Environmental Geology - Chapter 16: Water Pollution
Environmental Geology Chapter 16 Water Pollution Overview • • • • • General Principles Industrial Pollution Organic Matter Agricultural Pollution Reversing the Damage–Surface Water Overview (cont.) • Groundwater Pollution • Reversing the Damage–Ground Water General Principles • • • • Geochemical Cycles Residence Time Residence Time and Pollution Point and Nonpoint Pollution Sources Water Pollution Figure CO16 16-1 Source:Courtesy of Carla W Montgomery Residence Time • Residence time is the average length of time a component remains in a system; for natural substances at equilibrium, residence time equals capacity divided by rate of influx For most substances in seawater, capacity is controlled by solubility The element is weathered or leached out into streams and transported into the ocean, where it remains until it is precipitated out into sediments (This is a very simple case.) Point and Nonpoint Pollution Sources Figure 16.2 16-2 Source: After USDA Soil Conservation Service • Most often, human activities increase the rate-of-influx term, either by dumping of concentrated wastes or through accelerated weathering, as of mine tailings Industrial Pollution • • • • • Inorganic Pollutants–Metals Other Inorganic Pollutants Organic Compounds Problems of Control Thermal Pollution Settling Ponds Improve Surface Water Figure 16.14A 16-16 Source: Photograph courtesy USDA Soil Conservation Service Settling Pond Below Terraced Farm Fields Figure 16.14B 16-17 Source: Photograph courtesy USDA Soil Conservation Service Reducing water pollution • Some options include: aeration to restore oxygen levels (which may increase dissolved nitrogen to harmful levels if air, rather than just oxygen, is used); placing an impermeable barrier over nutrient-rich sediment to prevent cycling of the nutrients back into the water (expensive on any significant scale); in situ decontamination, especially destruction of organic wastes by microorganisms (rather slow and not fully reliable in the case of ground water); and chemical decontamination of extracted water (surface or subsurface) (expensive but typically effective) Point-Source Pollution in the U.S Figure 16.15A 16-18 Source: Modified from U.S Water Resources Council, The Nation’s Water Resources 1975-2000, vol 1, pp 61-63 Nonpoint-Source Pollution in the U.S Figure 16.15B 16-19 Source: Modified from U.S Water Resources Council, The Nation’s Water Resources 1975-2000, vol 1, pp 61-63 Groundwater Pollution • The Surface–Ground Water Connection Explored • Damage Control by Containment–The Rocky Mountain Arsenal Groundwater Pollution Problems Figure 16.17 16-20 Source: Modified from U.S Water Resources Council, The Nation’s Water Resources 1975-2000, vol 1, p 65 Nitrate Concentrations Higher in Ag Areas Figure 16.18 16-21 Source: U.S Geological Survey National Water Quality Assessment Program Risk of Ground Water Contamination Figure 16.19 16-22 Source: B.T Nelson and B.C Buddy, 1996, Fact Sheet FS-092-96 of the U.S Geological Survey National Water Quality Assessment Program Reversing the Damage–Ground Water • In Situ Decontamination • Decontamination After Extraction Control System for Contaminated Ground Water Figure 16.21 16-23 New Technology Meets Problems from the Past: California Gulch Superfund Site, Leadville, Colorado • Materials Mined • What Happened as a Result Traverse Track Across a Tailings Pile Figure 16.23 16-24 Source: USGS Spectroscopy Lab Acidity Conditions of Metals Figure 16.24B 16-25 Source: USGS Spectroscopy Lab Airborne-Spectroscopic Scan Figure 16.25 16-26 Source: USGS Spectroscopy Lab .. .Chapter 16 Water Pollution Overview • • • • • General Principles Industrial Pollution Organic Matter Agricultural Pollution Reversing the Damage–Surface Water Overview (cont.) • Groundwater Pollution. .. Modified from U.S Water Resources Council, The Nation’s Water Resources 197 5-2 000, vol 1, pp 6 1-6 3 Nonpoint-Source Pollution in the U.S Figure 16.15B 1 6-1 9 Source: Modified from U.S Water Resources... Nation’s Water Resources 197 5-2 000, vol 1, pp 6 1-6 3 Groundwater Pollution • The Surface–Ground Water Connection Explored • Damage Control by Containment–The Rocky Mountain Arsenal Groundwater Pollution