UMASS Amherst Hydraulic Modeling

Tata & Howard developed an extensive hydraulic model of the University of Massachusetts (UMass) Amherst campus. The model was verified under steady state and an extended period simulation (EPS) was completed.  Tata & Howard conducted a hydraulic review and criticality assessment and used the results to make improvement recommendations.  Tata & Howard also identified water distribution system sustainability projects for the irrigation, cooling tower makeup, and toilet flushing water.

This project included a supplemental water supply system analysis.  Potential ground and surface water sources on campus, including existing and potentially new stormwater retention ponds, were evaluated for process and irrigation water.  In addition, Tata & Howard created a hydraulic model of the UMass reclaimed water system.

The study also examined the effects that the proposed system improvements and interconnections would have on water quality.

A Decade of Infrastructure Improvements

Wiscasset Completes Capital Efficiency Plan™ Infrastructure Improvements

The Wiscasset Water District (WWD) completed its final phase of water main replacements for the Town of Wiscasset, ME. In 2007, Wiscasset, a rural coastal town in Maine, embarked on a long-awaited infrastructure improvement program to replace the Town’s century-old waterlines. The Wiscasset Water District, engaged Tata & Howard’s services in 2010, to prepare a Capital Efficiency Plan™ (CEP), to identify areas to the Town’s water distribution system needing rehabilitation, repair, and/or replacement.

CEP reportThe Capital Efficiency Plan™ report which included hydraulic modeling, system criticality, and an asset management plan, provided the Utility with a database and Geographic Information System (GIS) representation for each pipe segment within their underground piping system. The CEP report also prioritized the water distribution system piping improvements and provided estimated costs to replace or rehabilitate the water mains.

Wiscasset Main StreetIn response to the CEP™ findings, the Wiscasset Water District retained the services of Tata & Howard, to perform design, bidding, construction administration, and resident project representation services for a series of water main projects.

Phased over 10 years, the plan included replacing 33,150 feet of 12-inch and 8-inch piping, installation of a water storage tank mixer, SCADA upgrades, and office landscaping improvements.

The final phase of water main replacements is scheduled to be completed during the summer of 2018 and will fulfill all the Priority I water main improvements identified in the 2010 CEP™ report. The projects were funded in part by a combination of USDA Rural Development grants (6 total) and loans (7 total), as well as coordination with the Maine Department of Transportation and Rural Development.

With the water main improvements nearing completion, the Wiscasset Water District has retained Tata & Howard to reevaluate its 2010 Capital Efficiency Plan™. The revised plan will update the water main inventory database and review additional recommended water distribution improvements.

Extended Period Simulation and Hydraulic Study for Town of Avon, MA Water Division

Tata & Howard completed an Extended Period Simulation (EPS) hydraulic model of the water distribution system for the Town of Avon, Massachusetts. An EPS model was created to account for changes in the water distribution system over an extended period to include peak and minimum demands during both the summer and winter months. These changes included tank levels, pump controls, value operation, and demand variations.

The EPS model was used to estimate the water age in the water distribution system under winter and summer demand conditions. Water age is the time water takes to travel from a water supply source to a point within the distribution system.  It is used as an indicator of water quality based on the assumption that the older the water is, the greater the likelihood that water quality has deteriorated.  According to MassDEP Finished Water Storage Guidelines, a three to five-day complete water turnover is recommended in water storage tanks.

The EPS model was also utilized to evaluate the Town’s existing system operations. The model was used to determine the optimal tank operating range and the impact of the run times on the well pumps. Simulations were performed on both the Center Street and Page Street Tanks to evaluate operations under existing and projected average day demand (ADD), maximum day demand (MDD), and peak hour demands with a minimum pressure of 35 psi maintained throughout the distribution system.

In addition to analyzing the tank optimal operating levels, changes to the existing pump operations and the effect on tank levels and water age were evaluated. Two modified pump operations scenarios were evaluated. Both scenarios were run with the existing tank water level controls and allowing the Page Street Tank to drop four feet.  A second modified pump operation scenario evaluated the Town’s lead/lag system. Results for the pump and tank level operations under these simulations were recorded for both summer and winter operations.

Based on the results from each operational modification, Tata & Howard made several recommendations for improvement to the water distribution system. These included allowing the water level in the Page Street and Central Street tanks to drop an additional six feet to improve water age during both the summer and winter demands.

