NEC - Element 5 - Control of July 2014 Learning outcomes NEBOSH Certificate in Environmental Management 5.1 Outline the importance of the quality of water for life 5.2 Outline the main sources of water pollution 5.3 Outline the main control measures that are available to reduce 1 1 4 Element 5 Control of 2 2 5 Licence details RMS Publishing Victoria House, Lower High Street, Stourbridge DY8 1TA RMS Publishing. Third Edition June 2013. All rights reserved. No part of this presentation may be stored in a retrieval system, reproduced, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without either the prior written permission of the Publishers. This presentation may not be lent, resold, hired out or otherwise disposed of by way of trade in any form other than that in which it is published, without the prior consent of the Publishers. Whilst every effort is made to ensure the completeness and accuracy of the information contained herein, RMS can bear no liability for any omission or error. Issued to: Single Licence Licence No: 3 6 Sample of PowerPoint presentation for NEBOSH National Certificate in Environmental Management 1
NEC - Element 5 - Control of July 2014 Safe drinking water may be defined as water of sufficiently high quality (meeting international or national standards) that it can be available for human consumption and used without risk of immediate or long term harm Most common contamination is from human sewage Cholera, typhoid and diarrhoea were reduced significantly Exposure to high levels of toxic compounds fluoride and arsenic Water quality is concerned with three main classifications of contaminants: Physical Chemical Microbiological 7 10 8 Fluoride (F) contamination Source: AST. 11 Water is present on the planet in all three of its phases; that is as a solid, liquid and gas Water vapour is found within the atmosphere The oceans store most of the water in liquid phase The poles and high alpine regions store water in solid form as ice and snow Water moves between each of these three stores and it does this by processes such as: Evaporation Condensation Melting and freezing Arsenic (As) contamination Water moves between each of these three stores and it does this by processes such as: Evaporation Condensation Melting and freezing Known as the hydrological cycle Source: U.S. Geological Survey. Source: AST. 9 12 Sample of PowerPoint presentation for NEBOSH National Certificate in Environmental Management 2
NEC - Element 5 - Control of July 2014 Over 97% of all water on Earth is salt water Of the 3% that is fresh water, 77.5% is inaccessible in the ice caps and glaciers The atmosphere, rivers, lakes and underground stores hold less than 1% The largest volumes of freshwater are held in the Great Lakes of North America Water is also stored in its liquid phase in the ground and this is called groundwater Growth in world population 1804 2011 Source: RMS. 13 16 Block diagram of the catchment basin system Division of world population Division of world population Population circa 2011 World total 7 Developed North America, Canada, Europe, Asia: Russia 1.24 Less developed South Americas, Middle East, China, India Bangladesh 5.73 Least developed South East Asia: Afghanistan, Burma, Laos, Thailand, Cambodia, Central Africa 851 million Source: RMS. 14 15 17 Source: Environmental systems; I D White; 1984. Groundwater Global water supplies As the world's population reaches seven on the 31st October 2011, the United Nations (UN), Population Fund's State of World Population 2011 report, warns that the planet's water resources will come under intense pressure over future generations Groundwater is a source of water located beneath the earth's surface in rock fractures and soil pore spaces Where such water is accessible they are known as aquifers Groundwater is recharged from the surface from melting ice and rainfall Springs are the result of groundwater exiting from below the soils surface; many rivers and lakes may be fed with groundwater in a similar way Groundwater also helps maintain flows in rivers, streams and wetlands, supporting valuable wildlife habitats Source: Associated Press. 18 Sample of PowerPoint presentation for NEBOSH National Certificate in Environmental Management 3
NEC - Element 5 - Control of July 2014 Water for agriculture and industry Surface water Is water collecting on the ground or in a river, lake, manmade reservoir wetland or ocean Surface water is naturally replenished by rainfall, snow and melting ice Surface water is readily lost through evaporation to the atmosphere or seepage into porous ground or rock (groundwater) Industry The annual water volume used by industry is estimated (UNFAO) to rise to 1,170 km 3 per year in 2025 In 2025 the industrial component is expected to represent about 24% of total freshwater withdrawal Water withdrawals for industry vary with the level of development: Worldwide: 22% of total water use High income countries: 59% of total water use Low income countries: 8% of total water use 19 22 Impact of water pollution on wildlife Desalination Refers to processes used to remove salts from water, such as sea water and high levels of salt from land Uses very energy intensive processes Usually only used when freshwater is unavailable or in limited supply The need to produce water by desalination is increasing daily Desalination is carried out using two main techniques: 1. Vacuum distillation 2. Reverse osmosis Water pollutants Too much of something in the wrong place There are many potential water pollutants Pollutants come in many forms and each has an effect on one or more aspects of the complex eco system Marine and freshwater life is particularly susceptible to chemical pollution or Biochemical Oxygen Demand (BOD) overload 20 23 Water for agriculture and industry Over abstraction; water conservation; balancing the different needs Agriculture According to the UNFAO almost 70 percent of all available freshwater is used for agriculture Pumping of groundwater by the world's farmers exceeds natural replenishment by at least 160 cubic metres per year It takes an enormous amount of water to produce crops Many of the world's most important grain producing lands are consuming groundwater at unsustainable rates Industrial revolution in 1800 s created a major change in demand for fresh water The demand for fresh water has continued to grow exponentially Irrigation for agriculture uses the greatest amount of water Over extraction of groundwater resources in the last century has resulted in their depletion in many areas of the world 21 24 Sample of PowerPoint presentation for NEBOSH National Certificate in Environmental Management 4
NEC - Element 5 - Control of July 2014 Surface water drainage and risks of contamination from spills Surface water will include rainwater or any deliberate discharges to the ground Rainwater which falls onto a site will be liable to contamination from any work process being carried out Contamination can occur from roof ventilation exhaust extraction equipment Rainwater falling onto equipment, stored materials and the general ground areas and roadways may also become contaminated Deliberate discharges of water will be in addition to rainwater, for example, the use of jet washing equipment for vehicle cleaning or general washing down 25 28 Direct sources Drainage from mining, quarrying and ore processing Include: Effluent outfalls from factories Refineries Waste treatment plants etc Which emit fluids of varying quality directly into urban water supplies The major risks linked to mining waste for the environment are two fold: Contamination of soil, groundwater, surface water and air from acidity and heavy metal contamination The direct impact on local targets such as humans, animals, flora and aquatic life in the surrounding area 26 29 Indirect sources Include contaminants that enter the water supply from: Soils/groundwater systems The atmosphere via rain water Soils and groundwater contain the residue of human agricultural practices and improperly disposed of industrial wastes Atmospheric contaminants are also derived from human practices Contaminants can be broadly classified into organic, inorganic, radioactive and acid/base Part only of the complete Element 5 Control of 27 30 30 Sample of PowerPoint presentation for NEBOSH National Certificate in Environmental Management 5