Sewer Feasibility Study and Sewer System Design — New Fairfield, CT  

Tata & Howard completed a Sewer Feasibility Study for the Town of New Fairfield, CT to determine the feasibility of developing a sewer service area for the Town of New Fairfield town center/business district, municipal town buildings and schools, and other properties within the proposed sewer service area as well as transporting the wastewater to the City of Danbury’s Wastewater Treatment Facility. The assessment included an estimate of projected flows for all properties within the planned service area and a comparison of total estimated flows to available capacity at the Danbury Wastewater Treatment facility. Design concept plans for the planned sewer service area included determination of collection system sewers and pump station locations. Part of the study included an evaluation of potential routes for transporting flows from the Fairfield Town Center service area to the City of Danbury collection system for treatment. 

sewer feasibility studyEstimated project budgetary costs for the sewer service area collection system, pump stations, and transport to the City of Danbury along with a phasing and implementation plan were included in the final draft report to the Town of New Fairfield. 

Throughout the course of the project, a number of meetings with the Town were held to obtain Town input and comments including one meeting at the completion of the initial assessment phase, one meeting at the completion of the concept design phase, and a series of meetings and presentations at Town Selectboard meetings to obtain public input during the roll out of the final report.

Tata & Howard provided preliminary and final design of 2.7 miles of gravity sewers, one main pump station, four remote, submersible pump stations, 2.3 miles of force mains, , and 4,000 linear feet of low pressure sewer. The project also includes identifying easements, land acquisition plans, preparation of permitting, and bidding assistance. 

Preliminary design included survey, soil borings, preparation of base mapping, identification of utility requirements, a radio path survey and an opinion of probable cost. 

sewer studyFinal design development includes final design of the main pump station, remote pump stations, gravity sewers, force main, and low-pressure sewers for connection to the City of Danbury collection system including site plans, profiles of force main and gravity sewers, pump station structures and chambers, electrical and controls, emergency generators, odor control, erosion and control plans, etc. Also includes design of the main pump station building designed to match the local aesthetic and mask it as a non-utility structure.

Construction Documents will be prepared by phasing construction under four contracts: 

  • Year 1 – Phase 1: Main Pump Station and force main for connection to the Danbury System and Collection System for the Town Center and commercial district (Sewer Sheds 2 [commercial],
    4, 5 and 8);
  • Year 2 – Phase 2: Collection System connecting schools, police, and fire facilities (Sewer Sheds 1 and 2 [residential]);  
  • Year 3 – Phase 3: Additional Collection System connecting additional commercial properties, The Birches 55+ community, The Woods at Dunham Pond 55+ community, The Good Shepherd Lutheran Church, and potential future land development along Route 37 (Sewer Sheds 3, 6, and 7).

Barnstable, MA Maher WTP Upgrades

Photo courtesy of Waterline Industries Corporation

Tata & Howard provided engineering services for a completion of a pilot test proposal, pilot testing, and pilot test report to evaluate the use of granular activated carbon (GAC) to treat PFOS/PFOA, advanced oxidation to treat 1,4 dioxane, and LayneOx and greensand pressure filtration to remove iron and manganese from the source waters (Well No. 1, Well No. 2, and Well No. 3) at the existing Maher Water Treatment Plant. Pilot testing was performed, submitted, and approved by MassDEP in July 2017. The pilot test report was prepared and submitted in January 2018 to MassDEP.

Tata & Howard also provided engineering design, permitting, bidding, and construction services for the expansion of the existing Maher Water Treatment Plant. Upgrades include a new 90’ x 90’ pre-engineered metal building, GAC treatment, chemical feed upgrades, electrical upgrades at the existing plant including a new stand-by generator, and miscellaneous piping and site work. The new carbon filtration building include granular activated carbon (GAC) filters designed to remove PFAS. In addition to PFAS, the facility will include treatment processes to treat 1,4 dioxane and iron and manganese in the drinking water.

This project involved Massachusetts public construction laws and procedures.

