Management of Non-Point Source Pollution CE 296B

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Management of Non-Point Source PollutionCE 296B

• Department of Civil Engineering
• California State University, Sacramento

Lecture 15, March 31, 1998 Receiving Water
Impacts - Part II
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III. Alternative method of assessing receiving
water impacts - environmental indicators.

• A. As discussed last time, a traditional method
  for assessing receiving water impacts does a poor
  job of giving us an overall picture of the true
  state of the receiving water health.
• 1. What has been advocated by some is to take a
  holistic approach where the sum of many different
  aspects of the watershed are simultaneously
  examined to yield a picture of water quality and
  where the weak links are in terms of improving
  water quality.

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III. Alternative method of assessing receiving
water impacts - environmental indicators.
(cont.) A. As discussed last time, a traditional
method for assessing receiving water impacts does
a poor job of giving us an overall picture of the
true state of the receiving water health. (cont.)

• 2. A major motivation for developing the idea of
  environmental indicators was that it seemed
  impossible to ever collect enough samples to
  determine receiving water impacts in a
  traditional manner.
• 3. A major goal was to monitor in ways other than
  just collecting samples and analyzing.

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III. Alternative method of assessing receiving
water impacts - environmental indicators. (cont.)

• Disclaimer - What you are about to see is taken
  largely from one groups vision of what an
  alternative methodology for assessing receiving
  water impacts. That group is the Center for
  Watershed Protection. It is a non-profit
  organization based in Maryland and receives most
  of its funding from U.S. EPA.
• There are other ideas out there on the use of
  environmental indicators.

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III. Alternative method of assessing receiving
water impacts - environmental indicators. (cont.)

• B. The idea behind environmental indicators is to
  examine simultaneously several different aspects
  of the watershed that if done intelligently will
• Help identify the root cause of what is causing
  noticeable pollution effects to a water body.
• Help devise strategies that will be useful for
  many watersheds.
• Give warning to situation of a water body that is
  about to become polluted.

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III. Alternative method of assessing receiving
water impacts - environmental indicators. (cont.)

• C. A proposed scheme is to have six indicators of
  watershed health to be examined. They are
• Water Quality Indicators
• Physical and Hydrological Indicators
• Biological Indicators
• Social Indicators
• Programmatic Indicators
• Site Indicators

We will focus on these
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III. Alternative method of assessing receiving
water impacts - environmental indicators. (cont.)

• D. To examine this concept, we will first look at
  the four indicators that are generic measures of
  receiving water health.
• We will then look at how indicators from
  different groups relate to one another.
• Finally, we will examine how these indicators
  might be used to develop strategy for the
  improvement of a receiving water.

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III. Alternative method of assessing receiving
water impacts - environmental indicators. (cont.)

• E. Water quality indicators.
• The goal of these indicators is to establish a
  picture of the chemical composition of the water
  body and the discharges to that water body. In
  keeping with the concept of gathering an overall
  picture of the watershed, the frequency of sample
  would not be anywhere as often as in a
  traditional approach.
• I key idea for most of these is to capture
  normal conditions.

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III. Alternative method of assessing receiving
water impacts - environmental indicators.
(cont.) E. Water quality indicators. (cont.)

• 1. Water quality pollutant monitoring. One would
  select appropriate choices from
• Water quality pollutant constituent monitoring
• Toxicity testing
• Non-point source loadings
• Exceedance frequencies of water quality standards
• Sediment contamination
• Human health criteria

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Water Quality Pollutant Constituent Monitoring

• Completed in the receiving water. Establish
  under normal conditions
• What the overall chemical quality is.
• What pollutants are present.
• What the concentration ranges might be.
• Possibly look at seasonal variations of crucial
  parameters such as dissolved oxygen.
• Establish a baseline of data.
• Within the scope of using a broad base of
  environmental indicators, crucial not to read
  too much into the numbers.

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Toxicity Testing

• Standard toxicity tests conducted on non-point
  source runoff, either at full strength or
  diluted.
• Quality of data is likely to be limited,
  particularly since most toxicity tests currently
  focus on acute rather than chronic conditions.
• May be good for pointing particularly toxic
  constituents. Helpful in targeting constituents
  that have priority.

