Recycling Treated Municipal Wastewater for Industrial Water Use

TM3: Recycled Wastewater System Components and Costs
Recycling Treated Municipal Wastewater for Industrial Water Use
There are four main components of a typical water reuse system, regardless of the
system configuration: treatment, pumping, storage, and transmission pipelines.
Storage needs depend heavily on the demand patterns of the customer. Some systems
may not require separate reclaimed water storage facilities because the wastewater
treatment facility has a base wastewater flow greater than the reuse demand or
internal process storage to meet the demand. Storage at or near the point of use can be
used to reduce the size of pumping and transmission facilities (associated with capital
costs) by avoiding the need to pump at peak demand flow rates.
For centralized treatment, an existing WWTP may or may not need additional
treatment facilities, depending on the water quality requirements of the reclaimed
water user(s). For a new WWTP, the quality requirements for reclaimed water can be
incorporated into the design, and also into the siting of the facility to account for the
transmission costs of the reclaimed water. New treatment facilities will be required
for satellite and decentralized systems.
All system types will require pumping and transmission piping, with centralized
systems typically requiring longer transmission pipelines.
2.2 Basis for this Study
The technologies used to treat and convey water are similar for the centralized,
satellite, and decentralized systems. The system model used in this study to estimate
reclaimed system costs typifies the centralized system configuration. The reuse
system starts with the final effluent of an existing municipal WWTP and the end point
is an industry with a specific water supply quantity and quality requirement.
Transmission distances of 1 to 10 miles are evaluated. Satellite systems will have
similar facilities, but the longer transmission distances are not as likely to be
applicable. Decentralized systems will require considerations for solids residual
handling, which is assumed to be processed at the WWTP for centralized and satellite
systems.
It is important to note that many industries already reuse water from their onsite
industrial wastewater treatment systems. In most instances, onsite treatment is the
cost-effective alternative for those with sufficient space for new facilities and qualified
staff to operate the treatment systems. In addition, many industries also treat their
water supply prior to specific uses, such as for boiler feed water. The technologies
presented in this memorandum are also generally applicable to treatment of an
industrial wastewater and/or water supply.
2.3 Conceptual Model
A basic model of a water reuse or reclaimed water system includes facilities, as
depicted in Figure 2, and noted by the component number (1-7) on the schematic:
Craddock Consulting Engineers 3
In Association with CDM & James Crook
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