Operation of SAWS New Groundwater Desal Plant - Richard Donat

TWCA

Richard DonatExecutive Management Analyst, Engineering and Construction

San Antonio Water SystemBrackish Groundwater Desalination Project

March 1, 2017

March 1, 2017

SAWS Brackish Groundwater Desalination Project

Outline• Water Challenges • Project Background• Project Challenges• Facility Highlights

March 1, 2017


Water Supply Challenges

March 1, 2017


Why Brackish Inland Desalination

• Large volumes of available brackish water

• Resource close to San Antonio

• Identified in the SAWS 2005 Water Management Plan

• Diversification• Untapped resource

March 1, 2017


Desalination Program

• Phase I (2016) – 12 MGD – 13,440 Acre-feet / year– (~53,000 Households)

• Source Water– Lower Wilcox Formation– 12 Production wells (~1,500’ avg. depth)

• Treatment Process– Reverse Osmosis

• Concentrate Disposal– 2 Injection wells (5,000’ avg. depth)

General Information

March 1, 2017


Project Cost

• Project Cost: $192.7 million, $1,177 $/AF• Began producing water November 9, 2016

Phase I

March 1, 2017


Challenges• State and Local Groundwater

Regulation• Public Perception• Stakeholder Buy in• Funding/Value Engineering• Real Estate• Concentrate Disposal• Design • Construction • Operational

March 1, 2017


Concentrate DisposalOptions Considered

March 1, 2017


Design

• Prevent Membrane fouling – Open System vs. Closed

System– Pre-treatment

• Finish water quality standards

• Short design timeline– Multiple sub-consultants

Challenges

March 1, 2017


Construction Challenges

• Budget– Managing a budget

without owner contingency

• Schedule– Record Rainfall (2 yrs.)

• Complicated Construction– 13 Work Packages

Challenges

$

March 1, 2017


Operational

• Learning curve – Fully automated plant– Bring in operators early– 1 month RDT & 3 months

commissioning phase• Operational– Raw Water

• Cartridge Filters/Turbidity– Fouling– Meeting Finished Water Goals

Challenges

March 1, 2017


Stage 1

Stage 2

Reverse Osmosis Primary Trains

Stage 1

Stage 2

Stage 1

Stage 2

Stage 1

Stage 2

Lower Wilcox Wellfield

Pre-Filters

13.11 mgd

2 mgd

Anti-Scalant

Reverse Osmosis

Concentrator Trains

Stage 3

Stage 3

8.88 mgd 1.11 mgd

Injection Wells

12 mgd

1.11 mgd

H2SO4

Calcite Contactors

30%

70%

CO2

Degasifiers

NaOH Cl2

Process DiagramOperational

March 1, 2017


Construction 2014 to PresentBuilding Success

June 2014 April 2015

December 2016February 2016

March 1, 2017


Treatment Facility

March 1, 2017


Three Water Supplies at H2Oaks

March 1, 2017


Water Supply and Educational CenterEducation and Outreach

March 1, 2017


Grand Opening FestivitiesJanuary 27, 2017

March 1, 2017


Thank you

http://www.tetratech.com/en

TWCA

Richard DonatExecutive Management Analyst, Engineering and Construction

San Antonio Water SystemBrackish Groundwater Desalination Project

March 1, 2017

March 1, 2017


Regulatory

• State and Local Groundwater Regulation– 16 Groundwater

Management Areas– 100 Groundwater Districts

• Challenges:– Desired Future Conditions

(DFCs)– Groundwater Permits

Challenges

http://www.tceq.state.tx.us/assets/public/permitting/watersupply/groundwater/maps/gcdmap.pdf

March 1, 2017


Stakeholder Buy in

• Large project many different stakeholders across SAWS

• Partnering sessions with SAWS upper management

• Desal plant visits across the United States

• Outreach to San Antonio elected officials and SAWS Board of Trustees– Addressed Project concerns

• Construction Manager, Program Manager, and SAWS Workshops

Challenges

March 1, 2017


BudgetingDeveloping Cost Estimates

*For comparison purposes all estimates assume 5% annual debt service*2009/2010 Estimate 10 MGD / 2012 Estimate 10.9 MGD / 2014 Estimate 12 MGD

• Economy• Increase Plant

Capacity• Scope/Vision

Change• New

Information• Estimates vs.

Actual Bids

March 1, 2017


Funding

• Rate approval through SAWS board of Trustees and City Council

• Texas Water Development Board (TWDB) Low Interest Loans

• Construction estimates greater than budget estimates– Value Engineering– $17.7M reduction

Funding Sources for the ProgramInterest

Rate$/acre-

foot$/1,000 gallons

5% $1,370 $4.20 4% $1,266 $3.89 3% $1,177 $3.60

*Without and interest rate reduction SAWS would need to lower the capital cost by $40M to achieve $1,177 / acre-foot

March 1, 2017


Real Estate

• Purchasing land needed for well field– 3,200 acres already owned– Additional 2,800 acres

purchased – Takes time• Land is leased back for

agriculture and grazing– Livestock

• Working with neighbors– Public Meeting

Challenges

Operation of SAWS New Groundwater Desal Plant - Richard Donat

Environment

Transcript of Operation of SAWS New Groundwater Desal Plant - Richard Donat