Tata & Howard completed a test evaluation and design report for the Bomil Well site comparing ultrafiltration using ozone and chlorine dioxide as oxidants. The report also evaluated several coagulant aids to treat the organic color in the water. The design report became the basis for the 2.5 mgd water treatment facility designed by Tata & Howard. The facility uses membrane filtration with chlorine dioxide for treatment. Construction administration was also provided by Tata & Howard.
Tata & Howard conducted a Water Quality Study that reviewed the Town of North Attleboro, Massachusett’s corrosion control practices, and evaluated changes in quality, specifically the increased levels of iron and manganese. The manganese concentrations in these wells had consistently increased during the past decade. The pilot treatment study for manganese removal with greensand pressure filtration was conducted at the Kelley Wells 1 and 2 and was a success. Tata & Howard completed the design of the 2.0 mgd capacity treatment facility and provided engineering services during the construction of the facility.
The design included the installation of a SCADA system for monitoring and control of the treatment facility and two well pump stations. A second operator work station was installed at the remote Water Department office which allowed both monitoring and control of the treatment facilities from this remote site. In addition, the operator work station was linked to the existing Autocon SCADA system which continued to monitor and control the remaining water system pumping stations and storage tanks and provide tank level signals for the establishment of start/stop setpoint controls for the new treatment facility and associated wells.
Tata & Howard provided engineering services for permitting, design, and bidding of the 1.3 mgd chemical injection Trinity Avenue Pump Station at the Trinity Avenue Wellfield. The project included an evaluation of alternatives for the access road including installation of a bridge or an open bottomed culvert; assistance with the preparation of permanent easements for the installation of utilities and roadway to the well site; preparation and submittal of an NOI to the Grafton Conservation Commission. The design included an access road, bailey bridge with abutments, double wythe block building, interior concrete painted block with wood truss roof and asphaltic shingles, installation of three (3) submersible pumps and pitless adaptors, approximately 1,800 linear feet of 6-inch and 12-inch water main, emergency liquid propane tanks and generator, instrumentation and controls, a SCADA system for the pump station and wells, and a 24-inch transmission main for 4-log removal. Security included chain link fence, gates, locks, intrusion alarms, and lighting. Tata & Howard also assisted Owner with the coordination of the installation of three phase power to site. Chemical feed at the station includes KOH for pH adjustment and chlorine gas for disinfection. Standby power was included in an outdoor enclosure. The project is currently under construction and is expected to be completed by the end of 2017.
The Home Farm Water Treatment Plant (WTP) in Shrewsbury, Massachusetts was originally constructed in 1989. Although the WTP is still fully functional, its treatment capabilities are limited to chemical addition and air strippers for VOC removal, and the plant is capable of treating 6.0 million gallons per day (mgd). Manganese is present at all Home Farm wells, with widely varying levels from a low 0.03 parts per million (ppm) to a high 0.7 ppm. The existing treatment plant sequesters manganese, but does not have the ability to remove it from finished water.
Three treatment methodologies were piloted. The first two were greensand and pyrolucite, both commonly implemented catalytic media options for removing manganese and iron. The third was Mangazur®, a new technology. Mangazur® filter media contains the microscopic organism leptothrix ochracea, which consumes manganese and is naturally occurring in groundwater. Through consumption, the microbes oxidize the manganese to a state where it can precipitate onto the media. Unlike other media, Mangazur® does not require regeneration due to the continuous growth of microbes within the filter. Mangazur® technology also does not require chemical addition for pre-oxidation, minimizing the amount of chemical required for the plant.
Pilot testing for the biological treatment was performed over five one-week trials. Test parameters included a long shut-down on the filters, adding pre-oxidant, and adjusting pH or dissolved oxygen. The results of the testing indicated that although the Mangazur® does require a correct dissolved oxygen level and pH, it does not require a pre-oxidant, making the only chemical addition necessary for pretreatment potassium hydroxide for pH adjustment. Filter backwash efficiency is also a major benefit of the Mangazur® technology for the Home Farm application. With loading rates twice that of traditional catalytic media and filter runs exceeding 96 hours; the Town would only need to backwash the four filters once every four days rather than eight filters every day, saving a significant amount of water. The backwash flow rate and duration are also significantly lower for Mangazur® filters than for other traditional filter options. The results of the pilot tests indicated that all technologies were viable options to reduce manganese levels below 0.05 ppm; however, the biological treatment was the most efficient and attractive option.
