engineering a new drinking water supply · 5 east expansion i $7,167,350 6 west main service ii and...
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IGNACIO CADENA, P.E. – PROJECT MANAGER
NOVEMBER 3, 2011 – SHERMAN, TEXAS
ENGINEERING A NEW DRINKING WATER SUPPLY
HOW LONG DOES IT TAKE TO DEVELOP A NEW DRINKING WATER SUPPLY?
26 years
PROJECT LOCATION
SOMERVELL COUNTY WATER DISTRICT
• Glen Rose, Texas
• Somervell County Water District Incorporated in 1985
• Selling Water November 2011
• Dinosaur Valley
• Fossil Rim Wildlife Center
• Paluxy River
• Comanche Peak Nuclear Plant
ENGINEERING A NEW DRINKING WATER SUPPLY
Overview
OVERVIEW
• Current Water Supply
• Water Supply Evaluation
• Supply Facilities
• Demand Projections
• Water System Hydraulic Analysis
• Capital Improvements Plan
• Treatment Facilities
ENGINEERING A NEW DRINKING WATER SUPPLY
Current Water Supply
CURRENT WATER SUPPLY
• Somervell County Water Supply
• Groundwater Wells from the Trinity Aquifer
• Declining Water Table Elevations in Municipal Wells
Figure 1.1
Depth to Water - Glen Rose Municipal Well #2
0
20
40
60
80
100
120
140
160
180
Jan-60 Jan-65 Jan-70 Jan-75 Jan-80 Jan-85 Jan-90 Jan-95 Jan-00
Dep
th t
o w
ate
r (f
t)
CURRENT WATER SUPPLY
• Increasing Demands
• Uncertainty to meet Future needs Figure 1.2
Historical and Projected Municipal Water Use
0
500
1,000
1,500
2,000
2,500
3,000
1980 1990 2000 2010 2020 2030 2040 2050 2060
Wa
ter
Dem
an
ds
(ac-
ft/y
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Glen Rose Historical Glen Rose Projected Somervell County Historical Somervell County Projected
ENGINEERING A NEW DRINKING WATER SUPPLY
Water Supply Evaluation
WATER SUPPLY EVALUATION
• Mid 80’s Recommended Alternate Supply
• Diversion from Paluxy River
• Off-Channel Reservoir on Wheeler’s Branch
• Conservation Storage Capacity 4,118 acre-ft
• Diversion up to 2,000 acre feet/ yr for Municipal, Industrial and Irrigation
• Impound up to 5,000 acre feet/yr of Runoff
WATER SUPPLY EVALUATION
• Will not affect flow through Dinosaur Valley State Park
• Environmental impacts
• Archeological Impacts
• Is economically feasible and provides an adequate water supply
• Water quality suitable for municipal use
ENGINEERING A NEW DRINKING WATER SUPPLY
Channel Dam
CHANNEL DAM
• Upstream of Big Rocks Park on Paluxy River
• Diversion Dam 8-feet high & 100–feet long
• Constructed with reinforced concrete to allow overtopping
• Channel Dam Construction Completed 2007
• Channel Dam Cost - $1,351,000
CHANNEL DAM
CHANNEL DAM
ENGINEERING A NEW DRINKING WATER SUPPLY
Wheeler Branch Reservoir
WHEELER BRANCH RESERVOIR
• Located 2 miles NW of Glen Rose
• Constructed as earthen embankment
• 1,750–feet in length & max height of 90-feet
• Conservation capacity of 4,118 acre-feet
• Raw water supply 24-inch pipeline
• Reservoir Completed in 2007
• Construction Cost $9,869,000
WHEELER BRANCH RESERVOIR
WHEELER BRANCH RESERVOIR
ENGINEERING A NEW DRINKING WATER SUPPLY
Raw Water Pump Station
and Pipeline
RAW WATER PUMP STATION
• Raw Water Pump Station upstream of Channel Dam
• Designed variable diversion rates up to 50 cfs
• Operation contingent upon flow limits
• Pump Station and Pipeline Completed 2008
• Construction Cost $2,750,000
• 36-inch Pipeline approximately 2.0 miles long
• Pipeline Construction Cost $1,900,00
RAW WATER PUMP STATION & PIPELINE
ENGINEERING A NEW DRINKING WATER SUPPLY
Demand Projections
• Somervell County Population approx. 7,900
• Steady Growth Rate of 2.28% annually
Year Glen Rose Rest of County Total
2010 2,721 5,090 7,811
2015 2,914 5,706 8,620
2020 3,107 6,322 9,429
2030 3,493 7,889 11,382
POPULATION PROJECTION
• Somervell County average day demand estimated 85 gallons per capita day.
• Maximum Peaking Factor of 2.5
• Peak hour to max day peaking factor of 2.0.
