Aesthetic Effects

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EFFECT ENVIRONMEN T Eutrophication Decrease in dissolved oxygen level Increase turbidity and decrease in water clarity Decrease in water quality

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Transcript of Aesthetic Effects

AESTHETIC EFFECTS

EFFECTENVIRONMENT Eutrophication Decrease in dissolved oxygen level Increase turbidity and decrease in water clarity Decrease in water qualityENVIRONMENT Soil and crop yields Long run effect on quality of underground water EFFECT2EFFECT HUMAN & OTHER LIVING ORGANISMDamage and loss of aquatic species Contaminated drinking water Loss of habitat due to eutrophication Disease-related impact on fish that may impact human health PREVENTIONWaste Stabilization Pond A waste stabilization pond makes use of natural purification processes involved in an ecosystem through the regulating of such processes. The term "waste stabilization pond" in its simplest form is applied to a body of water, artificial or natural, employed with the intention of retaining sewage or organic waste waters until the wastes are rendered stable and inoffensive for discharge into receiving waters or on land, through physical, chemical and biological processes commonly referred to as "self-purification" and involving the symbiotic action of algae and bacteria under the influence of sunlight and air. Organic matter contained in the waste is stabilized and converted in the pond into more stable matter in the form of algal cells which find their way into the effluent and hence the term "stabilization pond"PREVENTION

Carp Fish One of the way to make sure that the secondary water treatment effluent are safe to discharged to the open water. Some country such as Japan has implement this prevention ways.

Steps to Prevent Sewage Pollution in your neighborhoodSewer overflows and backups can cause health hazards, damage home interiors, and threaten the environment. Sewage pollution gets into our local creeks when it escapes the sewage system. Following steps helps you to reduce sewer overflow in your apartment or neighborhood.Tree roots can invade even the smallest cracks in pipes. Tree roots can block the pipes causing sewers to backup and overflow. Careful thought needs to be given to the location of thirsty trees.Use basket/strainers in sinks to catch food scraps and empty them into trash for disposal.Cracked pipes have to be repaired or replaced.Broken sewer pipes not only let stormwater in, they can also allow untreated waste to enter the soil and create unhealthy conditions. If you suspect broken pipes, have your system inspected by a licensed plumber.Stormwater downpipes are not allowed to be connected to the sewerage system. The effect of doing so is overflows of diluted raw sewage further down the system. This is a major cause of sewer overflows.People pouring grease down sewer lines are other common reasons for sewage overflows. Never pour grease down sink drains or into toilets.Using contaminated sewage for fertilizer can result in epidemics of such diseases as cholera. These diseases can even become chronic where clean water supplies are lacking.

Water is polluted when it constitutes a health hazard or when its usefulness is impaired. The major sources of water pollution are municipal, manufacturing, mining, steam, electric power, cooling and agricultural. Municipal or sewage pollution forms a greater part of the man's activity and it is the immediate need of even smaller communities of today to combat sewage pollution. It is needless to stress that if an economic balance of the many varied services which a stream or a body of water is called upon to render is balanced and taken into consideration one could think of ending up in a wise management programme. In order to eliminate the existing water pollutional levels of the natural water one has to think of preventive and treatment methods. Of the various conventional and non-conventional methods of sewage treatment known today, in India, where the economic problems are complex, the waste stabilization ponds have become popular over the last two decades to let Public Health Engineers use them with confidence as a simple and reliable means of treatment of sewage and certain industrial wastes, at a fraction of the cost of conventional waste treatment plants used hitherto. A waste stabilization pond makes use of natural purification processes involved in an ecosystem through the regulating of such processes. The term "waste stabilization pond" in its simplest form is applied to a body of water, artificial or natural, employed with the intention of retaining sewage or organic waste waters until the wastes are rendered stable and inoffensive for discharge into receiving waters or on land, through physical, chemical and biological processes commonly referred to as "self-purification" and involving the symbiotic action of algae and bacteria under the influence of sunlight and air. Organic matter contained in the waste is stabilized and converted in the pond into more stable matter in the form of algal cells which find their way into the effluent and hence the term "stabilization pond"Use of untreated sewage water pose a high risk to human health and other living organisms.Wastewater contain salts that may accumulate in the root zone with possible harmful impacts on soil health and crop yields.Wastewater application has the potential to affect the quality of groundwater resources in the long run through excess nutrients and salts.When drainage water drains particularly into water bodies and surface water the remains of nutrients may cause eutrophication.Natural resource concerns such as pollution of vital water resources, loss of fish, wildlife, exotic species, etc.