In addition, to help improve the water age in the tanks to an optimal three to five-day complete water turnover as recommended by MassDEP Finished Water Storage Guidelines, Tata & Howard suggested installing mixing systems in each tank.

Wastewater Treatment Plant Evaluation, Manchester-By-The-Sea, MA

Tata & Howard completed a comprehensive evaluation of the Manchester-by-the-Sea wastewater treatment plant (WWTP).

The Manchester-the-Sea WWTP was originally constructed in 1998. The plant is designed to treat an average daily flow (ADF) of 1.20 mgd. The plant includes the following treatment processes: influent pumping, influent sewage grinding, manual bar rack, grit removal equipment, aeration tanks and blowers, clarifiers, chlorine disinfection, and sludge thickening.  The treated effluent is discharged into the ocean with effluent pumps through an ocean outfall pipe.

The treatment plant evaluation included a comprehensive assessment of the physical condition of the plant to provide an additional 20-year life for the facility.  The evaluation included all mechanical systems and equipment, electrical systems and controls, buildings, and structures.  The study included an evaluation of energy usage at the plant and developed recommendations to improve energy efficiency including replacement of influent and effluent pumps, and aeration blowers to better match plant flow requirements and system demands.

The final report includes an evaluation of existing conditions and proposed recommendations to improve current operations, upgrade aging equipment and facilities, improve energy efficiency,  and provide plant hardening against potential climate change and sea level rise.

 

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.

M36 Water Audit, Wayland, MA

Tata & Howard, Inc. was retained by the Town of Wayland, MA (Town) to complete a water audit of the water distribution system based on data and system information for the calendar years 2013, 2014, and 2015.  The project included assessing the amount of lost water using the American Water Works Association M36 water audit methods.  The report estimates the volume of lost water in terms of non-revenue water, identifies potential sources of lost water, and estimates system performance indicators including the Infrastructure Leakage Index.

The AWWA water audit results found that the Town’s non-revenue water was approximately 223 million gallons (mg) in 2013, 80 mg in 2014, and 93 mg in 2015.  The associated annual costs of water lost were approximately $425,000 in 2013, $320,000 in 2014, and $398,000 in 2015. In addition, 64% of the Town’s meters are over 15 years old.   The audit found that many of the losses are a result of customer meter reading and billing procedures.  Recommendations to reduce water loss included the following: volumetrically testing master meters at multiple flow rates and performing a field to database audit of SCADA flow reported from master meters; implementation of a customer meter testing and replacement program; upgrade of the customer billing system or replacement with advanced metering infrastructure (AMI); and documentation of unbilled and unmetered water use with the use of meters whenever possible.

To assist the Town with addressing the customer billing issues and aging meters, Tata & Howard completed a water meter and AMI evaluation. Next steps include assistance with a request for proposal (RFP) for AMI, and assistance during meter installation.

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Ozone Water Treatment Plant in Franklin, MA

Tata & Howard provided design and construction services for a new water treatment facility that houses a 1.2 mgd ultrafiltration system and completed a pilot test that consisted of an evaluation of two separate ultrafiltration technologies.  Franklin Wells No. 1 and 2, located off Hayward Street in Franklin, Massachusetts were installed in the 1940’s with a combined safe yield of 1.2 million gallons per day. Due to high concentrations of iron and manganese in the groundwater, the wells were only used to meet peak water demands during the summer months. The construction of the water treatment facility recaptures the yield from these two sources.  The water treatment facility consists of a main building which houses static mixers, ozone feed equipment, chemical feed equipment, prefilters, membrane filtration equipment, instrumentation and controls. Treatment consists of ozone oxidation followed by membrane ultrafiltration. The project was funded in part by the Massachusetts Water Pollution Abatement Trust through a low interest state revolving fund loan.

The overall treatment scheme is as follows: ozone injection, oxidation of iron and manganese in an ozone contact tank, prefiltration, treatment through two ultrafiltration membrane skids, chlorination prior to a clearwell, and fluoride addition prior to discharge into the distribution system. The plant is designed to recycle backwash water and membrane recirculation water to the head of the plant utilizing two decant tanks. Ozone is produced on site utilizing compressed air, while a LOX tank is available to allow for the production of additional ozone if required in the future.

 

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.