Table 1 summarizes the major facilities that comprise the GWF domestic treatment train. While the design average capacity of the facility is 16,000 m3/day, served by four membrane cells, the peak wet weather capacity is approximately 40,000 m3/day. Treatment of the peak wet weather flow can be accommodated in the MBR by use of the eight industrial membrane cells for domestic treatment duty during peak wet weather periods (membranes only, not the industrial bioreactor), effectively increasing the available membrane area by a factor of three (i.e., from 4 cells to 12 cells). Facilities are available to store industrial wastewater during such events, allowing the use of the industrial membranes for peak wet weather service. Twelve Memcor Memjet submerged hollow-fiber ultrafiltration membrane racks were initially installed in each of the 12 membrane cells. However, for a variety of operational and commercial reasons the 12 Memjet racks in each of the four dedicated domestic modules were replaced with 15 Mempulse racks.
GWF domestic train major treatment units
| Unit process . | Number . | Size/Capacity . | Description . |
|---|---|---|---|
| Domestic headworks | 1 | 40,000 m3/d | Two 5 mm screens followed by one vortex grit chamber; screening, washing and compaction, and grit classification and dewatering |
| Activated primary sedimentation tank | 1 | 21 m diameter, 4 m SWD | Circular unit designed to operate in either conventional or activated modes |
| Balance tank | 1 | 5,000 m3 | Lined earthen lagoon with membrane cover and liner, pumped mixing |
| Domestic pre-filters | 3 | 20,000 m3/d each | 1 mm opening automatic, self-cleaning units |
| Domestic biological nutrient removal bioreactors | 2 | 3,068 m3 each | Three-stage units consisting of initial mixed zone receiving ML recirculation from downstream aerated zone, main aeration zone receiving recirculation from membranes, and final mixed zone |
| Domestic membranes | 4 | 64 m3 each tank | Memcor Mempulse units each containing 15 racks per tank with 7,220 m2 of membrane area for each tank |
| Industrial membranes (used for peak wet weather domestic treatment | 8 | 64 m3 each tank | Memcor Memjet units each containing 12 racks per tank with 7,220 m2 of membrane area for each tank |
| RO | 2 Two-stage trains | 7,085 m3/d each train | Nominal 200 mm diameter elements with 7 elements per vessel. 26 vessels per train first stage; 13 vessels per train second stage. 75% average recovery, 85% max |
| Unit process . | Number . | Size/Capacity . | Description . |
|---|---|---|---|
| Domestic headworks | 1 | 40,000 m3/d | Two 5 mm screens followed by one vortex grit chamber; screening, washing and compaction, and grit classification and dewatering |
| Activated primary sedimentation tank | 1 | 21 m diameter, 4 m SWD | Circular unit designed to operate in either conventional or activated modes |
| Balance tank | 1 | 5,000 m3 | Lined earthen lagoon with membrane cover and liner, pumped mixing |
| Domestic pre-filters | 3 | 20,000 m3/d each | 1 mm opening automatic, self-cleaning units |
| Domestic biological nutrient removal bioreactors | 2 | 3,068 m3 each | Three-stage units consisting of initial mixed zone receiving ML recirculation from downstream aerated zone, main aeration zone receiving recirculation from membranes, and final mixed zone |
| Domestic membranes | 4 | 64 m3 each tank | Memcor Mempulse units each containing 15 racks per tank with 7,220 m2 of membrane area for each tank |
| Industrial membranes (used for peak wet weather domestic treatment | 8 | 64 m3 each tank | Memcor Memjet units each containing 12 racks per tank with 7,220 m2 of membrane area for each tank |
| RO | 2 Two-stage trains | 7,085 m3/d each train | Nominal 200 mm diameter elements with 7 elements per vessel. 26 vessels per train first stage; 13 vessels per train second stage. 75% average recovery, 85% max |