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Non-Point Source Loadings

• Use existing models to estimate non-point source
  loadings.
• Quality of models are limited. Results can only
  be used as providing a general estimate, with a
  huge 95 confidence interval, of how much is
  reaching receiving waters.
• May be useful in assessing the impact of new
  development in a water shed.

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Exceedance Frequencies of Water Quality Standards

• A measure of how often, when, and by what,but not
  for how long, water quality objectives are
  exceeded.
• Useful in determining during what types of
  occurrences, small storm, flood events, dry
  weather flow, etc., problems occur. Possibly
  give insight as to reasonable course of action.
• May possibly give rise to a more thoughtful
  examination of beneficial uses and associated
  water quality objectives. Example, is it, for
  most cases a good thing that streams are turbid
  during flood events.

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Sediment Contamination

• Intelligently sample and analyze sediments for
  pollutant concentrations.
• Typically, this does not have to be done very
  often.
• Yields some information, although quite
  imperfect, about the health of an ecosystem. If
  done very carefully, may yield a good historical
  record of pollutant loadings.
• Yields information about what bodies of water
  have received the largest pollutant loads.

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Human Health Criteria

• Little work that has the possibility of a real
  impact has been done in terms of assessing human
  health criteria.
• Limited to MCLs for chemicals and flawed
  indicator organisms for pathogens.
• Is however, the primary motivation behind the
  establishment of beneficial uses. Clearly, more
  thoughtful work is required here.

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III. Alternative method of assessing receiving
water impacts - environmental indicators.
(cont.) E. Water quality indicators. (cont.)

• 2. Physical and Hydrological Indicators. One
  would select appropriate choices from
• Stream widening / downcutting
• Physical habitat quality
• Changes in dry weather flow rates
• Increased flooding frequency
• Stream temperature monitoring

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Stream Widening / Downcutting

• Involves establishing a reference cross-section
  of a stream and measuring the changes in that
  cross-section annually.
• Provides a measure of how land use changes
  upstream are affecting the integrity of the
  stream in question. Has a close the barn door
  after the horses have been let out quality.
• May be used to assess potential impacts of
  similar land use changes in other watersheds.
• Is very inexpensive to perform.

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Physical Habitat Quality -I

• Involves surveying the area directly adjacent to
  the water body to measure for a stream, the
  amount of
• Channel stability
• Channel cover
• Instream sediment imbeddedness
• Riparian habitat
• Similar measures for a lake
• Submerged aquatic vegetation
• Percent littoral dominance
• Shoreline development

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Physical Habitat Quality -II

• Helps provide concrete numbers with respect to
  cost for any effort to engage in stream
  restoration.
• Relatively inexpensive process.
• Has the added benefit of educating the discharger
  and regulator as to what is actually there.
• Does require careful supervision of personnel
  conducting surveys. What constitutes valid
  riparian habitat is a matter of some difference
  of opinion.
• Quantifiable standards are not well developed.

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Physical Habitat Quality -II

• Helps provide concrete numbers with respect to
  cost for any effort to engage in stream
  restoration.
• Relatively inexpensive process.
• Has the added benefit of educating the discharger
  and regulator as to what is actually there.
• Does require careful supervision of personnel
  conducting surveys. What constitutes valid
  riparian habitat is a matter of some difference
  of opinion.
• Quantifiable standards are not well developed.

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Changes in Dry Weather Flow Rates

• The idea is to compare current dry weather flow
  rates with natural dry weather flow rates to
  measure the impact of land use on the water body.
• Moderately inexpensive process, records may
  already be available.
• In humid climates, urbanization reduces dry
  weather flow rates due to decreased ground water
  recharge.
• In dry climates, urbanization increases dry
  weather flow rates due to increased irrigation.
• In dry climates, many open range practices such
  as logging and cattle grazing decreases dry
  weather flow rates due to decreased ground water
  recharge.

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Increased Flooding Frequency

• Similar to the stream widening / downcutting
  indicator. Provides a measure of the effect of
  urbanization on stream hydrology.
• Relatively inexpensive to perform. Records are
  already available. Does have the potential for
  difference in perception from one reviewer to the
  next on what constitutes a flood.
• Has a close the barn door after the horses have
  been let out quality.

