WASTEWATER TREATMENT

CVEN 451, Public Works EngineeringTeam Members: Kenneth Anton Roy Aviles & Elkin Mosquera

WASTEWATER TREATMENT

Objective: To provide sewage treatment for a subdivision development of 10,000 people.

AssumptionsFour family members per house (2,500

units)¼ acre plot size (625 acres)Wastewater generation is 100 GPD/CAP

(1 MGPD)Period of analysis is 30-years Interest rate used is 7%67-year physical life of infrastructure

WASTEWATER TREATMENT

Option 1: New wastewater treatment plant (WWTP).Capital

investment includes land purchase, design, and construction cost

WASTEWATER TREATMENT

Option 2: Expansion of Lick Creek WWTP.Capital

investment includes design and construction of expansion & O&M is a prorated cost

WASTEWATER TREATMENT

Benefit of Option 1: A new wastewater treatment plant will support planed development in southern College Station.

Benefit of Option 2: Land zoned for another purpose will not need to be acquired and rezoned since existing plant will be used.

Recommendation: The recommended and lowest life-cycle cost (LCC) alternative is option 2, expansion of the Lick Creek Wastewater Treatment Plant. This option has an estimated Capital Investment cost of $16.3 M and LCC of $26.4 M.

WASTEWATER TREATMENT

ACTION ITEMS

Municipal bond rate – 7% 20-year rate Option 1 Capital Investment - $22.8 M ($35.6 M NPV) Option 2 Capital Investment - $16.3 M ($26.4 M NPV)

Sewage line cost

*price of pipe from U.S. Plastic Corporation*price of installation costs from RS Means Manual ($11.00/ft/inch of pipe diameter)

ACTION ITEMS Pipe sizes necessary for flow

Duration of new construction option is 2-years From approval to end of construction