Services: Design

Rehabilitation of a 130 Year Old Tank, Newton, MA 

About the System

The water distribution system in the City of Newton, MA (City) serves approximately 90,000 people and includes 319 miles of water main ranging from 2-inches up to 30-inches. There is a southern pressure zone, a northern pressure zone, and three additional high service areas. All water is supplied by Massachusetts Water Resources Authority (MWRA) and the system utilizes two tanks, the Waban Hill Reservoir and the Oak Hill Tank. 

Installation of the 24-inch cast iron piping in 1890

The Waban Hill Reservoir (Reservoir) is located in the Chestnut Hill area of Newton and serves the southern pressure zone.  The Commonwealth Avenue Pump Station, operated by the MWRA, serves Newton’s southern pressure zone and fills the Reservoir. The Reservoir has a capacity of approximately 10 million gallons (MG) with four chambers that were built in stages: Chamber 1 was constructed in 1891, Chamber 2 in 1901, and Chambers 3 and 4 in 1917.  Each chamber is approximately 2.5 MG.  At the center of the reservoir is a gate chamber building that houses the influent and effluent valves and piping to each of the chambers as well as the 90-inch diameter central core standpipe.

Figure 1

As shown in Figure 1, there is a 24-inch diameter common inlet/outlet line that fills the interior standpipe and then overflows equally into all four chambers. When drawing, the 24-inch diameter check valve opens and draws through the effluent lines and out the common inlet/outlet. An additional 24-inch diameter inlet/outlet pipe is located in the corner of Chamber 2 that operates Chamber 2 only if needed. During construction, Chamber 2 was used to feed the system through the secondary inlet/outlet pipe while work was completed on the effluent valves for all chambers.  During construction, the effluent pipe from Chamber 2 to the core was plugged so that work could be performed on the piping and valve while keeping Chamber 2 in service.

All chambers have a drain line and valve that manifold into a 24-inch diameter drain line that runs under the existing common inlet/outlet pipe. The bottom of the interior standpipe as well as the standpipe overflow both drain into the 24-inch drain line. 

Design

The original scope of the repair project included rehabilitating the 90-inch diameter standpipe, replacing four 24-inch effluent valves, and replacing the asphalt shingle roof. 

Figure 2

Prior to construction, it was important to review the impacts of removing Chambers 1, 3, and 4 from service on the distribution system.  The existing hydraulic model for the City was used to evaluate pressures and available fire flow throughout the system with just Chamber 2 online.  The inlet/outlet pipe for Chamber 2 runs down Commonwealth Avenue to the Pump Station (blue line in Figure 2) while the main inlet/outlet pipe from the Central Core runs down Ward Street to the Pump Station (red line in Figure 2). Changing the location of where water enters the system from the Reservoir in turn impacted the hydraulics at certain areas of the system, specifically at higher elevations north of the Reservoir.  A recently installed 12-inch diameter interconnection between the two feed lines was opened, reducing the overall headloss in the system.  

The design required a contingency plan, addressing potential challenges such as losing the entire Reservoir due to a water main break on the inlet/outlet pipe to Chamber 2. Through close coordination with T&H, the City, and MWRA, an emergency response plan was created that added enhanced scenarios.  T&H evaluated the model for the best location of a mobile pumping unit and location of pressure relief valves. The City installed additional hydrants so the City could use MWRA’s mobile pumping unit if needed to pump from the northern pressure zone to the southern pressure zone, which required coordinating availability of equipment with MWRA.

Following a review of the challenges, the design scope was revised. Final design and bidding on the project included standpipe rehabilitation, effluent valve and piping replacement, drain valve replacement, check valve replacement, and asphalt shingle roof replacement as well as the standpipe cover and man-way, interior lighting improvements, and instrumentation. 

Construction Challenges 

There were many construction challenges to overcome as part of the design. Record drawings indicated an isolation valve was located on the common inlet/outlet pipe; however, the valve was unable to be found. A new valve was installed as a change order for the project.

The construction contractor was limited to light loads due to the uncertainty of the structural integrity of the roof to support specific loads, meaning no cranes or heavy equipment could be used, and spanning a crane from the access road to the gate chamber was cost prohibitive. 

