Pollution is defined as “to make something impure”—in this case, the fresh water in lakes. The pollution of water restricts its use for some human need or a natural function in the ecosystem.
Pollution affects the water quality in freshwater lakes and other resources worldwide. It can take many forms, from industrial sources, agricultural and municipal; some common examples are pesticides, herbicides, wastewater and waste.
Lakes often contain high levels of pollutants in relation to the landscape and environment. Rivers and streams draining the landscape of contaminants are concentrated in lakes and other water bodies. Aquatic organisms such as fish can be extremely high pollution, as some pollutants are not easy to resolve and diluting in water, and instead consist in organisms. Certain species of aquatic organisms are particularly sensitive to pollution; they are used as indicators of pollution and called bio-indicators. Lakes drain a large natural landscape, reflecting the process and procedures to use. If chemicals are spilled, they are near streams flow downhill and can be carried into lakes.
Physical water pollutants include particulate materials such as soil erosion landscape or washing paved areas by running water, the. Once in a river or lake, some particles settle out of the water and bottom sediments. Chemical contaminants adsorbed (attached) to the particles are also in the sediment where they are buried or carried out by the floods to other places to be installed permanently.
Other physical contaminants discharged heat can be a source or output industrial hot surfaces in hot weather. Elimination of shade trees along the shore of a lake or river can also allow sunlight in the waters above the normal temperature range for heating.
Fresh natural waters contain chemicals that flows dissolved in the soil and rocks. Major inorganic elements comprise calcium, magnesium, sodium, potassium, carbon, chlorine and sulfur, and plant nutrients such as nitrogen, silicon and phosphorus. Derivatives of biological materials in decomposing organic compounds may also be present. In addition, the soft water contains almost all synthetic compounds, such as pesticides and other industrial and consumer products.
Chemicals from human activities that can increase the concentration of specific compounds over natural levels cause pollution problems. Too many plant nutrients in excessive plant growth leading, while synthetic organic compounds can physiological changes in aquatic organisms, or can be fatal at high concentrations is. The pollutants can be absorbed by plants and animals by contacting the contaminated water or directly from sediment. Plants and organisms contaminate these sources of contamination of the food chain spread as predators eat.
Although not generally considered contaminants, bacteria and plants living organisms, the proportions are increasingly harassment
The accidental release of cyanide from a recovery of precious metals in Romania polluted the Tisza in 2000, aquatic and terrestrial animals, as this horse has poisoned drinking water three weeks after the spill killed. Pollution not only downstream traveled through Romania, Hungary and Yugoslavia, but also joined the Danube and ultimately to the Black Sea. The release of about 100 tons of cyanide caused what.
Biological contamination may affect the use of fresh water. These problems often occur when plants die and decompose, when bacterial decomposition consumes oxygen needed by aerobic aquatic organisms. Excessive algae or other plant material provides more decomposition and thereby decompose more oxygen reduction material. In addition, non-native plants and animals that are introduced as a result of human activities alter the basic ecology of a lake or river that often great harm.
Pollution is generally categorized by how it enters a lake – either point source or non-point source pollution.
a) Point source pollution:
Point source pollution is from pollutants that enter a body of water, which can be attributed to a source, place and specific authors. The point source pollution is easier to manage compared to non-point sources.
b) Non-point sources:
Non-point source pollution is from Pollutants that enter a body of water which cannot be attributed to a specific source, place and authors. Rather, this pollution comes from many diffuse sources and often occurs in small amounts, but can focus on freshwater lakes and other resources.
Examples of point sources discharging are industrial waste, sewage from wastewater treatment plants, dumping deposit and other dangerous illegal chemical (nuclear waste). Heat can also be a contaminant.
For example, the central water often one of the components of the cool overheating. Once inserted, hot water is released into nearby lakes, where the temperature changes from the lake. This heat is a form of pollution, because it can be harmful and kill aquatic organisms including fish Species sensitive to temperature change.
