Glibane Gold Lecture on 1/29/01 in PowerPoint format
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Transcript Glibane Gold Lecture on 1/29/01 in PowerPoint format
“Gilbane Gold”
PHIL/ENGR 482
ETHICS & ENGINEERING
Gilbane Gold Case Study
Taxonomy of Obligations
To whom does an engineer have obligations?
To self?
To others?
Family and friends
Employer and fellow employees
Fellow professionals
Clients/Consumers/3rd Parties
Public; including future generations
To the environment?
Gilbane Gold Background
Allowable Lead and Arsenic
Concentration in Wastewater
Note: A person working a regular 40-h work week who
is able to sort 1 ping-pong ball per second would
take 139 years to sort through a billion balls.
Assumptions:
250,000 gal/day wastewater before expansion
Old test methods indicated 5 ppb lead, ok.
New test indicates 7.5+ ppb lead
Legal limit is 7.5 ppb lead
Planned expansion will cause 500% increase in
wastewater (and lead) volume
Impact of proposed expansion...
Wastewater
Current: 250,000 gal/day
Future: 1,250,000 gal/day
Lead
Current: 250,000 g/day @ 7.5 ppb = 5.7 lb/day
Future: 1,250,000 g/day @ 7.5 ppb = 28.5 lb/day
A problem…?
0.25 Mgpd
Wastewater
@7.5ppb lead
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…
Regulations do not require the new test
method be used...
7.5 ppb
Wastewater treatment plant
Sludge + treated effluent
A bigger problem…?
1.25 Mgpd
Wastewater
@7.5ppb lead
7.5 ppb
A proposed production increase
will increase the amount of
wastewater 500%...
Wastewater treatment plant
Sludge + treated effluent
A potential solution?
“The solution to polution is dilution…”
1.25 Mgpd
Wastewater
@7.5ppb lead
It is proposed to dilute
effluent to achieve an
acceptable concentration, say
5.75 ppb...
0.4 Mgpd
Clean
H2O
6 ppb
Wastewater treatment plant
Sludge + treated effluent
Annual cost of 0.4 Mgpd water...
Fresh water purchase
(@ $0.25/1,000 gal) = $35,000
Incremental sewage charges
(@ $0.75/1,000 gal) = $105,000
Total annual cost = $140,000
Potential solution 2?
Ion Exchange
Potential solution 3?
Artificial Wetland
Summary of three possible solutions
Method
Est. Annual Cost
Dilution
$140,000
Ion exchange
$270,000
Artificial wetland
$150,000