1. Pump Station Considerations for a Simple Duplex Station Discharging into a Combined Regional Force Main Rachel Rausch, EIT

2. Site Location

3. Project Background Private development client Development includes two large retail buildings, service station, bank, and general commercial No gravity sewer service in area

4. Project Background

5. Unique Design Considerations Donation of project to Beaufort Jasper Water and Sewer Authority (BJWSA) Little topographical variability on site Deep wetwell Site pump station will pump into 16” combined regional force main Unknown conditions in regional force main

6. Design Solution: Data Collection BJWSA Standards Force main record drawings Force main operating conditions Operating pressure Flow

7. Design Solutions: Calculations Wastewater Flow Estimate Site Storage Volume Force Main Operating Conditions Choosing Pumps

8. Design Solutions: Calculations Wastewater flow from site: Peaking Factor=4 Q peak =92.4 BJWSA storage volume requirement: Storage volume in site MH and pipes > 24 hour volume from site

9. Pump Selection Existing force main conditions analyzed Regional Force Main Pump station on 1,000 gpm @ 70’ TDH Regional Force Main Pump Station CP-67 off No flow in regional force main Two C factors analyzed for each system curve

10. System Curve-Pumps On Design Point:310 gpm at 102’ TDH Hazen-Williams C Factors: C 1 =110 C 2 =130

11. System Curves-Pumps Off Design Point:410 gpm at 96’ TDH Hazen-Williams C Factors: C 1 =110 C 2 =130

12. Pump Selection

13. Other Calculations Cycle time Buoyancy Calculations High groundwater table Deep wetwell, approximately 24 feet deep

14. Final Pump Station Layout

15. Project Status BJWSA Approval Construction Status

16. Questions?

17. Lessons Learned