Another example of widespread environmental contamination is the legal discharge of waste water and other chemicals. For example, Detroit, Michigan reports available more than 700 million gallons of wastewater per day and 150 million pounds of polychlorinated biphenyls (PCBs), toxic each year in the Detroit River, which serves as a link between Lake Huron and Lake Erie2. Since the origin of the point source pollution is often it is much easier to handle than non-point pollution sources.
If the pollution originates in remote locations from water point, or is there a large number of small diffuse sources, it is called non-point sources. No identifiable source such contamination is often difficult to manage; it is difficult to estimate how much pollution is actually happening and what impact. Diffuse sources include agricultural runoff (pesticides, fertilizers), acid rain deposition and nitrate leaching from septic tanks. Diffuse sources represent most of the impurities in the water systems.
3.4 Impacts of lake pollution
Whatever the source of the contamination can affect aquatic life in many ways. In general, the pollution reduces the quality of water. It can also be the variety of wildlife; particularly sensitive species.
Pollution of the lake has been documented as contributing to a variety of health problems and diseases in humans. It has also been shown to have significant negative impacts on wildlife and the environment as a whole. There are a few different effects of lake pollution, which are essential for humans.
The effects of pollution of the lake are not always immediate. They are not always seen on the contaminated site. They are sometimes never known by the person responsible for the pollution. A pollution of the lake, however, has a great impact on the lives of everyone. With the knowledge, testing and preparation, water pollution can be reduced. It does not take much effort – just a little thought.
Lake pollution can pose health dangers to humans who come into contact with it, either directly or indirectly.
The risk of your health being negatively impacted by polluted drinking water in a developed country is small in comparison with developing countries. However, it is possible to become ill from contaminated water.
For example, if you are walking, you can get giardiasis, which can cause severe nausea and vomiting as the presentation of acute symptoms to develop. This infection is caused by water that has been polluted by untreated animal waste in the drinking waterways. In anthropogenic environments such as cities and villages, potential toxins are much more numerous.
Another high risk of lake pollution is Mercury contamination. Mercury has been found to interfere with the development of the central nervous system in fetuses and young children, which could potentially lead to a large amount of long-term side effects.
3.6 Impact of lake pollution on ecosystem
Lake pollution also causes negative effects within the environment to animals and their habitats.
The entry of pollutants in lakes has a wide range of effects. It is possible for pollutants, to change the water temperature enough to fish force in search of colder waters. This can even create an ecological dead zone.
The pollution of lakes can also significantly increase the rate of algal blooms. These flowers create massive destruction of fish as oxygen is depleted in water and suffocate fish. Fish can be killed, even if excessive algae get caught in their gills.
3.7 Definition of lake maintenance
There are numerous reasons to pay close attention to the lake maintenance, including:
a) Preventing fish kill;
b) Reducing sediment buildup
c) Reducing aquatic weed growth
d) Reducing need for synthetic algaecides
e) Improving irrigation water quality
f) Reducing harmful gases like CO2 and Methane
g) Reducing mosquitoes
h) Increasing the Ozone content of the water
i) Reduce Bacteria and odor
To maintain a high water quality the lake requires a maintenance plan. Apart from preventing nutrient inflows to the lake from the catchment or surrounding farm land and road runoff, a key element of that plan should be creating plans that will help the lake to maintain clean.
3.8 Contribution of lake maintenance to the future of aquatic system
Fresh water is essential to human life and economic wellbeing, and societies draw strongly on rivers, lakes, wetlands, and underground aquifers to supply water for drinking, irrigating crops, and running industrial processes. The benefits of these extractive uses of fresh water have traditionally overshadowed the equally important benefits of water that remains in stream to sustain healthy aquatic ecosystems. There is growing recognition that functionally intact and biologically complex freshwater ecosystems provide many economically valuable commodities and services to society.
Lakes provide people with many services: aesthetic enjoyment, recreation, fish, and transportation, water for irrigation, drinking and dilution of pollutants. Lake degradation results from excessive nutrient inputs, toxic substances, habitat loss, overfishing, species invasions and extirpations. The goal of management is to balance the uses of lakes with conservation measures to sustain ecosystem services over time (Carpenter & Lathrop 1999).