The existing valves were embedded in concrete and the flanges were severely deteriorated.  Because of the age of the pipe, angles and bolt patterns were not easily matched with modern piping.  Therefore, stainless steel piping was used to fabricate the needed angles to connect the new valves to the common inlet/outlet pipe.

The standpipe was showing signs of severe deterioration.  Under recommendations from MassTank, specialty repairs were required to prolong the life of the standpipe. Steel plates were installed at the joints within the standpipe, both interior and exterior surfaces were sand blasted, a 200 mil epoxy coating was installed on the interior surfaces, and a 10 mil coating was applied to all exterior surfaces.

Initial filling of the reservoir caused Chamber 2 to fill faster than Chambers 1, 3, and 4 which caused the Commonwealth Ave. Pump Station to shut down.  Therefore, the MWRA mobile pumping unit was relocated to the Waban Hill Reservoir and water was pumped from the hatch in Chamber 2 through the hatch in Chamber 1 which was connected to Chamber 3 and 4 through the central core.

Conclusion

Construction was completed in February 2024 and the project was highly successful with minimal service interruption due to a close working partnership with Tata & Howard, the City of Newton (client), and MWRA.

Before
Before
Before
After
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After

Wading River Pilot Study — Attleboro, MA

Attleboro WTP

At the Wading River Water Treatment Plant, pilot testing, conducted by Blueleaf, Inc. and consulted by Tata & Howard, Inc., was performed to evaluate the removal of natural organic material for the reduction of disinfection byproduct formation in the distribution system, the reduction of manganese concentrations, and the removal of PFAS compounds. The removal of organic carbons by magnetic ion exchange (MIEX®), the removal of manganese by GreensandPlus™ filtration, and the removal of PFAS by FLOURO-SORB®-200 media, were found to be the most effective treatment processes. 

Scaled satellite imagery of the existing Wading River Water Treatment Plant

Project Background 

The City of Attleboro, Water Department (AWD) operates the Wading River Water Treatment Plant (WTP), located in Mansfield, MA, which includes two gravel packed supply wells and submersible well pumps, each pumping from a filter sand bed. The Wading River provides additional water to the filter sand basins via a steel pile dam and intake structure, and is considered a surface water source. The wells pump to the WTP where water is chemically treated with sodium hydroxide for pH adjustment, sodium hypochlorite for disinfection, polyphosphate for corrosion control, and hydrofluorosilicic acid for dental hygiene. Treated water flows through a 630,000-gallon, baffled concrete contact tank prior to being pumped into the water distribution system. 

The Wading River source is historically a high source of organic matter, which act as disinfection byproduct (DBP) precursors in the distribution system. Despite efforts by the City to optimize existing treatment to reduce the formation of trihalomethanes (TTHMs), a class of DBPs, test results have indicated levels above the maximum contaminant level (MCL) of 80 micrograms/liter (µg/L) in some quarters, with locational running annual averages (LRAA) up to almost 85 µg/L at some sampling locations. To reduce DBP precursors and operate the WTP year-round, targeted treatment for organics removal will be required. 

Locational Running Annual Average (LRAA) of TTHMs at several locations in the Attleboro drinking water distribution system

The Massachusetts Department of Environmental Protection (MassDEP) published a new combined MCL of 20 nanograms/liter (ng/L) for six perfluoroalkyl and polyfluoroalkyl compounds (PFAS) in October 2020. Following the publication of the new standard, testing for PFAS was conducted at the Wading River supply wells and the Wading River WTP finished water in September 2020, October 2020, January 2021, and monthly from April 2021 to September 2021. Laboratory results indicated PFAS results over the limit, suggesting a need for targeted treatment. 

MassDEP guidelines require the completion of a series of permit applications and an engineering study including a pilot test proposal, pilot testing, and a pilot test report to evaluate, optimize, and summarize the treatment results. In accordance with those guidelines, three seasons of pilot testing were conducted: Season I, from March to April of 2022, Season II, from August to September of 2022, and Season III, from July to August of 2023. Per the standards to conduct a pilot study on surface water sources, the pilot test included one cold weather season and one warm weather season.