Initially, the Town was only considering constructing filters along with the required backwash holding tanks in a new building and utilizing the chemical feed systems in the existing treatment facility. However, as the project progressed it was determined that it would be more cost effective to replace the existing aging air strippers rather than to continue to rehabilitate them, and eliminate the need to re-pipe the flow since the existing strippers added too much dissolved oxygen prior to the biological units. Since the existing chemical feed equipment in the plant is aging and the existing building itself was also in need of rehabilitation, the decision was made to construct an entirely new standalone 7.0 mgd facility. The new facility also contains three deep bubble aerators for VOC removal.
While Mangazur® technology has been approved in one other municipality in Massachusetts, there are few treatment plants in the northeast using this technology, and of those treatment plants, none have a design capacity above 5.0 mgd. Home Farm has a much higher design capacity and will be the largest Mangazur® water treatment plant in the northeast once completed. The Mangazur® filters at Home Farm will have the second highest design capacity in the country, after a 26.0 mgd treatment plant in Lake Havasu City, Arizona.
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Tata & Howard provided design and construction services for the construction of a 1.44 mgd water treatment facility. The water treatment facility consists of a concrete block masonry building housing filtration equipment, a laboratory and office space, and associated piping, instrumentation and controls. Building components including HVAC, plumbing, and electrical services were incorporated in the facility. Other work included, but is not necessarily limited to, site work, exterior piping systems, and electrical work at an existing well pump station.
Tata & Howard also provided design and construction services for the installation of approximately 5,000 linear feet of new 12-inch high-density polyethylene (HDPE) water main (two parallel pipes at 2,500 linear feet, each) via directional drilling beneath the Pemigewasset River, connecting the City’s Franklin Falls Well Site and the City’s Acme Well Site.
Tata & Howard provided design and construction services for the installation of approximately 2,655 linear feet of 12-inch diameter Class 52 ductile iron water main, water services, and associated valves, fittings, and hydrants on Hill Road (New Hampshire Route 3A) and a service road connecting Hill Road to the City’s Acme Well site; approximately 4,000 linear feet of 12-inch water main, water services, and associated valves, fittings, and hydrants on Lawndale Avenue, Webster Lake Road, and Kimball Street; approximately 3,200 linear feet along Lawndale Avenue; 1,200 linear feet along Webster Lake Road; and 600 linear feet along Kimball Street. The work also included pavement restoration on Lawndale Avenue, Webster Lake Road, and Kimball Street.
The project was funded by NHDES and the USDA Rural Development office.
Tata & Howard provided engineering services for the design, construction administration, and resident project representation for the installation of approximately 3,800 linear feet of 8-inch ductile iron water main on A, B, C, D, and Border Streets for the Whitinsville Water Company. All homes in the project area are multi-family ranging from duplexes to four units per building, and are of wood construction. The area has a history of fires, so fire protection was of utmost concern.
The project began in February of 2016. Each home had its water service replaced, and also received a 6-inch ductile iron water main that was installed with a gate valve and a cap so that the homeowner could install individual fire and water services to each unit. For example, the homes with four units could be tapped with eight new service lines, giving each home a fire service and a water service and increased protection from fire. As added fire protection, Tata & Howard also replaced all hydrants and added four additional hydrants to the project area.
All water main installation was completed in November of 2016, and final paving took place in the spring of 2017.
Bliss Street in Northampton, MA had experienced several water main breaks. Therefore, the City wanted the main to be replaced over the winter rather than waiting until spring. The project included design, bidding, and construction administration services for the water main replacement on Bliss Street from Scanlon Avenue to Willow Street. The design included new 8-inch diameter ductile iron water main, services, and appurtenances, as well as preparation of base plans from available City records, City GIS mapping data, and field measurements.
Construction occurred during the winter to meet the client’s schedule. Two change orders were issued to address hydrant extensions and sewer component repairs. The bid opening was the day before Thanksgiving. Construction started in December and was substantially completed by spring.
Tata & Howard recently developed a unidirectional flushing (UDF) program for the Town of Shrewsbury, MA. The project included converting the existing water distribution system hydraulic model from WaterGEMs to InfoWater, preparing water system flushing maps, delineating flushing zones, and preparing a sequential UDF for the water distribution system from sources to system extremities following the American Water Works Association (AWWA) published guidelines referred to as “Rules for Flushing.”
The program successfully identified sequences of valves to close, hydrants to flush, flow rates, and required duration. Worksheets were prepared for each sequence, including identification of hydrants and valves to be operated, pipes to be flushed, approximate discharge flow, and recommended flushing duration.
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.
Through 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:
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.