Water quality and water pollution: Nancy Mesner Aquatic, Watershed and Earth Resources

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Water quality and water
pollution:
Nancy Mesner
Aquatic, Watershed and Earth Resources
[email protected]
797-2465
Today and Wednesday:

Clean Water definitions

History of water quality legislation in U.S.

The Clean Water Act

Water quality standards

Some common pollutants in Utah

Assessing water quality

Where we stand after 25+ years

Current approaches
What is Clean Water?
Safe to drink ?
No dirt in water (clear
water)?
Distilled water?
There is no single, simple definition of
clean water. We define it according to
how we use it.
Legislation historically has reflected . . .
1. changes over time on role of federal government
2. changes in the pollutants of greatest concern
 1899
Rivers and Harbors Act
Applied to navigation obstructions

1924
Oil Pollution Act
Imposed liability for oil spills
 1948
Water Pollution Control Act
Driven by health concerns
1956 Amendments required state water pollution plans
1961 Scope expanded to include harm to persons within
the same state
 1965
Water Quality Act
States required to set water quality standards
for interstate navigable waters
 1972
Federal Water Pollution Control Act
(renamed Clean Water Act in 1977)
Set ambitious goals:
fishable swimmable waters by 1983
eliminate all pollution discharge by 1985
EPA (or states or tribes) implement the law.
 1977 Clean Water Act Amendments
• Strengthened controls on toxics
• Allowed states to assume responsibility
for federal programs
 1987 Water Quality Act
• Addressed nonpoint source pollution
and urban runoff
• Revolving loan funds replaced grants program
for construction of treatment plants
• Created programs to protect estuaries of
national importance
 1990
Coastal Zone Act Reauthorization
Amendments and Oil Pollution Act
• In response to Exxon Valdez spill
• Focused efforts on reducing polluted
runoff in 29 coastal states.
Basic Approach of the Clean Water Act.
 Set water quality standards (goals) for all
water bodies.
All standards have 3 parts:
Designated beneficial uses
Numeric criteria
Narrative standards
 Assess water bodies to determine if they are
impaired.
 If waters are impaired, identify and control
pollutants causing impairment.
Pollutants are divided into
“point sources”
“nonpoint sources”
Clean Water Act originally focused on point sources
• Controls of these sources were based on “Best
Available Technology” (didn’t “force” technology)
• Established permit system for discharges (a
“permit to pollute”)
• Provided billions of dollars for construction of
treatment plants
Later the focus has shifted to nonpoint sources
Approach is “voluntary, incentive based”
• No regulatory program for nonpoint sources
• Incentives are in the form of “cost share”
programs to polluters to improve how they
manage their lands (best management
practices).
Water Quality Standards
Designated beneficial uses
Numeric criteria
Narrative standards
Beneficial uses
(how do we use the water)
Aesthetics
Fisheries and other
aquatic life
Agriculture
Recreation
Drinking
water
Industry and power
Utah’s beneficial use categories:
·
1A Domestic Water Source
·
·
2A Primary Recreation
2B Secondary Recreation
·
·
·
·
3A
3B
3C
3D
·
4 Agriculture
·
5 Great Salt Lake
Cold Water Aquatic Life
Warm Water Aquatic Life
Non-Game Fish & Other Aquatic Life
Wildlife Habitat
R317-2. Standards of Quality for Waters of the State
Water quality criteria:
Critical concentrations of pollutants that result in
loss of beneficial uses.
What pollutants affect the beneficial
use of agriculture?
Salts and a few
metals
What pollutants affect the beneficial
use of recreation?
Bacteria, pH,
turbidity, nitrate,
phosphorus,
sediments
What pollutants affect the beneficial
use of drinking water source?
Bacteria, metals, organic
pollutants, nitrates, pH,
sediments
What pollutants affect the beneficial
use of aquatic life?
metals, organic
pollutants, pH,
temperature, dissolved
oxygen, ammonia,
sediments
Common water quality pollutants in Utah