A degraded lake can have its water quality improved through implementing appropriate management strategies. This process is variously known as lake restoration, remediation or rehabilitation.
4.1 Lake restoration
It is important to recognize that the restoration program will take time and will not return the lake to a once untouched condition that it may have had earlier in its life, but it could improve the water quality to meet a specified water quality goal. The ability to achieve that goal for a specific degraded lake will be determined by the nutrient budget (internal versus external loads), how well the in-lake processes are known, the degree of restoration required to achieve the goal and the funding available to implement the management strategies required to achieve that degree of restoration. Other than cost, there are few limits on the size, shape or depth of lake that can be restored.
While there is an implicit expectation that restoration will return the lake to its original condition, the reality is that some processes on the way to degradation are irreversible (Carpenter & Lathrop, 1999). Consequently, the expectation of restoration needs to be tempered with the knowledge that the lake may never reach its original state and that the objective of a restoration project will be to rehabilitate the lake to improve the water quality and lake conditions to an achievable level. This rehabilitation level then becomes a management goal. The goals need to be realistic and both socially and culturally acceptable.
Restoring a degraded lake to a new desirable condition is an adaptive management process which must include a monitoring program to assess the success of management strategies employed to reach that goal, and the flexibility to adapt the management strategies based on those monitoring results.
Figure 4.1.a. shows the maintenance flow diagram for the rehabilitation of a lake.
The issues, goals and measures of success can be filled in and additional sections listing the tools to be used can be added. The role of the environmental consultant at key points indicated by red arrows is optional depending on the competence of the lake manager and the size of the lake. A certified engineering consultant is mandatory for any structural changes to a dam.
4.2 Practical maintenance goals in Lake Restoration
Practical maintenance goals for that lake would include:
a. To reduce or eliminate the occurrence of nuisance cyanobacteria blooms
b. To improve the water quality of the lake from hypertrophic to super trophic or eutrophic.
c. To reduce the abundance of aquatic macrophysics in the lake to enable unimpeded use of the lake for contact recreation, and
d. To maintain or enhance the fishery in the lake and its tributaries.
These goals are essential to restoring of the lake. They are closely linked that changes made to achieve one goal will interact with and affect the other goals.
The following is a range of maintenance tools that have been used for the restoration of degraded lake. The most recent tool ‘Computer modelling’ uses environmental, climate and water quality / biogeochemical monitoring data from the lake to build a simulation of the lake to estimate the likely benefits to the lake of applying one or more of the maintenance tools.
These tools are including:
The weight of evidence indicates that the key to restoring the water quality of lake and its fishery is the management of the lake weed. There are four approaches to this issue:
(1) Mechanical weeds harvesting;
(3) Bio manipulation and
(4) Changing water levels.
Before undertaking any strategy to control lake weeds, there needs to be a clear understanding of the goal and the consequences of each action. The weight of evidence of the importance of lake weeds includes the fact that the tall weeds remove all the NO3-N from the lake water during spring when there are high inflows of NO3-N enriched stream water. This evidence also suggests that under low flows the weeds become N-limited and, being unable to sustain the amount of biomass with the nutrients available, they senesce releasing the nutrients in the plants back into the water.
Waste water treatment uses holding ponds and wetlands for reducing the nutrient load before the water is released into an open waterway. The main disadvantages of the technique are that,
1) To be efficient they cover a large area to give sufficient contact time for nutrient and sediment stripping,
2) They are less efficient at removing P than N, and
3) They may not cope with flood flows and the stream short circuits directly to the lake with no renovation.
Floating treatment wetlands (FTW) are a new restoration concept where emergent wetland plants are grown in buoyant rafts which are moored in a lake or stream.
These rafts are constructed from recycled plastic (PET drink bottles) in various sized sections that could be 2 m by 3 m for ease of handling and joined together later. The plants are grown in recesses in the raft and their roots extend down into the water where they assimilate the N and P. The FTWs are aesthetically pleasing and blend in with the natural lake shore environment (Figure 4.2.a) and provide additional habitat for birds and koura.