Pilot Testing 

Two systems for organics removal were tested: 1) dissolved-air flotation (DAF) followed by dual-media filtration, and 2) magnetic ion-exchange (MIEX®) followed by GreensandPlus™ filtration. The MIEX® & GreensandPlus™ filtration process train was added to the pilot test following the discovery of elevated manganese levels during Season I of testing. 

DAF clarification is a process similar to clarification by sedimentation, except that particles formed by coagulation are floated to the surface by the injection of air through a recycle stream at the bottom of the clarifier tank, instead of being allowed to settle to the bottom. The recycle stream is injected through specially designed nozzles, resulting in the formation of bubbles which adhere to formulated flocc particles and float to the surface, effectively clarifying the source water. Depending on the system utilized, typical DAF systems can operate with a surface loading rate of between 4 and 8 gallons per minute per square foot (gpm/sf). Optimal coagulation and flocculation conditions for DAF can be predicted by standard jar tests, which were conducted prior to Season I of testing. Polyaluminum chloride (PACI) was selected as the coagulant. 

Dual-media filtration is a gravity operated, rapid-flow process widely used in water treatment. It is necessary to follow the coagulation, flocculation, and clarification processes with filtration to remove excess turbidity. Dual-media filters contain a layer of anthracite on top of a layer of fine sand, which rapidly remove residual solids from the water, trapping larger particles in the anthracite and smaller particles in the fine sand. The filters can be backwashed on a schedule determined by differential pressure across the filter or at periodic time increments. 

Pilot mixers, flocculators, and dissolved-air flotation clarifier during Season III of pilot testing at the Wading River WTP

MIEX® is a specialized treatment process targeted at the removal of organic carbon, specifially dissolved organic carbon (DOC).  MIEX® resin consists of ion exchange beads that contain magnetized components to form agglomerates from negatively charged organic particles. The MIEX® system utilizes a stirred up-flow contactor, resin settler, and a regeneration/recycle loop to remove total organic compound (TOC) in an efficient manner. Batches of resin are periodically regenerated in a sodium chloride brine solution, replacing the TOC with target chloride anions and leaving a concentrated brine and organics waste stream. Freshly regenerated resin, as well as new resin to make up for carryover losses, is fed to the reactor to maintain a consistent ion exchange capacity. Depending on the system utilized, hydraulic loading rates can range from 6 to 12 gpm/sf. Residuals from MIEX® systems consist of waste from the regeneration process, and depending on the frequency of regenerations, are typically 0.02% to 0.06% of the treatment flow. 

Schematic of a typical MIEX® treatment system

GreensandPlus™, the trade name for Inversand’s oxide-coated sand product, is a manufactured filter media used for the removal of iron, manganese, hydrogen sulfide, arsenic, and radium from water supplies. The GreensandPlus™ process utilizes a layer of anthracite which acts as a physical filter for the manganese precipitated by the addition of the chlorine oxidant. Below the anthracite top layer is the oxide-coated sand media, which acts as a catalyst in the oxidation of the manganese. Manganese that is oxidized in this part of the process is then removed via adsorption or physical filtration. 

For PFAS removal, two treatments were compared: 1) granular activated carbon (GAC) and 2) an anion-exchange removal, clay bentonite media, FLOUROSORB®-200. 

GAC filtration has proven to be effective in removal of PFAS from drinking water at many locations throughout New England. GAC removes PFAS by adsorption, which is a physical process of accumulating a substance at the interface between the liquid and solid media phases. The GAC used in this pilot study was Calgon FILTRASORB 400, which is made from select grades of bituminous coal through a process known as reagglomeration to produce a highly active, durable, granular product capable of withstanding the abrasion associated with repeated backwashing, hydraulic transport, and reactivation for reuse. The Calgon FILTRASORB 400 can be recycled and reused through thermal reactivation to restore its adsorptive capacity, which eliminates the costs and long-term liability associated with the disposal of spent media. 

