Water Archives - Page 5 of 10

Manganese Filtration Using Biological Pressure Filtration

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.

Ground breaking on the new WTP took place in July 2017.

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.

You may download the complete whitepaper by clicking here.

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Water Treatment Facility, Water Mains, and River Crossing Horizontal Directional Drilling

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.

New Water Main, Whitinsville Water Company, MA

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 Water Main, Northampton, MA

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.

Unidirectional Flushing Program, Shrewsbury, MA

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.

Southern Maine Regional Water Council (SMRWC) Regional System Study

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

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:

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.

Bellemont, AZ Water Treatment

Tata & Howard provided general engineering services to Bellemont Water System associated with responding to Arizona Department of Environmental Quality (ADEQ) violations and preparing an Application for the Groundwater Compliance 4-Log Removal of Viruses. Randall Pellatz, P.E., from Tata & Howard’s Flagstaff office, served as Project Manager.

Located west of Flagstaff in the unincorporated community of Bellemont, the water system served approximately 100 customers — the majority of whom receive water hauled by truck to cisterns at their homes — as well as a few businesses, including a strip mall. The system also provides some fire protection. After the system repeatedly tested positive for E. coli bacteria and total coliform bacteria, a boil water notice was issued in August of 2012. In June of 2013, ADEQ issued a compliance order that required the Bellemont Water System to notify all customers of the boil water advisory and to install a treatment system that satisfactorily removes bacteria and viruses from the water. The source of the contamination was unknown.

Tata & Howard’s scope of services included providing a response to ADEQ’s compliance order and developing a preliminary plan of action for maintaining 4-Log Removal of Viruses for the Bellemont Water System. In addition, a preliminary schematic plan for a chlorination system was developed to provide a residual chlorine concentration throughout the Bellemont Water System. Tata & Howard also provided design services for the proposed disinfection system and completed an assessment of the existing conditions of the Bellemont Water System, including recommendations, in a letter report.

The system’s operator, Jeremy McCabe, installed the disinfection system, and in June of 2016, the Bellemont Water System underwent their final field inspection from ADEQ for chlorine residual and 4-log removal. They passed easily, and ADEQ was pleased to remove the boil water requirement. Mr. McCabe commented on how well the system now operates, and the system’s customers have expressed how happy they are to once again have safe, clean water.

Raw Water Transmission Main Replacement in Stamford, CT

Owner: Aquarion Water Company, Shelton, Connecticut

Tata & Howard provided professional engineering services for surveys and mapping; subsurface explorations; preliminary and final design; bidding; and construction phase services, including resident project representation, for the partial replacement of Laurel Reservoir Raw Water Transmission Main located on Lakeside Drive in Stamford, CT. The main was replaced after a history of multiple pipe failures.

This project included replacing approximately 3,670 feet of an existing 13,540 feet of 42-inch diameter prestressed concrete cylinder pipe (PCCP) used to transfer raw water by gravity from Laurel Reservoir to the Stamford Water Treatment Plant (WTP). The pipe was replaced with 48-inch Class 52 ductile iron pipe. Three existing 8-inch blowoffs and two existing 4-inch diameter automatic air release valves in this section of main were replaced and upsized with new 12-inch diameter blowoffs and 12-inch diameter valves. The main was encased in concrete at three culvert crossings. Additionally, two 24-inch diameter access openings were installed in the existing 42-inch diameter main that was not being replaced to allow for inspections while the pipe was drained and out of service. The project also included replacement of four existing automatic air release valves on the existing 42-inch diameter PCCP that was to remain in service.

Water Distribution System Evaluation and Tank Design, Paxton, MA

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

Town of Paxton, MA

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:

To download “Town of Paxton, Massachusetts Distribution System Evaluation and Improvements” whitepaper instantly, simply fill out the form below:

Project Category: Water