Onshore management to reduce nutrient inputs to the lake should look at the sources of those nutrients. However, because the lag time between the contamination of the groundwater and that contaminated groundwater reaching the lake, nutrient stripping of the groundwater at the lake edge is also essential. This is best achieved using marginal wetland buffer zones (Figure 4.2.b). The surface or unconfined groundwater aquifer is the most vulnerable to contamination in the catchment as it receives the infiltrating rainwater percolating down through the soil. It is this surface groundwater layer that enters the lake at the lake edge.
• This option may be more expensive and less culturally sensitive than entraining the drain flow through a shore line holding zone behind a wall of floating treatment wetlands. Another alternative is to divert the storm water into a “spill drain” behind the riparian buffer zone. Both of these options dissipate the energy of the storm water inflow so that it does not move out into the body of the lake. Dispersing the flow behind the riparian buffer zone will cause all the sediment to remain on shore and the nutrients in the storm water to be assimilated by the buffer zone plants.
A stream diversion channel is a temporary practice to convey stream flow in an environmentally safe manner around or through a construction site while a permanent structure or conveyance is being installed in the stream channel.
• Flushing – external source water.
A simple expedient in small lakes overseas is to divert a proportion of a clean stream or river through the lake to reduce the residence time and thus flush the N and P in solution and in particulates, such as algae, down the outlet stream. An in-depth analysis of the water quality of the source water would be needed if this option was a serious consideration.
• Enhanced flushing using fluctuating water levels.
This technique requires manipulation of the weir on the lake to increase and decrease the lake water level at different times of the year to take advantage of specific parts of the lake cycle. Seasonal changes in water level are potentially good for fisheries with the most productive fisheries having low water levels in summer (J. Boubeé, NIWA, pers. comm.).
Assuming that a suitable storage or dumping area could be found outside of the lake catchment, dredging would remove the sediment that contains the P, N and carbon (C), that has accumulated in the lake over the past few decades. It would also remove the seed bank for lake weeds. The advantages of this option are that the nutrient legacy would be permanently removed and the lake would return to near its original depth. The disadvantages of this option are the cost to remove the estimated 3 km3 of sediment, the destruction of the existing ecosystem, and the release of nutrients and other toxic chemicals such as Sulphides during the process of dredging. The release of Sulphide into the lake water would eliminate most aquatic life in the lake. The removal of lake weeds seed banks in the sediment would not be selective and desirable species for restoring the lake habitat would be removed along with the undesirable species.
Aeration replaces the oxygen consumed by decomposition processes and prevents the development of anoxic conditions which allow P release from the sediments. This technique is often used in water supply reservoirs to prevent the anoxic release of P, which favors cyanobacteria growth, and the release of minerals such as iron and manganese, which would stain baths, toilets and hand basins in homes and would cause black marks on washing as the water re-oxygenates and these metals precipitate. The advantages of the technique is that it is relatively cheap, requiring an air compressor, connection hoses and an aeration bar with anchor blocks, and only needs to run in summer when low oxygen concentrations develop.
In shallow lakes, giant discs pulled through the lake sediments open up the sediment allowing deep penetration of oxygen from the water column. The concept behind this tool is that the P will be bound to the iron and manganese oxides in the sediment. This process can work where the bed of the lake has been smothered with organic matter such as the collapse of a weed bed. Modelling of this option (White & Gibbs 1991) indicates that the beneficial effect for P binding is short lived because as soon as the sediments go anoxic once more, the P is released. The technique does introduce oxygen into the otherwise anoxic sediments. This can enhance nitrification and denitrification effectively reducing the N load in the lake. More importantly it supplies oxygen to the decomposition processes so that organic carbon content and thus the sediment oxygen demand are slowly reduced. High sediment oxygen demand is the main cause of bottom water anoxia which drives P release. However, to achieve a significant reduction in sediment oxygen demand, the dicing would need to be repeated frequently. There are three major disadvantage of dicing through weed beds:
1) The organic matter could be driven into the sediment raising the organic carbon content,
2) Every leaf node of most aquatic macrophysics can grow so the dicing would most likely spread the weed more widely, and
3) The dicing would devastate the benthic mussel beds destroying that part of the fishery.
