Decentralization = New Supply?Decentralization = New Supply?

The North Bay Watershed Association’sThe North Bay Watershed Association’s

Satellite Treatment Plant StudySatellite Treatment Plant Study

The Satellite Treatment Plant The Satellite Treatment Plant Study develops a framework for Study develops a framework for

evaluating the feasibility of evaluating the feasibility of decentralized Water Recycling decentralized Water Recycling

SystemsSystems

That Framework is then applied to case studies in Marin, Sonoma and Napa Counties

The Study is a Cooperative Effort The Study is a Cooperative Effort between DWR & NBWAbetween 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 The General Criteria Outlined a number of basic Analysis number of basic Analysis

TechniquesTechniques

• Decision Criteria

• Market Analysis Techniques

• Influent Flow Considerations

• Process & Distribution Overview

• Cost Calculator

• Economic Evaluation Techniques

Decision Criteria Balances Costs Decision Criteria Balances Costs of new Supply and Benefits of of new Supply and Benefits of

RecyclingRecycling

Need for New Water

Supply

Reduced Wastewater Discharge & Mass Loading

Expand Raw Potable

Centralized Recycling

Satellite Recycling

Desalination

Considerations for The Initial Considerations for The Initial Screening Analysis are Outlined 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 Conceptual Facility is the Basis of Cost EstimatesEstimates

The General Criteria includes a The General Criteria includes a “Cost Calculator” “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 Updated

For Changing Variables

Capital Cost for Satellite Treatment

y = 1E+07x-0.4788

$-

$10,000,000

$20,000,000

$30,000,000

$40,000,000

$50,000,000

$60,000,000

0.000 0.200 0.400 0.600 0.800 1.000 1.200

Plant Size (mgd)

Ca

pit

al C

os

t p

er

MG

D

Area Served: Sir Francis Drake Blvd area in San Anselmo and FairfaxWastewater Taken from: Center Blvd. at Sycamore Ave.

Satellite Plant Size (mgd) 0.19Distance from Central Plant to Anchor User (mi) 5.1 Change in elevation (ft) 150Distance from Satellite Plant to Anchor User (mi) 0.9 Change in elevation (ft) 100Cost of land for Satellite Plant (thousands of dollars) 250Cost of Electricity ($/kWh) 0.15$ Reverse Osmosis Required at Central? (Y/N) y

Current ENRCCI SF 7801

Cost Analysis Cost/AF Total CapitalAnnual O&M

Cost of Satellite Plant 3,194$ 3,700,000$ 45,000$ Cost of Satellite Distribution 532$ 620,000$ 6,000$ Total Satellite Cost 3,726$ 4,320,000$ 51,000$

Cost of Central Plant 6,707$ 3,830,000$ 402,000$ Cost of Central Distribution 3,015$ 3,500,000$ 35,000$ Total Central Cost 9,722$ 7,330,000$ 437,000$

More Cost Effective: Satellite

Calculator “output” facilitates Calculator “output” facilitates Economic AnalysisEconomic Analysis

A

B

C

Total Discounted Project Costs 2 ($) $4,621,000

Benefit/Cost Ratio (A/B) 3.06

Table 6 Benefit/Cost Ratio

Total Discounted Water Supply Benefits1 ($) $14,157,035

The Site Specific Analysis The Site Specific Analysis Applies the General CriteriaApplies 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 ExpectedTypes 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 The Site Specific Analysis can also be described ascan also be described as

“ “reality sets in” reality sets in”

Central Marin ChallengesCentral 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 AnalysisCentral Marin Analysis

Central Marin AnalysisCentral Marin Analysis

Entitlement

(AF/yr) (1)

J S FINK 3FAIR-ANSELM PLAZA 3MARIN TOWN & COUNTRY 10TAMALPAIS UNION HS DIST 45UNION HS DIST TAMALPAIS 0TOWN OF SAN ANSELMO 0UNION HS DIST TAMALPAIS 1TOWN OF SAN ANSELMO 9UNION HS DIST TAMALPAIS 0DONALD M ARNTZ 7SAN ANSELMO 1SAN ANSELMO 4REDHILL HOLIDAY CLEANERS 2TOWN OF SAN ANSELMO 2REDHILL FASTBREAK 76 1SUNNY HILLS CHILDREN'S SERVICE 9ROSS VALLEY 5SAN ANSELMO 1Total 103

User Site(s) (1)

Central Marin ConclusionsCentral 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 $7,200 Expand SASM $2,300 Central

Strawberry Peninsula

102 $4,324 Expand SASM $9,067 Satellite

Mt. Tamalpias Cemetery

64 $5,633 Expand

Las Gallinas

$2,605 Central

Peacock Gap Golf Course

248 $2,803 Upgrade CMSA $7,820 Satellite

San Anselmo 103 $3,726 Upgrade CMSA $9,722 Satellite

Central Marin ConclusionsCentral Marin Conclusions2. 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

145 Expand SASM

Central $1,800 $500

Strawberry Peninsula

102 Expand SASM

Satellite $1,800 $2,524

Mt. Tamalpias Cemetery

64 Expand

Las Gallinas

Central $1,800 $805

Peacock Gap Golf Course

248 Upgrade CMSA

Satellite $1,800 $1,003

San Anselmo 103 Upgrade CMSA

Satellite $1,800 $1,926

Central Marin ConclusionsCentral Marin Conclusions

3. Outside Contributions Can tip the Balance!!

Location Capital Cost Outside Contribution

(25%)

Annualized 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 WaterDecentralized Recycled Water

• Presents a new frame for reviewing feasibilityPresents a new frame for reviewing feasibility

• Can provide a potential new supply in urban Can provide a potential new supply in urban areasareas