How do nutrients from wastewater treatment enter waterways?Wastewater contains inorganic and organic nutrients and suspended solids. These can pollutewaterways if left untreated and affect invertebrate and mahinga kai communities. Groundwaters and surface water may be contaminated if their assimilative capacity is exceeded or nutrients are flushed down the drain. Treatment plants that purify water to a high standard (tertiary treatment) can minimise the risks of harm to waterways. Landfills also can produce leachate which can escape into waterways when rainfall picks up decomposing organic wastes.Potential impacts of high nutrients on water quality and mahinga kai

Eutrophication - excess nutrients in lakes, estuaries, or slow-moving streams and rivers can lead to an increase in primary productivity which stimulates excessive plant growth (algae and nuisance plants and weeds), thereby degrading water quality.Loss of species - an increase in plant growth, sometimes called an algal bloom, reduces dissolved oxygen (DO) in the water when dead plant material decomposes and can cause organisms (fish and invertebrates) to die.Loss of habitat - eutrophication of the water can kill off plants that fish depend on for their habitat.Increase in turbidity and a decrease in visibility - when the phytoplankton community increases in response to nutrients this reduces water clarity, visibility and recreational suitability. It also reduces the ability of some fish to see prey or predators.What are the impacts of infectious substances in wastewater on water quality and mahinga kai?Wastewater dischargescontain pathogenic micro-organisms. Surface and groundwaters can easily become contaminated by pathogens when effluent is discharged to a waterway or is discharged/deposited onto land near waterways. Treatment plants that purify water to a high standard (tertiary treatment) can minimise the risks of harm to waterways. Disinfection of wastewater prior to discharging into the environment greatly reduces the impact of pathogens.Potential impacts of infectious substances on water quality and mahinga kaiA decrease in water quality.Contamination of water and mahinga kai, especially shellfish, downstream of the discharge (source) that makes it unsuitable for harvesting (fishing or food gathering).Water becomes unsuitable for swimming or recreational use.Greater probability of disease-related impacts on fish populations.

Chemical contamination and wastewaterWhat are the potential sources of chemical contaminants in wastewaters?Wastewater contains heavy metals and potentially hazardous wastes. These can contaminate a waterwayif left untreated and affect invertebrate and mahinga kai communities. Ground and surface waters may be contaminated if their assimilative capacity is exceeded or contaminants are flushed down the drain. Treatment plants that purify water to a high standard (tertiary treatment) can minimise the risks of harm to waterways. However, decomposing waste in landfills generates methane, a harmful greenhouse gas. Landfills also can produce leachate which can escape into waterways when rainfall picks up heavy metals and decomposing organic wastes.Potential impacts of chemical contaminants on water quality and mahinga kaiLocal loss of fish species - fish may be harmed by contaminated water. Discharges and runoff into waterways can be lethal to aquatic life, causing fish kills from contaminants such as pesticides.Local loss of invertebrate species - invertebrates are food for fish and persistent discharges that kill invertebrates could cause fish to travel farther in search of food, exposing them to greater risks and stress.Decrease in dissolved oxygen (DO) levels - waste compounds released into waterways initiate biochemical reactions that use up oxygen as the naturally present bacteria break down the organic matter (Biogeochemical Oxygen Demand, BOD). Excess nutrients can also lead to algal blooms and oxygen is used up when the algae die and decompose. Fish breath oxygen through their gills; a decrease in available oxygen (anoxia) in the water column threatens their ability to respire, which may lead to death. Fish that tolerate low levels of dissolved oxygen (such as the introduced species gambusia) may replace native populations that are less tolerant.Increase turbidity and decrease in water clarity - water becomes cloudy and coloured green and brown, which reduces the ability of fish to see prey and detect predators.Damage to species - repeated exposure to sub-lethal doses of some contaminants can cause physiological and behavioural changes in fish that have long term effects on the population, such as reduced reproductive success, abandonment of nests and broods, a decreased immunity to disease, tumours and lesions, impairment of the central nervous system, and increased failure to avoid predators.

