What is water quality monitoring?
Getting organised
The monitoring plan
Five kinds of surveys
Setting goals
Quality of data
Fixing water quality problems
Staying credible
What to measure
Activities for schools
Water quality monitoring
means examining the physical, chemical and biological characteristics
of water - observing how these factors change over time, and over
different positions along a water body.
Physical characteristics
include, colour, smell, water velocity, temperature, acidity and
turbidity (ie the quantity of suspended solids in the water giving
it a murky or cloudy appearance). Important chemical characteristics
are the levels of nitrates, phosphates and salt in the water.
The physical characteristics
of rivers can change rapidly and over a wide range. Seasonal changesin rainfall make rivers run fast or slow, pollution can be a shockwave
of chemicals let loose in the night, gone the next day. The kinds
of plants and animals living in the water are a better long term
index of the health of the water. Some creatures are easier to
measure than others and are useful biological indicators. One
useful index of river water condition is derived from the presence
or absence of macroinvertebrates (animals, not including fish
and frogs, larger than 5-mm in length). In New Zealand rivers,
water bugs such as dragonflies, beetles, and other insects, have
different tolerances to pollution. By identifying which ones are
present, and which ones are absent, it is possible to determine
how much pollution has been in the water during the length of
time it took the creatures to become established and grow up there.
By making records of
these, and other factors, at a number of points along local waterways
community groups build up a picture of local water quality and
pinpoint problem areas. Collected data may then be exchanged through
electronic networks with neighbouring groups to create a picture
of water quality through an entire catchment - and beyond.
Water quality monitoring
programs are set up as a means of identifying problems and working
out ways to improve conditions in the waterways. Depending on
the problem, enhancement of waterways might be accomplished by
tree planting and fencing of some areas of river banks to exclude
stock, reducing the community's use of fertilisers and pesticides,
or constructing artificial wetlands downstream of agricultural
settlement ponds.
After you have organised
your Water Watch group and discovered what is already known about
your river, the next step is to devise a monitoring plan.
The monitoring plan
determines where, what, how, and how often you will take measurements
or observations of the waterway. It depends on the concerns of
people in your community, what monitoring is already being done,
and observations made during your baseline survey.
Like all plans, the
monitoring plan must be reviewed and revised as new discoveries
are made. In the beginning, it is best to start with easily obtained
observations and measurements.
1. The preliminary survey is
a critical first step. Working out where you will take your measurementsmakes all the difference in the world to the ease and validity
of your efforts. It's a question of checking out the river for
the best and most meaningful sites, ones that are easy to get
to, can be found again with little effort, and safe. The preliminary
survey is done in two parts, first using maps and asking questions
of people and councils in the catchment area to find out what
is already known, and second, visiting likely places to survey
and recording general information about them.
2. A baseline survey
establishes what the health of the river is now so later surveys
can tell if water quality is improving, or getting worse. It's
important to take measurements that can be replicated in later
surveys. Since the data is the foundation (baseline) for future
comparisons, sampling sites should be selected to represent the
complete range of conditions in the catchment.
3. A water quality
standards survey determines whether the water meets water
quality standards for designated uses (such as swimming) and values
(such as aquatic habitat or aesthetics). Obtain copies of the
Ministry for the Environment's Water Quality Standards for information on the standards that apply to the waters you are monitoring.
4. A pollution sources
survey measures the affects of people on the waterway. Generally,
three sites should be chosen. Immediately upstream of the impact.
Immediately downstream of the impact where the water has mixed,
and even further downstream, where the water has at least partially
recovered from the impact.
5. An event survey
measures the amount of sediment, nutrients, salt or litter that
is washed into a waterway during heavy rain. Measurements are
taken before, during and after a storm.
Hold a meeting
of your whole community group and, using maps and information
from the preliminary survey, consider questions such as: what do we know
about the water body's uses and values? is it safe to swim
in? does it meet state
water quality standards? does it support
aquatic life? what human impacts
threaten the health of the water? where are the information
gaps that our monitoring could fill in? what should be our
long and short-term goals? what types of samples
should we take? where and how often
should we sample? who will use the
information we collect? how, and how often,
should we report?how can we get a
good training program run by skilled and experienced people?
