Lower Pilarcitos Creek Groundwater Basin Study - Coastside ...

and titration, and finally (3) disinfected and pH adjustment by caustic soda for corrosion
control.
Two types of aeration have been considered: one would be stripping through a
packed tower, the other by providing a tank of 10,000 gallons resulting in about 20-
minute retention at peak flow, and diffused air stripping and oxidation. Costs are based
on the latter approach as either double pumping from a packed tower aerator or locating
the bottom of its 20 plus feet height above the level of the flash mixers (Kennedy/Jenks,
1988). The latter approach is not considered to be as feasible or cost effective.
The construction costs of the aeration facilities are estimated at $105,500, and of
the chemical storage feed facilities, $39,000. An additional $15,000 is estimated for
contractor’s contingency for water treatment plant disruption, which provide for a total
construction cost of $159,000 at the WTP
as follows:
Capital Costs. The capital costs of the various project elements are summarized
Land Purchase, five lots at $100,000 $ 500,000
Construction Wells, five wells at $146,000 730,000
Transmission Pipeline 832,000
Water Treatment 159,000
SCADA 87,000
Construction Subtotal $2,308,000
Engineering Design & Construction Management at 15 percent $ 346,000
Construction Total $2,654,000
Other Costs:
Environmental – CEQA – 5 percent Construction 115,000
Coastal Development Permits & Acquisition 50,000
CCWD Staff Costs, Legal, Administrative & Engineering 50,000
Subtotal $ 215,000
Total Current Budget Cost Estimate $2,869,000
Escalation at 3 percent per year – 3 years (9 percent) $ 258,000
Budget Total $3,127,000
Operations and Maintenance Costs. The operations and maintenance costs
are based upon the cost of an annual supply from the Lower Pilarcitos Creek
groundwater basin of 75 MGY (146 gpm; 0.21 MGD). Energy costs are based upon the
current average cost of 10.1¢ per kilowatt-hour (KWH) and Nunes WTP costs of 7.1¢ per
100 cubic feet (ft 3 ) of treated water (Mier, February 2003). Labor costs are estimated to
be 5 hours per week additional at the Nunes WTP, and 2 hours per week at the wells.
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