Everett, MA Lead Service Line Replacement

Tata & Howard assisted the City of Everett, MA with their Lead Service Replacement Project from 2018-2024. Phases 1 and 2 included replacement or material confirmation of approximately 580 services between spring 2019 and fall 2022. Phase 3 of the project addressed an additional 300 services. Tata & Howard provided design, construction administration, and resident project representative services for all three phases of the project.

lead-service-line-replacementDesign services included attending the kickoff meeting with City and reviewing existing information including tie-cards, the City’s existing GIS database that includes service material, and the City’s master list of services with service material.  Each service was field verified to confirm exterior conditions. Each design phase included completion of 50% and 95% design documents, preparation of probable cost estimates, preparation of bid documents and coordination with purchasing agent, attending meetings with City, and providing recommendation to award contract to the lowest qualified bidder. 

Construction Administration services for each phase included attendance at progress meetings and site visits, review of submittals, request for information, and purchasing change orders and payment applications. As-built record tie-cards were completed for each address and the master inventory of service material was updated as construction on each phase progressed.  

Resident Project Representation services included full time on-site observation during construction, reviewing schedules, serving as Engineers’ liaison with Contractor, completing reports, reviewing pay apps, and issuing certification of substantial completion.

Grafton Water District, Trinity Avenue Well Site and Pump Station

Tata & Howard provided engineering services for permitting, design, and bidding of the Trinity Avenue Pump Station at the Trinity Avenue Wellfield (new source) and provided assistance with permitting, design, and reporting to the Massachusetts Department of Environmental Protection (MassDEP) for the proposed Trinity Avenue Well site. 

The property was owned by the Massachusetts Division of Fisheries and Wildlife (DFW), and the Grafton Water District swapped land with the DFW to obtain ownership and control of the Trinity Avenue site. Test wells were installed and short-term pump tests were completed on each of the wells. Based on the results of the tests, it was recommended to install a three well configuration of 18-inch x 12-inch gravel packed wells resulting in approximately 840 gallons per minute (gpm). The work under this contract included the completion of the Request for Site Exam and Pump Test Proposal for submission to MassDEP, installation and development of three (3) 18” x 12” gravel packed wells and pitless adapters, installation and development of approximately five 2-1/2” diameter observation wells, installation of two staff gages and piezometers, performing a five-day pump test, and collection and analysis of water quality.

The project also included an evaluation of alternatives for the access road including installation of a bridge or an open bottomed culvert, and Tata & Howard assisted with the preparation of permanent easements for the installation of utilities and roadway to the well site. In addition, Tata & Howard prepared and submitted an NOI to the Grafon Conservation Commission.

Design included double wythe block and interior concrete painted block with wood truss roof and asphaltic shingles. Security included chain link fence, gates, locks, intrusion alarms, and lighting. Tata & Howard also assisted 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 design also included 900 feet of new 12-inch water main for 4-log removal.

Tata & Howard also provided construction administration and resident observation services.

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
After
After

Maher Water Treatment Plant – Groundbreaking Ceremony

On Wednesday, August 7, 2019, the Hyannis Water System and officials from MassDEP held a ceremonial groundbreaking for construction of the new Maher Water Treatment Plant designed by Tata & Howard, Inc.

The $12 million water system upgrade, funded by the MassDEP SRF program, will enable the Town to meet new and stricter federal and state regulations for emerging contaminants. The new plant will treat elevated levels of Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), 1,4-Dioxane, iron, and manganese in the three drinking water production wells at the existing facility.

The water filtration building at the Maher Water Treatment Plant has a design capacity of 1,500 gallons per minute. Using granular activated carbon filtration, the successful removal of PFOS/PFOA will be obtained. Advanced oxidation with peroxide and ultraviolent (UV) light will treat 1,4-Dioxane. Lastly, greensand pressure filtration will not only remove the iron and manganese, but also extend the useful life of the granular activated carbon.

Tata & Howard has been instrumental in the evolution of this project. In December of 2016, Tata & Howard provided a conceptual design report to Barnstable’s Department of Public Works. A pilot test report was submitted in early 2018 and design began shortly thereafter.