Year
City of Glen Rose Served
(%)
Somervell County Served
(%)
Served Avg Day Demand
(MGD)
Served Max Day Demand
(MGD)
Served Peak Hour Demand
(MGD)
2010 100% 10% 0.99 1.82 3.22 2015 100% 30% 1.17 2.29 4.15 2020 100% 50% 1.39 2.83 5.23 2030 100% 70% 1.75 3.73 7.03
WATER DEMANDS
ENGINEERING A NEW DRINKING WATER SUPPLY
Water System Hydraulic
Analysis
• Water System Model
• Model Analysis using Maximum Day Demands
• Model using Adequate Pressures and Fire Flow Demand of 500 gpm
• Model used to Develop CIP for 2030 Improvements
WATER SYSTEM HYDRAULIC ANALYSIS
ENGINEERING A NEW DRINKING WATER SUPPLY
Capital Improvements Plan
• Phases
Project Description Total Project
1 WTP and Transmission to Glen Rose and Luminant $18,352,569
2 East Main Service I $5,730,000
3 East Main Service II $1,950,000
4 West Main I $2,701,350
5 East Expansion I $7,167,350
6 West Main Service II and East Expansion I $5,336,350
7 East Expansion II $8,650,000
8 East Expansion III $7,100,000
9 Heights/ Methodist Encampment Improvements $8,459,350
10 South Expansion $12,008,000
11 West Expansion II $6,876,750
12 West Expansion III $6,756,500
13 East IV and South II Expansion $8,937,550
TOTAL $100,033,769
CAPITAL IMPROVEMENTS PLAN
WATER SYSTEM HYDRAULIC ANALYSIS
WATER SYSTEM HYDRAULIC ANALYSIS
ENGINEERING A NEW DRINKING WATER SUPPLY
Treatment Planning
• Paluxy River Quality
• Low Salts Concentration
• Low Organics
• Clear water low in particulates except following rain events
• Non-corrosive
• Hardness compared to Groundwater
WATER QUALITY ANALYSIS
• Paluxy River Water Sampling December 2001
ENGINEERING A DRINKING WATER SUPPLY
• Remove / Inactivate Pathogens, including Cryptosporidium and Giardia
• Remove Colloidal Particulates
• Remove Organics
• Provide Hardness similar to Groundwater (Secondary Objective)
• Primary Drinking Water Quality Standards
TREATMENT OBJECTIVES
• Five Treatment Alternatives Evaluated:
–Alternative # 1: Solids Contact Clarifiers with Conventional Filtration Treatment
–Alternative # 2: Package Water Treatment Plant with Ion Exchange Sidestream Treatment for Softening
–Alternative # 3: Conventional Treatment with MF/UF-Membranes & NF-Membrane Sidestream Treatment for Softening.
TREATMENT ALTERNATIVES
• Treatment Alternatives Evaluated (Cont…):
–Alternative # 4: Direct MF/UF-Membranes Filtration & NF-Membrane Sidestream Treatment for Softening.
–Alternative # 5: Direct MF/UF-Membranes Filtration with Ion Exchange Sidestream Treatment for Softening.
–Alternative # 6: Direct MF/UF-Membranes Filtration (No Softening)
TREATMENT ALTERNATIVES
TREATMENT ALTERNATIVES
Clearwell
Backwash Pump
Disinfection
Distribution System
High Service Pumps
Wheeler Branch
Reservoir
Waste Discharge
Micro-Filtration Membranes
Reservoir
To Brazos Tributary
RWPS
Paluxy River
Channel Dam
River Water
MF/UF
• Selected Treatment Alternative
–Alternative # 6: Direct MF/UF-Membranes Filtration (No Softening)
ENGINEERING A NEW DRINKING WATER SUPPLY
Water Treatment Plant
Design
• Per 30 TAC Chapter 290.42 (g) Membrane Technology is Innovative or alternate treatment techniques.
• Pilot Study included Two (Preselected) Membrane Manufacturers
• Pilot Study Pretreatment
• Pilot Study conducted Inside Raw Water Pump Station
TREATABILITY STUDY – MEMBRANES
• Protocol Submitted to TCEQ for Approval
• Pilot Study Protocol Described a 3 Stage Evaluation
–Stage 1: Membrane system optimization flow rates, backwash rates, chemical doses, etc.
–Stage 2: Performance Stage using optimum conditions for 30 days (uninterrupted)
–Stage 3: Evaluation of Membrane Irreversible Fouling
TREATABILITY STUDY – PILOT STUDY
MEMBRANE PILOT STUDY
• Membrane Treatment Capacity 2.5 MGD
• Design Parameters: – Membrane Flux: 45 GFD
– Membrane Recovery: 96% Recovery
– Membrane Modules: 108
– Membrane Backwash: 20 Minutes
– Enhanced Flux Maintenance: 24 Hours
– Clean in Place Cleaning: 30 – 60 Days
WATER TREATMENT PLANT DESIGN
• Raw Water Feed System:
• Y-Strainers & Self-Cleaning Strainers
• Reverse Filtration Pumps
• Compressed Air System:
• Chemical Dosing System
• Neutralization System
WATER TREATMENT PLANT DESIGN
• Membrane Equipment September 2011
ENGINEERING A DRINKING WATER SUPPLY
• Residual Handling Lagoons (TPDES Permit)
• Disinfection Strategy
• Two 125-Gallon Concrete Clearwells
• High Service Pump Station
–Firm Capacity 3.75 MGD
–Horizontal Split-Case Centrifugal Pumps
• Construction Completed in November 2011
• Construction Cost $8,633,000
WATER TREATMENT PLANT DESIGN
• Membrane Building November 2011
ENGINEERING A DRINKING WATER SUPPLY
QUESTIONS ?
ENGINEERING A NEW DRINKING WATER SUPPLY
THANK YOU
ENGINEERING A NEW DRINKING WATER SUPPLY
Ignacio Cadena, P.E. Ph: 817 735 7283 E-mail: ica@freese.com
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