PREDICTION AND ASSESSMENT OF IMPACTS – SURFACE WATER ENVIRONMENT (SWE)

1. PREDICTION AND ASSESSMENT OF IMPACTS – SURFACE WATER ENVIRONMENT (SWE)

2. INTRODUCTION SWE • EXAMPLES OF PROJECT WHICH CREATE IMPACT ON SWE • Industrial plants or power plants withdrawing surface water for use as cooling water • power plants discharging heated wastewater – industries discharging process wastewater • Municipal WWTP • dredging projects • project involving fill or creation of fast lands along rivers, lakes, estuaries and coastal areas • surface mining projects • construction of dams • River channelization projects • deforestation and agricultural development • commercial hazardous • waste disposal sites • tourism projects

3. BASIC INFORMATION ON SW QUANTITY & QUALITY SURFACE WATER HYDROLOG

4. SW QUALITY PARAMETERS Surface water comprises - rainfall, runoff, base flow • Each of this input components can affect water quality • Rainfall – acid rain (industrialized area), Runoff – Nutrients and sediments- base flow – elevated levels of hardness • Human activities – increase the pollutant loads to this inputs • Discharge of wastewater – increase organic load in surface water • Construction activities – increased erosion and sediment load • Surface water pollution can be defined as – Excessive conc. Of particular pollutant for sufficient periods of time to cause identifiable effects • Water quality defined as in terms of physical, chemical and biological characterization of water • Physical parameters include : color, odur, temp. solids, turbidity, oil and grease • Each physical parameter can be broken down into sub categories TS DS SS VSS FSS DVSS DFSS

5. SW QUALITY PARAMETERS • SWPI – associated with construction project – two main sources of water pollutant should be considered • NON POINT: referred as “area” or “diffuse” sources • It reffer to those substances which can be introduced into receiving waters as a result of urban-area, industrial-area or rural runoff • POINT: related to specific discharges from municipalities or industrial complexes • E.g. organics enter in to surface water as a result of discharge from a manufacturing plant

6. GENERAL CHARACTERISTICS OF NP • NP – discharges enter surface water in a diffuse manner and at intermittent intervals- related to meteorological events • Pollution arise over extensive area of land and it travels via transit land before enter in SW • It can’t be monitored at the point of origin and exact source is difficult or impossible to trace • Elimination or control of these pollutants must be directed at specific sites • Most effective and economic controls are land management techniques and conservation practices

7. The effect of pollutant • Depends upon conc. and type of pollutant. • Soluble organics (BOD)- decrease DO, biomagnified • SS – water clarity, decrease photosynthesis, settled SS for sludge bed- affect benthic ecosystem • N and P – Eutrophication • Chloride – cause salty taste in water • Acids, alkalis, toxic substances – toxic to fish and other aquatic organisms • Thermal – imbalance and reduction in waste assimilative capacity