Recycling Treated Municipal Wastewater for Industrial Water Use

5.4 Base Water Reuse System Costs
5.4.1 Treatment
TM3: Recycled Wastewater System Components and Costs
Recycling Treated Municipal Wastewater for Industrial Water Use
Section 3.3.3 defined the base water reuse system to be an advanced secondary
WWTP with disinfection facilities. It was assumed the facility had all the required
facilities to meet the base level water quality established except for additional
disinfection system equipment to disinfect year-round and provide a residual
disinfectant for transmission. The base system disinfects to a total coliform limit of
23/100 ml and provides a 2.5 mg/L chlorine dose for residual. Newdisinfection
equipment and the associated O&M costs are the only additional treatment system
requirements identified for the base water reuse treatment system.
The chlorine doses and disinfection assumptions identified in Section 3.3.3 are applied
to all WWTPs regardless of the disinfection process. The cost model reflects having
the facilities sized to meet the highest dose requirement (with a peaking factor
considered for feed rate ranges). As shown in Table 14, the capital cost for disinfection
is estimated as a base system cost plus a cost per gallon/day (gpd) to account for the
incremental costs of metering pumps, tank storage, and building footprint.
Table 14. Base System: Sodium Hypochlorite Capital Costs
Capacity, mgd Construction Cost
Base, $ ($/gpd)
≤ 0.5 $100,000 $0.10
0.5 - 5 $150,000 $0.03
>5 $250,000 $0.02
The O&M costs for the sodium hypochlorite system in the cost model include the
chemical cost at $0.70/gallon of 12.5% sodium hypochlorite and equipment
maintenance. The electrical costs are considered negligible.
5.4.2 Storage
Storage is not considered in the base water reuse system.
5.4.3 Pump Station
The cost model uses a flow-based cost equation, as shown in Table 15, to determine
the pump station costs. The pump station cost equations reflect some economy of
scale and are based on Camp Dresser & McKee (CDM) estimates prepared for other
projects (CDM, 2006 & 2003). These cost equations were checked with data compiled
by MCES in review of lift station costs (MCES, 2006a & 2006b) and were found to be
representative and on the conservative side. The capacity shown is for the annual
average flow and assumes a peaking factor of 3 for the maximum flow pumped.
Craddock Consulting Engineers 31
In Association with CDM & James Crook
TM3-Component&Costs_0707