Transcript Defining Water Quality - Northern Arizona University

MODULE 5: The Case of Water
Chapter 14
Defining Water Quality
The Standard-Setting Process
"Water, water, everywhere, nor any drop to drink"
It's from The Rime of the Ancient Mariner by Samuel
Taylor Coleridge when the Ancient Mariner is stuck in the
middle of the sea.
1. Water Resources
Water Resources and Their Interdependence
• Surface water
– water bodies ________________________, such as
rivers, lakes, oceans, streams, springs, wells, or other
collectors directly influenced by surface water
• Groundwater
– Fresh water _________ the earth’s surface, generally in
aquifers
• Linked together by the __________________
– Natural movement of water from the atmosphere to the
surface, underground, and back to the atmosphere
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– Explains the interdependence of water resources
Polluting Sources
• Point Source
– Any ________________ source from which
pollutants are released, such as a factory
smokestack, a pipe, or a ship
• Nonpoint Source
– A source that cannot be identified accurately
and degrades the environment in a _______,
________ way over a relatively ______ area
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2. Overview of US Legislation
• Similar to U.S. air quality laws, no federal legislation dealing
with water pollution until _____
– Even then, federal responsibility was limited
• In the 1970s, landmark legislation was passed, the Federal
Water Pollution Control Act (FWPCA) of _____
– Guides much of today’s policy
– Main responsibility for water quality shifted to the
federal level
– Specific goals for water quality were established
– New technology-based effluent limitations were set
• Clean Water Act (CWA) of 1977 extended compliance
deadlines and strengthened the law on toxic pollutants
FWPCA of 1972 was overly ambitious
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Current U.S. Legislation
• _____________________________ governs
policy today
– Required states to set up programs for
nonpoint sources
• Its reauthorization is still pending
• Meanwhile, in 2002, Congress passed the Great
Lakes Legacy Act, amending CWA to fund
addressing contaminated sediments in the Great
Lakes basin.
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3. Federal Policy Goals (from FWPCA of 1972)
• Zero discharge goal
– Eliminate release of all effluents into navigable
waters by 1985
• Fishable-swimmable goal
Interim goal
– Requires that surface waters be capable of
supporting _________________ activities and the
propagation of fish and wildlife by 1983
• No toxics in toxic amounts
– Prohibit release of toxic pollutants in toxic amounts
into all water resources
None of them were met by deadlines,
nor have they been achieved
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Water Pollutants Under the Law
• Toxic pollutants
– upon exposure will cause death, disease,
abnormalities, etc.
common pollutants
• Conventional pollutants produced in large
amounts
– identified and well understood by scientists, in
forms of organic waste, sediment, bacteria,
nutrients, oil, heat…
• Non-conventional pollutants
– default category
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4. Standards to Define Water Quality
Receiving Water Quality Standards (1965 law)
• Set by states for each water body
• Two components
1. Use designation: intended purpose of water
body; at minimum must meet swimmablefishable standard
2. Water quality criteria: biological and chemical
attributes to sustain or achieve use
designation; pollutant specific
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State Use-Support Status
• Periodically, states must determine use-support status
for each water body
– Assess the water body’s present condition and
compare it with what is needed to maintain its
designated uses
• Use-support status is characterized using one of five
classifications:
– Fully supporting; threatened; partially supporting;
not supporting; and not attainable
– Findings are reported to Congress as part of a
biennial National Water Quality Inventory
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5. Analyzing the Standards
Absence of Benefit-Cost Analysis
• States could use benefit-cost analysis in setting
the receiving water quality standards, but they
were not required by law to do so
• Use designation had to be consistent with
national goals, meaning at minimum achieving
swimmable-fishable quality, a goal that is solely
____________________
• Therefore, no assurance that efficiency is
achieved
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Inconsistency Issues
• Standards are not consistent with technologybased effluent limits set at the federal level
• In some cases, the limits are met, but the
standards are not achieved. Why?
– Standards (the objective) are motivated by
use
– Effluent limits (policy instrument) are
motivated by technology, i.e., by what is
feasible
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• Law requires states to identify waters for which
the effluent limitations are insufficient
• These water bodies are to be labeled "water
quality limited" and placed in a priority ranking
– For these waters, more stringent controls are
set, called total maximum daily loads (TMDLs)
– These TMDLs specify the maximum amount of
pollution that can be received without violating
the standards
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6. Updated Benefit-Cost Analysis (Carson and
Mitchell’s Analysis of Post-1972 Policy Revisions)
Total Social Benefits
• Based on ____________________________
(CVM)
– CVM can account for existence value and user
value
• TSB1990 = _______________ ($1990)
– Represents the value of improving water
quality from nonboatable up to swimmable
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Total Social Costs
• Average two estimates
– TSC1988 = $37.3 billon ($1990)
• Dept of Commerce data used by Carson &
Mitchell
– TSC1990 = $50.6 billion ($1990)
• EPA projected data
• TSC1990 = _______________ ($1990)
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Benefit-Cost Comparison
• Result: ________________
– So net benefit is positive
• Question: Is allocative efficiency achieved?
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Marginal Analysis
• Approximated with incrementals using Freeman’s
(1982) earlier estimates for 1985
• MSC1990 = TSC1990  TSC1985
= $44.0B  34.6B = ________ ($1990)
• MSB1990 = TSB1990  TSB1985
= $46.7B  20.1B = ________ ($1990)
• Since ________________
– abatement levels are not efficient
– water quality control is likely ______________
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Benefit Cost Comparison
post-1972 policy
At A1990, MSB > MSC

underregulation
MSC
26.6
9.4
MSB
0
A1990
AE
Abatement
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