CETCO’s FLOURO-SORB®-200 is a proprietary, NSF-certified, bentonite-clay adsorption media that is proven to effectively treat multiple variants of PFAS. The removal mechanism is similar to anion-exchange resins. FLOURO-SORB®-200 adsorbent media binds the entire spectrum of PFAS compounds, is not negatively impacted by most other water quality parameters such as dissolved or total organic carbon and chlorine and requires short empty bed contact times of two to three minutes. 

Removal of Organic Compounds and Manganese 

As mentioned previously, manganese concentrations were found to be higher than expected during Season I of testing. The first organics removal process, DAF and dual-media filtration, was utilized to remove manganese by several oxidation strategies. The oxidation of manganese causes it to precipitate out of solution, allowing it to be removed by direct filtration through the dual-media filters. The oxidation strategies included the oxidation of manganese by potassium permanganate, sodium hypochlorite, and chlorine dioxide. While potassium permanganate was the most effective oxidation chemical for direct filtration of manganese, none of the oxidation strategies were able to consistently maintain manganese concentrations below the secondary maximum contaminant level (SMCL) of 0.05 mg/L. Additionally, DAF followed by dual-media filtration did not consistently reduce DBP precursors to maintain TTHMs below the MCL of 80 μg/L in simulated distribution system sampling. 

Box Plot of Pilot Influent Manganese Concentrations Compared to Monthly Historical Data, from Blueleaf’s “Warm-Water Season Pilot Study Report (September-August 2022).”

While GreensandPlus™ is more effective than dual-media filtration for manganese removal, providing additional oxidation of manganese with its oxide-coated media, the coagulated particles formed by DAF can be problematic for GreensandPlus™ media, “gumming up” the small particles with coagulant and reducing filter run times. Therefore, MIEX®, which does not coagulate organic particles for removal, was provided as an alternate pretreatment for the removal of organic compounds prior to manganese removal. MIEX® followed by GreensandPlus™ filtration was found to be effective for both organics and manganese removal, maintaining manganese concentrations below the SMCL, and removing DBP precursors to reduce TTHMs below 80 μg/L in simulated distribution sampling. 

Removal of PFAS 

Since many media have been shown to remove PFAS to non-detect levels, one way to measure the relative effectiveness of PFAS removal by a particular media is in terms of empty bed volumes (EBVs) between media replacement. By measuring PFAS breakthrough (defined as PFAS being higher than non-detect levels) at sampling points located 25%, 50%, 75%, and 100% through the treatment beds, EBVs for each treatment option were estimated. After 16 weeks of PFAS testing, GAC had treated almost 14,000 EBVs, and was providing 23% PFAS removal at the 25% tap, 41% removal at the 50% tap, 69% removal at the 75% tap, and 90% removal at the 100% tap. At the same time, FLOURO-SORB®-200 had treated approximately 68,600 bed volumes, and was providing 87% removal at the 25% tap, 85% removal at the 50% tap, and 100% removal at the 100% tap. The FLOURO-SORB®-200 media was determined to have a higher treatment capacity than GAC for PFAS removal.

Empty Bed Volumes Treated and PFAS6 result, by PFAS-removal process and sampling point

Conclusions

The DAF and dual-media filtration treatment process was utilized throughout the study to evaluate TOC removal and manganese removal by coagulation, oxidation, clarification, and filtration. A MIEX® and GreensandPlus™ treatment process was added during Seasons II and III as an alternate for TOC and manganese removal. Both processes were found to be effective in removing TOC, however, the MIEX® & GreensandPlus™ process was more effective than the DAF & dual-media filtration process in removing TOC and reducing DBP formation. Additionally, the MIEX® & GreensandPlus™ process more consistently removed manganese to concentrations under the SMCL than the DAF & dual-media filtration process. FLOURO-SORB®-200 clay bentonite anion-exchange media was found to have a higher capacity for PFAS removal than GAC. FLOURO-SORB®-200 showed significantly more bed volumes treated before PFAS breakthrough at the 25% and 50% taps than GAC showed at breakthrough of the equivalent sample tap, making it a more effective treatment media for removal of PFAS.

