Water Filtration Plant Improvements Project Summary Groton Utilities Meeting Presentation January 30, 2017

Project Pricing: Sitework Electrical Mechanical Building Improvements WTP Rebuild $43,901,043 Engineering $4,198,508 Contingency $5,900,449 Mechanical Building Improvements Finished Water Storage DAF – Dissolved Air Flotation GAC – Granular Activated Carbon TOTAL PROJECT COST: $54,000,000 Mn Contractors Miscellaneous Process Control THM Removal Hazmat Removal Contingency Engineering

Project Facility History 1890’s Pumping Station 1938 – Unit 1 Construction 1947 to1952 – Unit 2 Construction 1960 – Unit 3 Construction 1974 – Sedimentation Basin Addition to Unit 3 1978 – Booster Station Added 1986 to 1989 – Spent Backwash Water & Sludge Lagoons 1989 – Chemical Feed Upgrades 1991 – Low Lift Pump Upgrade 1993 – Emergency Generators Replaced 2007 – SCADA system

Project History - Study & Preliminary Design 2007 – Sedimentation Basin Study & Recommendations 2008 – Pilot Study - Dissolved Air Floatation , Granular Activated Carbon and Manganese Contactors 2009 – Water Treatment Plant Evaluation & Conceptual Design Report Opinion of Construction Cost $30M to $46M 2013 – Preliminary Design of Improvements DAF/GAC/Mn Contactors Opinion of Construction Cost $29M to $41M Project Review with Drs. Knocke & Edzwald

Project History - Design 2014 – Value Engineering Study at 30% Opinion of Construction Cost $30M to $35M 2014 – Value Engineering Study at 60% Opinion of Construction Cost $37.5M 2014 – Pilot Testing of Manganese Contactors 2016 February – Final Design Sent to CTDPH for review 2016 Summer – Address CTDPH Comments August 2016 – Receive CTDPH approval to Bid the project

Project History – Bid Phase August 24, 2016 – Advertise For Bid September 2016 – Mandatory Prebid Conference for General Contractors September 2016 - General Contractor Site Visits November 8, 2016 – General Contractor Bids Received RH White Banton Carlin DOC Nickerson Walsh Base Bid $43.9 $44.6 $45.67 $45.7 $47.9 $51.95 w/Deducts $39.3 $40.8 $40.9 $41.6 $48.3 % Difference 1.6% 4% 4.1% 9% 18%

Architect Drawing

Overview of the Main Project Components

Overview of the Main Project Components ELECTRICAL – Upgrade of 60 year old electrical system MECHANICAL – Upgrade of 60 year old pump and piping systems ENERGY CONSERVATION – Building envelope/equipment/HVAC FIRE PROTECTION / EMERGENCY – Elevated Water Storage CLARIFICATION – Construction of dissolved air flotation system FILTRATION – Construction of deep bed granular activated carbon filters. MANGANESE REMOVAL – Retrofit manganese contactors PROCESS CONTROL – Supervisory control and data acquisition of all systems TRIHALOMETHANE REMOVAL – Construction of systems in storage tanks existing and new

Operators View of Importance Electrical Upgrade Convert to Modern Voltage Compatibility with GU electric system upgrade Replace Outdated Electrical Equipment Emergency Generators Odd Voltage Switchgear No Longer supported

Operators View of Importance Mechanical Pumping & Piping Aged Pumps (1948 to 1991) Variable Frequency Drives Increase Reliability & Efficiency Piping (Buried & Internal) Aged Pipe Inoperable Valves

Operators View of Importance Energy Conservation Upgrade Electrical System Building Envelop Improvements Insulation, new windows Modern Heating, Ventilation and Air Conditioning System Credits / Rebates Overall Energy Savings

Operators View of Importance Finished Water Storage Limited useable depth in the existing Increase for Fire Protection Backwashing Filters Capacity for Regional Demands Allow for WFP shutdowns for maintenance

Importance of Treatment & Chemical Systems CLARIFICATION Better at removing small light particles, color compounds, and algae than current sedimentation treatment Chemical application - same dose of coagulant is more effective at removing turbidity SAFETY – Operators don’t have to enter basins to remove solids

Importance of Treatment & Chemical Systems Filtration Granular Activated Carbon More effective at removing a wide assortment of contaminants, especially organics, than rapid sand filters Deep bed GAC is more effective than GAC-capped rapid sand filters (1930s technology with a “lid” of GAC) New filters will have filter-to-waste technology as required by regulations

Importance of Treatment & Chemical Systems Manganese Removal Contactors Retrofit Removes Mn without chemical treatment (currently CIO2; by-products = Chlorite, Chlorate Currently a Health Advisory for Mn (0.3 mg/L), not an MCL On test list for UCMR4 (2018-2020 sampling period) for possible regulation Regulated in Ontario, Canada

Operators View of Importance Process Control Upgrade Chemical Feed Systems SCADA Upgrades Increase Flexibility & Reliability Improve regulatory compliance

Importance of Treatment & Chemical Systems Trihalomethanes (THMs) Removal Regulations are Stricter Current Plant does not address removal of Precursors Form within Distribution System Trihalomethanes are compounds formed when chlorine comes in contact with natural organic matter in water; they are an issue for any WTP that uses surface water reservoirs as their source water Previous upgrades to current WTP were not able to address THM reductions, new plant processes and distribution system upgrade will achieve reductions in THMs (better turnover in Bailey Hill tank = less water age = less THMs

Project Pricing: Sitework Electrical Mechanical Building Improvements WTP Rebuild $43,901,043 Engineering $4,198,508 Contingency $5,900,449 Mechanical Building Improvements Finished Water Storage DAF – Dissolved Air Flotation GAC – Granular Activated Carbon TOTAL PROJECT COST: $54,000,000 Mn Contractors Miscellaneous Process Control THM Removal Hazmat Removal Contingency Engineering

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