How accurate do
your measurements need to be? Organisation of a Quality Control
Program will be very important to the usefulness of your information.
The quality of data is described in terms of: Sensitivity
(the smallest unit measured). This is obtained from the manufacturer
of any special equipment used. Precision
(the ability to repeat the same measurement). Check this by taking
more than one sample and comparing the results. Accuracy
(how close your measurement is to a known reference). Systematically
check on the accuracy of your results by testing standard solutions
of known concentrations from scientific supply companies or by
monitoring alongside professional staff working in your area.
Comparability
(how well samples taken from one location can be compared to those
taken at another). Select your sampling sites so they can be easily
compared. This is especially important when doing a pollution
sources survey or recording the impact of an outfall. Completeness
(the number and variety of samples needed to meet your objectives).
The key here is to take enough samples but not more than you need
to find out what you really want to know. Taking too many samples
or measurements can be as much of a problem as taking too few.
A good detective goes after the important clues. Compatibility
(the way you enter data onto forms or into a database so it can
be used by others). This can be critical. Work with professionals
to find out how they record data in your catchment area. Set up
your database to match theirs so they can use your data and you
can use theirs. It is best to actually use the same software programme
and get a copy of their spreadsheet or database files to use as
a template.
Check your results against
those obtained by council or NIWAR professionals for a similar
waterway or at other locations in your waterway. If the results
are similar to the professionals, you are probably doing OK.
If your data shows a
water quality problem, or is well outside the limits of other
data, check over your work carefully. Go back to the site and
take replicate samples. Do you get the same results again?
Check to be sure the
results are not a result of incorrect recording (such as an impossible
reading like pH 15 or 125 degrees C.)
Could the samples have
been contaminated in some way?
Could you be measuring
some unusual natural weather or water flow conditions?
Show your work to at
least two experts and clarify any seeming contradictions or confusing
facts. If you have made a mistake, be the first to admit it, then
correct it. If the result is valid, find out what is causing the
problem. You may need help here from your city, district, or regional
councils.
There may be occasions
when a problem can be traced to a particular source such as high
nutrients from a piggery, a sewage overflow, or an unauthorised
industrial emission. In these situations it is important that
a non-confrontational approach is adopted. Select a capable person
to coordinate contact between your group and those responsible
for pollution. The following procedure should be followed:
The monitor who
identifies a problem, contacts the coordinator. The coordinator
confirms the monitor's observations (perhaps by re-testing) If the coordinator
determines that a problem does exist, he or she either makes personal
contact with the person responsible, or presents a written report
to the responsible agency - whichever seems most likely to result
in positive long term change. Whatever decision
is made, the aim is always to achieve a 'win-win' outcome for
the waterbody and the person responsible for the pollution.Where the cause
of the problem can be traced to the activities of a group; such
as householders, factory owners or shopkeepers: try to involve all
the affected parties in a discussion of the issue explain your findings
and state the need for action in terms that make clear the community
benefits. separate the personalities
from the issue and listen to all sides talk about real
needs, not positions invite those involved
to help you to develop solutions that protect resources and meet
everyone's needs. monitor the results
of any agreed changes and renegotiate if necessary. If an agency
has been notified, the coordinator should contact the agency within
a specified time, to make sure the problem has been investigated
and corrected. publicise any improvements
in water quality that result.
Remember, if people
have willingly worked together to arrive at a solution, they are
more likely to make that solution work.
A credible program
incorporates regular reviews and analyses of training, satisfaction
and morale as well as technical matters like monitoring techniques,
equipment performance, data recording and reporting.
Use newsletters, phone
calls and easily understood and useable reports to keep your group
informed of results, program progress and events. Most important,
be sure to publicise any action or improvement in water quality
that results from your monitoring.
References: Waterwatch Australia
