Littleton, MA – – Smart Sewering Strategy: Smart Sewering Strategy: Littleton, MA Affordable Green Sewering, Fit- -For For- -Purpose Purpose Affordable Green Sewering, Fit Paul Knowles Paul Knowles Green First: December 8, 2011 Falmouth MA
Introduction • Intro to Littleton challenge and principles of smart sewering • The six steps of smart sewering analysis • Opportunities for green decentralized solutions for the cape, provided by a Responsible Management Entity
Motivation for sewer in Littleton • Affordable at small-scale • Concentrate growth in the commercial center • Consider social and ecological benefits
Anticipated Wastewater Flows – 20 year build-out Use Flow (gpd) Yr. 0 Yr. 5 Yr. 10 Yr. 15 Yr. 20 Park & Co. Retail 10,000 - 7,000 3,000 - - Restaurant 28,000 - 19,600 8,400 - - Hotel 11,000 - 7,700 3,300 - - Medical 4,800 - 3,360 1,440 - - Office VCB Retail 7,500 1,000 - 3,275 - 3,225 Restaurant 20,000 500 - 10,900 - 8,600 Residential 38,500 11,000 - 10,945 - 16,555 Office 20,000 11,000 - 400 - 8,600 VOD Industrial 14,400 - - 7,200 3,312 3,888 Office 7,500 - - 3,750 1,725 2,025 Commercial Wells/IBM Office 47,000 25,000 12,500 4,500 - 5,000 Commercial KIMBALL* Commercial 15,000 15,000 - - - - TOTAL 63,500 50,160 57,110 5,037 47,893 CUMULATIVE 63,500 113,660 170,770 175,807 223,700
Smart Sewering Case Study: Littleton, MA Q) How do we keep a 185,000 gpd system affordable without requiring a larger sewer disctrict? A) Perform a Smart Sewering Study which considers: 1. Community values 2. Environmental issues 3. Minimizing risk to tax base 4. Appropriate technology 5. Improving affordability for users 6. Economic Feasibility Analysis
Community Values 20 Parameters: Environmental, Economic and Social
Community Values 232 responses: top 4 parameters by score
Environmental Issues 3 town wells in Merrimack River Watershed STUDY AREA MERRIMACK RIVER WATERSHED I-495 CONCORD RIVER WATERSHED
Environmental Issues • Water distribution in Littleton MERRIMACK • Recharges are RIVER on-lot septic WATERSHED system • Net transfer of water from CONCORD Merrimack to RIVER WATERSHE Concord D The Massachusetts Executive Office of Environmental Affairs (EOEA) and the Charles River Watershed Association/ESS Group (2007), Community Water Budget Report, Town of Littleton
Environmental Issues Resulting change in natural stream flow during high and low seasonal flow – green are Merrimack sub- basins, pink are Concord sub-basins APRIL (HIGH FLOW) SEPTEMBER (LOW FLOW) Human Natural Human Human Natural Human Total Sub-basin Relative Stream Total Vol Relative Area (Mi²) Stream Flow Vol Impact Name Impact Flow Impact Impact (MGD) (MGD) (%) (MGD) (MGD) (%) Bennet's 7.1 14.67 -2.32 -15.83 2.25 -1.5 -66.57 Beaver 13.1 27.49 -0.9 -3.28 4.27 -1.15 -26.87 Gilson 3.4 6.73 -0.19 -2.77 0.11 0 2.33 Vine 9.9 19.62 -0.37 -1.9 2.95 0.09 2.93 Fort Pond 7.2 14.27 -0.08 -0.58 1.3 0.05 3.72 Nagog Pond 0.6 1.16 0 0.18 1.05 0.05 4.87
Environmental Issues Considered when locating recharge facilities Alternative recharge area 72 acres within 1.5 miles away Zone III. Mix of I-495 DOT and developer land MERRIMACK WATERSHED Suitable recharge area within study area
Minimizing Financial Risk - Phasing Reducing carrying costs by using technologies that are affordable at small scale and then installing capacity in phases to match growth Large carrying costs – higher risk of tax increase to subsidize user rate Small carrying costs – reduced risk to tax base and user
Minimizing Financial Risk - Phasing Conventional Phasing Assumptions: • Includes cost of: onsite appurtenance, collection, TOTAL secondary treatment and groundwater dispersal Year 0 • Does not include cost of land • In both scenarios the majority of land is required Flow (gpd) 182,000 for dispersal Anticipated Connections 607 • Treatment costs based on the ability to achieve Capital Cost ($) 17,024,590 secondary treatment at $20/gpd installed between scale of 23,500 and 182,000 gpd by using available Sewer Length Required (LF) 43,550 technologies Area Required (acres) 9 Smart Phasing Phase 1 2 3 4 5 TOTAL Year 0 5 10 15 20 Flow (gpd) 30,000 38,000 61,000 23,500 29,500 182,000 Anticipated Connections 100 127 203 78 98 607 Capital Cost ($) 4,182,400 3,610,302 6,718,555 3,000,544 4,366,569 21,878,371 Sewer Length Required (LF) 18,200 6,333 10,167 3,917 4,917 43,550 Area Required (acres) 1.67 2.11 3.39 1.31 1.64 10.12
