Environmental Science ENSC 2800

1
Environmental Science ENSC 2800

• Spring 2002 - Class 15
• Pollution in the Bay-Delta

2
Pollution

• (Chapman, 1993)The introduction by people,
  directly or indirectly, of substances or energy
  which result in such deleterious effects as
• harm to living resources
• hazards to human health
• hindrance to human activities
• impairment of agricultural, industrial and other
  economic activities
• reduction of amenities
• Contaminant - any constituent in the
  air/water/etc. harmful to a particular end use
  regardless of its origin
• Pollutant - any constituent in the air/water/etc.
  harmful to a particular end use that is of
  anthropogenic origin.

3
The Water (Hydrologic) Cycle
(From Nebel and Wright, 2002)
4
Point and Non-Point Pollution
(Source Nebel Wright, 2002)
5
Pristine and Protected Water?
6
Bay-Delta Sources

• There are a wide range of pollution sources to
  the Bay-Delta, both direct and indirect.
• Direct (to water) industrial discharges, sewer
  plant discharges, oil spills, boat heads and
  exhausts, leaching landfills (to groundwater),
  etc.
• Indirect (to land, via air) urban runoff,
  agricultural runoff, agricultural drainage,
  forested area runoff, air pollution, etc.

7
Standard Pollutant Classes

• Water professionals separately categorize
• Physical pollutant variables - solids,
  organoleptic aspects (color, taste, etc.),
  turbidity, electrical conductivity, temperature,
  radioactivity.
• Chemical pollutant variables (ever increasing
  number) - synthetic organic chemicals (e.g.
  pesticides), volatile organic chemicals (e.g.
  PAHs), inorganic chemicals (e.g. nutrients, heavy
  metals).
• Biological pollutant variables (pathogens) -
  bacteria (also viruses and increasingly parasites
  - protozoa like cryptosporidium, giardia, amoeba,
  etc.) 

8
Clean Water Act

• The Clean Water Act is a 1977 amendment to the
  Federal Water Pollution Control Act of 1972,
  which set the basic structure for regulating
  discharges of pollutants in the US.
• The law gave EPA the authority to set effluent
  standards on an industry basis (technology-based)
  and continued the requirements to set water
  quality standards for all contaminants in surface
  waters.
• The CWA makes it unlawful for any person to
  discharge any pollutant from a point source into
  navigable waters unless a permit (NPDES) is
  obtained under the Act.
• The act now uses a watershed framework for
  setting standards and controlling non-point
  source pollution.
• The amounts and types of pollutants than can be
  discharged or allowed to run in to waters from
  watersheds are determined based on the uses of
  the receiving body and its sensitivities.

9
Porter-Cologne Act

• This Act (1969), California Water Code 13000 et
  seq., provides for aesthetic values, fish and
  wildlife preservation, water reclamation, and
  comprehensive planning and regulation to attain
  the highest "reasonable" water quality in
  consideration of conflicting demands.
• The Act requires the State Water Resources
  Control Board to establish water quality
  objectives and adopt water quality control plans
  through their Regional Water Quality Control
  Boards (commonly referred to as Basin Plans).
• It is the CA equivalent of the Clean Water Act.
• The Bay Area Regional Water Quality Control Board
  does this for the Bay-Delta out of its offices in
  Oakland although clearly it must work with the
  other boards governing the Central Valley.

10
Safe Drinking Water Act

• The Safe Drinking Water Act (1974) was
  established to protect the quality of drinking
  water in the U.S.
• This law focuses on all waters actually or
  potentially designed for drinking use, whether
  from above ground or underground sources.
• The Act authorized the EPA to establish safe
  standards of purity and required all owners or
  operators of public water systems to comply with
  primary (health-related) standards.
• State governments, which assume this power from
  EPA in CA the Department of Health Services -
  also encourage attainment of secondary standards
  (nuisance-related).

11
California Safe Drinking Water and Toxic
Enforcement Act

• This 1986 law (Prop 65) had two major provisions
• That no person in the course of doing business
  shall knowingly discharge or release a chemical
  known to the state to cause cancer or
  reproductive toxicity into water or onto or into
  land where such chemical passes or probably will
  pass into any source of drinking water,
  notwithstanding any other provision.
• No person in the course of doing business shall
  knowingly and intentionally expose any individual
  to a chemical known to the state to cause cancer
  or reproductive toxicity without first giving
  clear and reasonable warning.
• It strengthened both the Federal CWA and SDWA.

