Decentralization = New Supply? The North Bay Watershed Association’s Satellite Treatment Plant Study

The Satellite Treatment Plant Study develops a framework for evaluating the feasibility of decentralized Water Recycling Systems That Framework is then applied to case studies in Marin, Sonoma and Napa Counties

The Study is a Cooperative Effort between DWR & NBWA General Criteria that can be translated Attention to Energy Efficiency Reliable New Water Supply Wastewater Benefits from Reduced Mass Loading Innovative Solution for a Tough Market

The General Criteria Outlined a number of basic Analysis Techniques Decision Criteria Market Analysis Techniques Influent Flow Considerations Process & Distribution Overview Cost Calculator Economic Evaluation Techniques

Decision Criteria Balances Costs of new Supply and Benefits of Recycling Need for New Water Supply Reduced Wastewater Discharge & Mass Loading Expand Raw Potable Centralized Recycling Satellite Recycling Desalination

Considerations for The Initial Screening Analysis are Outlined Quantifying Water Use –Available Records or Assumptions Based on Land Use Quantifying Wastewater Flow –Available Records or Assumptions Based on Land Use Available Mapping –GIS is a great tool Point of View of the “Client” –Water Agency; Wastewater Agency; Full-Service City Operational Realities –Satellite Plants required Wastewater Operators

Conceptual Facility is the Basis of Cost Estimates

The General Criteria includes a “Cost Calculator” Treatment Direct Filtration for Central Plant Upgrade Membrane Bio Reactor for Satellite Plant Land Included for Satellite Electricity Rates $0.15 kw/hr Piping Costs $150 - $260/ linear foot MMWD data – constrained urban conditions Cost Data Points Are Curves Used to Build Comparative Data can be UpdatedFor Changing Variables

Calculator “output” facilitates Economic Analysis

The Site Specific Analysis Applies the General Criteria Central Marin Service Area – 6 sites North Marin Service Area – 2 sites Sonoma Valley Service Area – 2 sites Napa Service Area – 2 sites

Types of Conclusions We Expected General Rule of Thumb…. Satellites become cost effective at distances greater than 4 miles from the Central Plant

The Site Specific Analysis can also be described as “reality sets in” “reality sets in”

Central Marin Challenges Coordination with thirteen distinct sanitation agencies A relatively wet climate damps irrigation demand A strong conservation ethic results in “frugal” landscaping A mature residential community without many “anchor tenants”

Central Marin Analysis

Central Marin Conclusions 1. Satellites Can be Cost Effective!! Satellite Location Reliable Yield AF/Y Cost $/AF/Y Central Plant Alternative Cost $/AF/Y Least Cost Alternative Mill Valley Golf Course 145$7,200Expand SASM$2,300Central Strawberry Peninsula 102$4,324Expand SASM$9,067Satellite Mt. Tamalpias Cemetery 64$5,633Expand Las Gallinas $2,605Central Peacock Gap Golf Course 248$2,803Upgrade CMSA$7,820Satellite San Anselmo103$3,726Upgrade CMSA$9,722Satellite

Central Marin Conclusions 2. But Not at Cost Effective as the Next Increment of Potable Water Satellite Location Reliable Yield AF/Y Central Plant Alternative Least Cost Alternative Potable Cost $/AF/Y Cost Above Potable Mill Valley Golf Course 145Expand SASM Central$1,800$500 Strawberry Peninsula 102Expand SASM Satellite$1,800$2,524 Mt. Tamalpias Cemetery 64Expand Las Gallinas Central$1,800$805 Peacock Gap Golf Course 248Upgrade CMSA Satellite$1,800$1,003 San Anselmo103Upgrade CMSA Satellite$1,800$1,926

Central Marin Conclusions 3. Outside Contributions Can tip the Balance!! LocationCapital CostOutside Contribution (25%) Annualize d Capital Cost $/AF/Y O&M $/AF/Y Total Cost $/AF/Y Potable Cost $/AF/Y Cost Above Potable $/AF/Y Mill Valley$3,146,000$786,500$1,182$545$1,727$1,800($73) Strawberry Peninsula $5,000,000$1,250,000$2,671$578$3,249$1,800$1,449 Mt. Tamalpias $896,000$224,500$765$245$1,010$1,800($790) Peacock Gap $4,570,000$1,142,500$1,004$216$1,222$1,800($578) San Anselmo $4,320,000$1,080,000$2,285$495$2,780$1,800$960 Totals$17,932,000$4,483,500

Decentralized Recycled Water Presents a new frame for reviewing feasibility Presents a new frame for reviewing feasibility Can provide a potential new supply in urban areas Can provide a potential new supply in urban areas