NPDES LATEST 2026 TEST PAPER QUESTIONS AND
ANSWERS GUARANTEE A+
✔✔Point source - ✔✔EPA (1973) tried to exempt some agriculture, feedlots, silviculture
from NPDES due to feasibility/admin burden.
✔✔NRDC v. Costle - ✔✔EPA cannot create categorical exemptions from statutory
definition; could use general permits/practice standards instead.
✔✔Return flows - ✔✔Congress responded: Excludes return flows from irrigated
agriculture from 'point source'; EPA cannot require permits for 'discharges composed
entirely of return flow from irrigated agriculture.'
✔✔Stormwater - ✔✔NPDES required for MS4s (municipal separate storm sewers) and
industrial stormwater.
✔✔Addition of a pollutant - ✔✔Dams: generally not 'adding' pollutants; courts wary of
intruding on state water allocation (Section 101(g) - Wallop Amendment).
✔✔Water transfers - ✔✔Transfer of turbid/warm water into clearer/colder creek required
NPDES (Catskills 2d Cir. 2001).
✔✔EPA 2008 Water Transfers Rule - ✔✔Transfers between navigable waters don't
require NPDES if no intervening industrial/municipal/commercial use.
✔✔Section 303 framework - ✔✔Designated uses for each water body (e.g., public
supply, fish/wildlife propagation, recreation).
✔✔Water quality criteria/standards - ✔✔Quantitative; toxics must be numeric. EPA
publishes criteria guidance; states adopt; EPA can promulgate if states fail.
✔✔Impaired waters list - ✔✔A total maximum daily load per pollutant that will still attain
standards (+ seasonal variation + margin of safety). Must allocate loads to point &
nonpoint sources and describe how to achieve.
✔✔Constructive submissions doctrine - ✔✔A legal principle from the 1980s-90s related
to courts forcing action.
✔✔Arbitrary approval findings - ✔✔Decisions made without a clear basis or justification.
✔✔TMDL - ✔✔Total Maximum Daily Load; the maximum amount of a pollutant that a
waterbody can receive while still meeting water quality standards.
, ✔✔Flow augmentation - ✔✔The practice of increasing water flow to meet environmental
or economic standards.
✔✔CWA §102(b)(1) - ✔✔A section of the Clean Water Act stating that federal agencies
cannot release project water as a substitute for adequate treatment at the source.
✔✔Anti-backsliding - ✔✔A policy that prevents the weakening of permits unless new
information or technological re-evaluation justifies it.
✔✔Anti-degradation policy - ✔✔A policy that maintains existing uses and protects high-
quality waters unless justified by social or economic needs.
✔✔Trading (water quality markets) - ✔✔A system where water quality credits can be
traded, endorsed by the EPA, to promote cost savings and innovation.
✔✔Point-point trading - ✔✔Trading between point sources of pollution, such as
nutrients, leading to cost savings.
✔✔Point-nonpoint trading - ✔✔Trading between point sources and nonpoint sources,
potentially leading to large savings and co-benefits.
✔✔Dead Zone (Gulf) - ✔✔An area in the Gulf of Mexico where hypoxia occurs due to
nutrient runoff from the Mississippi Basin.
✔✔CWA §103 - ✔✔A section of the Clean Water Act that encourages state cooperation
and compacts.
✔✔Arkansas v. Oklahoma (U.S. 1992) - ✔✔A case where the EPA was required to
consider downstream standards but not ban all upstream discharges.
✔✔Milwaukee I (1972) - ✔✔A case recognizing federal nuisance in environmental law.
✔✔Milwaukee II (1981) - ✔✔A case stating that the Clean Water Act preempts federal
common law.
✔✔International Paper v. Ouellette (1987) - ✔✔A case ruling that a downstream state
cannot use its own nuisance law to regulate out-of-state dischargers.
✔✔NRDC v. Costle (D.C. Cir. 1977) - ✔✔A case determining that EPA cannot exempt
certain agricultural discharges from NPDES.
✔✔South Florida WMD v. Miccosukee Tribe (U.S. 2004) - ✔✔A case addressing
whether pumping polluted water from a canal to a wetland constitutes an 'addition'
requiring NPDES.
