Lecture 10. surface waters
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Surface waters include streams, rivers, lakes, wetlands and oceans. They can become polluted from a variety of sources, both point sources like wastewater treatment plants and non-point sources like agricultural runoff. Common surface water pollutants include nutrients, pathogens, toxins, sediments and oxygen-depleting substances which can harm aquatic life and contaminate drinking water sources. Governments establish regulations and standards to monitor surface water quality and limit pollution. Reducing surface water pollution will require efforts from governments, industries and individuals.
Lecture 10. surface waters
- 2. WHAT ARE SURFACE WATERS? Water collected on the ground as in streams, rivers, lakes, wetland or oceans are surface waters.
- 3. WET SURFACE LANDS WATERS STREAMS LAKES RIVERS OCEAN
- 5. Basic Information on Surface-Water Quality and Quantity
- 6. Surface-Water Quality Parameters • Physical Parameters Color, odor, temperature, solids (residues), turbidity, oil content, and grease content. • Chemical Parameters - Organic Content: BOD, COD, TOC, TOD - Inorganic Content: salinity, hardness, pH, acidity, alkalinity, presence of substances. • Biological Properties - Bacteriological parameters: coliforms, fecal coliforms, specific pathogens, and viruses.
- 7. Two Main Sources of Water Pollutants • Non-point Sources • Point Sources • SURFACE-WATER POLLUTION – excessive concentrations of particular substances for sufficient periods of time to cause identifiable effects.
- 8. Surface-Water Contaminants • SUSPENDED SOLIDS - development of sludge deposits • BIODEGRADABLE ORGANICS - depletion of natural oxygen resources and septic conditions • PATHOGENS - communicable diseases • NUTRIENTS - lead to growth of undesirable aquatic life • PRIORITY POLLUTANTS - carcinogenicity, mutagenicity, teratogenicity, or high acute toxicity
- 9. • HEAVY METALS - may have to be removed if the wastewater is to be reused • DISSOLVED INORGANICS - may have to be removed if the wastewater is to be reused
- 10. • Legislations Pertaining to Surface- Water Quality
- 11. Philippine Surface Water • Surface freshwater resources are found in rivers and lakes. • There are 421 principal river basins in 119 proclaimed watersheds, 19 of which are identified as major river basins. • The largest lakes in the principal islands are the Laguna de Bay Lake Lanao in Mindanao, which is a major source of hydropower. • The potential supply from surface water sources is estimated at 125,790 mcm per year. • Philippines ranks among the lowest in terms of freshwater availability per capita at 1,907 cubic meters, compared with the average of 7,045 cubic meters worldwide and 3,668 cubic meters in Asia • The National Water Resources Board ("NWRB") is the lead government agency in the Philippine water sector, conferred with policy-making, regulatory and quasi-judicial functions
- 12. Water Quality regulations (surface water) • Standards are set for water quality management • PD 1152 (1977)/DAO 34(1993)
- 13. CAUSES OF SURFACE WATER POLLUTION
- 14. Cause of Impairment Potential Source of Pollution Sediment Construction and mining sites, disturbed land areas, streambank erosion and alterations, cultivated farmland Nutrients Fertilizer on agricultural, residential, commercial and recreational lawns, animal wastes, effluent from aquaculture facilities, leaky sewers and septic tanks, atmospheric deposition, municipal wastewater Toxic and Synthetic Pesticide applications, disinfectants (chlorine), automobile fluids, Chemicals accidental spills, illegal dumping, urban stormwater runoff, industrial effluent Oxygen-Consuming Wastewater effluent, organic matter, leaking sewers and septic tanks, Substances animal waste Fecal Coliform Bacteria Failing septic tanks, animal waste, runoff from livestock operations, wildlife, improperly disinfected wastewater effluent Road Salt Applications to snow and ice Oil and Grease Leaky automobiles, industrial areas, illegal dumping Salinity Variations Hydrological modifications that influence the amount of fresh or saline waters entering a system Thermal Impacts Heated landscape areas, runoff from impervious areas, tree removal along streams, wet detention ponds
- 15. Fecal Coliform Bacteria • Fecal coliform bacteria are typically associated with the intestinal tract of warm-blooded animals. They are widely used as an indicator of the potential presence of waterborne pathogenic, or disease-causing, bacteria and viruses (e.g., those which cause such diseases as typhoid fever, dysentery, and cholera) because they are easier and less costly to detect than the actual pathogens.
- 16. Toxic Substances • any substance or combination of substances which after discharge and upon exposure, ingestion, inhalation, or assimilation into any organism, either directly from the environment or indirectly by ingestion through food chains, has the potential to cause death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions (including malfunctions or suppression in reproduction or growth) or physical deformities in such organisms or their offspring or other adverse health effects".
