Recycling Treated Municipal Wastewater for Industrial Water Use

TM4: WWTP Effluent Quality
Recycling Treated Municipal Wastewater for Industrial Water Use
3.0 Summary
The majority of the municipal WWTPs in Minnesota produce a good quality
secondary effluent with low nutrient levels (CBOD5 < 5 mg/L, TSS < 5 mg/L, TP < 1
mg/L, NH3 < 5 mg/L, and fecal coliform < 10/100 mL). This provides a good “base
level” water quality for supplying reclaimed wastewater from municipalities to
industries. Specific industry water quality requirements will determine if additional
treatment processes will be required. It is most likely that additional disinfection
treatment will be required to meet the total coliform limits required by Minnesota
permitting practices. The majority of plants, particularly the larger WWTPs, will not
need further reduction of organics, particulate solids, and nutrients for industrial uses
requiring lower levels of quality or little concern for dissolved solid concentrations. If
hardness, dissolved salts, or trace constituents need to be removed, then additional
reduction of organic, suspended solids and nutrients will be required for optimum
treatment process performance.
4.0 References
Minnesota Pollution Control Agency (MPCA). 2005. Minnesota Discharge Monitoring
Report data obtained through the Environmental Data Access system, April 2006.
Refer to: http://www.pca.state.mn.us/data/edaWater/index.cfm.
28 Craddock Consulting Engineers
In Association with CDM & James Crook
TM4-WWTP Eff Quality_0707.doc