PFAS Mitigation, Shrewsbury, MA

A PFAS Journey to Determine Effective Management and Treatment Options

Tata & Howard is working with the Town of Shrewsbury, MA to address perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the groundwater. The Town of Shrewsbury water system serves a population of approximately 38,300. The system consists of about 200 miles of main, nine active groundwater wells from three well sites, three pressure zones, six storage tanks, and one water treatment plant. The 7.0 million gallon per day (mgd) Home Farm Water Treatment Facility utilizes biological treatment for removal of manganese.

In 2020, Shrewsbury detected PFAS in the wells. Sampling has indicated that PFAS is present in most of the wells operated by the Town but under the maximum contaminant level (MCL) of 20 nanograms per liter (ng/L) for PFAS6 as regulated by the Massachusetts Department of Environmental Protection (MassDEP) which includes the sum of concentrations for PFOS, PFOA, PFHxS, PFNA, PFHpA, and PFDA. Raw water from one well site, the Sewell Well, has been consistently higher than 20 ng/L; but the finished water from all wells after treatment at the Home Farm Water Treatment Plant has been in compliance and consistently less than 16 ng/L. Most of the PFAS is in the form of PFOA and PFOS which are the two compounds for which the EPA has developed a proposed MCL. The PFOA indicated by the green bar in Table 1 is higher than the proposed Federal MCL of 4 ng/L.

Currently, the Town has been managing the sources to improve water quality and stay under the current MCL of 20 ng/L for PFAS6. A mass balance is utilized to estimate finished water PFAS concentrations based on updated sample results and changes in the operation of the sources. Tata & Howard created the base tool which can be used to see how changes to PFAS levels or flow rates can affect the finished water concentration.

Table 2 represents existing conditions. The numbers used for PFAS are the highest results from each individual well observed in a year of sampling data, showing the finished water level is about 16 ng/L.  As long as the PFAS concentrations in the wells remain consistent, the Town will remain in compliance. If sample results change and they see an increase in PFAS concentration at Sewell, the Town will make adjustments using the mass balance to manage the sources to remain in compliance.

 The Town cannot manage sources like this indefinitely. They decided to move forward with reviewing PFAS treatment options and pilot testing to determine the best course of action if/when treatment is required.

Tata & Howard and the Town considered three treatment options. The first option is anion exchange, which uses a resin with positively charged ions. These are typically single use resins and require one to three minutes of empty bed contact time. The next option is Granular Activate Carbon (GAC) which uses adsorption. This media can be made from different types of carbon sources that can be recycled through thermal reactivations and requires a ten minute empty bed contact time. There are limitations with GAC on some of the short chain PFAS. The third type is novel media, which includes other types of media that do not fall into the first two categories. The novel media piloted uses an adsorption process that is classified as a single use resin and has a two to three minute empty bed contact time.

Pilot System

Shrewsbury’s pilot testing utilized three anion exchange resins from two suppliers (one of which was regenerative), a coal-based GAC, and a novel media. The novel media selected works like GAC since it is not as sensitive to chlorine and chlorides, which can impact the effectiveness of anion exchange resins.

The GAC pilot test utilized two 6-inch columns in series rather than one very tall column to give more flexibility for installation and backwashing. A total of 10 gallons of media were installed with a loading rate of 7.5 gal/ft2 and an empty bed contact time of approximately ten minutes. The anion exchange and novel medias each utilized one 6-inch column with five gallons of media installed, a loading rate of 11.25 gal/ft2, and an empty bed contact time of approximately two minutes.

The water source was a tap on the effluent line from the existing filters using finished water that had been treated for manganese removal but not any of the chemical additions of KOH, phosphate, chlorine, and fluoride. There were control valves so the water only came through the unit when the treatment plant was online, which is typically more than 20 hours per day.

There was an initial baseline water quality sampling event at the start, at the end of week 20, and at the end of piloting. PFAS samples were taken day one, day seven, and then monthly for the duration of the pilot. Samples were taken from the 25% sample tap until breakthrough (50% of the raw water PFAS levels, so between 6 and 7 ppt), then at the 50% tap.