The Hyannis Water System currently consists of four water treatment facilities, four storage tanks, 12 well pumping stations, and a 107-mile distribution system. The water system provides drinking water services to approximately 18,000 residents through 7,249 metered service connections to residential and commercial properties.

Waterline Industries Corporation of Seabrook, NH constructed the filtration building, and Tata & Howard provided construction administration and resident observation. The facility was operational in October 2020.

Chamberlain Highway Receives New Water Main Connections

The Chamberlain Highway in Meridan, Connecticut has 536 linear feet of new 16-inch ductile iron main and two new fire hydrants. After Tata & Howard completed several test pits to verify connection locations at each end of the new main, construction work started on May 3, 2018 with the installation of a 16” x 16” tapping sleeve and valve at the north end of the project. This existing water main at the north end connection was originally installed in 1894.

Chamberlain West Main

Work progressed south until the new main was approximately 50 feet away from the other connection point in West Main Street. Connections to the existing main in West Main Street was performed over a 36-hour period due to the complexity and amount of utilities around the service connection, including a live 24-inch water main five feet away and multiple telephone conduits located 6 inches above the replaced main. Tata & Howard personnel on site at all times to observe that work was in performed in accordance to the plans and specifications.

Following the completion of the Chamberlain Highway water infrastructure improvement project, work to replace two water mains on the state-owned bridge crossing Sodom Brook in Meridan will begin.

UMASS Amherst Hydraulic Modeling

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

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

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

Historic Bridge Rehabilitation (circa 1865)

CLIENT: Watertown, CT

PROJECT: Skilton Road Bridge Rehabilitation

DSCN9198

THE CHALLENGE: Skilton Road Bridge was originally built in 1865 as a one lane, dry stone masonry arch bridge over the Skilton Gorge in Watertown, Connecticut. Rehabilitation in 1988 included strengthening of the stone masonry with reinforced concrete, and adding concrete guide rails to the bridge. On December 10, 1991, Skilton Road Bridge was added to the National List of Historic Places, and in 2013, the bridge was found to be structurally deficient.

Before rehabilitation
Before rehabilitation

THE SOLUTION: Tata & Howard’s design for the rehabilitation and repair of the bridge required careful consideration of the historical nature of the structure. The design was approved and construction took place in 2015. All structural deficiencies were addressed and the project included the following:

  • Removed existing guide rails
  • Installed prestressed concrete beams across the top of the existing bridge
  • Widened the bridge for two 9’ travel lanes and a sidewalk
  • Installed new aluminum bridge rails covered with wood
  • Repaired the stone masonry on the west abutment wall
  • Added new storm drainage
After rehabilitation
After rehabilitation

PROGRESS: Construction on the Skilton Road Bridge was completed in October of 2015, and a ribbon cutting ceremony was held on December 10, 2015. The bridge maintains its historic integrity.

A ribbon cutting ceremony was held December 10, 2015
A ribbon cutting ceremony was held December 10, 2015

Dam Reconstruction, Meriden, CT

dam_reconstruction_ct

The Fosters Pond Dam reconstruction project presented several challenges. The existing spillway was inadequate to discharge the 100-year spillway design flood, and the existing dam was in extremely poor condition. The embankments lacked erosion protection and were very steep, the crest was narrow, and the outlet had fallen into disrepair, rendering it inoperable. Therefore, it was imperative that the reconstruction design of Fosters Pond Dam be designed to improve both safety and reliability, provide a functional and operable outlet, and provide ease of maintenance.

fosters_pond_dam_reconstruction_ct

The reconstruction included the construction of new and higher reinforced concrete spillway training walls, upstream riprap erosion protection, a new reinforced concrete gate structure with 24″ inlet and outlet pipes and sluice gate, widened embankment crests to 12′, flattened slopes for ease of maintenance, and a gravel road to allow access to the embankment and gate structure. Riprap erosion protection is now provided on the upstream slopes as well as in the discharge channel. Because of these improvements, the dam can safely pass the 100-year spillway design flood with over a foot of freeboard. The length and level of the spillway weir remains unchanged.