POTABLE WATERCVEN 451 Term Project

Demand Estimate

Water Use Average Flow (GPD/Capita)

# of People

ADD (GPD)

MDD^(ADD*2.4)

PHD^(MDD*1.85)

Residential 100 10,000 1,000,000 2,400,000 4,440,000Commercial/Retail 25 1,500 37,500 90,000 166,500

TOTAL Gal/d 1,037,500 2,490,000 4,606,500

TOTAL MGD 1.04 2.49 4.6065

Assuming that there are an average of 4 people per house, then a total of 2,500 service connections will be required.

^TCEQ RG-195.

Service Level Measures

Surface Water Supply System0.6 gpm/unit Raw water pump capacity with largest

pump out of service0.6 gpm/unit Treatment plant capacity

200 gal/unit TOTAL Storage Capacity

100 gal/unit Elevated Storage Capacity

10 gal/unit Pressure Tank Storage Capacity35 gal/unit Ground Storage

TCEQ 290.45

Service Level Measures

Ground Water Supply System1.0 gpm/unit Well capacity; <100 units w/o ground storage

0.6 gpm/unit Well Capacity; <100 units with ground storage

• Well capacity which meets or exceeds the MDD

• Ground storage capacity equal to 50% of the MDD• At least two service pumps with total capacity of 3X the MDD• Minimum pressure tank capacity of 220 gallons

TCEQ 290.45

Service Level MeasuresTCEQ 290.44

Pressure (PSI)

Flowrate (GPM/connection)

Minimum 35 (normal)20 (fire flows)

1.5

Maximum 80 -

Alternative Methods of Service• Alternative 1: Drill a new water well to be operated by CS

utilities• Water will be treated at existing treatment facilities, and

citizens will purchase water from CS• Alternative 2: Drill a new water well and treat the water at

new treatment facilities• Alternative 3:Use surface water and construct a treatment plant • Alternative 4: Shared water wells located in the development

Schematic

Infrastructure RequiredItem TypeStorage Tank ElevatedWater Well 100 GPMPipes 6” PVC, 18” and 24” concretePumps/Stations Booster, 1500 GPM centrifugalValves Isolation, 6” and 18”HydrantsTreatment Plant 2.5 MGD (Option 2)

Estimate of Facilities and Cost – Option 1 Capital Costs

Item Description Quantity Unit Cost Total Cost1000 GPM water wells 2 1,000,000 2,000,000 [1]site work 1 100,000 100,000 [1]

Piping Booster pump station 2 37,000 74,000 [1]6" PVC 64,000 50 3,200,000 [2]18" Concrete 9,500 200 1,900,000 [3]Piping to Community (24" Concrete) 52,800 200 10,560,000 [3]

Valves Booster pump station 2 13,000 26,000 [1]6" valves 2,500 1,000 2,500,000 [4]18" valves 80 4,800 384,000 [5].75 MG EST 1 2,000,000 2,000,000 [6]

Pumps Add to Sandy Point Pump Station 4 30,000 120,000 [7]Booster Pump Sta on site – 1500G GPM Centrifugal Pumps 4 30,000 120,000 [7]Booster Pump Building 1 85,000 85,000 [1]electrical and controls 1 138,000 138,000 [1]

Hydrants 500 2,350 1,175,000 [5]TOTAL$24,382,000

Estimate of Facilities and Cost – Option 2 Capital Costs

Item Description Quantity Unit Cost Total Cost1000 GPM Water well 2 1,000,000 2,000,000 [1]

Site work 1 100,000 100,000 [1]Piping Booster pump sta 2 37,000 74,000 [1]

6" PVC 64,000 50 3,200,000 [2]18" Concrete 9,500 200 1,900,000 [3]

Piping to Community (24" Concrete) 158,400 200 31,680,000 [3]Valves Booster pump sta 2 13,000 26,000 [1]

6" valves 2,500 1,000 2,500,000 [4]18" valves 80 4,800 384,000 [5]

.75 MG EST 1 2,000,000 2,000,000 [6]Pumps Booster Pump Sta on site 4 30,000 120,000 [7]

Booster Pump Sta by well 4 30,000 120,000 [7]Booster Pump Building 2 85,000 170,000 [1]electrical and controls 1 138,000 138,000 [1]

Hydrants 500 2,350 1,175,000 [5]TOTAL$45,587,000

Summary

• Option 1 was selected as providing the lowest cost.• Recommendation: Drill a new water well to be operated by

CS utilities• Water will be treated at the existing treatment facilities,

and citizens will purchase water from CS

Option Total Per New Household

Per Capita in College Station

1 $31.7 M $12,700 $300

2 $59.3 M $23,700 $560

Questions?

AcknowledgementsThank you to Dr. Stockton for taking the time to join our class, and for teaching us about Public Works

Works Cited[1] Atkinson Engineering Cost Data[2] http://www.tudwater.com/pdf/WestBigHill_Cost.pdf[3] Texas Water Development Board[4] Vermont Agency of Natural Resources[5] Riverdale City Public Works Department[6] Houston Engineering, Inc. [7] City of South St. Paul, MN Feasibility Study