July 25, 2012 - Toho Water Authority

Toho currently hauls approximately 603 loads (5,000 gallons/load) of biosolids from the Lake
Marion WRF to the South Bermuda WRF at $133.27/load. The annual biosolids hauling cost
from Lake Marion WRF to South Bermuda is $80,362. The dewatering box would reduce the
hauling to approximately 74 loads annually at a cost of $29,600. The estimated annual
savings using the dewatering box for Lake Marion WRF is $50,762.
The capital costs associated with this request include three (3) dewatering boxes at $40,000
each, two (2) concrete slabs and piping at $15,000 each, and two (2) Polymer feed systems at
$7,500 each, for a total of $165,000. The estimated return on investment is less than two
years based on the estimated savings.
A dewatering box polymer feed system will be constructed at the Lake Marion WRF and the
Walnut Street WRF. The Cypress West WRF biosolids will be hauled to the Walnut Street
WRF for logistical reasons. The third dewatering box will be mobile between the Lake Marion
WRF and the Walnut WRF to provide staff the flexibility to provide a consistent feed to
biosolids handling and will logistically serve both plants.
The project will be funded in account number 421-1410-536-63-00.
Recommendation: Staff recommends the approval to purchase from Patrick Anthony
Technologies, Inc., as a sole source, three (3) dewatering boxes, two (2) Polymer systems,
and the construction of two (2) concrete pads for a total of $165,000.
Sole Source Purchase of Dewatering Boxes.07.25.12.rln