Minimizing Risk – Private ownership Risk Allocation Table: Private vs. Public Ownership Cost of private debt will result in higher user rates but will remove the risk to the tax base Design-Bid-Build Design-Build-Operate- Conventional Approach Finance (implementation through (implementation through public ownership) private ownership) Design Build Cost Town Private Entity Design Build Schedule Completion Town Private Entity Construction Warranty Town Private Entity Compliance Guarantee Town Private Entity Capital Replacement Town Private Entity Asset Management O&M Cost Town Private Entity Residual Disposal Cost Town Private Entity Life Cycle Cost Town Private Entity Long-Term Financing Town Private Entity Finance Interest Rate Risk Town Private Entity
Minimizing Risk – Private Ownership Conventional WW Ownership Options in MA: • Governmental - Municipal/County • Quasi-Governmental Authority, Special District, Public Nonprofit • Private Nonprofit Cooperative or Association Alternative WW Ownership Options in MA: • Private For-Profit Utility • Public Private Partnerships – P3
Minimizing Risk – Private ownership Private For-Profit Utility: In MA Private wastewater entities are not regulated by the Department of Public Utilities. MassDEP regulates Privately Owned Wastewater Treatment Facilities (PWTF) under 314 CMR 5.15 based on conditions which are aimed towards Homeowners Associations etc. Public Private Partnerships (P3): The town retains ownership and transfers operation and financial obligations to a private entity under a long term contract, generally 20 years or longer. It appears that special state legislation would be required for a municipality to procure a design-build-operate type contract.
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RME – Decentralized water reuse in MA MA Case Study: Gillette Stadium • MBR technology with design flow of 1.3 MGD. Capital cost in 2005 was $5.2M • Recycles flush water from 69,000 football fans on game day. • Sewer enabled economic expansion around the stadium – multi-user private for-profit utility operation • 20 year DBO contract with performance risk – reduces recharge by reuse
Appropriate Technology Capital costs for small-scale treatment technologies Subsurface Flow Packaged Activated Treatment Wetlands Sludge Process systems Relationship between capacity in gallons per day (gpd) and unit capital cost ($/gpd capacity) for five small- scale wastewater treatment technologies: Activated Sludge Plant (ASP), Sequencing Batch Reactor (SBR), Oxidation Dith (Oxi-Ditch), Membrane Bioreactor (MBR) and Subsurface Flow Treatment Wetland (SSF TW).
Appropriate Technology Operating costs for small-scale treatment technologies Subsurface Packaged Flow Activated Sludge Treatment Process systems Wetlands Relationship between capacity in gallons per day (gpd) and unit operating cost ($/1000 gallons treated) for five small-scale wastewater treatment technologies: Activated Sludge Plant (ASP), Sequencing Batch Reactor (SBR), Oxidation Dith (Oxi-Ditch), Membrane Bioreactor (MBR) and Subsurface Flow Treatment Wetland (SSF TW).
Appropriate Technology “The system is not an unsightly eyesore, does not emit odors and emits no loud noise” Open surface technologies Subsurface technologies
Appropriate Technology Landscape architecture - Flower and the Butterfly Constructed Wetland at Ko Phi Phi, Thailand http://mit.biology.au.dk
Appropriate Technology Indoor natural systems that achieve reuse Courtesy of Worrell Water
Advanced Treatment with Natural Systems Living Machine by Worrell Water Technologies Port of Portland building, OR
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