ANSWERS GUARANTEE A+
✔✔Point source - ✔✔EPA (1973) tried to exempt some agriculture, feedlots, silviculture
from NPDES due to feasibility/admin burden.
✔✔NRDC v. Costle - ✔✔EPA cannot create categorical exemptions from statutory
definition; could use general permits/practice standards instead.
✔✔Return flows - ✔✔Congress responded: Excludes return flows from irrigated
agriculture from 'point source'; EPA cannot require permits for 'discharges composed
entirely of return flow from irrigated agriculture.'
✔✔Stormwater - ✔✔NPDES required for MS4s (municipal separate storm sewers) and
industrial stormwater.
✔✔Addition of a pollutant - ✔✔Dams: generally not 'adding' pollutants; courts wary of
intruding on state water allocation (Section 101(g) - Wallop Amendment).
✔✔Water transfers - ✔✔Transfer of turbid/warm water into clearer/colder creek required
NPDES (Catskills 2d Cir. 2001).
✔✔EPA 2008 Water Transfers Rule - ✔✔Transfers between navigable waters don't
require NPDES if no intervening industrial/municipal/commercial use.
✔✔Section 303 framework - ✔✔Designated uses for each water body (e.g., public
supply, fish/wildlife propagation, recreation).
✔✔Water quality criteria/standards - ✔✔Quantitative; toxics must be numeric. EPA
publishes criteria guidance; states adopt; EPA can promulgate if states fail.
✔✔Impaired waters list - ✔✔A total maximum daily load per pollutant that will still attain
standards (+ seasonal variation + margin of safety). Must allocate loads to point &
nonpoint sources and describe how to achieve.
✔✔Constructive submissions doctrine - ✔✔A legal principle from the 1980s-90s related
to courts forcing action.
✔✔Arbitrary approval findings - ✔✔Decisions made without a clear basis or justification.
✔✔TMDL - ✔✔Total Maximum Daily Load; the maximum amount of a pollutant that a
waterbody can receive while still meeting water quality standards.
, ✔✔Flow augmentation - ✔✔The practice of increasing water flow to meet environmental
or economic standards.
✔✔CWA §102(b)(1) - ✔✔A section of the Clean Water Act stating that federal agencies
cannot release project water as a substitute for adequate treatment at the source.
✔✔Anti-backsliding - ✔✔A policy that prevents the weakening of permits unless new
information or technological re-evaluation justifies it.
✔✔Anti-degradation policy - ✔✔A policy that maintains existing uses and protects high-
quality waters unless justified by social or economic needs.
✔✔Trading (water quality markets) - ✔✔A system where water quality credits can be
traded, endorsed by the EPA, to promote cost savings and innovation.
✔✔Point-point trading - ✔✔Trading between point sources of pollution, such as
nutrients, leading to cost savings.
✔✔Point-nonpoint trading - ✔✔Trading between point sources and nonpoint sources,
potentially leading to large savings and co-benefits.
✔✔Dead Zone (Gulf) - ✔✔An area in the Gulf of Mexico where hypoxia occurs due to
nutrient runoff from the Mississippi Basin.
✔✔CWA §103 - ✔✔A section of the Clean Water Act that encourages state cooperation
and compacts.
✔✔Arkansas v. Oklahoma (U.S. 1992) - ✔✔A case where the EPA was required to
consider downstream standards but not ban all upstream discharges.
✔✔Milwaukee I (1972) - ✔✔A case recognizing federal nuisance in environmental law.
✔✔Milwaukee II (1981) - ✔✔A case stating that the Clean Water Act preempts federal
common law.
✔✔International Paper v. Ouellette (1987) - ✔✔A case ruling that a downstream state
cannot use its own nuisance law to regulate out-of-state dischargers.
✔✔NRDC v. Costle (D.C. Cir. 1977) - ✔✔A case determining that EPA cannot exempt
certain agricultural discharges from NPDES.
✔✔South Florida WMD v. Miccosukee Tribe (U.S. 2004) - ✔✔A case addressing
whether pumping polluted water from a canal to a wetland constitutes an 'addition'
requiring NPDES.
