providing water to southern systems. The study evaluated the needed infrastructure improvements, each system’s available water supply, and demands through the potential and existing interconnections.

The study also examined the effects that the proposed system improvements and interconnections would have on water quality. Not all water systems treat water in the same way; therefore, finished water is unique to the chemicals and treatment techniques used by each system. Specifically, pertinent available data was collected and chemicals used for coagulation, sequestering, primary disinfection, secondary disinfection, corrosion control, pH adjustment, and dental health were reviewed.  Raw and finished water parameters such as turbidity, alkalinity, temperature, pH, and total hardness were also collected.  Of the seven participating water systems in the study, three disinfect with chloramines and four disinfect with only chlorine solution. Operating the systems together as a permanent solution to water supply concerns would require modifications to the treatment processes in some if not all of the systems.  Ideally, each water system involved in water sharing would need to agree to a treatment method to give each system acceptable water quality and eliminate concerns with blending systems.

The identified improvements were based on hydraulic feasibility.  Infrastructure recommendations at the interconnection locations include construction of new water mains, pressure reducing valves, and booster pumping stations.

Regional Intermunicipal Interconnection Evaluation, MA

Northampton interconnection mapThrough a grant from the Pioneer Valley Planning Commission, Tata & Howard was retained by the City of Northampton Department of Public Works (Northampton) and the City of Easthampton Water Works (Easthampton) to complete a Regional Intermunicipal Interconnection Evaluation for the Easthampton, Hatfield, Northampton, Southampton, and Williamsburg water systems.  The purpose of the study is to evaluate potential water distribution system intermunicipal connections and emergency water supply.  A combined water distribution system regional hydraulic model was developed and used to evaluate the hydraulic feasibility and impacts of the proposed interconnections.  The study evaluated the needed infrastructure improvements, system available supply and demands, and available supply through the potential interconnections.

Potential interconnection locations between Northampton and Easthampton were considered at four locations, between Northampton and Hatfield, between Northampton and Williamsburg, and between Easthampton and Southampton.  Infrastructure recommendations at the locations include construction of new water mains, meter pits, flow meters, pressure reducing valves (PRV) and portable pumping systems. The Massachusetts Department of Environmental Protection (MassDEP) Water Management Act (WMA) permitted and registered pumping volumes for each system’s sources was evaluated for potential supply to other communities.  Northampton and Easthampton have surplus supply, while Hatfield, Williamsburg, and Southampton are approaching their WMA permit or registration allowable withdrawal volumes.

The study determined the following:

  • Three of the four potential interconnection locations between Northampton and Easthampton could be utilized in an emergency by isolating portions of Northampton’s system. An interconnection that could serve all of Northampton would require a pumping system.
  • A pressure reducing valve would be required to supply Hatfield from Northampton and a pumping system would be required to supply Northampton from Hatfield.
  • Due to the location of the Williamsburg interconnection along Northampton’s transmission main route, and the limited amount of water available from Williamsburg, an interconnection from Williamsburg to Northampton is not feasible.

There is an existing hydrant to hydrant interconnection between Easthampton and Southampton that has been utilized to supply water to Southampton during periods of high summer demands. To supply the entire Southampton system, a pumping system would be required, and a PRV would be required to maintain adequate pressures if Southampton were to supply Easthampton.

Water Distribution System Evaluation and Tank Design, Paxton, MA

Town of Paxton, MA

The new tank was completed in 2015
The new tank was completed in 2016.

Tata & Howard provided engineering services for a comprehensive water distribution system evaluation and study. The work included development of a hydraulic model using WaterCad software. The plan included fire flow tests, review of the water supply agreement with the City of Worcester, preparation of projected water demands based on historical use and population trends, and evaluation of storage. The plan also included an evaluation of potential water supply sources within Town boundaries.

This project included an evaluation of the system prior to design of the tank to determine the best solution.  Work included calibrating the model under extended period simulation (EPS).  The hydraulic model was used to determine the best hydraulic gradeline elevation of the system to reduce the storage surplus.  Additionally, the model was used to track the chlorine residual from the Worcester Pump Station to the extremities.  Jar testing was completed to determine the chlorine demand in the water supply while water quality testing results assisted with determining the chlorine demand in the piping system.  The model was used to simulate the chlorine degradation.  Improvements were input into the hydraulic model and the effects on the chlorine residual in the extremities reported.  Improvements such as an elevated tank at Maple Street with a total usable volume, reduction in hydraulic gradeline elevation, and cleaning and lining water mains were evaluated.  The analysis determined that a new tank at Maple Street is necessary based on water quality and cost.

Tata & Howard provided assistance with the preparation and submittal of a Project Evaluation Form to the Massachusetts Department of Environmental Protection for the construction of a new elevated tank with a capacity of 0.2 million gallons. The new tank reduced the water age in the system by replacing the deteriorating ground level tank. Tata & Howard provided construction administration and resident observation services for the new tank, which was completed in 2016.


Whitepaper:

ABSTRACT: In 2012, the Town of Paxton, MA was experiencing significantly reduced chlorine residuals in the extremities of the system along with an aging water tank that required extensive rehabilitation. As a result, the Paxton Department of Public Works (DPW) determined the need to create an extended period simulation (EPS) hydraulic model to evaluate the water age and water quality in the distribution system. The study examined the residual chlorine concentrations and water age throughout the distribution system and presented various options to help mitigate these issues, including replacing the aging tank and adding a chlorine booster pump station at the existing site. Construction of the new tank and pump station was completed in the summer of 2016.  Read the complete whitepaper by clicking below:

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CHALLENGE: Water Storage Tank Painting, Cleaning in Residential Setting

Chester Street 0.5 million gallon water storage tank in Worcester, MA

CLIENT: City of Worcester, Massachusetts

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.