Aesthetic Effects

Odor and Taste are useful indicators of water quality even though odor-free water is not necessarily safe to drink. Odor is also an indicator of the effectiveness of different kinds of treatment. However, present methods of measuring taste and odor are still fairly subjective and the task of identifying an unacceptable level for each chemical in different waters requires more study. Also, some contaminant odors are noticeable even when present in extremely small amounts. It is usually very expensive and often impossible to identify, much less remove, the odor-producing substance.

Standards related to odor and taste: Chloride, Copper, Foaming Agents, Iron, Manganese pH, Sulfate, Threshold Odor Number (TON), Total Dissolved Solids, Zinc.Color may be indicative of dissolved organic material, inadequate treatment, high disinfectant demand and the potential for the production of excess amounts of disinfectant by-products. Inorganic contaminants such as metals are also common causes of color. In general, the point of consumer complaint is variable over a range from 5 to 30 color units, though most people find color objectionable over 15 color units. Rapid changes in color levels may provoke more citizen complaints than a relatively high, constant color level.

Standards related to color: Aluminum, Color, Copper, Foaming Agents, Iron, Manganese, Total Dissolved Solids.Foaming is usually caused by detergents and similar substances when water has been agitated or aerated as in many faucets. An off-taste described as oily, fishy, or perfume-like is commonly associated with foaming. However, these tastes and odors may be due to the breakdown of waste products rather than the detergents themselves.

Standards related to foaming: Foaming Agents.Skin discoloration is a cosmetic effect related to silver ingestion. This effect, called argyria, does not impair body function, and has never been found to be caused by drinking water in the United States. A standard has been set, however, because silver is used as an antibacterial agent in many home water treatment devices, and so presents a potential problem which deserves attention.Standard related to this effect: Silver.Tooth discoloration and/or pitting is caused by excess fluoride exposures during the formative period prior to eruption of the teeth in children. The secondary standard of 2.0mg/Lis intended as a guideline for an upper boundary level in areas which have high levels of naturally occurring fluoride.The level of the SMCLwas set based upon a balancing of the beneficial effects of protection from tooth decay and the undesirable effects of excessive exposures leading to discoloration. Information about the Centers for Disease Control's(CDC)recommendations regarding optimal fluoridation levels and the beneficial effects for protection from tooth decay can be found on itsCommunity Water Fluoridationpage.Standard related to this effect: Fluoride.

Corrosivity, and staining related to corrosion, not only affect the aesthetic quality of water, but may also have significant economic implications. Other effects of corrosive water, such as the corrosion of iron and copper, may stain household fixtures, and impart objectionable metallic taste and red or blue-green color to the water supply as well. Corrosion of distribution system pipes can reduce water flow.Standards related to corrosion and staining: Chloride, Copper, Corrosivity, Iron, Manganese, pH, Total Dissolved Solids, Zinc.Scaling and sedimentation are other processes which have economic impacts. Scale is a mineral deposit which builds up on the insides of hot water pipes, boilers, and heat exchangers, restricting or even blocking water flow. Sediments are loose deposits in the distribution system or home plumbing.Standards related to scale and sediments: Iron, pH, Total Dissolved Solids, Aluminum.

Secondary (biological) treatmentremoves the dissolved organic matter that escapes primary treatment. This is achieved by microbes consuming the organic matter as food, and converting it to carbon dioxide, water, and energy for their own growth and reproduction. The biological process is then followed by additional settling tanks (secondary sedimentation", see photo) to remove more of the suspended solids. About 85% of the suspended solids and BOD can be removed by a well running plant with secondary treatment. Secondary treatment technologies include the basic activated sludge process, the variants of pond and constructed wetland systems, trickling filters and other forms of treatment which use biological activity to break down organic matter.