2. Outlines
Lake and source of pollution
Lake water quality monitoring
Sampling Technique for water quality
monitoring
3. Eco -system balance
Phytoplankton (predominantly algae. form the base of a lake's
food chain), require sunlight, water, and nutrients for
photosynthesis. primary producers .
Zooplankton, such as the shrimp, are the primary consumers
because they eat the primary producers (algae
Planktivores are organisms include fish that eat zooplankton
The piscivores are at the top of the aquatic food web and are fish-
eating fish
Benthic macroinvertebrates are some of the organisms living on or
in the lake sediment that consume algae, bacteria, detritus
6. Lakes: Physical Processes
Temp.
seasonal air temperatures directly affect
lake temperatures.
Summer. 3 layer s are formed
The epilimnion is the upper layer. It is warm, well-mixed, and
rich in dissolved oxygen.
The metalimnion is also called the thermocline region. The
thermocline is the point of maximum temperature change within
the metalimnion. The drastic density change in this layer
prevents the epilimnion and hypolimnionfrom mixing
7. The hypolimnion: is the bottom layer of cold water.
Because this layer is isolated from the atmosphere and
the epilimnion, it becomes anoxic. the release of
phosphorus, a nutrient, from the lake bottom
sediment into the hypolimnion.
Winter: 2 layers are formed
Spring & fall: Over turn is formed
8.
9. Erosion
Erosion is the detachment and movement of soil
particles by natural forces, primarily water and wind.
It is the process of wearing away rocks, geologic, and
soil material via water, wind, or ice.
Erosion will transport materials after
mechanical weathering has broken rock and geologic
materials down into smaller, moveable pieces.
10. Wind.
Wind can move sediment grains over long
distances when they are carried through the air.
Water.
Flowing water plays a major role in erosion by
carrying away soils and other materials on the land
surface.
11. Ecological and Economic Impacts of erosion
Causes can result in the destruction of aquatic
habitat and a reduction in the diversity and
abundance of aquatic life
Suspended sediment causes the water to be cloudy
(turbid). Increased turbidity reduces light
transmission (and hence photosynthesis ), thereby
reducing the growth of algae and aquatic plants,
which can adversely affect the entire
aquatic ecosystem.
12. Increased turbidity decreases the water's aesthetic
appeal and the human enjoyment of recreational
activities.
Some metal ions , pesticides , and nutrients may
adhere to sediment particles and be transported
downstream
13. Lake: Chemical process
Oxygen
Oxygen concentration is often considered the most
important indicator for lake health. For a lake to
maintain health there must be enough oxygen for the
aerobic organisms and in the lower water layers of the
lake, where much decomposition occurs.
14. Without sufficient oxygen, the hypolimnion may
become anoxic (devoid of oxygen) during
decomposition Anoxic conditions near the
sediment-water interface are normal and help
regenerate important nutrients such as phosphorus.
Byproducts of decomposition include carbon
dioxide, methane, phosphorus, and ammonia– a
form of nitrogen.
15. Nutrients
Lakes can be categorized on the basis of their richness in nutrients, which typically affect plant growth.
Oligtrophic lake (nutrient poor) and are generally
clear, having a low concentration of plant life.
Mesotrophic Lake(moderately productive) have
good clarity and an average level of nutrients.
16. Eutrophic lake (very productive and fertile) are
enriched with nutrients, resulting in good plant
growth and possible Algea Bloom.
Hypertophic lakes (excessively enriched with
nutrients) have poor clarity and are subject to
devastating algal blooms.
20. Industrial pollution
Toxins can harm aquatic and human life.
They are created by a wide variety of human
practices and products like Heavy metals,
pesticides and organic compounds like PCB’s.
Many pops are resistant to breakdown and
tend to be passed through the food chain to
be concentrated in top predators.
21. Hydrocarbon (PAHs) and volatile organic compounds
discharged from petrochemical industries.
Detergents ( cationic, anionic, nonionic) from
laundries and softening process in many industries are
toxic to aquatic life.
Heavy metals in the effluents from electroplating
industries, dying, printing, batteries manufacturing,
Tanning, mine drainage
22. Thermal Pollution and Thermal Shocks
Raising water temperatures from normal levels can
adversely affect water quality and aquatic life.
Higher temperature of water can adversely affects its use
as coolant in industries.
• less D.O in warm water than in cold, aquatic life
suffers and less D.O is available for natural biological
degradation of any organic pollution discharged into
these warm surface waters.
• bacterial action increases in higher temperatures,
resulting in accelerated depletion of the
streams oxygen resources.
23. Domestic wastewater (Sewage) outfall
Untreated waste:
Fecal contamination sources.
Organic waste .
Nitrogen and phosphorous .
Detergents.
Anaerobic condition leading to bad smell as H2s-
NH3
25. Urban runoff.
Roofs, streets, and parking lots, and rain rapidly run
off into lakes and rivers through drainage ways and
storm sewers.
This urban runoff may contain nonpoint-source
pollutants such as trash, pet wastes, lawn fertilizers,
and herbicides, as well as ,other pollutants from
vehicles.