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Stream Temperature Monitoring

• Stream temperatures are measured continuously in
  an automated fashion. Are then compared to
• Beneficial uses, particularly fish requirements.
• A relatively undisturbed similar reference
  stream.
• Provides a direct measure of land use on a easily
  understood water quality parameter that does have
  a clear impact on many beneficial uses.
• Is an inexpensive way to gather continuous
  information about a water bodies quality.

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Discussion Break

• What physical and hydrological feature that has
  had profound impacts on streams, particularly in
  the western U.S. has not been covered?
• How might that feature be incorporated into an
  environmental indicator.

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III. Alternative method of assessing receiving
water impacts - environmental indicators.
(cont.) E. Water quality indicators. (cont.)

• 3. Biological Indicators. One would select
  appropriate choices from
• Fish assemblage analyses
• Macro-invertebrate assemblage analyses
• Single species indicators
• Composite indicators
• Other biological indicators
• It is important to note that these indicators
  are a particularly direct measure of beneficial
  use attainment.

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Fish Assemblage Analyses - I

• A resident fish community, as complete as
  possible, is collected using electrofishing or
  seining. If possible, multiple habitats in the
  same water body are sampled.
• Fish are counted by
• Number and type of different species present
• Total fish present
• Biodiversity type indices are used to assess the
  biological health of the system. These indices
  have such names as
• Index of Biotic Integrity

• Index of Well Being

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Fish Assemblage Analyses - II

• If a pristine reference stream is available, this
  is a particularly powerful method for assessing
  the health of a water body.
• The number of different species typically found
  in a fresh water body make this a reasonable
  tool. In a salt water body, directly connected
  to the ocean, nobody has come up with any
  reasonable index to use.
• The use of this tool requires considerable
  expertise, but its use is a great good will
  builder.

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Macro-Invertebrate Assemblage

• Using similar techniques and ideas as the fish
  assemblage, assess the species diversity and
  total numbers of macro-invertebrates (aquatic
  insects).
• Is less expensive to perform than fish
  assemblages and due to the short life span of
  insects, impacts of non-point source pollution
  are observed sooner.
• One does need to be careful in interpreting data,
  particularly after substantial flow events which
  can in the short run have a large negative impact
  on invertebrates.

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Single Species Indicator -I

• A single species that is known to be particularly
  sensitive to ecological changes is selected and
  counted regularly.
• Is less expensive to perform assemblages of any
  kind.
• The reaction of the public is bound to be
  stronger with such an indicator. Two polar
  reactions
• The decline in trout numbers means that serious
  action must be taken.
• The use of such an indicator is nothing more than
  a device to stop development of any kind.

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Single Species Indicator -II

• The kind of species most likely to be chosen also
  have migration patterns, possibly distorting
  results.
• Reasons completely divorced from pollution
  effects can severely change the numbers of a
  single species. A classic example was the
  introduction of the European Brown Trout into
  U.S. waters. Native species such as Rainbow or
  Brook Trout were often displaced.

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Biological Indicators - I

• This is going nuclear on the use of
  assemblages. Assemblages of several different
  groups of living things are simultaneously
  examined. Included would be
• Fish
• Macro-Invertebrates
• Micro-Invertebrates (nematodes, etc.)
• Algal Communities
• Very expensive, requires substantial expertise to
  interpret.

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Biological Indicators - II

• If done carefully, could be used to direct less
  expensive future efforts. One might learn
• What kind of chemical monitoring would be most
  useful
• What kind of toxicity tests would be most useful
• What assemblage (fish or macro-invertebrate)
  would be most useful

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III. Alternative method of assessing receiving
water impacts - environmental indicators.
(cont.) E. Water quality indicators. (cont.)

• 4. Social Indicators. One would select
  appropriate choices from
• Public attitude surveys
• Industrial / commercial pollution prevention
• Public involvement and monitoring
• User perception
• These are indicators that give an indication as
  to how much support can be expected in the long
  run for the management of non-point source
  pollution.

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Discussion Break

• Recalling the Pogo Cartoon of old. We have met
  the enemy and it is us or a more erudite version
  The fault dear Brutus is not in our stars but
  ourselves, why might these social indicators be
  crucial to the success of a non-point source
  management program?