Cycling or movement through watershed


Seasonal or annual variability
Special considerations
Nutrients
Phosphorus
Nitrogen
Plant growth is typically limited by one nutrient or
another. Excess nutrients result in excess plant growth,
leading to “eutrophication”
UNCE, Reno, NV
Over-fertilization of waters
(Cultural Eutrophication)
Excess nutrients in runoff
 Leads to excess plant growth in waters
(some algal blooms for toxins)
 Leads to low oxygen concentrations
as this plant material decomposes
 Leads to fish kills
Nutrient Limitation:
Plants require Nitrogen and Phosphorus in a fixed ratio
(~16/1 by atoms)
Typically one or the other is “limiting” to aquatic plant
production
Adding more of the limiting nutrient  increased biological
production until another nutrient or other factor limits
growth
Phosphorus Cycle
Natural P sources:
Terrestrial rocks
Marine sediments
Guano
Organic material
Atmospheric deposition
Human P sources
(often more biologically
available)
Fertilizers
Sediment
(ag, construction)
Animal waste
Septic tanks
Wastewater treatment
Phosphorus Cycle
 No gaseous phase on earth
 Globally, total phosphorus cycles relatively slowly
 Occurs in many mineral forms and in biological material
Particulate P (eg. in in soils) may be very abundant
but not readily available for aquatic plants.
Dissolved forms of P are more biologically “available”.
Temperature, concentrations of oxygen, calcium and
other cations, and pH of water will all determine how
much of the total phosphorus is in a dissolved form.
Variability in Phosphorus in natural waters:
 Higher concentrations of TP during high flows
(associated with high sediment)
 Biologically available forms may be extremely low
during growing season
 Daily and seasonal fluctuations in DO, pH
may result in fluctuations of some forms of
phosphorus
Nitrogen Cycle
Natural nitrogen sources:
Fixed atmospheric N
Decomposition of organic
materials
Human nitrogen sources
Synthetic fertilizers
Nitric and nitrous oxides in
atmosphere (from burning
fossil fuels)
Animal waste
Septic tanks
Wastewater treatment
Nitrogen cycle:
Atmospheric N:
N2 , NxO, and NH3
Nitrogen Fixation
N2  NH3
(bacteria)
Nitrification
NH3  NO2
NO2-  NO3
(aerobic bacteria)
Denitrification
NO3  N2O or N2
(anaerobic bacteria)
Soils
(clay surfaces)
Water:
NO3 and NH3
Plants
(proteins)
Animal
(Proteins)
Detritus and Manure:
Organic N and NH3
Nitrogen Cycle
Very soluble
May cycle rapidly through soils into groundwater
Transformed through multiple biological
reactions.
Abundant in the atmosphere.
Variability in nitrogen in surface waters:
 May have higher concentrations of TN during high flows
(associated with runoff)
 Generally ammonia and nitrite very low
in unpolluted waters
Nitrate may decline during growing season
 Toxic forms of ammonia (NH3+) may vary
due to daily and seasonal fluctuations
in pH and temperature
Phosphorus
Nitrogen
Geochemical Cycling
Slow
Rapid
Gaseous phase
No
Yes
Soluble inorganic forms
Atmospheric deposition?
Limiting nutrient in
aquatic systems
Toxic forms?
Phosphate
Dust
Sometimes
No
Nitrate/ nitrite/ammonia
NOx deposition
Sometimes
Nitrate > 10 ppm
Ammonia at high pH
and temperature
Why focus on phosphorus?
 Phosphorus assumed to be limiting in many pristine waters in midlatitudes
 Lots of studies have demonstrated relationship between phosphorus
loading to lakes and increased algae
 In many cases, reducing phosphorus reduces algae
 Phosphorus removal much more feasible and less expensive
Nitrogen tends to be limiting in marine
systems
Drainage from Mississippi River Basin
 Hypoxia Zone in Gulf of Mexico
Areal extent of bottom water
hypoxia
Mississippi River nitrates at St. Francisvile
...Nitrate-N (mg/liter)
__ Nitrate_N flux (million MT/yr)
Estimated nitrogen fertilizer use
in the Mississippi River Basin
Estimated land drainage in
Mississippi River Basin
Pathogens
UNCE, Reno, NV
Sources:
 Failing septic systems
 Animal waste
 Marine sanitation devices
Total coliforms and fecal coliforms are not disease
causing but are indicators of pollution
Testing for disease causing microbes (Giardia parasites, etc.) difficult and
expensive
 In general, coliforms have short life span in environment
 Therefore, “hot spots” tend to be close to source
 Holding times for samples only ~ 6 hours, therefore often not monitored
