Southern Maine Regional Water Council (SMRWC) Regional System Study

SMRWC graphicv1 - Dist-Flows

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

Northampton interconnection mapThrough 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

bellemont-water-system-az-chlorine-injection-768x399Tata & 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

awc-laurel-street-raw-water-mainOwner: 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.

Interceptor Sewer, Danbury, CT

interceptor_sewer
Jacking a 48-inch steel casing under I-84 in Danbury, CT

The Oakland Avenue sanitary sewer project consists of jacking a 48-inch steel casing pipe through the Interstate-84 embankment in Danbury, CT and installing a new 24-inch sanitary sewer to replace the existing 16-inch sewer that is undersized. The project will alleviate the restriction that is causing sewer overflows. Services included surveys and mapping, review of easements, review and updating of original design, preparation of plans and specifications, bidding, construction administration, and resident observation. Construction is currently underway and the project is expected to be completed by the end of this October. The new sewer line installation will complete an interceptor project that was constructed in 1994.

Water Distribution System Evaluation and Tank Design, Paxton, MA

Town of Paxton, MA

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

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:

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Environmental Services and Dam Inspection in MA

Larkin Lumber DamIn November 2015, Tata & Howard provided peer review on work that had been completed at a former lumber mill, and all documentation that had been prepared to date was reviewed. The primary concern was an area where pressure treated lumber had been stored, as the lumber was treated with chromated copper arsenate and the residual arsenic concentrations in soil were very high. The previous recommendation was to put a deed restriction (specifically, an Activity and Use Limitation or AUL) on the area to limit the exposure. Because the planned future use for the property is to convert the existing mill building into residential condominiums, this approach was inadequate. In an effort to find a more suitable solution, T&H obtained and analyzed additional soil samples from this area and found that less than 200 cubic yards had been affected. The contaminated soil can be removed for under $30,000 and will bring residual concentrations below that allowed for residential use.

Because the mill is located on a brook, a filing with the local Conservation Commission was required.  T&H suggested that, due to the limited work being done and the fact that the affected area is separated from the brook by a retaining wall, an Abbreviated Notice of Intent (ANOI) would be sufficient. The Conservation Commission agreed, and the ANOI was approved at a Public Hearing. T&H is currently in the process of preparing a Release Abatement Measure (RAM) Plan, which must be submitted to the MassDEP prior to excavation.

During the first onsite project meeting, T&H noticed a dam located in front of the mill building which the client acknowledged was out of compliance and would likely result in financial penalties. T&H contacted the Department of Conservation and Recreation (DCR) and requested an extension for the completion of the dam inspection, assuring DCR that the inspection would be completed in a timely manner.  DCR agreed to waive the penalties, and the inspection report was completed in January 2016.

Treating Arsenic in Water in Arizona

shangri la ranch sunsetThe 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

CHALLENGE: Lead contaminated soil at site in Franklin, MA

CLIENT: Private client in Franklin, Massachusetts

PROJECT: Brownfield remediation

THE CHALLENGE: The Town of Franklin, MA planned to develop a site to be used by the Parks & Recreation Department. However, several potential environmental concerns were identified at the site.

THE SOLUTION: Based on information provided by the Town, Tata & Howard performed subsurface evaluation services to assess the potential presence of oil and hazardous material in soil and groundwater at the site, including the following:

  • Evaluated the site and found contaminated fill material under the building;
  • Evaluated the significance of our findings with respect to Massachusetts General Law c.21E and the Massachusetts Contingency Plan 310 CMR 40.0000; and
  • Prepared a Subsurface Evaluation Report for the site, which included a summary of activities performed, site figures and data tables, and conclusions and recommendations.

T&H then coordinated the removal of the lead contaminated soil, which contained hundreds of battery casings. The soil was treated onsite to stabilize the leachable lead, then transported to the Turnkey Landfill in Rochester, NH for disposal.

PROGRESS: Since it has been remediated and the Brownfield is now a Greenfield, the Town has purchased the site and begun renovating for future use as an indoor recreation facility. T&H filed a Permanent Solution report with the Massachusetts Department of Environmental Protection (MassDEP) in October 2015.

CHALLENGE: Northampton, MA WTP Check Valve Failures

CLIENT: Northampton, Massachusetts

PROJECT: Mountain Street Water Treatment Plant Valve Replacement

Hole in clarifier pipe caused by failed check valve
Hole in clarifier pipe caused by failed check valve

THE CHALLENGE: The three check valves on the clarifier influent feed lines were failing and, as a result, the disc was consistently hitting the downstream pipe spool piece, eventually causing each section to develop holes and leaks.

THE SOLUTION: Rather than simply replacing the check valves with the same style valve, we decided to dig deeper. We believed the discs were failing due to turbulence generated by an upstream modulating valve, so we researched alternative valves. We found that most alternative valves required a longer lay length than the existing check valves, which would have required replacement of the influent piping as well as reconfiguration of the valves and flow meters on each of the clarifier influents that feed the three units back to the header.

With additional research, we identified a flanged duckbill check valve that could actually be inserted between two flanges within the pipe, with the flange of the check valve sandwiched between the two flanges of the existing pipe configuration. The valve itself was located within the influent piping and allowed for installation without having to significantly alter the clarifier influent piping. As a result, the Owner saved on the cost of the valve replacement as well as avoided an extended shutdown time, as each clarifier would have been out of service for a far longer duration if extensive influent piping modifications were necessary.

PROGRESS: The project was successfully completed in October of 2014.