Table 3 shows the result from the different taps at the end of the pilot.  The anion exchange results are from the best performing anion exchange resin. GAC was first detected in week 8 with breakthrough in the 25% tap in week 16 and the 50% tap in week 44. There was a detected amount in the final sample tap in week 64, which was the final week of the testing.

Anion exchange had the longest time to first detect but the 25% breakthrough for all anion exchange and novel media were all within a sample event or so of each other and occurred between weeks 44 and 52. The novel media had breakthrough of the 50% tap at week 60 and was detected in the 100% tap at the final week while the anion exchange was ND in the 100% tap at the end of the pilot.

Table 4 is a summary as to what the permanent filter system may look like. The filters are similar in size but the number of recommended filters differs for each resin. The overall building footprint is similar as well. The anion exchange did perform slightly better than the novel media, however, the overall PFAS removal results over the duration of the pilot was similar. Because of this, construction costs, long term media replacement costs, and operational considerations were included as part of the media selection process.

The Town has chosen to use novel media because it allows for some backwashing and chlorination, reducing the potential of biofilm buildup and potential capacity loss due to increased headloss through the media. Additionally, the novel media has a smaller footprint in comparison to GAC.  The Town of Shrewsbury’s current PFAS levels do contain mostly PFOS and PFOA at concentrations higher than the proposed Federal regulations for those two compounds. Also, based on reviewing the data of the PFAS6 compounds, PFOA was the compound first detected for all media; also, the majority of the detected PFAS6 concentrations in the effluent throughout the pilot were PFOA.

One additional challenge moving forward is the design of the facility so the water goes through the manganese treatment first, the new PFAS treatment next, and finally utilizes the existing clearwell for chlorine contact, with finished water pumping into the system, all while keeping the existing treatment online during construction and start up.  Tata & Howard is currently designing the facility which is being funded through the MassDEP State Revolving Fund.

Water Treatment Plant, Amherst, MA

Tata & Howard contracted with the Town of Amherst for design, permitting, and bidding of the 1.5 million gallon per day (MGD) Centennial Water Treatment Plant, to treat surface water from the Pelham Reservoir System. The existing Centennial WTP, located in the Town of Pelham but supplying the Amherst Public Water System, has a history of issues with turbidity, color, and disinfection byproducts in the form of total trihalomethanes (TTHM) and haloacetic acids (HAA5) because of high levels of organics in the Pelham Reservoir System. Due to the age and condition of the existing WTP, the filters which were the primary treatment process at the existing WTP were no longer effective at removing organics, leading to a decrease in finished water quality and total WTP capacity.  The existing Centennial WTP has been offline since 2018 due to water quality, as well as infrastructure concerns related to a lightning strike which impacted pumping equipment and communications at the Centennial Water Treatment Plant’s raw water pump station.

Based on the results of the pilot study performed by the Town of Amherst, Tata & Howard completed design of the new Centennial Water Treatment Plant including dissolved air flotation (DAF) clarifiers and granular activated carbon (GAC) filtration for treatment of organics, color, turbidity, and low levels of iron and manganese. The DAF system includes polyaluminaum chloride for coagulation, two rapid mix chambers, and three package DAF units which each include two high rate flocculation chambers, two low-rate flocculation chambers, a saturation tank, effluent collection system, discharge weir, mechanical skimmers and beach, and associated appurtenances and controls. Three dual media filter chambers with a silica sand/course garnet base layer and GAC above are located downstream of the DAF units, prior to final chemical addition.

Additional chemical feed includes a gaseous chlorine system for 4-log inactivation of viruses, gaseous ammonia for chloramine formation, sodium fluoride for dental health, and sodium hydroxide for pH adjustment and corrosion control. The new facility also includes an advanced Supervisory Control and Data Acquisition (SCADA) system for automated control of the water treatment plant. Operators for the Town of Amherst will be able to remotely monitor and control operation of the Centennial WTP, through a recently extended town fiber optic cable network.

