Recycling Treated Municipal Wastewater for Industrial Water Use

TM4: WWTP Effluent Quality
Recycling Treated Municipal Wastewater for Industrial Water Use
Craddock Consulting Engineers 13
In Association with CDM & James Crook
TM4-WWTP Eff Quality_0707.doc
Total Phosphorous (TP)
Elevated phosphorus concentrations together with high residual organic constituents
in reclaimed water can cause biological fouling and scaling in industrial water
systems.
Figure 15 presents the frequency of occurrence of TP concentration in the effluent of
all Minnesota WWTPs. Similar information is shown in Figure 16 for WWTPs with
design capacities greater than 1 mgd. The variability of effluent TP is also
characterized for the following ranges: < 1 mg/L, 1-5 mg/L, and >5 mg/L.
The average WWTP effluent TP concentrations are depicted by location and facility
capacity in Figure 17 and further detailed in Figures 18-21. Over 25% of the WWTPs,
corresponding to more than 60% of the WWTP capacity, have phosphorus treatment
removal processes, indicative of those facilities with effluent concentrations less than
1 mg/L. The majority of the facilities have effluent TP concentrations between 1-5
mg/L. There were 35 facilities with effluent TP greater than 5 mg/L. Those facilities
have a combined design capacity of 63 mgd. The remaining facilities did not measure
TP in 2005.