- 17. • Dioxin • Metals • Chlorine • Ammonia (NH3)
- 18. Oxygen-Consuming Wastes •Oxygen-consuming wastes include decomposing organic matter or chemicals which reduce dissolved oxygen in the water column through chemical reactions or biological activity. Sources of dissolved oxygen depletion include wastewater treatment plant effluent, the decomposition of organic matter (such as leaves, dead plants and animals) and organic waste matter that is washed or discharged into the water. Sewage from human and household wastes is high in organic waste matter, as is waste from trout farms. Bacterial decomposition can rapidly deplete dissolved oxygen levels unless these wastes are adequately treated at a wastewater treatment plant.
- 19. Nutrients • The term nutrients in this document refers to two major plant nutrients, phosphorus and nitrogen. These are common components of fertilizers, animal and human wastes, vegetation, effluent from aquaculture facilities and some industrial processes. Nutrients in surface waters come from both point and nonpoint sources. Nutrients are beneficial to aquatic life in small amounts. However, in over-abundance and under favorable conditions, they can stimulate the occurrence of algal blooms and excessive plant growth in quiet waters such as ponds, lakes, reservoirs, creeks, rivers and estuaries.
- 20. Effects of Salinity • in salinity as little as 2-3 ppt above current levels have the potential to drastically affect the abundance of many species of submerged aquatic vegetation (SAV). The overall abundance and diversity of species of SAV have been key factors in maintaining the rich natural resources . significant declines in SAV in the sound have coincided with declines in the largemouth bass populations and in wintering waterfowl populations that depend on it for food.
- 21. Sedimentation • Sedimentation is the most widespread cause of nonpoint source pollution in the state and results from land- disturbing activities including agriculture, building and highway construction, uncontrolled urban runoff which erodes streambanks, mining and timber harvesting. The concentration of suspended sediments affects the availability of light for photosynthesis, as well as the ability of aquatic animals to see their prey.
- 22. Point Sources • Point sources refers to discharges that enter surface waters through a pipe, ditch or other well-defined point of discharge. Wastewater point source discharges include municipal (city and county) and industrial wastewater treatment plants and small domestic wastewater treatment systems that may serve schools, commercial offices, residential subdivisions and individual homes. The primary pollutants associated with point source discharges are oxygen-demanding wastes, nutrients, sediment, color and toxic substances including chlorine, ammonia and metals.
- 23. Non – Point Source • Nonpoint source (NPS) pollution refers to runoff that enters surface waters through stormwater, snowmelt or atmospheric deposition (e.g., acid rain). There are many types of land use activities that can serve as sources of nonpoint source pollution including land development, construction, mining operations, crop production, animal feeding lots, timber harvesting, failing septic systems, landfills, roads and parking lots.
- 27. • Agriculture • Urban/Residential • Onsite Wastewater Disposal • Construction • Timber Harvesting • Mining • Solid Waste Disposal
- 29. CONCLUSION Clearly, the problems associated with water pollution have the capabilities to disrupt life on our planet to a great extent. Congress has passed laws to try to combat water pollution thus acknowledging the fact that water pollution is, indeed, a seriousissue. But the government alone cannot solve the entire problem. It is ultimately up to us, to be informed, responsible and involved when it comes to the problems we face with our water. We must become familiar with our local water resources and learn about ways for disposing harmful household wastes so they don?t end up in sewage treatment plants that can?t handle them or landfills not designed to receive hazardous materials. In our yards, we must determine whether additional nutrients are needed before fertilizers are applied, and look for alternatives where fertilizers might run off into surface waters. We have to preserve existing trees and plant new trees and shrubs to help prevent soil erosion and promote infiltration of water into the soil. Around our houses, we must keep litter, pet waste, leaves, and grass clippings out of gutters and storm drains.
- 30. These are just a few of the many ways in which we, as humans, have the ability to combat water pollution. As we head into the 21st century, awareness and education will most assuredly continue to be the two most important ways to prevent water pollution. If these measures are not taken and water pollution continues, life on earth will suffer severely. Global environmental collapse is not inevitable. But the developed world must work with the developing world to ensure that new industrialized economies do not add to the world's environmental problems. Politicians must think of sustainable development rather than economic expansion. Conservation strategies have to become more widely accepted, and people must learn that energy use can be dramatically diminished without sacrificing comfort. In short, with the technology that currently exists, the years of global environmental mistreatment can begin to be reversed.
- 31. ITS A CHOICE