In some overseas restoration studies, concentrated nitrate is injected into the sediment with equipment similar to the giant discs to provide an oxygen source for decomposition processes in summer (Hemond & Lin, 2010). The advantages of this technique are that the release of P is reduced and thus the dominant algal species are not cyanobacteria. The release of arsenic (As) is also suppressed. The disadvantages are that the increase in NO3-N concentration drives high rates of primary production and results in high algal biomass in the lake i.e., the lake goes very green. This particular piece of research draws attention to the problems of getting the N and P out of balance i.e., heavy metals such as As and lead (Pb) can be released from the sediments.
• When a cyanobacterial bloom has developed, it is too late to use many of the restoration techniques and it is more appropriate to treat the bloom directly to get immediate results. To that end, much research has focused on the use of clay to floc the bloom so that it settles out of the water column (Sengco & Anderson, 2004; Beaulieu et al. 2005; Padilla et al. 2006; Zouet al. 2006; Biyu et al. 2010; Chen & Pan, 2012; Pan et al. 2012). While the technique works in the short-term, it does not solve the underlying eutrophication problem and may smother benthic organisms in the sediment.
The phosphorus released from the lake sediments is in the form of phosphate which is readily usable by plants, especially algae, for growth. While all plants use N and P in the ratio of 16 N to 1 P (Redfield 1958), the symbiotic bacteria inside blue-green algae, hence the name ‘cyanobacteria’, can convert N2 gas in the atmosphere to NO3-N which the algal host can use for growth. This gives cyanobacteria a competitive advantage over all other algal species when there is a surplus of P and a deficit of nutrient N in the lake water, and they dominate the algal species assemblage. Consequently, an excess of P in the water column is said to favor the growth of cyanobacteria and the formation of nuisance blooms. Phosphorus inactivation is used to make that P unavailable for algal growth by binding it to a metal. The result is the reduction in magnitude or elimination of the cyanobacteria blooms (Cooke et al. 2005). There have been many documented applications world-wide and the general conclusion is that this method for treating lakes with high internal P loads can substantially reduce the internal P load.
• Phosphorus inactivation with sediment capping.
The alternative to alum is to use a granular P inactivation agent. These products are designed to inactivate P either in the water column or at the sediment surface before settling on the lake bed as a thin (1–2 mm thick) layer. This is the layer referred to as the sediment cap
While a combination of these tools can address the internal problems in the lake, there is also an overriding requirement to address the sources of nutrients from the catchment.
The Great Lakes form the largest surface freshwater system on Earth. More than 30 million people live in the Great Lakes basin, and the impact of their daily activities, from the water consumed to the waste returned, directly affects the Great Lakes environment. EPA leads U.S. efforts to restore and maintain the quality and ecosystems of the Great Lakes watershed.
The Great Lakes (also called the Laurentian Great Lakes or the Great Lakes of North America) are a series of interconnected freshwater lakes located in northeastern North America, on the Canada–United States border, which connect to the Atlantic Ocean through the Saint Lawrence River. Consisting of Lakes Superior, Michigan, Huron (or Michigan–Huron), Erie, and Ontario, they form the largest group of freshwater lakes on Earth, containing 21% of the world\’s surface fresh water by volume. The total surface is 94,250 square miles (244,106 km2), and the total volume (measured at the low water datum) is 5,439 cubic miles (22,671 km3). Due to their sea-like characteristics (rolling waves, sustained winds, strong currents, great depths, and distant horizons) the five Great Lakes have also long been referred to as inland seas. Lake Superior is the second largest lake in the world by area, and Lake Michigan is the largest lake that is entirely within one country. The southern half of the Great Lakes is surrounded by the Great Lakes Megalopolis. The Great Lakes began to form at the end of the last glacial period around 14,000 years ago, as retreating ice sheets carved basins into the land and they became filled with meltwater. The lakes have been a major highway for transportation, migration and trade, and they are home to a large number of aquatic species. Many invasive species have been introduced due to trade, and some threaten the region\’s biodiversity.