Variability in coliforms:
 May be higher during runoff periods
 May be higher in summer at boat launches
Sediment
USDA NRCS
Impacts due to:
Excess sediment covering stream substrate
Increased turbidity
Other compounds carried by sediment
Sediments enter water from:
runoff (construction, agriculture, forestry, mining,
road sand, disturbed areas)
stream banks
remobilized bedload sediment
Variability in suspended sediment:
 High flows
 Storm events
 Change in gradient (lower velocity)
 May see variability from irrigation return flows
Metals
UNCE, Reno, NV
Sources:
 Mine waste - tailings
 Direct discharge – acid mine leakage, other
discharge
 Urban runoff
Metals:
 Many more toxic in soluble form
 Solubility often a function of hardness, pH or oxygen
content of water
 Often associated with sediments
 In Utah, ancient sediment rock layers may contain high
concentrations
Pharmaceuticals
Sources:
Pharmaceutical industries
Hospitals, medical facilities
Household medicines
Personal care products
Farm animals
Endocrine disruptors
Sources:
Hospitals, medical facilities
Households
Pesticides
Industrial byproducts
• Pharmaceuticals have now been found in
treated sewage effluents, surface waters,
soils and tap water.
• Up to 90% of oral drugs can pass through
humans unchanged.
• Many do not biodegrade
• Some persist in groundwater for years.
Impacts:
• Mostly unknown
• Concentrations in parts per trillion
(well below therapeutic doses)
• Concern about chronic exposure
– hormone disruption
– antibiotic resistance
Assessing our waters: How do you
know if you’ve got clean water?
Water column monitoring
(water chemistry)
Advantages:
Standardized methods
 repeatable , comparable
Easy to collect
Related to toxicity or other impacts
Disadvantages:
Discontinuous in time and space
Physical habitat monitoring
(Stream form, substrate)
Advantages:
Reflects hydrologic
impacts
Relatively low cost
Disadvantages:
May not reflect actual
water quality
May be subjective, lack of
repeatability
Biological monitoring
(macroinvertebrates, algae, fish)
Advantages:
Integrates impacts over
time
Biological impacts = loss of
beneficial use
Easy to collect
Disadvantages:
Need for reference sites
High degree of
heterogeneity in samples
How effective has the CWA been?
Water quality problems 25 years ago….
 Water Quality after 25 years of CWA
~ 60% of nation’s surveyed waters meet wq standards
Wetland losses estimated at ~ 70,000 to 90,000 acres
Sediment runoff from agriculture reduced to 1 billion tons
Phosphorus and nitrogen levels down
173 million people served by modern wwtps
1998
Clean Water Action Plan identified remaining problems
Identified future needs and actions:
• Watershed approach to water quality to address
nonpoint sources
• Reduce pollution from animal feeding operation
• Protect wetlands and coastal waters
• Address Urban runoff
•Coordination with other legislation
•Endangered Species Act
•Safe Drinking Water Act
•Clean Air Act
Current approaches to pollution control:
•
Better approaches to manage nonpoint sources
•
Watershed management
•
Source water Protection
•
•
Regulate more point sources
•
Phase II Storm water Discharge Permits
•
Utah’s Animal Feeding Operation Strategy
Education
All states and tribes must evaluate all
their waters every 2-3 years, identify
which waters are impaired
Watershed Approach
• State divided into watershed
units
• Holistic approach (look at all
sources)
• Maximizes involvement of public
and of other agencies
• Develops plans and attempts to
implement these
Urban impacts
Urban water quality issues:
More types of pollutants
Greater concentrations of pollutants reaching waters
Modified streams and
landscapes
New approaches to
agricultural sources
Permitting Concentrated Animal
Feeding operations
Determining how well best
management practices work
Do behaviors change even when
dollars are spent?
Related programs and legislation:
•
•
•
•
•
•
•
•
•
Coordinated Resource Management Plans and other
watershed planning efforts (eg. Forest Service)
Wetlands Protection
Endangered Species Act
Groundwater Recharge Protection
Mining regulations and remediation
Hazardous Waste Programs
Farmland Protection Programs
Wildlife Enhancement Programs
Conservation Reserve Program
Education and outreach
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