The design of the Centennial WTP included provisions to maintain the Amherst water distribution system, as even with the Centennial WTP offline, the clearwell of the existing facility also serves to maintain pressure in a small portion of the water distribution system between the Centennial WTP and a booster pump station. The Centennial WTP feeds the majority of the water system (excluding the portion between the WTP and the booster pump station) by gravity. Since the existing WTP including the clearwell will be demolished prior to construction of the new WTP, design and construction of the new WTP will include a temporary water storage tank to maintain pressure and keep all connections active in the high service area of the Amherst Public Water System.

Permitting for this project included a BRP WS 24 New Treatment Plant application with MassDEP, Site Plan Review with the Pelham Zoning Board of Appeals, and a Request for Determination of Applicability (RDA) with Pelham Conservation Commission.

The Centennial Water Treatment Plant was recently bid and awarded to R.H. White Construction Co. of Auburn, MA for a contract amount of $18,876,000.  This project received funding though the Drinking Water State Revolving Fund program, and construction is expected to be completed by the summer of 2025.

Godfrey Brook Water Treatment Plant

Today’s volume and demand for daily water use may have changed since the town incorporated in 1881, but one goal remains constant to this day: safe water.

Team T&H continues to deliver safe, potable water through engineering excellence of precision, collaboration, feedback, and commitment between all team members, water department operators, and project managers. The Godfrey Brook WTP project scope involves construction administration and resident project representative services. Process elements of the project include biological iron and manganese pressure filters, a packed tower aerator, and chemical addition for the purpose of pH adjustment, corrosion control, and disinfection.  The new WTP includes a clearwell to achieve 4-Log inactivation of viruses prior to the distribution system. The WTP also includes HVAC, plumbing, electrical, and advanced SCADA systems for monitoring and control of the new treatment plant and the wells. Site work includes new raw and finished water mains, stormwater controls in the form of a sub-grade stormwater infiltration system, and residuals storage tanks for solids handling after backwashing the biological filters, and electrical including a new electrical standby generator. The project also includes site upgrades to the wells and access road, including an RCP culvert replacement to improve drainage of Godfrey Brook (a tributary stream into the Charles River), submersible well pumps and motors for the seven wells, and a precast concrete raw water metering vault for flow control. Currently, the biological filters are in the acclimation phase, the final step prior to a performance test to confirm effectiveness of removing iron and manganese.


Located to the left of the Godfrey Brook WTP’s exterior stands a packed tower aerator (shown above). The tower aerator removes carbon dioxide to increase pH in a more cost effective manner than chemical addition, and adds dissolved oxygen before the biological manganese filters, which is critical to biological filtration.

Biological manganese filters (above) come after the packed tower aerator for efficient removal of manganese. Biological iron filter is upstream of the packed tower to optimize the performance of all downstream processes.

The project included a culvert reconstruction to replace a damaged pipe. Culverts are trench-like constructs designed to allow free-flowing water beneath a road or railway, whether stormwater or a stream. Pictured is the finished culvert over Godfrey Brook, a tributary to the Charles River. 

T&H team members Matt O’Dowd, Juliette Burcham, Mitch Garon, and Barry Pociask review the electrical connection for the disconnect of the submersible well pump for well 1A. The Godfrey Brook Wellfield features seven total gravel packed wells: five rehabilitated and two newly installed.

The newly installed chemical feed system includes skid-mounted chemical metering pumps used for potassium hydroxide; here, chemical addition occurs for pH adjustment, along with the addition of sodium hypochlorite for disinfection and zinc orthophosphate for corrosion control prior to entering the water distribution system. 

New Hampton Road Water Main Project

Tata & Howard completed design, funding, and construction phase services in the City of Franklin, NH for the $3.5M New Hampton Road Water Main Project. The new 16-inch and 12-inch ductile iron water mains replaced a 1940s era unlined cast iron water main (approximately 14,000 linear feet) with a history of main breaks and extends over three miles from the Babbitt Road Booster Station to the Sanbornton Wellfield.

The water main was identified as a priority in the 2016 Capital Efficiency Plan prepared by Tata & Howard and will provide improved water quality, distribution pressure, and fire protection.