Contaminated sediments are a significant problem in the Great Lakes basin. Although significant progress over the past 20 years has substantially reduced the discharge of toxic and persistent chemicals to the Great Lakes, persistent high concentrations of contaminants in the bottom sediments of rivers and harbors have raised considerable concern about potential risks to aquatic organisms, wildlife, and humans. As a result, advisories against fish consumption are in place in most locations around the Great Lakes.
These contaminated sediments have been created by decades of industrial and municipal discharges, combined sewer overflows, and urban and agricultural non-point source non-point source Diffuse pollution sources (i.e., without a single point of origin or not introduced into a receiving stream from a specific outlet). The pollutants are generally carried off the land by storm water. Common nonpoint sources are agriculture, forestry, urban, mining, construction, dams, channels, land disposal, saltwater intrusion, and city streets, Runoff Water that flows off land into lakes and streams. Buried contaminants posing serious human and ecological health concerns can be dredged up by storms, ship propellers, and bottom-dwelling organisms. Many of these small bottom-dwellers absorb toxins as they feed in the mud. As larger animals eat these smaller animals, the toxins move up the food chain, with their concentrations getting higher, often thousands of times higher. Fish at the top of the food chain, such as lake trout and salmon, can be unsafe to eat in some areas because of the heavy concentrations of toxic substances in their tissues. Fish-eating birds, including the bald eagle, may suffer low reproductive rates or produce offspring with birth defects.
While the problem of contaminated sediments persists in the Great Lakes, efforts are being made in the pursuit of remediating these contaminated sediments. In the years 1997 through 2007, 5.5 million cubic yards of contaminated sediments have been remediated in the U.S. Great Lakes Basin.
Another primary reason for water pollution in the Great Lake is due to the use of pesticides in agricultural areas. A large percentage of all of pollution in the United States comes from nonpoint source pollution. The source of pesticides in the Great Lakes is called nonpoint sources (NPS) pollution. Can refers to either water or air pollution. NPS source water pollution is more common in the Great Lakes. The pollution from the pesticides is caused due to the agricultural areas around the Great Lakes.
The NSP pollution is transported into the Great Lakes when water from rainfall, snowmelt or irrigation runs through the ground into the soil that was exposed to pesticides. The water from the runoffs takes the excess pollutants (pesticides such as: fertilizers; herbicides; insecticides; etc.) lead the pollutants directly into the Great Lakes. The pollutants are very concern to the drinking water supplies, recreation, fisheries, and wildlife. “Many toxic substances tend to bio accumulate as they pass up the food chain in the aquatic ecosystem” (epa.gov/Greatlakes).
Another problem faced in Great Lakes is the invasive species. An invasive species is a plant or animal that is foreign to an ecosystem. During the past two centuries, invasive species have significantly changed the Great Lakes ecosystem. These changes have greatly affected the economy, health, and wellbeing of the people that rely on the system for food, water, and recreation. Once established, it is extremely difficult to control their spread.
At least 25 invasive species of fish have entered the Great Lakes since the 1800s, including:
Alewife, A small silver-colored fish that is not native to Lake Erie.
Spiny water flea
The Great Lakes have also been troubled by fast-growing invasive plants, which displace the native plants that support wildlife habitat and prevent erosion. These include:
Reed canary grass
o Ballast Water Regulation
Ballast water is taken onto or discharged from a ship as it loads or unloads its cargo, to accommodate the ship\’s weight changes.
Thirty percent of invasive species in the Great Lakes have been introduced through ship ballast water. In the early 1990s, the U.S. Coast Guard began requiring ships to exchange their ballast water, or seal their ballast tanks for the duration of their stay. The Coast Guard later used their success in the Great Lakes to develop a ballast management program for the entire nation. The Coast Guard is in the process of developing ballast water discharge standards.
o Preventing Potential Invaders
Based on the problems caused by invasive species, scientists are also closely watching other species that have invaded nearby ecosystems. Asian carp are of particular concern because they have been found in nearby waterways that eventually connect to the Great Lakes. In 2004, EPA and other state and local agencies began construction of a permanent electric barrier to prevent the fish from entering Lake Michigan.
