1. “Gilbane Gold” PHIL/ENGR 482 ETHICS & ENGINEERING Gilbane Gold Case Study

2. Taxonomy of Obligations XTo whom does an engineer have obligations? s To self? s To others? l Family and friends l Employer and fellow employees l Fellow professionals l Clients/Consumers/3 rd Parties l Public; including future generations s To the environment?

3. Sources of Obligations XParticular roles s Parent, Engineer, … XPromises and Contracts XBeing a Human Being

4. Gilbane Gold Background

5. Allowable Lead and Arsenic Concentration in Wastewater Note:

6. Assumptions: X250,000 gal/day wastewater before expansion XOld test methods indicated 5 ppb lead, ok. XNew test indicates 7.5+ ppb lead XLegal limit is 7.5 ppb lead XPlanned expansion will cause 500% increase in wastewater (and lead) volume

7. Impact of proposed expansion... XWastewater s Current: 250,000 gal/day s Future: 1,250,000 gal/day XLead s Current: 250,000 g/day @ 7.5 ppb = 5.7 lb/day s Future: 1,250,000 g/day @ 7.5 ppb = 28.5 lb/day

8. Option 1 The solution to pollution is dilution.

9. A problem…? X When trying a new and more accurate test method, we discover that the plant is discharging wastewater concentrations at or above the legal limit of 7.5 ppb lead… X Regulations do not require the new test method be used... 0.25 Mgpd Wastewater @7.5ppb lead 7.5 ppb Wastewater treatment plant Sludge + treated effluent

10. A bigger problem…? X A proposed production increase will increase the amount of wastewater 500%... 1.25 Mgpd Wastewater @7.5ppb lead 7.5 ppb Wastewater treatment plant Sludge + treated effluent

11. A potential solution? “The solution to polution is dilution…” X It is proposed to dilute effluent to achieve an acceptable concentration, say 5.75 ppb... 1.25 Mgpd Wastewater @7.5ppb lead 6 ppb Wastewater treatment plant Sludge + treated effluent 0.4 Mgpd Clean H 2 O

12. Annual cost of 0.4 Mgpd water... XFresh water purchase s (@ $0.25/1,000 gal) = $35,000 XIncremental sewage charges s (@ $0.75/1,000 gal) = $105,000 XTotal annual cost = $140,000

13. Potential solution 2? Ion Exchange

14. Capital Cost

15. Potential solution 3? Artificial Wetland

16. Summary of three possible solutions