Tata & Howard assisted the City with maximizing the NHDES SRF Loan with the City’s paving program funds to fully reconstruct 9,000 linear feet of New Hampton Road as part of the project.

Auburn, MA Water Storage Tank

Tata & Howard was contracted to provide Design, Construction Administration, and Resident Project Representation services for the construction of the Prospect Street Water Storage Tank in Auburn, MA.

The project consists of the construction of a 1.0-million-gallon capacity glass-fused-to-steel water storage tank with associated piping and appurtenances, electrical work, a tank mixing system, and site work.  Other work included the decommissioning and demolition of the pre-existing 500,000-gallon capacity welded steel water storage tank at the site.

 

 

 

Newton, MA – Lead Service Replacement Program

Tata & Howard was contracted to provide design, construction administration and resident project representation for the replacement of 588 lead services in Newton, MA. Although the water that services the City is not corrosive, replacing lead services is a cautious and preventative measure to avoid lead from potentially leaching into tap water via the service connection which is located from the water main to the meter.

Lead service replacement program in Newton, MA. Excavator and men.

Lead pipes are more likely to be found in older cities and homes built before 1986. As such, the affected lead services in Newton were installed between 1875 and 1915. Of the 588 total services;

  • 318 were full-service replacements (from water main to meter)
  • 266 were partial-service replacements (from curb stop to meter)
  • 4 were street only replacements (from water main to curb stop)

Prior to the construction phase of this project, Newton residents were notified about the City’s Lead Service Replacement Program (LSRP). Although not required, those wishing to participate in the program were able to take advantage of a ten-year, no interest payment plan through the City.
Under the LSRP, the City replaced, at its own expense, the portion of the water service pipe which was within the public way from the street line in front of the homeowner’s property, to the City water main. The homeowner then had the option to replace the portion of the water service pipe that ran from their meter to the property line.

Lead service replacement program in Newton, MA. Newton home with construction cones.

Tata & Howard scheduled construction and coordinated with the residents who elected to participate in the LSRP. Crews from C.J.P & Sons Construction worked to excavate the properties and remove/replace the water service pipes. In most cases, limited excavation of homeowner property was needed.

When the project reached completion, 427 total services had been replaced.

Lead service replacement program in Newton, MA. Excavator and men. Construction worker replacing pipes.

(De)leading the Way – Marlborough, MA

The City of Marlborough, MA (home of T&H headquarters) contracted Tata & Howard for the design, pre-construction services, construction administration and resident observation of approximately 1,200 lead water service connections.
Until 1944, lead was widely used in service lines and is quite common in many of the older cities and towns in Massachusetts.

Lead pipes currently placed between the streets and homes of identified Marlborough residents will be replaced with copper pipes in five phases – each phase consisting of approximately 250 homes.

Tata & Howard will be involved in each phase, reviewing tie cards, attending field surveys to determine what each service placement will entail, and advising contractors on the quantity of pipes to be installed in each location.

Although lead is known to be  a major health risk to children and pregnant women, the supplier of Marlborough’s water, Massachusetts Water Resources Authority (MWRA), treats all water to reduce lead from getting into drinking water.
   
   

Falmouth Main Street Water Main Construction

Tata & Howard was contracted to provide design, construction administration and resident observation for the installation of 18,000 linear feet (approximately 3.5 miles) of 16-inch ductile iron water main in Falmouth, MA. Water main replacement will be in Main Street and Route 28. That is, from the intersection of West Main Street and Locust Street, to the intersection of Teaticket Highway and Oxbow Road

New water main will be replacing the town’s 10-inch cast iron water pipes that were originally installed in 1898. Falmouth’s 121-year-old water infrastructure has stood strong for more than a century; however, it has become clear that it’s nearing the end of its useful life and approaching the age at which it needs to be replaced. Evidence of this can be seen in the three water main breaks that have occurred since August of 2018. In addition, the original water main is hydraulically deficient and needs to be up-sized to meet the increasing demands in the system.

Construction began at the beginning of April and continued up until Memorial Day of this year. Construction was limited to off season times due to the heavy tourist months in Cape Cod. Project completion was in the spring of 2021.