EPA is also studying how existing invasive species have become established in the Great Lakes. These studies will help develop new techniques to predict future invasions.
Clean water is fundamental to the health of the Great Lakes. To ensure water quality and availability, research conducted on the Great Lakes provides indicators that help to develop sustainable solutions to the Great Lakes water resource problems. The Great Lakes National Program Office (GLNPO) coordinates U.S. efforts with Canada under the Great Lakes Water Quality Agreement (GLWQA) to restore and maintain the chemical, physical and biological integrity of the Great Lakes Basin Ecosystem, which includes Lakes Superior, Michigan, Huron, Erie, and Ontario. GLNPO brings together federal, state, tribal, local, and industry partners under the strategic framework of the Great Lakes Restoration Initiative (GLRI) to accomplish the objectives of GLRI action plan which in turn fulfills the aims of the GLWQA.
The agenda of these organizations is to:
Remediate contaminated sediments under the Great Lakes Legacy Act;
Prevent pollution and work to reduce persistent toxic chemicals, as well as to identify emerging contaminants;
Identify, protect, and restore important habitats;
Monitor and report on environmental status and trends;
Provide assistance for community-based Remedial Action Plans for Areas of Concern and for Lake wide Management Plans;
Use our funding to assist Great Lakes partners through grants, interagency agreements, and contracts, and
Coordinate and communicate with a wide variety of partners to achieve environmental progress.
Great Lakes Restoration Initiative:
The Great Lakes Restoration Initiative is the largest investment in the Great Lakes in two decades. A task force of 11 federal agencies developed an action plan to implement the initiative. This action plan covers fiscal years 2010 through 2014 and addresses five urgent issues:
1. Cleaning up toxics and areas of concern;
2. Combating invasive species;
3. Promoting nearshore health by protecting watersheds from polluted run-off;
4. Restoring wetlands and other habitats; and
5. Tracking progress and working with strategic partners.
The project was developed to assist in demonstrating community based approach to improve quality of rivers in Malaysia. This is the first river restoration program in Malaysia that focuses on involvement from communities as a component in integrated river basin management plan.
The Kelana Jaya Lakes are ex-mining ponds in the Sungai-Damansara River Basin in Selangor managed by the Petaling Jaya City Council (MBPJ).They were initially managed solely as flood retention areas until they were developed as a public park in 1996.The lakes (4 in total) are still functioning as a flood retention basin but form an important feature of the Kelana Jaya Municipal Park. The lakes are also a popular spot for anglers.
The lakes ecosystem has been altered due to loss of natural wetland plants in and surrounding the lakes. They have been replaced with rock, concrete or landscaping plants during the Park development and the catchment areas around the lakes have been developed for housing and commercial centers. In 1998, the Lebuhraya Damansara Puchong was build adjacent to the park.
As a result of these changes, the water quality of the lakes declined. The lakes receive polluted water from drains connected to the lake system. This has led to major loss of local fish species which are sensitive to pollution. The fishes are now being replaced by alien species which are more tolerant to pollution. Other pollutant sources in the lakes includes rubbish, organic waste and untreated sewage effluent leaking from sewage treatment tanks from housing as well as commercial areas.
The project has met encouraging local citizen support. Petaling Jaya City Council alongside the local citizen is aiming to achieve these goals in the Kelana Jaya Lake Restoration project:
To reduce the level of pollution flowing into the lakes.
To increase community awareness.
Rehabilitating biodiversity of the lake.
To stop the pollution source from entering the lake system by Informing the community about the importance of re-establishing a more natural ecosystem which can provide better habitats for wildlife.