26. Oil, grease and gasoline from roadways, and
chemicals used in home, gardens, yards and on
farm crops, are major sources of toxic
contaminants.
Leaching of metals from garbage, solid wastes
dump, domestic effluents and urban storm-water
runoff.
27. Agriculture run off
Chemical fertilizers, phosphorus, pesticides,
insecticides , herbicides , Metals contained in
pesticides may be run- off into stream.
Animal wastes create water pollution introduce
nutrients and disease-causing organisms into the
water.
28. Feedlots often collect wastes from thousands of
animals and store the wastes in central facilities
from which they may be withdrawn and applied as
fertilizer or soil conditioner.
Improperly maintained storage facilities or
improperly applied fertilizer can create water
pollution problems.
29. Pesticide leaching
Leaching may not only originate from treated fields, but
also from, pesticide application machinery washing sites,
or disposal areas.
Contamination may also occur when soil and pesticides
are washed into surface water by heavy rains. This
contamination may come from urban areas, lawns, golf
courses, parks, or agricultural fields.
Runoff pollution is difficult to control. The best method
of control is limited use of chemical pesticides.
30. Fertilizers Leaching, runoff
The nitrogen (N) and phosphorous (P) applied to
agricultural land (via synthetic fertilizers), if not
managed correctly, excess N and P can have negative
environmental impacts.
The nitrate form is water-soluble and moves with the
water into surface water. The ammonium form attaches
to soil particles. it will wash into surface water if the soil
erodes.
Eutrophication can occur downstream due to excess
nutrient supply, leading to anoxic areas called dead
zones.
31.
32. The symptoms and impacts of eutrophication
Increase in production and biomass of phytoplankton,
attached algae, and macrophytes.
Replacement of desirable fish; by less desirable
species.
Production of toxins by certain algae (blue green).
Loss of recreational use of water due to slime, weed
infestation, and noxious odour from decaying algae.
33. Organic contaminants& Pathogens
Manure and Biosolids manures and biosolids
contain not only nutrients such as carbon, nitrogen,
and phosphorus, but they may also contain
contaminants such as pharmaceuticals.
Pathogens wash off the land from wild animal,
farm animal and pet waste, and can also enter
the lake from improperly functioning septic systems,
leaky sewer lines and boat sanitary disposal systems.
This lead to contaminations of aquatic life.
35. Lake Maryut receives numerous inflows from
different sources mainly from:
- El Qalaa and El Omoum Agriculture Drains,
Sewage West Treatment Plant,
-El Nubaria Canal and Industrial direct discharge.
There are other subsidiary sources of inflows
namely sea locks and ground water seepage.
36. The main basin of Lake Mariut is receiving industrial discharge
indirectly through the main municipal wastewater treatment
plants in Alexandria; West wastewater treatment plant (WTP)
and East wastewater treatment plant (ETP).
The design capacity of ETP and WTP is 607,000 m3/ day and
462,000 m3/ day respectively.
The main basin (21 km2) with an average depth of
1.2 meters;
The northwest basin (10.5 km2) with an average depth of 1.25
meters;
37. The fishery basin (4.2 km2) with an average depth of
1.35 meters;
The southwest basin (21 km2) with an average depth of
0.5 meters; and
The west basin (8.4 km2) with an average depth of 0.6
meters.
The concentration of dissolved oxygen in all the basins
is less the 5 mg/l.
38. Sources ofLake Mariut pollution
It is a eutrophic lake receiving massive and numerous
discharges: domestic, agricultural and industrial.
these waters bear high organic matter, nutrients, various
chemicals, and pesticides.
Lake Maryut receives numerous inflows from different sources
mainly from:
El Qalaa and El Omoum Agriculture Drains, Sewage West
Treatment Plant,
39. El Nubaria, Canal and Industrial direct discharge.
There are other subsidiary sources of inflows ground
water seepage.
The fact that domestic sewage, industrial, and
agricultural waste are discharged continuously to
the lake makes this pumping station essential to
maintain water level at 1.88 – 2.0 m below sea level.
Companies discharging directly or indirectly into
Mariut Lake.
40. These companies are classified in three groups:
A) Seven Companies Connected to the Public Sewer
and Disposing their Effluents to Lake through ETP:
B) Seven Companies Connected to the Public Sewer
and Disposing their Effluents to Lake through WTP:
C) Two Companies Discharging their Effluent
Directly to the Lake:
42. ARTICLE 68
Table 2-1: Water Quality Parameters of Water Surfaces that are approved as
discharge water receiving bodies (law 48/1982 – article 68)
Parameter Concentration
Temperature Not more than 5 over the prevailing
average
Dissolved oxygen Not less than 4 mg/L at any time
Hydrogen(basin)exponent Not less than 7 and mot more
than 8.5
Industrial detergents Not more than0.5 mg/L
Phenol Not more than 0.005 mg/L
Sediment Not more than50 units
Dissolved solid substances Not more than 650 mg/L
Probable counting for
the colon group in 100cm3 Not more than 5000