Water Treatment Plant in North Chelmsford, MA

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.

Iron and Manganese Removal Using Greensand Pressure Filtration


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.

 

 

 

 

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Trinity Ave. Chemical Feed Pump Station, Grafton, MA

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.

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.

Pilot test setup

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

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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.

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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.

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.

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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.

Water System Upgrades including Manganese Removal, Montgomery, VT

Tata & Howard designed and constructed the improvements to eliminate low and inadequate system pressures, construct a new source, pilot test filtration for manganese removal, design and construct required distribution system piping to connect the plant and storage tank with the system, design a new concrete storage tank, booster pump stations, and the filtration facility for manganese removal.  The  project was very successful and remains in great condition today.

Water Treatment Plant with Dehumidification System, Whitinsville, MA

Tata & Howard provided the design of a 1.44 million gallon per day (mgd) water treatment plant to treat water from the Whitinsville Water Company’s Whitin Wellfield. The existing facilities consisted of a chemical injection facility and pump station, and historical high levels of iron and manganese led to water discoloration issues in the distribution system.

The new treatment facility for the Whitin Wellfield utilizes chlorine oxidation and GreensandPlus™ media filtration to remove iron and manganese from the raw water to concentrations below Secondary Maximum Contaminant Levels. The installation of 16-inch pipe between the existing facility and the water treatment facility is utilized in combination with filtration to provide contact time to achieve log removal of Giardia Lamblia (Giardia), Cryptosporidium, and viruses, if it becomes necessary in the future.

The treatment plant components include a three cell horizontal pressure filter vessel, a backwash water tank, and backwash pumping systems. The design also included a dehumidification system and the installation of crushed stone below the filter vessel and spent backwash tank. This allows for water to infiltrate into the ground and prevent puddling on the concrete floor in the event that condensation does occur on the equipment.

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Treating Arsenic in Water in Arizona

shangri la ranch sunset

The Shangri La Ranch water supply, located in New River, Arizona, exceeded the running annual average maximum contaminant level (MCL) for arsenic. For the first quarter of 2015, the running annual average (RAA) was 0.0107 mg/L, and the RAA for the second quarter of 2015 was 0.0106 mg/L. The MCL for arsenic is 0.01 mg/L.  Arsenic contamination within aquifers is not uncommon and is generally from natural mineral deposits. Arsenic in high enough concentrations can result in skin legions and damage to the circulatory system and cancer; therefore, it is important to monitor and minimize this contaminant from drinking water.

The Shangri La Ranch is a non-transient, non-community water system that services approximately 240 customers. The actual number of customers served varies and is dependent on the number of people that are visiting the resort during a given period of time. Tata & Howard prepared an Arsenic Treatment Report for the Arizona Department of Environmental Quality (ADEQ) to address arsenic levels in the Shangri La Ranch’s water supply. It included a summary of the existing layout and operation of the water supply wells, representative treatment provided, and recommendations for additional treatment to meet the State and Federal MCL for arsenic.

The results of the study indicated that the arsenic concentrations in Well No. 1 was low enough that blending from the existing wells would adequately reduce the arsenic concentration to below the MCL. It was also recommended that the system install two ISOLUX® cartridges, in parallel, to reduce the arsenic level in Well No. 4 to levels below the MCL prior to blending with the remaining water supplies. ISOLUX® utilizes a zirconium adsorption system to remove arsenic from water

Water System Improvements and Funding Assistance, VT

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Greensboro Fire District No. 1 (GFD#1), situated on the Northern portion of the Green Mountains in Vermont, requested assistance with their water distribution and treatment systems due to deficiencies identified in a sanitary survey conducted by the State of Vermont. This contract addresses these deficiencies and provides the District a more robust covered water storage tank, secure buildings that house controls and chemicals and related equipment, emergency power generation, and water metering.

As part of the project, Tata & Howard helped GFD#1 secure funding that included a 45% USDA Grant for the originally planned project with an estimated budget of $2,900,000. During the design phase, the District lost their primary well source due to an extended drought. Tata & Howard engineers worked with the District to secure a 100% USDA grant for the cost of constructing a new municipal well source and associated emergency generator and related appurtenances.

Tata & Howard provided design, construction administration, and resident observation for the water system improvements project. Construction began in the spring of 2015 with the setup of a temporary water storage system and demolition of the existing water storage tank roof structure. Precast planks and a ballasted membrane roof were then installed, providing safe, quality water. Two new small buildings were constructed to house chemicals and water well piping and controls, along with an emergency generator to provide continuous water in case of interruption to electrical power.