12
Pollution Standards

• Standards depend on the particular variable.
• The USEPA/CA DHS sets a maximum contaminant level
  or MCL based on cancer (generally long exposure)
  and non-cancer (generally short exposure) health
  risks in its Safe Drinking Water Act regulations
  (important to those taking their water from the
  Delta, e.g. Contra Costa Water District).
• A cancer related MCL supposedly limits an
  individuals risk of cancer from that contaminant
  to between 1 in 10,000 and 1 in 1,000,000 over a
  lifetime.
• A non-cancer MCL limits exposure to a level below
  which no adverse effects, lifetime or immediate,
  are expected.
• Usually, one liter samples of water are taken to
  a laboratory and standard tests are run to
  determine mg/l, µg/l, ppmv or ppbv of
  contaminants.

13
Sources of Water Contamination

• The climate and atmospheric air quality -
  characteristics picked up while still in the
  atmosphere as water vapor or descending
  precipitation.
• The physical and chemical character of the
  watershed - characteristics picked up in the
  hydrological cycle e.g. natural selenium picked
  up by water running through soil and rock.
• Pollution - point source and non-point sources
  introduced directly or indirectly to the water by
  humans.
• Clearly, humans can pollute the air and the soil
  and bedrock over a watershed leading to indirect
  pollution of the water bodies this is usually
  considered non-point source pollution since it
  takes multiple, diffuse pathways to the water
  body.
• For example, Bay Area residents could tip
  pesticide residues down the storm drain
  (non-point direct), apply excessive pesticide to
  lawns (non-point indirect) or pour pesticide
  residues in the toilet (becomes point via sewer
  plant discharge to Bay)

14
Resource impacts of pollution

• Pollutants will have different impacts depending
  on their character and properties and the
  purposes to which the water resource is to be
  used for.
• The most exacting water quality requirements are
  for drinking, although some specialized
  industrial uses require higher standards.
• Many synthetic and volatile organics (pesticides,
  PAHs, etc.) are not easily removed from water
  with standard treatment processes and may prevent
  the water from being used (e.g. MTBE
  contamination of groundwater).
• Many pollutants can bioaccumulate in and
  biomagnify up the food webs, e.g. pesticides like
  DDT or metals like mercury and selenium.

15
Pollution Control Logic

• Natural water bodies like rivers and streams are
  to some degree self-cleansing they flush
  themselves (e.g. to the ocean), they dilute to
  very low concentrations, they offer opportunities
  to lock up contaminants (sinks) or convert them
  to harmless substances.
• However, too much input of a given contaminant in
  a given place over a given period can exceed
  these assimilative and neutralizing capabilities
  and lead to harmful concentrations of pollutants
  in the water column, sediments, and/or food webs.
• Pollution input controls (CWA) prevent the
  addition of excessive quantities of pollutants
  that would impair the water body (for drinking,
  recreation, etc. not specifically for ecology
  but this tends to be covered by the others).
• Pollution output controls (SDWA) protect the
  public health by requiring adequate treatment to
  remove pollutants that do end up in the water
  bodies used for drinking.

16
Dynamics of pollution

• Depending on travel times, residence times,
  mixing rates, flushing action and so forth, and
  the time character and magnitude of pollution
  input (continuous, spill, etc.), impacts may be
  long-term or short-term.
• For many surface sources, removing the source of
  pollution will rapidly result in the
  establishment of adequate water quality
  conditions (unless historically accumulated
  quantities in sediments are disturbed e.g.
  mercury, PCBs).
• Many groundwater sources may remain contaminated
  for years, decades or longer even though the
  pollution source is eliminated because they flush
  so slowly.
• The Bay-Delta has historical accumulated (e.g.
  mercury in sediment), historical on-going (e.g.
  mercury mine tailing seepage) and current sources
  of contamination (e.g. mercury fall-out from
  crematorium smoke).

17
Pollution Prevention

• For centuries, the effects of pollution were
  ignored.
• Water bodies were large compared to the volume
  and concentration of pollution, therefore
  assimilation was adequate - the solution to
  pollution was dilution.
• As and where pollution loads were exceeded such
  that harm was done, this usually occurred
  elsewhere (downstream impacts), thus no action
  was taken.
• Only after the 1960s excesses of rivers catching
  fire and mass fish kills in the Great Lakes was
  legislation passed to protect water bodies the
  solution to pollution became prevention.
• Watershed management programs to eliminate
  sources of non-point source pollution (either the
  pollutant or the opportunity for its
  mobilization) and coordinate point pollution
  goals.
• Wastewater treatment to eliminate specific
  sources of effluent e.g. sewage, collected
  stormwater (containing the non-points),
  industrial waste.