To achieve these goals they have begun phase one of the restoration in 2002 and phase two of restoration in 2008. The restoration activities in phase two consist of:
1. Aquatic Vegetation restoration
2. Non-native animal species control
3. Decaying vegetation removal
4. Litter control and floating vegetation management
Tangible impact of these activities result in solid waste and wastewater from storm drains were reduced by 60 percent and the quality of discharge from oxidation pond improved after refurbishment work was carried out. Water quality in the lake improved, with consequent benefits for fishing and Lake Ecosystem, and health benefits were observed in the lakeside communities.
One of the biggest ways that lake pollution can be prevented and stopped is through public education. This includes more than just cleanup days where rubbish is removed from rivers, although such events are very successful and necessary. Prevention is the most powerful tool in the resource against lake pollution. Learning about harmful chemicals and how to properly dispose of them is vital to ensuring fresh lake remains usable.
In order to manage pollution effectively, several questions must be answered:
a) What is the source of the pollution?
b) How much pollution is occurring?
c) What is the projected lifetime of the pollution?
d) What are the expected effects of the pollution?
Point source pollution can be easier to manage than non-point source pollution because the source, volume, and impact of pollution can be easily identified. Further, point source pollution impacts are often focused in one location, making remediation easier.
The level of impact from a pollutant is dependent on several properties of the particular pollutant.
First, its level of toxicity is an important consideration; some pollutants such as PCBs are highly toxic, meaning only a small amount is enough to harm humans and other organisms. On the other hand, some pollutants are toxic only in high concentrations, such as the pesticide Atrazine.
The amount of a particular pollutant in the environment is also an important factor regulating its effects. For example, if a particular chemical is only mildly toxic to fish, yet is found in the environment in high amounts because of a widespread application, it can be very harmful.
Finally, the lifetime of a pollutant – the length of time it is expected to stay in the environment – is another vital factor. Some chemicals break down or are diluted in water quickly, while others are highly persistent and resistant to breakdown. Examples of long-lived pollutants include chemicals DDT, PCBs, and mercury; these chemicals are highly resistant to degradation and can remain for decades after their release has stopped. For example, studies from the Great Lakes in the U.S. and other important lakes show that while the release of these toxic pollutants had decreased their levels in fish and other aquatic organisms have actually increased because they stay in the environment and accumulate in fish over long periods of time. Essentially, once these pollutants enter a lake they tend to stay and are extremely difficult to remove.
Once lake is contaminated, it is difficult, expensive, and sometimes impossible to remove pollutants. Preventing pollution is obviously important. Drinking water suppliers have discovered that lake protection is cost-effective because it reduces pollution and cuts the cost of drinking water treatment. Through a combination of government intervention and increased awareness of the importance and fragility of freshwater resources, pollution can be effectively managed in the future.
There are many difficulties faced while observing the results of lake restoration projects and basically lake restoration also includes a high proportion of trial and error, in which the means for a successful recovery is still largely uncertain. Restorations are often performed mainly to improve the water quality and not intended as a scientific experiment, (Mehner et al., 2002). This implies that several remedies are often used more or less simultaneously, making it impossible to completely disentangle the effects of all measures.
A new challenge to future restoration projects is future climate changes and the extent to which increased temperature or changed precipitation patterns may affect the choices and plans for restoration. There are several signs that climatic changes will increase the risk of eutrophication and thus counteract restoration measures and destabilize the macrophyte-dominated clear-water state in coastal north temperate lakes (Mooij et al. 2005; Jeppesen et al. 2007): higher precipitation will increase the external nutrient loading and higher temperatures might improve the conditions for Zooplanktivorous fish species such as carp Cyprius carpio and other cyprinids, and in combination this may reduce the possibility of obtaining top-down control of phytoplankton.
Lake restoration can be recommended to improve water quality of eutrophic and shallow lakes considerably. Long-term effects (more than 5–10 years) can, however, be difficult to achieve, and in many cases lake restoration may need to be conducted on a regular basis to maintain positive effects. Therefore lake restoration in relatively nutrient-rich lakes should probably be perceived as a management tool rather than a ‘once and for all’ solution.
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