Recycling Treated Municipal Wastewater for Industrial Water Use

Section 3: Recycled Wastewater System Components and Costs
Recycling Treated Municipal Wastewater for Industrial Water Use
Industrial Site Treatment (7)
— Some industries already treat their existing water supply. These same processes or modifications
may be required with a recycled supply.
— Some industries may require new treatment processes with a recycled supply. It may be a costeffective
option to locate the treatment system at the industry site.
Figure 3.1. Recycled Wastewater System Conceptual Model
WWTP
1 -
2 -
3 -
4 -
5 -
1
Treatment
Existing Facilities
Potential New Facilities
New or Refurbished Facilities
2
Additional
Disinfection
Storage
Additional treatment processes to meet industrial
water supply requirements
Additional disinfection for reclaimed regulatory limits
and residual in the transmission system
Storage for smaller WWTPs and where industrial
demand does not match wastewater flow
Pump station to supply industries
Recycled wastewater transmission main and branch
transmission lines
3
Pump Station
Industry A
Industry C
Industry B
Treatment
WWTP Site Transmission
Area/Industry Site
Treatment
Industry D
38 Metropolitan Council Environmental Services
4
5
6 -
7 -
6
7
Booster pump for transmission
to some industries
Industry on-site treatment
Schematic shows possible
combination of facilities for
Industries A-D supplied from
recycled wastewater transmission
main line
Many industries have their own wastewater treatment systems. Some industries treat their wastewater and
recycle the water for traditional water supply uses. For many industrial facilities, treatment of their own
WWTP effluent for reuse is the cost-effective alternative, given adequate space, facilities and staff to
operate the treatment systems. The technologies presented in this memorandum can also be applied to
wastewater recycling within an industrial facility, recognizing that industrial wastewater effluent
characteristics are industry-specific and different from domestic wastewater effluent.
3.2 Water Quality Requirements
The suitability of a treated wastewater supply for industrial water use will depend on the effluent quality
from the specific WWTP and the requirements of a particular industry. Some industrial water uses will
require no additional treatment of wastewater effluent, except for modifications to disinfection facilities.
Modifications to disinfection facilities and/or practices are usually needed to meet more stringent
requirements for destruction of pathogenic organisms in a recycled wastewater supply than is typically
required for discharge to surface waters. Other industrial water uses will require additional treatment
beyond the conventional and advanced secondary treatment system processes used at most Minnesota
WWTPs. This subsection identifies the regulatory and industry-specific constituents of concern to
consider in assessing the suitability and selection of treatment processes to provide a recycled wastewater
supply to an industry.